Title: Residential construction glossary | Cercha

Description: Look up residential construction terms for trades, credentials, materials, inspections, and payment records before your next job.

Canonical: https://cercha.pages.dev/glossary/

# Residential construction glossary

Building language

You need the same words on the scope, the order, and the jobsite. Find plain definitions for the next conversation.

Look up the word that is holding up a scope conversation, supplier inquiry, or site handoff. Each entry gives you a plain definition, common aliases, a source, and related terms. Start with the term on the drawing or document. Then follow the related entries when you need to separate two similar ideas.

Read a definition alongside your project documents. For truss vocabulary, use the [component industry glossary](https://www.sbcacomponents.com/terminology). A certificate of insurance summarizes listed policies; it does not replace them. The [ACORD certificate](https://tdi.texas.gov/certificates/documentcr/s21357a.pdf) states that boundary.

Use the glossary to prepare a clearer question for the GC, trade, supplier, building department, or insurance agent. Ask which item, document, or responsibility the other person means. Entries that use a state or federal example name that context.

Follow the cited source for its exact scope. Keep job-specific dimensions, approvals, coverage, and payment terms with the people responsible for them.

## Where Cercha fits

Use Cercha’s Search filters for trade, ZIP code, and radius to find a member to contact. Supplier profiles list brands carried, and Messages lets you ask that member about the work or materials you need.


<a id="abs-pipe"></a>

## ABS pipe

Acrylonitrile butadiene styrene pipe used in nonpressure drain, waste, and vent systems. ABS identifies a drainage-pipe material; PEX and CPVC are other material names associated with water-distribution applications. [Oatey](https://www.oatey.com/articles-videos-faqs/plumbing-terms).

Aliases: ABS, acrylonitrile butadiene styrene pipe.

Category: materials and supply.

[Air admittance valve](#air-admittance-valve) · [Backwater valve](#backwater-valve)

[Related resource](/suppliers/plumbing/)

<a id="additional-insured"></a>

## Additional insured

A person or business granted insured status through the policy’s provisions or an endorsement. Texas insurance guidance distinguishes that status from being a certificate holder. Ask the insurer about the applicable policy language. [Texas Department of Insurance](https://www.tdi.texas.gov/certificates/faq.html).

Aliases: AI.

Category: documents and money.

[Certificate holder](#certificate-holder) · [Certificate of insurance](#certificate-of-insurance) · [General liability insurance](#general-liability-insurance)

[Related resource](/guides/additional-insured/)

<a id="aggregate"></a>

## Aggregate

Granular material combined with a cementing medium to produce concrete or mortar. Examples include sand, gravel, crushed stone, crushed concrete, and certain slags; the mixture specification identifies the required aggregate. [American Concrete Institute](https://www.concrete.org/portals/0/files/pdf/ACI_Concrete_Terminology.pdf).

Category: materials and supply.

[Concrete](#concrete) · [Slump](#slump)

[Related resource](/suppliers/concrete-and-masonry/)

<a id="air-admittance-valve"></a>

## Air admittance valve

A one-way drainage valve that admits air when negative pressure develops, then closes to limit escaping sewer gases. It manages drainage-system air; a backwater valve addresses reverse wastewater flow. [Oatey](https://www.oatey.com/articles-videos-faqs/plumbing-terms).

Aliases: AAV.

Category: materials and supply.

[ABS pipe](#abs-pipe) · [Rough-in](#rough-in)

[Related resource](/trades/plumbing/)

<a id="air-duct"></a>

## Air duct

A passage carrying air through a heating, cooling, or ventilation system. Supply ducts distribute air to rooms, while return ducts carry air back; those paths serve different functions in the system. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2022-08/energy-saver-guide-2022.pdf).

Aliases: duct, ductwork.

Category: materials and supply.

[Heat pump](#heat-pump) · [Rough-in](#rough-in)

[Related resource](/trades/hvac/)

<a id="air-sealing"></a>

## Air sealing

Closing enclosure gaps that allow unwanted air leakage. Caulk seals stationary joints, while weatherstripping seals around moving window and door parts; those materials address different openings in the same enclosure. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2021-08/ES-Air%20Sealing_080421.pdf).

Category: materials and supply.

[Caulk](#caulk) · [Weatherstripping](#weatherstripping) · [Blower door test](#blower-door-test)

[Related resource](/trades/insulation/)

<a id="air-source-heat-pump"></a>

## Air-source heat pump

A heat pump that exchanges heat with outdoor air to heat or cool a home. Identify the specified equipment and design loads with the HVAC contractor. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2022-08/energy-saver-guide-2022.pdf).

Aliases: ASHP.

Category: materials and supply.

[Heat pump](#heat-pump) · [Ground-source heat pump](#ground-source-heat-pump) · [Manual J](#manual-j)

[Related resource](/trades/hvac/)

<a id="afci"></a>

## Arc-fault circuit interrupter

A device designed to detect dangerous electrical arcing and interrupt the circuit to help prevent fires. AFCI identifies this fire-protection function, while GFCI addresses ground-fault shock protection for people. [Eaton](https://www.eaton.com/us/en-us/products/wiring-devices-connectivity/afci-gfci-afgf.html).

Aliases: AFCI.

Category: materials and supply.

[Ground-fault circuit interrupter](#gfci) · [Circuit breaker](#circuit-breaker)

[Related resource](/trades/electrical/)

<a id="ashlar"></a>

## Ashlar

Building stone cut into squared shapes. Use the stone specification and layout drawings to identify the intended material and arrangement. [U.S. Department of Housing and Urban Development](https://www.huduser.gov/portal/portal/sites/default/files/pdf/Historic-Structures-Report-HUD-Building-Glossary.pdf).

Aliases: ashlar stone.

Category: materials and supply.

[Mortar](#mortar) · [Grout](#grout)

[Related resource](/trades/masonry/)

<a id="asphalt-shingle"></a>

## Asphalt shingle

An asphalt-based roof covering installed over the roof’s protective layers. Identify the specified shingle product separately from starter strips and ridge caps. [GAF](https://www.gaf.com/en-us/plan-design/homeowner-education/roof-parts).

Aliases: shingle, roofing shingle.

Category: materials and supply.

[Starter strip](#starter-strip) · [Ridge cap](#ridge-cap) · [Roof underlayment](#roof-underlayment)

[Related resource](/suppliers/roofing/)

<a id="awning-window"></a>

## Awning window

A window hinged at the top that opens outward at the bottom. Identify this operation separately from a side-hinged casement. [Andersen Windows](https://www.andersenwindows.com/support/window-door-glossary).

Aliases: awning.

Category: materials and supply.

[Casement window](#casement-window) · [Window sash](#sash) · [Rough opening](#rough-opening)

[Related resource](/trades/windows-and-doors/)

<a id="backcharge"></a>

## Backcharge

A cost claimed against another party for correcting defective work or fulfilling that party’s responsibility. It differs from routine retainage. Ask a construction attorney how the contract and applicable law govern a disputed deduction. [ConsensusDocs](https://www.consensusdocs.org/wp-content/uploads/2023/08/ConsensusDocs-GuideBook-Aug-2023.pdf).

Aliases: back charge.

Category: documents and money.

[Retainage](#retainage) · [Scope of work](#scope-of-work) · [Progress payment](#progress-payment)

[Related resource](/guides/retainage/)

<a id="backwater-valve"></a>

## Backwater valve

A valve installed in a building drain or sewer to limit reverse wastewater flow. It helps prevent backed-up drainage from reaching lower fixtures, where sewage could cause a flooding condition. [Oatey](https://www.oatey.com/articles-videos-faqs/plumbing-terms).

Category: materials and supply.

[ABS pipe](#abs-pipe) · [Air admittance valve](#air-admittance-valve)

[Related resource](/trades/plumbing/)

<a id="baluster"></a>

## Baluster

One of the short upright members supporting a stair handrail or coping. Identify the member and its location when discussing a stair or railing scope. [U.S. Department of Housing and Urban Development](https://www.huduser.gov/portal/portal/sites/default/files/pdf/Historic-Structures-Report-HUD-Building-Glossary.pdf).

Aliases: stair baluster.

Category: materials and supply.

[Construction documents](#construction-documents) · [Scope of work](#scope-of-work)

[Related resource](/trades/stairs-and-railings/)

<a id="batt-insulation"></a>

## Batt insulation

Precut sections of blanket insulation placed in building cavities. Blanket products can use fiberglass, rock wool, or recycled fibers, and come in widths suited to stud spacing or attic and floor joists. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2022-08/energy-saver-guide-2022.pdf).

Aliases: batts.

Category: materials and supply.

[Insulation](#insulation) · [R-value](#r-value) · [Loose-fill insulation](#loose-fill-insulation)

[Related resource](/suppliers/insulation/)

<a id="beam"></a>

## Beam

A structural member carrying loads transverse to its length. Joists, girders, rafters, and purlins perform this function in different parts of a building, so drawings identify the particular member and location. [U.S. Department of Housing and Urban Development](https://www.huduser.gov/portal/portal/sites/default/files/pdf/Historic-Structures-Report-HUD-Building-Glossary.pdf).

Category: structure.

[Column](#column) · [Load-bearing wall](#load-bearing-wall) · [Cantilever](#cantilever)

[Related resource](/trades/framing/)

<a id="blocking"></a>

## Blocking

Solid framing pieces between structural members that provide lateral support or transfer loads. Confirm the required location and detail on the drawings. [Structural Building Components Association](https://www.sbcacomponents.com/terminology).

Aliases: framing blocking, solid blocking.

Category: structure.

[Bracing](#bracing) · [Diaphragm](#diaphragm) · [Roof truss](#roof-truss)

[Related resource](/trades/framing/)

<a id="blower-door-test"></a>

## Blower door test

An air-leakage test using a fan mounted in an exterior doorway. The fan changes indoor air pressure so leakage can be evaluated and problem locations identified during an enclosure assessment. [National Trust for Historic Preservation](https://archive.epa.gov/region5/sustainable/web/html/energyadvice.html).

