You are choosing a roof package. Use truss names to describe the roof shape, room space, and support role. Start with the required roof and ceiling geometry, then have the designer and manufacturer select components for the loads and supports. A shape name alone does not establish span, capacity, or usable attic space. SBCA configurations Component design responsibilities
Distinguish web patterns, profiles, and support roles
Use the roof-truss glossary definition for the component itself.
Some names describe an internal web pattern, such as Fink or Howe. Others describe the outer profile or intended interior space, such as mono, scissor, or attic. A girder truss describes a support role. Keep those categories separate when discussing alternatives. Configuration families Girder definition
Start with what is a roof truss if you need the component definition. Then use parts of a roof truss to identify chords, webs, and support locations in the proposed package.
SBCA explains that chord size and web configuration depend on span, load, and spacing. A type name does not tell you its span range or cost. Obtain the design and quote for this building. Configuration design factors
Compare common truss shapes and their uses
The following table uses SBCA’s configuration resource and a component manufacturer’s illustrated guide. Use it to discuss applications. It does not approve a design or show which types are popular locally. SBCA profile examples Rigid Component Systems guide Gable-end terminology
Scroll to read all columns.
| Type or pattern | What the name describes | Project question |
|---|---|---|
| Pitched or common | Triangular roof profile; web arrangements vary | Which web pattern, supports, and ceiling profile fit this building? |
| Gable-end frame | Component closing the end wall, with continuous support below | Does the end-wall or beam support match the design? |
| King post | Pitched profile with a central vertical member | Does the engineered arrangement fit the required loads and span? |
| Queen post | Pitched arrangement using paired vertical members | Which space and web layout does the proposed design provide? |
| Fink | Common pitched form with a W-like web pattern | Are the intended service routes coordinated with the webs? |
| Howe | A different vertical and diagonal web arrangement | What design basis governs this component? |
| Mono | Single-pitch roof profile | How do unequal roof edges and supports connect to the building? |
| Parallel chord | Top and bottom chords with equal slopes | How are roof drainage, supports, and services coordinated? |
| Scissor | Sloping lower chords shaping a vaulted ceiling | What interior slope and room height does the design deliver? |
| Attic | Profile arranged around intended attic room or space | Which floor use, loading, access, and enclosure are designed? |
| Gambrel | Roof with changing slopes resembling a barn profile | What room, eave, and support geometry is required? |
| Hip set | Coordinated components forming the roof’s end slopes | How are short framing members and support components connected? |
Use the table to prepare questions, then check the component layout for your roof. One roof can contain several types and roles. Do not request an entire package by naming only the repeated common truss.
Identify pitched, parallel-chord, and gable-end components
SBCA groups basic trusses into pitched and parallel-chord families. A pitched truss has a triangular outline; a parallel-chord truss has upper and lower chords with equal slopes. Parallel-chord trusses also appear in roof applications. Match the proposed profile to the intended ceiling and roof geometry. Basic configuration families Parallel-chord definition
For a gable roof, distinguish the repeated interior components from the gable-end frame on the placement drawing. SBCA defines the gable-end frame by its end-wall function and continuous support beneath the lower chord. A similar outline does not make it interchangeable with an interior spanning truss. Gable-end frame definition
Ask the supplier to identify each component mark, support condition, and connection to adjoining work. Give the framing crew those distinctions with the installation package. Do not pick a span or substitute one component from its shape name.
A girder truss carries other framing
SBCA defines a girder truss as a truss designed to carry loads from other structural members framing into it. Check its connections, bearings, and supported members together. A girder has a different job from an ordinary truss. Girder definition
A girder can be supplied as a multi-ply assembly. SBCA defines multi-ply trusses as separate plies fastened together to act as one, with ply connections specified on the truss design drawing. Check