Aliases: blower door.

Category: schedule and inspections.

[Air sealing](#air-sealing) · [Weatherstripping](#weatherstripping)

[Related resource](/trades/insulation/)

<a id="boom-and-scatter"></a>

## Boom-and-scatter delivery

A delivery service that places building materials at designated locations within the jobsite, beyond a basic drop. GMS advertises this service. Confirm placement locations, access, and service scope with the delivering branch. [GMS](https://www.gms.com/services/delivery).

Aliases: stock-and-scatter, jobsite stocking.

Category: materials and supply.

[Jobsite delivery](#jobsite-delivery) · [Delivery confirmation](#delivery-confirmation)

[Related resource](/suppliers/drywall/)

<a id="bottom-chord"></a>

## Bottom chord

The horizontal or pitched member forming a truss’s lower edge. It commonly carries combined tension and bending stresses; its location distinguishes it from the top chord and the internal webs. [Structural Building Components Association](https://www.sbcacomponents.com/terminology).

Category: structure.

[Top chord](#top-chord) · [Web member](#web-member) · [Roof truss](#roof-truss)

[Related resource](/trades/framing/)

<a id="bracing"></a>

## Bracing

Members that stabilize framing and prevent unintended movement. Temporary components serve construction and installation; permanent components form part of the finished structure. The distinction matters when reading the truss package. [Structural Building Components Association](https://www.sbcacomponents.com/terminology).

Aliases: brace.

Category: structure.

[Roof truss](#roof-truss) · [Top chord](#top-chord)

[Related resource](/trades/framing/)

<a id="building-drain"></a>

## Building drain

The lowest drainage piping receiving discharge from inside the building and conveying it to the building sewer. Confirm the boundary used by the governing plumbing code. [Oatey](https://www.oatey.com/articles-videos-faqs/plumbing-terms).

Category: materials and supply.

[Building sewer](#building-sewer) · [Drain, waste, and vent system](#dwv) · [Backwater valve](#backwater-valve)

[Related resource](/trades/plumbing/)

<a id="building-inspection"></a>

## Building inspection

A review of construction for compliance with applicable codes, regulations, and specifications. Inspectors examine different systems and stages. Ask the local building department which inspection applies and when the work must remain accessible. [U.S. Bureau of Labor Statistics](https://www.bls.gov/ooh/construction-and-extraction/construction-and-building-inspectors.htm).

Aliases: code inspection.

Category: schedule and inspections.

[Building permit](#building-permit) · [Building official](#building-official) · [Rough-in](#rough-in)

[Related resource](/guides/why-residential-inspections-fail/)

<a id="building-official"></a>

## Building official

The officer or designated authority responsible for administering and enforcing the building code, including a duly authorized representative. Your local building department identifies the authority handling the project’s code questions. [Structural Building Components Association](https://www.sbcacomponents.com/terminology).

Aliases: code official.

Category: schedule and inspections.

[Building inspection](#building-inspection) · [Building permit](#building-permit)

[Related resource](/guides/wake-county-building-permits/)

<a id="building-permit"></a>

## Building permit

Approval from a local jurisdiction to proceed with a construction project. Permit requirements depend on location and work. Ask the responsible building department what approvals the specific project requires before starting. [U.S. Census Bureau](https://www.census.gov/construction/bps/definitions.html).

Aliases: permit.

Category: schedule and inspections.

[Building inspection](#building-inspection) · [Building official](#building-official) · [Construction documents](#construction-documents)

[Related resource](/guides/wake-county-building-permits/)

<a id="building-sewer"></a>

## Building sewer

Drainage piping continuing from the end of the building drain to a sewer or other disposal point. Confirm the connection and inspection responsibilities with the plumber. [Oatey](https://www.oatey.com/articles-videos-faqs/plumbing-terms).

Category: materials and supply.

[Building drain](#building-drain) · [Drain, waste, and vent system](#dwv) · [Backwater valve](#backwater-valve)

[Related resource](/trades/plumbing/)

<a id="building-material-distributor"></a>

## Building-material distributor

A business supplying building products through a distribution channel. Weyerhaeuser’s engineered-wood offering includes I-joists, LVL, and glulam; local product availability and service arrangements are questions for the supplying branch. [Weyerhaeuser](https://www.weyerhaeuser.com/woodproducts/distribution/engineered-wood/).

Aliases: material distributor.

Category: business.

[Engineered wood products](#engineered-wood-products) · [Outside sales representative](#outside-sales-representative)

[Related resource](/suppliers/)

<a id="bullnose"></a>

## Bullnose

A rounded edge on trim or another building member, or a curved outside corner. Specify the affected material and edge profile when ordering. [U.S. Department of Housing and Urban Development](https://www.huduser.gov/portal/portal/sites/default/files/pdf/Historic-Structures-Report-HUD-Building-Glossary.pdf).

Aliases: bullnose edge.

Category: materials and supply.

[Casing](#casing) · [Mortar](#mortar)

[Related resource](/trades/trim-carpentry/)

<a id="cantilever"></a>

## Cantilever

A structural member projecting beyond its supporting wall or column. Beams, girders, and trusses can have cantilevered portions; drawings locate the support and show how far the member extends past it. [U.S. Department of Housing and Urban Development](https://www.huduser.gov/portal/portal/sites/default/files/pdf/Historic-Structures-Report-HUD-Building-Glossary.pdf).

Category: structure.

[Beam](#beam) · [Column](#column)

[Related resource](/trades/framing/)

<a id="casement-window"></a>

## Casement window

A window with a side-hinged sash that swings outward. Confirm the operating direction and clearance when selecting the unit. [Andersen Windows](https://www.andersenwindows.com/support/window-door-glossary).

Aliases: casement.

Category: materials and supply.

[Window sash](#sash) · [Awning window](#awning-window) · [Rough opening](#rough-opening)

[Related resource](/trades/windows-and-doors/)

<a id="casing"></a>

## Casing

Decorative molding around the interior perimeter of a window or door, covering the gap between the unit and surrounding opening. Casing is finish trim; jamb identifies a member of the frame. [Andersen Windows](https://www.andersenwindows.com/support/window-door-glossary).

Aliases: window casing, door casing.

Category: materials and supply.

[Jamb](#jamb) · [Rough opening](#rough-opening)

[Related resource](/trades/trim-carpentry/)

<a id="caulk"></a>

## Caulk

A sealant used to close gaps between stationary building components, such as fixed joints around openings. Weatherstripping addresses moving window and door parts, so the two materials serve different joint conditions. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2021-08/ES-Air%20Sealing_080421.pdf).

Aliases: caulking.

Category: materials and supply.

[Air sealing](#air-sealing) · [Weatherstripping](#weatherstripping)

[Related resource](/suppliers/insulation/)

<a id="cercha"></a>

## cercha

A Spanish construction word for a roof truss or supporting roof framework. Sense two in the RAE dictionary refers to the framework holding a building’s roof. [Real Academia Española and Asociación de Academias de la Lengua Española](https://dle.rae.es/cercha).

Category: structure.

[Roof truss](#roof-truss) · [Top chord](#top-chord) · [Bottom chord](#bottom-chord)

[Related resource](/suppliers/trusses-and-engineered-wood/)

<a id="certificate-holder"></a>

## Certificate holder

The person or business named in a certificate’s holder field. That entry identifies the certificate recipient. It does not, by itself, establish additional-insured status or change the referenced insurance policy. [ACORD](https://tdi.texas.gov/certificates/documentcr/s21357a.pdf).

Category: documents and money.

[Certificate of insurance](#certificate-of-insurance) · [Additional insured](#additional-insured)

[Related resource](/guides/certificate-of-insurance/)

<a id="certificate-of-insurance"></a>

## Certificate of insurance

A document summarizing the listed insurance policies, dates, types of coverage, and limits. It does not change those policies or create coverage. Ask the producer or insurer about the actual policy terms. [ACORD](https://tdi.texas.gov/certificates/documentcr/s21357a.pdf).

Aliases: COI, ACORD 25.

Category: documents and money.

[Certificate holder](#certificate-holder) · [Named insured](#named-insured) · [Additional insured](#additional-insured) · [General liability insurance](#general-liability-insurance)

[Related resource](/guides/certificate-of-insurance/)

<a id="certificate-of-occupancy"></a>

## Certificate of occupancy

A building-department document stating an approved use or occupancy. New York City uses a CO to identify legal use and permitted occupancy. Ask your local department which occupancy approval applies to your project. [New York City Department of Buildings](https://www.nyc.gov/site/buildings/property-or-business-owner/certificate-of-occupancy.page).

Aliases: CO, C of O.

Category: schedule and inspections.

[Building permit](#building-permit) · [Closeout](#closeout)

[Related resource](/guides/certificate-of-occupancy-nc/)

<a id="change-order"></a>

## Change order

A document modifying contracted work. Federal procurement treats change orders as one type of contract modification. For your residential project, check the agreement’s process for authorizing changes and documenting their consequences. [Federal Acquisition Regulatory Council](https://www.acquisition.gov/far/43.103).

Aliases: contract change.

Category: documents and money.

[Scope of work](#scope-of-work) · [Construction documents](#construction-documents) · [Progress payment](#progress-payment)

[Related resource](/guides/change-order/)

<a id="chase"></a>

## Chase

A recess in a wall that provides a route for pipes or ducts. [U.S. Department of Housing and Urban Development](https://www.huduser.gov/portal/portal/sites/default/files/pdf/Historic-Structures-Report-HUD-Building-Glossary.pdf).

Aliases: pipe chase, wall chase.

Category: structure.

[Rough-in](#rough-in) · [Air duct](#air-duct) · [Construction documents](#construction-documents)

[Related resource](/trades/framing/)

<a id="admixture"></a>

## Chemical admixture

An ingredient added to a cementitious mixture to alter its properties. Identify the specified admixture and purpose with the concrete supplier before changing a mix order. [American Concrete Institute](https://www.concrete.org/portals/0/files/pdf/ACI_Concrete_Terminology.pdf).

Aliases: admixture, concrete admixture.

Category: materials and supply.

[Concrete](#concrete) · [Slump](#slump) · [Curing](#curing)

[Related resource](/suppliers/concrete-and-masonry/)

<a id="circuit-breaker"></a>

## Circuit breaker

A switching device that interrupts current during specified faults, including overloads or short circuits. Its protective ratings and application matter; the name alone does not identify additional GFCI or AFCI functions. [Eaton](https://www.eaton.com/us/en-us/products/electrical-circuit-protection/circuit-breakers/circuit-breakers-fundamentals.html).

Aliases: breaker.

Category: materials and supply.

[Ground-fault circuit interrupter](#gfci) · [Arc-fault circuit interrupter](#afci)

[Related resource](/suppliers/electrical/)

<a id="clear-span"></a>

## Clear span

The opening measured from one support’s inside face to the other’s. Keep this dimension distinct from support spacing measured on center. [APA – The Engineered Wood Association](https://www.anthonyforest.com/assets/pdf/apa/APA_EW_Handbook_Grade_Glossary.pdf).

Category: structure.

[Beam](#beam) · [Roof truss](#roof-truss) · [I-joist](#i-joist)

[Related resource](/trades/framing/)

<a id="closeout"></a>

## Closeout

The concluding project stage covering punch work, cleaning, demobilization, and owner orientation. A punch list identifies remaining physical tasks; closeout also addresses the completion steps surrounding those tasks. [Grand County Builders’ Association](https://www.nahb.org/-/media/NAHB/advocacy/docs/industry-issues/disaster-resources/home-building-overview.pdf?rev=6f76493d1a3e493fb717f52f0fa47d7e).

Aliases: project closeout.

Category: schedule and inspections.

[Punch list](#punch-list) · [Certificate of occupancy](#certificate-of-occupancy)

[Related resource](/guides/closeout/)

<a id="column"></a>

## Column

A relatively slender structural member that primarily carries compression along its axis. Columns are usually vertical; post and pillar are related names, while beam describes a different load-carrying function. [U.S. Department of Housing and Urban Development](https://www.huduser.gov/portal/portal/sites/default/files/pdf/Historic-Structures-Report-HUD-Building-Glossary.pdf).

Aliases: structural post.

Category: structure.

[Beam](#beam) · [Foundation](#foundation)

[Related resource](/trades/framing/)

<a id="concrete"></a>

## Concrete

A composite of cementitious binder, water, and aggregate, with other ingredients where specified. Cement is the binding ingredient; concrete is the mixture that includes the sand, gravel, or other aggregate. [American Concrete Institute](https://www.concrete.org/portals/0/files/pdf/ACI_Concrete_Terminology.pdf).

Category: materials and supply.

[Aggregate](#aggregate) · [Curing](#curing) · [Reinforcing bar](#reinforcing-bar)

[Related resource](/trades/concrete/)

<a id="conditional-lien-waiver"></a>

## Conditional lien waiver

A release whose effectiveness depends on payment being received. California publishes separate progress-payment and final-payment forms. The term describes a payment condition; it does not identify the correct form for every state. [California Contractors State License Board](https://cslb.ca.gov/consumers/Legal_Issues_For_Consumers/Mechanics_Lien/Conditional_And_Unconditional_Waiver_Release_Form.aspx).

Aliases: conditional waiver and release.

Category: documents and money.

[Lien waiver](#lien-waiver) · [Unconditional lien waiver](#unconditional-lien-waiver) · [Progress payment](#progress-payment)

[Related resource](/guides/lien-waiver/)

<a id="allowance"></a>

## Construction allowance

An amount included in the contract sum for an identified item whose final cost is unsettled. Check what the allowance includes and how later selections change the contract price. [AIA Contract Documents](https://learn.aiacontracts.com/articles/construction-allowance-contracting-basics/).

Aliases: allowance, allowances, cash allowance.

Category: documents and money.

[Change order](#change-order) · [Scope of work](#scope-of-work) · [Schedule of values](#schedule-of-values)

[Related resource](/guides/find-a-general-contractor/)

<a id="construction-documents"></a>

## Construction documents

Written and graphic information describing a project’s design, location, and physical characteristics for permitting. Plans and specifications belong to this document set; a material takeoff extracts quantities for a different purpose. [Structural Building Components Association](https://www.sbcacomponents.com/terminology).

Aliases: CDs, plans and specifications.

Category: documents and money.

[Material takeoff](#material-takeoff) · [Building permit](#building-permit) · [Scope of work](#scope-of-work)

[Related resource](/guides/trade-scope-of-work/)

<a id="control-joint"></a>

## Contraction joint

A formed, tooled, or sawed groove intended to direct concrete cracking to a planned location. ACI uses contraction joint for this feature; it differs from an expansion joint. [American Concrete Institute](https://www.concrete.org/portals/0/files/pdf/ACI_Concrete_Terminology.pdf).

Aliases: control joint, concrete control joint.

Category: materials and supply.

[Concrete](#concrete) · [Curing](#curing) · [Construction documents](#construction-documents)

[Related resource](/trades/concrete/)

<a id="contractor-license"></a>

## Contractor license

Authorization issued under a jurisdiction’s contractor-licensing system. North Carolina licenses a named legal entity, separately from its qualifier. Check the relevant issuing board for the entity, current status, and permitted work. [North Carolina Licensing Board for General Contractors](https://www.nclbgc.org/faq-contractors/).

Aliases: GC license.

Category: documents and money.

[License qualifier](#license-qualifier) · [License classification](#license-classification) · [Workers’ compensation](#workers-compensation)

[Related resource](/guides/verify-contractor-license/)

<a id="countertop-template"></a>

## Countertop template

A field measurement or template used to establish the countertop’s fit. Cambria requires installed cabinets and says fixtures should be available for accurate measuring. Confirm the fabricator’s readiness checklist before arranging the measurement visit. [Cambria](https://www.cambriausa.com/quartz-countertops/faq/installation).

Aliases: templating, countertop field measure.

Category: schedule and inspections.

[Material takeoff](#material-takeoff) · [Construction documents](#construction-documents)

[Related resource](/suppliers/countertops/)

<a id="cpvc-pipe"></a>

## CPVC pipe

Pipe made from chlorinated polyvinyl chloride, used for applications including hot and cold water distribution. Confirm the specified pipe and compatible fittings. [Oatey](https://www.oatey.com/articles-videos-faqs/plumbing-terms).

Aliases: CPVC, chlorinated polyvinyl chloride pipe.

Category: materials and supply.

[Cross-linked polyethylene pipe](#pex) · [ABS pipe](#abs-pipe) · [Rough-in](#rough-in)

[Related resource](/guides/pex-vs-cpvc/)

<a id="pex"></a>

## Cross-linked polyethylene pipe

Cross-linked polyethylene tubing used for hot and cold water distribution. PEX identifies the tubing material, while ABS pipe is associated with nonpressure drainage; those names refer to different plumbing applications. [Oatey](https://www.oatey.com/articles-videos-faqs/plumbing-terms).

Aliases: PEX.

Category: materials and supply.

[Water-supply air gap](#air-gap) · [Rough-in](#rough-in)

[Related resource](/suppliers/plumbing/)

<a id="curing"></a>

## Curing

Maintaining moisture and temperature conditions that support cement hydration and development of concrete properties. The curing plan addresses how those conditions are maintained after placement, including the selected method and protection. [American Concrete Institute](https://www.concrete.org/portals/0/files/pdf/ACI_Concrete_Terminology.pdf).

Aliases: concrete curing.

Category: schedule and inspections.

[Concrete](#concrete) · [Slump](#slump)

[Related resource](/trades/concrete/)

<a id="custom-home-builder"></a>

## Custom home builder

A builder constructing a home under an agreement with its owner. Census distinguishes owner-contracted construction from builders working on their own account to produce homes for sale; those are different contracting arrangements. [Office of Management and Budget](https://www.census.gov/naics/reference_files_tools/2022_NAICS_Manual.pdf).

Aliases: custom builder.

Category: trades.

[General contractor](#general-contractor) · [For-sale home builder](#for-sale-home-builder)

[Related resource](/guides/custom-home-builder/)

<a id="delivery-confirmation"></a>

## Delivery confirmation

A record showing a delivery has occurred. Builders FirstSource uses photographs to show material type, quantity, and jobsite location. Ask which confirmation your supplier provides and what your receiving team still checks. [Builders FirstSource](https://www.bldr.com/services/delivery-pickup).

Aliases: proof of delivery, POD.

Category: documents and money.

[Jobsite delivery](#jobsite-delivery) · [Purchase order](#purchase-order)

[Related resource](/suppliers/)

<a id="delivery-ticket"></a>

## Delivery ticket

A supplier’s document accompanying a material delivery and identifying its items. Keep it with the order and receiving record. ABC Supply distinguishes delivery tickets from invoices and statements in its terms. [ABC Supply](https://www.abcsupply.com/legal/).

Aliases: material delivery ticket, delivery docket.

Category: materials and supply.

[Purchase order](#purchase-order) · [Delivery confirmation](#delivery-confirmation) · [Jobsite delivery](#jobsite-delivery)

[Related resource](/guides/jobsite-material-delivery/)

<a id="diaphragm"></a>

## Diaphragm

A floor, roof, or ceiling system that transfers lateral forces to the building’s vertical resisting system. Follow the designed sheathing and connection details. [Structural Building Components Association](https://www.sbcacomponents.com/terminology).

Category: structure.

[Sheathing](#sheathing) · [Blocking](#blocking) · [Bracing](#bracing)

[Related resource](/trades/framing/)

<a id="dwv"></a>

## Drain, waste, and vent system

The drainage, waste, and vent piping system. Identify it separately from water-supply piping when assigning the plumbing scope and reviewing materials. [Oatey](https://www.oatey.com/articles-videos-faqs/plumbing-terms).

Aliases: DWV, drain waste and vent.

Category: materials and supply.

[Building drain](#building-drain) · [Building sewer](#building-sewer) · [Air admittance valve](#air-admittance-valve)

[Related resource](/trades/plumbing/)

<a id="drainage-fixture-unit"></a>

## Drainage fixture unit

A measure of a fixture’s probable drainage load, based on discharge rate, duration, and frequency. It describes drainage demand rather than pipe diameter. [Oatey](https://www.oatey.com/articles-videos-faqs/plumbing-terms).

Aliases: DFU, drainage fixture units.

Category: materials and supply.

[Drain, waste, and vent system](#dwv) · [Building drain](#building-drain)

[Related resource](/trades/plumbing/)

<a id="drip-edge"></a>

## Drip edge

Roof-edge flashing that helps direct runoff away from the roof edge and fascia. It serves the edge detail, while flashing around chimneys or other penetrations protects different locations on the roof. [GAF](https://www.gaf.com/en-us/plan-design/homeowner-education/roof-parts).

Category: materials and supply.

[Roof flashing](#roof-flashing) · [Roof deck](#roof-deck)

[Related resource](/suppliers/roofing/)

<a id="dry-in"></a>

## Dry-in

Enclosing the building shell against weather through coordinated roofing, weather barriers, flashing, windows, and exterior doors. The homebuilding overview places these tasks within shell work, before later interior stages. [Grand County Builders’ Association](https://www.nahb.org/-/media/NAHB/advocacy/docs/industry-issues/disaster-resources/home-building-overview.pdf?rev=6f76493d1a3e493fb717f52f0fa47d7e).

Aliases: roof dry-in.

Category: schedule and inspections.

[Roof underlayment](#roof-underlayment) · [Roof flashing](#roof-flashing) · [Rough-in](#rough-in)

[Related resource](/trades/roofing/)

<a id="drywall-primer"></a>

## Drywall primer

A base coating used to reduce differences in porosity and texture between gypsum-panel faces and finished joints. Confirm the specified surface treatment before paint. [USG](https://assemblies-tools.usg.com/content/dam/USG_Marketing_Communications/united_states/product_promotional_materials/finished_assets/finishing-decorating-gypsum-panels-white-paper-en-J2010.pdf).

Aliases: gypsum board primer.

Category: materials and supply.

[Joint compound](#joint-compound) · [Level 5 finish](#level-5-finish) · [Skim coat](#skim-coat)

[Related resource](/trades/drywall/)

<a id="ductless-mini-split"></a>

## Ductless mini-split

A system connecting an outdoor heating or cooling unit to indoor units without distribution ducts. Each indoor unit serves its space; the term distinguishes this arrangement from a ducted air-distribution system. [GE Appliances](https://www.geappliances.com/ductless/).

Aliases: mini-split.

Category: materials and supply.

[Heat pump](#heat-pump) · [Air duct](#air-duct)

[Related resource](/suppliers/hvac/)

<a id="engineered-wood-products"></a>

## Engineered wood products

Manufactured wood-based structural products, including I-joists, laminated veneer lumber, and glued laminated timber. The category covers different products. Identify the specified manufacturer, product, and member dimensions when you discuss the supply package. [Weyerhaeuser](https://www.weyerhaeuser.com/woodproducts/distribution/engineered-wood/).

Aliases: EWP.

Category: materials and supply.

[Laminated veneer lumber](#lvl) · [Glued laminated timber](#glulam) · [I-joist](#i-joist)

[Related resource](/suppliers/trusses-and-engineered-wood/)

<a id="excavation"></a>

## Excavation

A cut, cavity, trench, or depression made by removing earth. OSHA uses excavation as the broader term; a trench is a particular narrow opening, with its own defined dimensional limits. [Occupational Safety and Health Administration](https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.650).

Aliases: earth excavation.

Category: trades.

[Trench](#trench) · [Shoring](#shoring) · [Trench shield](#trench-shield)

[Related resource](/trades/excavation/)

<a id="flood-level-rim"></a>

## Flood level rim

The edge of a fixture over which water spills when it overflows. It provides the reference level for a water-supply air gap. [Oatey](https://www.oatey.com/articles-videos-faqs/plumbing-terms).

Aliases: flood-level rim.

Category: materials and supply.

[Water-supply air gap](#air-gap) · [Drainage fixture unit](#drainage-fixture-unit)

[Related resource](/trades/plumbing/)

<a id="for-sale-home-builder"></a>

## For-sale home builder

A builder constructing homes on its own account for sale. Census distinguishes this arrangement from owner-contracted homebuilding; the builder’s role in the sale differs from a contractor hired by the future homeowner. [Office of Management and Budget](https://www.census.gov/naics/reference_files_tools/2022_NAICS_Manual.pdf).

Aliases: merchant builder.

Category: trades.

[Custom home builder](#custom-home-builder) · [General contractor](#general-contractor)

[Related resource](/guides/production-builder/)

<a id="form-1099-nec"></a>

## Form 1099-NEC

An IRS information return for reportable nonemployee compensation paid in a business relationship. It serves a different purpose from Form W-9. Check the current tax-year instructions with your tax professional. [Internal Revenue Service](https://www.irs.gov/businesses/small-businesses-self-employed/forms-and-associated-taxes-for-independent-contractors).

Aliases: 1099-NEC, nonemployee compensation form.

Category: documents and money.

[Form W-9](#w-9) · [Subcontractor](#subcontractor)

[Related resource](/guides/which-1099-form-for-subcontractors/)

<a id="w-9"></a>

## Form W-9

The IRS form used to request a payee’s correct name and taxpayer identification number. After determining independent-contractor status, the payer obtains the form and keeps it in its own records. [Internal Revenue Service](https://www.irs.gov/businesses/small-businesses-self-employed/forms-and-associated-taxes-for-independent-contractors).

Aliases: W-9, taxpayer identification form.

Category: documents and money.

[Form 1099-NEC](#form-1099-nec) · [Subcontractor](#subcontractor)

[Related resource](/guides/w-9-for-subcontractors/)

<a id="formwork"></a>

## Formwork

The complete system supporting freshly placed concrete, including the mold or concrete-contacting surface, supporting members, hardware, and bracing. Together, these components hold the concrete in the required shape as it develops strength. [American Concrete Institute](https://www.concrete.org/portals/0/files/pdf/ACI_Concrete_Terminology.pdf).

Category: materials and supply.

[Concrete](#concrete) · [Curing](#curing) · [Reinforcing bar](#reinforcing-bar)

[Related resource](/trades/concrete/)

<a id="foundation"></a>

## Foundation

The supporting part of a structure transferring building loads to earth or rock, usually below ground. The term covers the building’s supporting system; a foundation scope identifies the particular elements being built. [U.S. Department of Housing and Urban Development](https://www.huduser.gov/portal/portal/sites/default/files/pdf/Historic-Structures-Report-HUD-Building-Glossary.pdf).

Category: structure.

[Column](#column) · [Load-bearing wall](#load-bearing-wall) · [Concrete](#concrete)

[Related resource](/trades/concrete/)

<a id="general-contractor"></a>

## General contractor

The contractor responsible for overall building construction, including coordinating specialty work. Census distinguishes building construction from specialty-trade businesses; a GC’s overall project role differs from the individual scopes performed by its subs. [Office of Management and Budget](https://www.census.gov/naics/reference_files_tools/2022_NAICS_Manual.pdf).

Aliases: GC, residential GC.

Category: trades.

[Subcontractor](#subcontractor) · [Specialty trade contractor](#specialty-trade-contractor) · [Residential remodeler](#residential-remodeler)

[Related resource](/guides/what-is-a-general-contractor/)

<a id="general-liability-insurance"></a>

## General liability insurance

Business insurance addressing liability exposures such as bodily injury, property damage, and lawsuit defense. The SBA lists these uses. Ask a licensed insurance agent which policy provisions apply to your work. [U.S. Small Business Administration](https://www.sba.gov/counseling/launch-your-business/).

Aliases: GL, commercial general liability, CGL.

Category: documents and money.

[Certificate of insurance](#certificate-of-insurance) · [Additional insured](#additional-insured) · [Workers’ compensation](#workers-compensation)

[Related resource](/guides/general-liability-for-subcontractors/)

<a id="girder-truss"></a>

## Girder truss

A truss designed to carry loads from other structural members connecting to it. In a component package, the individual truss drawing describes that component and the placement diagram identifies its assumed location. [Structural Building Components Association](https://www.sbcacomponents.com/terminology).

Category: structure.

[Roof truss](#roof-truss) · [Beam](#beam) · [Panel point](#panel-point)

[Related resource](/suppliers/trusses-and-engineered-wood/)

<a id="glulam"></a>

## Glued laminated timber

A structural wood member made from lumber laminations bonded with their grain running along its length. It differs from LVL, which uses veneers; both can appear in a specified beam package. [APA – The Engineered Wood Association](https://www.anthonyforest.com/assets/pdf/apa/APA_EW_Handbook_Grade_Glossary.pdf).

Aliases: glulam, glue-laminated timber.

Category: structure.

[Laminated veneer lumber](#lvl) · [Beam](#beam)

[Related resource](/suppliers/trusses-and-engineered-wood/)

<a id="gfci"></a>

## Ground-fault circuit interrupter

A device that detects ground-fault current and interrupts power to help protect people from electric shock. GFCI identifies this shock-protection function; AFCI addresses the separate hazard of dangerous electrical arcing. [Eaton](https://www.eaton.com/us/en-us/products/wiring-devices-connectivity/afci-gfci-afgf.html).

Aliases: GFCI.

Category: materials and supply.

[Arc-fault circuit interrupter](#afci) · [Circuit breaker](#circuit-breaker)

[Related resource](/trades/electrical/)

<a id="ground-source-heat-pump"></a>

## Ground-source heat pump

A heat pump exchanging heat with the ground or a water source. Its heat source differs from the outdoor air used by an air-source system. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2022-08/energy-saver-guide-2022.pdf).

Aliases: geothermal heat pump, GSHP.

Category: materials and supply.

[Heat pump](#heat-pump) · [Air-source heat pump](#air-source-heat-pump) · [Manual J](#manual-j)

[Related resource](/trades/hvac/)

<a id="grout"></a>

## Grout

Material used to fill joints or voids. Cementitious grout contains cementitious material and water, with optional aggregate or admixtures. Identify the specified product and application before ordering. [American Concrete Institute](https://www.concrete.org/portals/0/files/pdf/ACI_Concrete_Terminology.pdf).

Aliases: cementitious grout, tile grout.

Category: materials and supply.

[Mortar](#mortar) · [Chemical admixture](#admixture)

[Related resource](/trades/tile/)

<a id="heat-pump"></a>

## Heat pump

Equipment that transfers heat to provide heating or cooling. An air-source heat pump exchanges heat with outdoor air, while a ground-source system exchanges heat with the ground or a water source. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2022-08/energy-saver-guide-2022.pdf).

Category: materials and supply.

[Ductless mini-split](#ductless-mini-split) · [Air duct](#air-duct)

[Related resource](/trades/hvac/)

<a id="heel-height"></a>

## Heel height

The vertical depth of a truss at the outside face of its bearing. The measurement’s location matters: ask the supplier to identify that bearing face when explaining the dimensions on a truss drawing. [Structural Building Components Association](https://www.sbcacomponents.com/terminology).

Aliases: truss heel height.

Category: structure.

[Roof truss](#roof-truss) · [Top chord](#top-chord) · [Bottom chord](#bottom-chord)

[Related resource](/suppliers/trusses-and-engineered-wood/)

<a id="i-joist"></a>

## I-joist

An engineered joist with upper and lower wood flanges joined by a plywood or OSB web. Its I-shaped cross section distinguishes it from solid lumber; the web and flanges are separate components. [APA – The Engineered Wood Association](https://www.anthonyforest.com/assets/pdf/apa/APA_EW_Handbook_Grade_Glossary.pdf).

Aliases: engineered wood joist.

Category: structure.

[Laminated veneer lumber](#lvl) · [Oriented strand board](#osb)

[Related resource](/suppliers/trusses-and-engineered-wood/)

<a id="insulation"></a>

## Insulation

Material that resists heat flow through a building assembly. Its R-value expresses thermal resistance, while batt, loose-fill, and other product forms describe how the insulating material is supplied and installed. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2021-11/ES-HomeInsulation_081721E-a.pdf).

Aliases: thermal insulation.

Category: materials and supply.

[R-value](#r-value) · [Batt insulation](#batt-insulation) · [Loose-fill insulation](#loose-fill-insulation)

[Related resource](/trades/insulation/)

<a id="jamb"></a>

## Jamb

A side or top member of a window or door frame. Jamb identifies part of the frame itself, while casing is decorative trim covering the gap around the installed unit. [Andersen Windows](https://www.andersenwindows.com/support/window-door-glossary).

Aliases: window jamb, door jamb.

Category: materials and supply.

[Rough opening](#rough-opening) · [Casing](#casing) · [Window sash](#sash)

[Related resource](/trades/windows-and-doors/)

<a id="jobsite-delivery"></a>

## Jobsite delivery

Transporting ordered materials to the construction site. Delivery is a supplier service with its own arrangements. Confirm the date, location, unloading plan, and available service with the branch handling your order. [Builders FirstSource](https://www.bldr.com/services/delivery-pickup).

Aliases: material delivery, delivery drop.

Category: materials and supply.

[Pickup order](#pickup-order) · [Delivery confirmation](#delivery-confirmation) · [Purchase order](#purchase-order)

[Related resource](/suppliers/)

<a id="joint-compound"></a>

## Joint compound

Material applied to gypsum-panel joints, fasteners, and related details before decoration. The finishing scope identifies treatment of those locations and any additional full-surface skim coat required for the specified finish level. [USG](https://assemblies-tools.usg.com/content/dam/USG_Marketing_Communications/united_states/product_promotional_materials/finished_assets/finishing-decorating-gypsum-panels-white-paper-en-J2010.pdf).

Aliases: drywall mud.

Category: materials and supply.

[Skim coat](#skim-coat) · [Level 5 finish](#level-5-finish)

[Related resource](/suppliers/drywall/)

<a id="lvl"></a>

## Laminated veneer lumber

Structural lumber made from thin wood veneers bonded with their grain running mainly lengthwise. LVL differs from glulam’s lumber laminations and can serve as a beam or an I-joist flange. [APA – The Engineered Wood Association](https://www.anthonyforest.com/assets/pdf/apa/APA_EW_Handbook_Grade_Glossary.pdf).

Aliases: LVL.

Category: structure.

[Glued laminated timber](#glulam) · [Beam](#beam)

[Related resource](/suppliers/trusses-and-engineered-wood/)

<a id="lead-time"></a>

## Lead time

The interval between an agreed ordering milestone and product availability. Suppliers’ lead times vary by product line. Ask whether the quoted endpoint means production completion, branch arrival, or site delivery. [Pella](https://media.pella.com/brnd_fam/lowes/Lowes_Window_Door_Portfolio.pdf).

Aliases: supplier lead time, procurement lead time.

Category: schedule and inspections.

[Special order](#special-order) · [Purchase order](#purchase-order) · [Jobsite delivery](#jobsite-delivery)

[Related resource](/guides/special-orders-and-lead-times/)

<a id="level-5-finish"></a>

## Level 5 finish

A gypsum-panel finish adding a skim coat or comparable full-surface treatment to Level 4 preparation. The additional treatment addresses surface uniformity where the specified lighting or decoration makes irregularities more visible. [USG](https://assemblies-tools.usg.com/content/dam/USG_Marketing_Communications/united_states/product_promotional_materials/finished_assets/finishing-decorating-gypsum-panels-white-paper-en-J2010.pdf).

Aliases: Level 5 drywall.

Category: materials and supply.

[Skim coat](#skim-coat) · [Joint compound](#joint-compound)

[Related resource](/trades/drywall/)

<a id="license-classification"></a>

## License classification

A category that identifies the scope of work permitted by a licensing system. North Carolina lists separate GC classifications. Use the issuing board’s description when comparing a license with your proposed work. [North Carolina Licensing Board for General Contractors](https://www.nclbgc.org/classifications-and-limitations/).

Category: documents and money.

[Contractor license](#contractor-license) · [Specialty trade contractor](#specialty-trade-contractor)

[Related resource](/guides/nc-license-classifications/)

<a id="license-qualifier"></a>

## License qualifier

A person whose examination credential qualifies a company for licensing in North Carolina’s GC system. The qualifier is distinct from the licensed entity. Ask the issuing board about the record you are reviewing. [North Carolina Licensing Board for General Contractors](https://www.nclbgc.org/faq-contractors/).

Aliases: qualifier.

Category: business.

[Contractor license](#contractor-license) · [License classification](#license-classification)

[Related resource](/guides/nc-license-lookup/)

<a id="lien-waiver"></a>

## Lien waiver

A document relinquishing specified construction lien rights. California distinguishes conditional and unconditional releases for progress and final payments. Use that distinction to understand the term; ask a construction attorney about your jurisdiction’s forms. [California Contractors State License Board](https://cslb.ca.gov/consumers/Legal_Issues_For_Consumers/Mechanics_Lien/Conditional_And_Unconditional_Waiver_Release_Form.aspx).

Aliases: lien release.

Category: documents and money.

[Conditional lien waiver](#conditional-lien-waiver) · [Unconditional lien waiver](#unconditional-lien-waiver) · [Progress payment](#progress-payment)

[Related resource](/guides/lien-waiver/)

<a id="load-bearing-wall"></a>

## Load-bearing wall

A wall supporting an imposed structural load in addition to its own weight. In a scope review, ask the responsible designer about its load-carrying role before discussing a new opening or alteration. [U.S. Department of Housing and Urban Development](https://www.huduser.gov/portal/portal/sites/default/files/pdf/Historic-Structures-Report-HUD-Building-Glossary.pdf).

Aliases: bearing wall.

Category: structure.

[Beam](#beam) · [Foundation](#foundation)

[Related resource](/trades/framing/)

<a id="loose-fill-insulation"></a>

## Loose-fill insulation

Insulating fibers or particles placed into cavities and other spaces, often with blowing equipment. Unlike precut batts, the loose material can conform around obstructions within the area being insulated. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2022-08/energy-saver-guide-2022.pdf).

Aliases: blown-in insulation.

Category: materials and supply.

[Batt insulation](#batt-insulation) · [Insulation](#insulation)

[Related resource](/suppliers/insulation/)

<a id="manual-j"></a>

## Manual J

ACCA’s residential heating and cooling load calculation method. The calculation establishes equipment sizing loads for a specific dwelling. Request the assumptions and results with the HVAC design documents. [Air Conditioning Contractors of America](https://www.acca.org/standards/technical-manuals/manual-j).

Aliases: Manual J calculation, residential load calculation.

Category: documents and money.

[Heat pump](#heat-pump) · [Air duct](#air-duct) · [Insulation](#insulation)

[Related resource](/guides/manual-j/)

<a id="material-takeoff"></a>

## Material takeoff

A quantity list derived from project drawings to support a material estimate or order. Builders FirstSource describes digital takeoffs in its workflow. Identify the plan revision and included scope before using the list. [Builders FirstSource](https://www.bldr.com/resources/blog/how-technology-makes-builder-journey-seamless-digital-solutions?topic=Construction+Strategies).

Aliases: takeoff, quantity takeoff.

Category: materials and supply.

[Construction documents](#construction-documents) · [Purchase order](#purchase-order)

[Related resource](/suppliers/lumber/)

<a id="mortar"></a>

## Mortar

A mixture of cement paste and fine aggregate. In masonry, joint mortar can contain masonry cement or hydraulic cement with lime; its composition differs from concrete containing coarse aggregate. [American Concrete Institute](https://www.concrete.org/portals/0/files/pdf/ACI_Concrete_Terminology.pdf).

Category: materials and supply.

[Concrete](#concrete) · [Aggregate](#aggregate)

[Related resource](/suppliers/concrete-and-masonry/)

<a id="mullion"></a>

## Mullion

A member joining adjacent window or door units into an assembly. It sits between units, unlike a sash holding the glass within one unit or casing trimming the assembly’s perimeter. [Andersen Windows](https://www.andersenwindows.com/support/window-door-glossary).

Aliases: mull.

Category: materials and supply.

[Window sash](#sash) · [Rough opening](#rough-opening)

[Related resource](/suppliers/windows-and-doors/)

<a id="named-insured"></a>

## Named insured

The person or business identified as the insured in the policy information. A certificate lists the insured alongside its policies. Compare that identity with the company whose work you are considering. [ACORD](https://tdi.texas.gov/certificates/documentcr/s21357a.pdf).

Aliases: insured entity.

Category: documents and money.

[Certificate of insurance](#certificate-of-insurance) · [Additional insured](#additional-insured)

[Related resource](/guides/check-subcontractor-insurance/)

<a id="osb"></a>

## Oriented strand board

A structural panel made from bonded wood strands arranged in oriented layers. APA panel grades and span ratings identify its intended use in wall sheathing, roof sheathing, and subfloor applications. [APA – The Engineered Wood Association](https://www.anthonyforest.com/assets/pdf/apa/APA_EW_Handbook_Grade_Glossary.pdf).

Aliases: OSB.

Category: materials and supply.

[Plywood](#plywood) · [I-joist](#i-joist)

[Related resource](/suppliers/lumber/)

<a id="outside-sales-representative"></a>

## Outside sales representative

A supplier representative who works with professional customers beyond the store counter. Home Depot describes help with quotes, sourcing, and deliveries. Ask who handles your account and which services apply locally. [The Home Depot](https://corporate.homedepot.com/news/company/osr).

Aliases: outside sales rep, OSR.

Category: business.

[Pro desk](#pro-desk) · [Building-material distributor](#building-material-distributor)

[Related resource](/suppliers/)

<a id="panel-point"></a>

## Panel point

A location where truss webs intersect the top or bottom chord and are joined by connector plates. Panel point identifies that connection location, while web and chord name the intersecting members. [Structural Building Components Association](https://www.sbcacomponents.com/terminology).

Aliases: truss joint.

Category: structure.

[Top chord](#top-chord) · [Bottom chord](#bottom-chord) · [Web member](#web-member)

[Related resource](/trades/framing/)

<a id="pickup-order"></a>

## Pickup order

A material order the customer collects from the supplier’s location. Builders FirstSource describes notifying customers when pickup is ready. Confirm readiness and collection arrangements with the branch before sending your crew. [Builders FirstSource](https://www.bldr.com/services/delivery-pickup).

Aliases: will-call pickup, customer pickup.

Category: materials and supply.

[Jobsite delivery](#jobsite-delivery) · [Purchase order](#purchase-order)

[Related resource](/suppliers/)

<a id="plywood"></a>

## Plywood

A panel made from bonded wood veneers with adjacent layers generally running in different directions. Veneer layers distinguish it from OSB, while its grade and span rating identify the panel’s intended use. [APA – The Engineered Wood Association](https://www.anthonyforest.com/assets/pdf/apa/APA_EW_Handbook_Grade_Glossary.pdf).

Category: materials and supply.

[Oriented strand board](#osb) · [Roof deck](#roof-deck)

[Related resource](/suppliers/lumber/)

<a id="policy-period"></a>

## Policy period

The effective and expiration dates listed for an insurance policy. A certificate shows those dates beside the policy information; ask the producer or insurer whether later changes affect its current status. [ACORD](https://tdi.texas.gov/certificates/documentcr/s21357a.pdf).

Aliases: effective and expiration dates.

Category: documents and money.

[Certificate of insurance](#certificate-of-insurance) · [Named insured](#named-insured)

[Related resource](/guides/check-subcontractor-insurance/)

<a id="pro-desk"></a>

## Pro desk

A store counter serving professional customers with ordering and sourcing help. Home Depot directs pros there for special orders. Ask your local desk which products and services it can provide for your job. [The Home Depot](https://www.homedepot.com/c/pro-special-order).

Aliases: contractor desk.

Category: materials and supply.

[Special order](#special-order) · [Outside sales representative](#outside-sales-representative)

[Related resource](/suppliers/)

<a id="programmable-thermostat"></a>

## Programmable thermostat

A temperature control that follows a schedule you set. Confirm the programmed settings and compatibility with the heating and cooling system. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2022-08/energy-saver-guide-2022.pdf).

Category: materials and supply.

[Thermostat](#thermostat) · [Smart thermostat](#smart-thermostat)

[Related resource](/trades/hvac/)

<a id="progress-payment"></a>

## Progress payment

A payment for work accomplished as a project proceeds. The federal construction clause ties requests to supported work estimates. For a residential job, confirm the payment basis and timing in the agreement. [Federal Acquisition Regulatory Council](https://www.acquisition.gov/far/52.232-5).

Aliases: draw, progress draw.

Category: documents and money.

[Retainage](#retainage) · [Lien waiver](#lien-waiver) · [Scope of work](#scope-of-work)

[Related resource](/guides/pay-application/)

<a id="punch-list"></a>

## Punch list

A list of incomplete work and corrections identified near project completion. It tracks individual remaining tasks, while closeout covers the broader process of cleaning, demobilization, and owner orientation. [Grand County Builders’ Association](https://www.nahb.org/-/media/NAHB/advocacy/docs/industry-issues/disaster-resources/home-building-overview.pdf?rev=6f76493d1a3e493fb717f52f0fa47d7e).

Aliases: punch work, punchlist.

Category: schedule and inspections.

[Closeout](#closeout) · [Progress payment](#progress-payment)

[Related resource](/guides/punch-list/)

<a id="purchase-order"></a>

## Purchase order

An ordering document used to purchase specified supplies or services. Federal procurement defines it as an offer to buy on stated terms. Confirm your supplier’s acceptance process and the applicable order terms. [Federal Acquisition Regulatory Council](https://www.acquisition.gov/far/2.101).

Aliases: PO.

Category: documents and money.

[Special order](#special-order) · [Material takeoff](#material-takeoff) · [Jobsite delivery](#jobsite-delivery)

[Related resource](/suppliers/)

<a id="r-value"></a>

## R-value

A measure of resistance to heat flow, with higher values indicating greater insulating resistance. DOE’s home-insulation guide explains that recommended R-values for new homes depend on regional climate and the installed heating and cooling system. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2021-11/ES-HomeInsulation_081721E-a.pdf).

Aliases: thermal resistance.

Category: materials and supply.

[Insulation](#insulation) · [Batt insulation](#batt-insulation)

[Related resource](/suppliers/insulation/)

<a id="reinforcing-bar"></a>

## Reinforcing bar

A slender steel bar used to reinforce concrete. The reinforcing bar schedule identifies required bar shapes, quantities, sizes, and dimensions for the structure or portion of work shown in the drawings. [American Concrete Institute](https://www.concrete.org/portals/0/files/pdf/ACI_Concrete_Terminology.pdf).

Aliases: rebar.

Category: structure.

[Concrete](#concrete) · [Foundation](#foundation)

[Related resource](/trades/concrete/)

<a id="residential-remodeler"></a>

## Residential remodeler

A business responsible for residential additions, alterations, reconstruction, maintenance, or repairs. Census places whole-project remodeling in this category, while firms performing only individual specialties remain within their respective trade industries. [Office of Management and Budget](https://www.census.gov/naics/reference_files_tools/2022_NAICS_Manual.pdf).

Aliases: remodeling contractor, renovation GC.

Category: trades.

[General contractor](#general-contractor) · [Subcontractor](#subcontractor)

[Related resource](/for/general-contractors/)

<a id="retainage"></a>

## Retainage

An amount withheld from a payment until specified release conditions are met. Federal construction contracts provide one example. Residential agreements and local law determine the applicable conditions; ask your construction attorney about them. [Federal Acquisition Regulatory Council](https://www.acquisition.gov/far/52.232-5).

Aliases: retention.

Category: documents and money.

[Progress payment](#progress-payment) · [Closeout](#closeout)

[Related resource](/guides/retainage/)

<a id="ridge-cap"></a>

## Ridge cap

A covering over a roof’s ridge or hip intersection. Include the specified cap product when checking a shingle package. [GAF](https://www.gaf.com/en-us/plan-design/homeowner-education/roof-parts).

Aliases: ridge cap shingle, hip cap.

Category: materials and supply.

[Asphalt shingle](#asphalt-shingle) · [Roof hip](#roof-hip) · [Roof pitch](#roof-pitch)

[Related resource](/trades/roofing/)

<a id="rigid-insulation"></a>

## Rigid insulation

Insulation supplied as stiff panels or boards. Identify the material, thickness, and intended location when comparing the specified assembly with other insulation options. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2021-11/ES-HomeInsulation_081721E-a.pdf).

Aliases: foam board, rigid foam board.

Category: materials and supply.

[Spray foam insulation](#spray-foam) · [R-value](#r-value) · [Insulation](#insulation)

[Related resource](/suppliers/insulation/)

<a id="rim-board"></a>

## Rim board

A full-depth structural member closing the edge of a framed floor or roof assembly. It transfers loads and supports the joist ends as detailed in the assembly. [APA – The Engineered Wood Association](https://www.anthonyforest.com/assets/pdf/apa/APA_EW_Handbook_Grade_Glossary.pdf).

Category: structure.

[I-joist](#i-joist) · [Subfloor](#subfloor) · [Diaphragm](#diaphragm)

[Related resource](/trades/framing/)

<a id="roof-deck"></a>

## Roof deck

The structural surface beneath the roof covering, with other parts of the roof attached to it. Underlayment lies above the deck, beneath the exposed roofing material. [GAF](https://www.gaf.com/en-us/plan-design/homeowner-education/roof-parts).

Aliases: roof decking.

Category: structure.

[Plywood](#plywood) · [Oriented strand board](#osb) · [Roof underlayment](#roof-underlayment)

[Related resource](/trades/framing/)

<a id="roof-flashing"></a>

## Roof flashing

Material that directs water away from roof joints and penetrations, including locations around chimneys and other openings. Flashing protects these transitions; underlayment covers the broader area beneath the roof covering. [GAF](https://www.gaf.com/en-us/plan-design/homeowner-education/roof-parts).

Aliases: flashing.

Category: materials and supply.

[Drip edge](#drip-edge) · [Roof underlayment](#roof-underlayment)

[Related resource](/trades/roofing/)

<a id="roof-hip"></a>

## Roof hip

The outward sloping intersection where two roof planes meet. Identify this line separately from the roof’s ridge when discussing covering and cap details. [GAF](https://www.gaf.com/en-us/plan-design/homeowner-education/roof-parts).

Aliases: hip.

Category: structure.

[Ridge cap](#ridge-cap) · [Roof pitch](#roof-pitch) · [Roof truss](#roof-truss)

[Related resource](/trades/roofing/)

<a id="roof-pitch"></a>

## Roof pitch

The roof’s steepness, commonly expressed as vertical rise relative to horizontal run. A rise-to-run description identifies the slope; it does not describe the roof’s area or the length of its rafters. [Joanna C. Rodriguez, AIA](https://www.gaf.com/en-us/blog/residential-roofing/minimum-slope-for-shingles-what-contractors-need-to-know-62ebb846-13b5-4619-80c4-d408b50e11e3).

Aliases: roof slope.

Category: structure.

[Roof deck](#roof-deck) · [Top chord](#top-chord)

[Related resource](/trades/roofing/)

<a id="roof-rake"></a>

## Roof rake

The sloped edge along a gable roof. Identify its starter-strip and edge details separately from the horizontal eave. [GAF](https://www.gaf.com/en-us/plan-design/homeowner-education/roof-parts).

Aliases: rake, gable rake.

Category: structure.

[Starter strip](#starter-strip) · [Drip edge](#drip-edge) · [Roof deck](#roof-deck)

[Related resource](/trades/roofing/)

<a id="roof-truss"></a>

## Roof truss

An engineered framework supporting a roof. A metal plate connected wood truss uses wood chords and webs joined by connector plates, with members commonly arranged as triangles to carry the specified loads. [Structural Building Components Association](https://www.sbcacomponents.com/terminology).

Aliases: metal plate connected wood truss, MPCWT.

Category: structure.

[Top chord](#top-chord) · [Bottom chord](#bottom-chord) · [Web member](#web-member) · [cercha](#cercha)

[Related resource](/suppliers/trusses-and-engineered-wood/)

<a id="roof-underlayment"></a>

## Roof underlayment

A layer between the roof covering and roof deck that provides secondary rain protection in a shingle system. It is distinct from the structural deck and the exposed shingles above it. [GAF](https://www.gaf.com/en-us/plan-design/homeowner-education/roof-parts).

Aliases: roof deck protection.

Category: materials and supply.

[Roof deck](#roof-deck) · [Roof flashing](#roof-flashing)

[Related resource](/trades/roofing/)

<a id="rough-opening"></a>

## Rough opening

The framed wall opening provided for a window or door, including space around the unit for installation. Rough-opening dimensions differ from the unit’s dimensions, so the two measurements must remain distinct. [Andersen Windows](https://www.andersenwindows.com/support/window-door-glossary).

Aliases: RO.

Category: structure.

[Jamb](#jamb) · [Casing](#casing)

[Related resource](/trades/windows-and-doors/)

<a id="rough-in"></a>

## Rough-in

Installation of the concealed portions of plumbing, HVAC, electrical, and other systems before finishes cover the work. The homebuilding overview separates rough-ins and rough inspections from the later interior-finish stage. [Grand County Builders’ Association](https://www.nahb.org/-/media/NAHB/advocacy/docs/industry-issues/disaster-resources/home-building-overview.pdf?rev=6f76493d1a3e493fb717f52f0fa47d7e).

Aliases: rough-in work.

Category: schedule and inspections.

[Dry-in](#dry-in) · [Punch list](#punch-list) · [Construction documents](#construction-documents)

[Related resource](/guides/rough-in/)

<a id="schedule-of-values"></a>

## Schedule of values

A breakdown of contract value into work items that supports progress-payment requests. AIA’s G703 organizes these line items alongside completed work, stored materials, and retainage. [AIA Contract Documents](https://learn.aiacontracts.com/articles/how-to-complete-the-g702-payment-application/).

Aliases: SOV.

Category: documents and money.

[Progress payment](#progress-payment) · [Retainage](#retainage) · [Scope of work](#scope-of-work)

[Related resource](/guides/pay-application/)

<a id="scope-of-work"></a>

## Scope of work

A description of the work a party must perform and the results expected. Federal performance-work guidance emphasizes required results. In your residential agreement, identify the included tasks, exclusions, and acceptance expectations. [Federal Acquisition Regulatory Council](https://www.acquisition.gov/far/37.602).

Aliases: SOW, work scope.

Category: documents and money.

[Construction documents](#construction-documents) · [Change order](#change-order) · [Subcontractor](#subcontractor)

[Related resource](/guides/trade-scope-of-work/)

<a id="sheathing"></a>

## Sheathing

Panels covering framing to form wall, roof, or floor surfaces. Structural sheathing differs from finish cladding; APA panel grades and span ratings identify the intended structural applications of wood panels. [APA – The Engineered Wood Association](https://www.anthonyforest.com/assets/pdf/apa/APA_EW_Handbook_Grade_Glossary.pdf).

Aliases: structural sheathing.

Category: structure.

[Oriented strand board](#osb) · [Plywood](#plywood) · [Roof deck](#roof-deck)

[Related resource](/suppliers/lumber/)

<a id="shoring"></a>

## Shoring

A system designed to support excavation sides and prevent cave-ins, using components such as hydraulic, mechanical, or timber supports. It holds the sides; a shield instead protects workers within its structure. [Occupational Safety and Health Administration](https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.650).

Aliases: shoring system.

Category: materials and supply.

[Trench](#trench) · [Trench shield](#trench-shield)

[Related resource](/trades/excavation/)

<a id="skim-coat"></a>

## Skim coat

A thin application of joint compound across a gypsum-panel surface. It treats the board face beyond individual joints and fasteners, and forms part of the preparation associated with a Level 5 finish. [USG](https://assemblies-tools.usg.com/content/dam/USG_Marketing_Communications/united_states/product_promotional_materials/finished_assets/finishing-decorating-gypsum-panels-white-paper-en-J2010.pdf).

Category: materials and supply.

[Joint compound](#joint-compound) · [Level 5 finish](#level-5-finish)

[Related resource](/trades/drywall/)

<a id="sloping"></a>

## Sloping

Cutting excavation sides back from the excavation to help protect against cave-ins. OSHA distinguishes this protective method from shoring and shielding. Follow the applicable excavation protection requirements. [Occupational Safety and Health Administration](https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.650).

Aliases: excavation sloping.

Category: trades.

[Excavation](#excavation) · [Shoring](#shoring) · [Trench shield](#trench-shield)

[Related resource](/trades/excavation/)

<a id="slump"></a>

## Slump

A measurement of fresh concrete’s consistency. After the slump cone is removed, the molded sample settles; the vertical change is measured and reported as the slump of that tested mixture. [American Concrete Institute](https://www.concrete.org/portals/0/files/pdf/ACI_Concrete_Terminology.pdf).

Aliases: slump test.

Category: materials and supply.

[Concrete](#concrete) · [Aggregate](#aggregate)

[Related resource](/trades/concrete/)

<a id="smart-thermostat"></a>

## Smart thermostat

A Wi-Fi-connected control that can adjust heating and cooling settings automatically. Features vary by model; confirm the equipment compatibility and controls included in the scope. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2022-08/energy-saver-guide-2022.pdf).

Aliases: connected thermostat.

Category: materials and supply.

[Thermostat](#thermostat) · [Programmable thermostat](#programmable-thermostat)

[Related resource](/suppliers/hvac/)

<a id="soffit"></a>

## Soffit

The exposed underside of an overhead building component, such as an eave, balcony, beam, cornice, or arch. When you discuss a soffit scope, identify both its location and the specified finish material. [U.S. Department of Housing and Urban Development](https://www.huduser.gov/portal/portal/sites/default/files/pdf/Historic-Structures-Report-HUD-Building-Glossary.pdf).

Category: materials and supply.

[Roof deck](#roof-deck) · [Casing](#casing)

[Related resource](/trades/siding/)

<a id="shgc"></a>

## Solar heat gain coefficient

A rating describing solar heat admitted through a window or door. A lower value means less solar heat gain. Keep it distinct from U-factor when comparing products. [Andersen Windows](https://www.andersenwindows.com/support/window-door-glossary).

Aliases: SHGC.

Category: materials and supply.

[U-factor](#u-factor) · [Window sash](#sash)

[Related resource](/suppliers/windows-and-doors/)

<a id="stc"></a>

## Sound transmission class

A single-number rating for comparing airborne sound attenuation through tested partitions, including walls and floor-ceiling assemblies. Compare the complete tested assembly when reviewing a proposal. [USG](https://www.usg.com/en-US/learning-reference/performance/acoustic/principles).

Aliases: STC, STC rating.

Category: materials and supply.

[Insulation](#insulation) · [Batt insulation](#batt-insulation) · [Joint compound](#joint-compound)

[Related resource](/trades/insulation/)

<a id="special-order"></a>

## Special order

An order for a product sourced beyond a store’s standard assortment. Home Depot describes this option for pros. Confirm the exact item, expected arrival, deposit, and return terms with your supplier. [The Home Depot](https://www.homedepot.com/c/pro-special-order).

Aliases: non-stock order.

Category: materials and supply.

[Pro desk](#pro-desk) · [Purchase order](#purchase-order)

[Related resource](/suppliers/)

<a id="specialty-trade-contractor"></a>

## Specialty trade contractor

A business performing a defined part of construction, such as framing, roofing, or electrical installation. Its customer can be a GC or an owner, and its contract identifies the specific work undertaken. [Office of Management and Budget](https://www.census.gov/naics/reference_files_tools/2022_NAICS_Manual.pdf).

Aliases: trade contractor, specialty contractor.

Category: trades.

[Subcontractor](#subcontractor) · [General contractor](#general-contractor)

[Related resource](/trades/)

<a id="spray-foam"></a>

## Spray foam insulation

Foam insulation applied in place with spraying equipment. Identify the specified foam type and application area when comparing it with batts or rigid boards. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2021-11/ES-HomeInsulation_081721E-a.pdf).

Aliases: spray foam, spray polyurethane foam.

Category: materials and supply.

[Insulation](#insulation) · [R-value](#r-value) · [Rigid insulation](#rigid-insulation)

[Related resource](/suppliers/insulation/)

<a id="starter-strip"></a>

## Starter strip

Roofing material installed at eaves and rakes beneath the first shingle course. Factory-positioned sealant helps resist shingle blow-offs in the described GAF system. [GAF](https://www.gaf.com/en-us/plan-design/homeowner-education/roof-parts).

Aliases: starter shingle, starter course.

Category: materials and supply.

[Asphalt shingle](#asphalt-shingle) · [Roof rake](#roof-rake) · [Drip edge](#drip-edge)

[Related resource](/trades/roofing/)

<a id="subcontractor"></a>

## Subcontractor

A firm furnishing work, supplies, or services under another contractor’s contract. Federal procurement includes suppliers in its subcontractor definition. For a residential scope conversation, identify the contracting relationship and specific responsibilities. [Federal Acquisition Regulatory Council](https://www.acquisition.gov/far/44.101).

Aliases: sub.

Category: business.

[General contractor](#general-contractor) · [Specialty trade contractor](#specialty-trade-contractor) · [Scope of work](#scope-of-work)

[Related resource](/guides/find-subcontractors/)

<a id="subfloor"></a>

## Subfloor

The structural floor layer supported by the floor framing. Wood-panel subflooring provides strength and stiffness; a separate underlayment can sit above it to prepare the surface for finished flooring. [APA – The Engineered Wood Association](https://www.anthonyforest.com/assets/pdf/apa/APA_EW_Handbook_Grade_Glossary.pdf).

Aliases: subflooring.

Category: structure.

[Sheathing](#sheathing) · [Plywood](#plywood) · [I-joist](#i-joist)

[Related resource](/trades/framing/)

<a id="submittal"></a>

## Submittal

Documents or product information submitted for review or approval. A truss submittal package includes individual truss design drawings and applicable placement and bracing details. Confirm which package and revision the team means. [Structural Building Components Association](https://www.sbcacomponents.com/terminology).

Aliases: submittal documents, truss submittal package.

Category: documents and money.

[Construction documents](#construction-documents) · [Roof truss](#roof-truss) · [Bracing](#bracing)

[Related resource](/guides/framer-and-truss-supplier/)

<a id="thermostat"></a>

## Thermostat

A control used to set heating and cooling temperatures. Confirm the control type and its compatibility with the installed HVAC equipment. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2022-08/energy-saver-guide-2022.pdf).

Category: materials and supply.

[Programmable thermostat](#programmable-thermostat) · [Smart thermostat](#smart-thermostat) · [Heat pump](#heat-pump)

[Related resource](/trades/hvac/)

<a id="tongue-and-groove"></a>

## Tongue-and-groove joint

An edge joint with a projecting tongue fitting into a matching groove. Identify the panel or board edge profile when preparing a material order. [APA – The Engineered Wood Association](https://www.anthonyforest.com/assets/pdf/apa/APA_EW_Handbook_Grade_Glossary.pdf).

Aliases: T&G, tongue and groove.

Category: structure.

[Subfloor](#subfloor) · [Plywood](#plywood) · [Oriented strand board](#osb)

[Related resource](/suppliers/lumber/)

<a id="top-chord"></a>

## Top chord

The inclined or horizontal member forming a truss’s upper edge. It commonly carries combined compression and bending stresses, while the bottom chord forms the lower edge of the same component. [Structural Building Components Association](https://www.sbcacomponents.com/terminology).

Category: structure.

[Bottom chord](#bottom-chord) · [Web member](#web-member) · [Roof truss](#roof-truss)

[Related resource](/trades/framing/)

<a id="transom-window"></a>

## Transom window

A window located directly above another window or door. Identify its position in the opening schedule when confirming the window package. [Andersen Windows](https://www.andersenwindows.com/support/window-door-glossary).

Aliases: transom.

Category: materials and supply.

[Rough opening](#rough-opening) · [Mullion](#mullion) · [Window sash](#sash)

[Related resource](/suppliers/windows-and-doors/)

<a id="trench"></a>

## Trench

A narrow excavation below ground, generally deeper than it is wide. OSHA’s definition also limits bottom width; an excavation can fall outside that trench definition and still present cave-in hazards. [Occupational Safety and Health Administration](https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.650).

Category: trades.

[Excavation](#excavation) · [Shoring](#shoring) · [Trench shield](#trench-shield)

[Related resource](/trades/excavation/)

<a id="trench-shield"></a>

## Trench shield

A structure designed to withstand cave-in forces and protect workers inside it, often called a trench box. Shields can be permanent structures or portable units moved as excavation work progresses. [Occupational Safety and Health Administration](https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.650).

Aliases: trench box.

Category: materials and supply.

[Shoring](#shoring) · [Trench](#trench)

[Related resource](/trades/excavation/)

<a id="u-factor"></a>

## U-factor

A measure of heat transfer through a window or door. A lower value indicates greater resistance to heat transfer. Compare the specified product rating. [Andersen Windows](https://www.andersenwindows.com/support/window-door-glossary).

Aliases: U factor, window U-factor.

Category: materials and supply.

[Solar heat gain coefficient](#shgc) · [R-value](#r-value) · [Rough opening](#rough-opening)

[Related resource](/suppliers/windows-and-doors/)

<a id="unconditional-lien-waiver"></a>

## Unconditional lien waiver

A release that is not conditioned on later receipt of payment. California’s guidance warns that signing can affect lien rights before payment clears. Ask a construction attorney about your jurisdiction and document. [California Contractors State License Board](https://cslb.ca.gov/consumers/Legal_Issues_For_Consumers/Mechanics_Lien/Conditional_And_Unconditional_Waiver_Release_Form.aspx).

Aliases: unconditional waiver and release.

Category: documents and money.

[Conditional lien waiver](#conditional-lien-waiver) · [Lien waiver](#lien-waiver)

[Related resource](/guides/lien-waiver/)

<a id="air-gap"></a>

## Water-supply air gap

An unobstructed vertical separation between a water-supply outlet and the receiving fixture’s flood-level rim. That rim is the edge where water spills over the fixture; Oatey separately defines drainage-system air gaps. [Oatey](https://www.oatey.com/articles-videos-faqs/plumbing-terms).

Aliases: air gap.

Category: materials and supply.

[Cross-linked polyethylene pipe](#pex) · [Rough-in](#rough-in)

[Related resource](/trades/plumbing/)

<a id="weatherstripping"></a>

## Weatherstripping

Sealing material fitted around moving parts of windows and doors to limit air leakage. It accommodates those operable joints, while caulk is used for gaps between stationary building components. [U.S. Department of Energy](https://www.energy.gov/sites/default/files/2021-08/ES-Air%20Sealing_080421.pdf).

Aliases: weather-strip.

Category: materials and supply.

[Air sealing](#air-sealing) · [Caulk](#caulk)

[Related resource](/trades/windows-and-doors/)

<a id="web-member"></a>

## Web member

An internal truss member joining the top and bottom chords. Webs meet the chords at panel points, where connector plates join the intersecting members in a metal plate connected wood truss. [Structural Building Components Association](https://www.sbcacomponents.com/terminology).

Aliases: truss web.

Category: structure.

[Top chord](#top-chord) · [Bottom chord](#bottom-chord)

[Related resource](/trades/framing/)

<a id="wet-sanding"></a>

## Wet sanding

Smoothing dry joint compound with a damp sponge. USG distinguishes this finishing method from removing large amounts of compound or correcting poorly finished joints. [USG](https://assemblies-tools.usg.com/content/dam/USG_Marketing_Communications/united_states/product_promotional_materials/finished_assets/finishing-decorating-gypsum-panels-white-paper-en-J2010.pdf).

Aliases: sponge sanding.

Category: materials and supply.

[Joint compound](#joint-compound) · [Drywall primer](#drywall-primer) · [Skim coat](#skim-coat)

[Related resource](/trades/drywall/)

<a id="sash"></a>

## Window sash

The framework holding a window’s glass, either movable or fixed. The sash sits within the window assembly; it is a different component from the surrounding frame and its jambs. [Andersen Windows](https://www.andersenwindows.com/support/window-door-glossary).

Aliases: sash.

Category: materials and supply.

[Jamb](#jamb) · [Mullion](#mullion)

[Related resource](/suppliers/windows-and-doors/)

<a id="workers-compensation"></a>

## Workers’ compensation

Insurance or an approved self-insurance arrangement addressing work-related employee injuries and illnesses. North Carolina’s employer guidance describes its coverage requirements and exceptions. Ask the relevant agency or insurer about your specific situation. [North Carolina Industrial Commission](https://www.ic.nc.gov/workers-compensation-claims/employers).

Aliases: workers' comp, workers compensation.

Category: documents and money.

[Contractor license](#contractor-license) · [Certificate of insurance](#certificate-of-insurance)

[Related resource](/guides/subcontractor-workers-comp/)

## Build your connections

[Ask about the beta](</beta/>)

## Sources

<a id="source-1"></a>

1. APA – The Engineered Wood Association. (2012). *Engineered Wood Handbook and Grade Glossary*. https://www.anthonyforest.com/assets/pdf/apa/APA_EW_Handbook_Grade_Glossary.pdf

<a id="source-2"></a>

2. Structural Building Components Association. (n.d.). *Terminology*. Retrieved October 14, 2026, from https://www.sbcacomponents.com/terminology

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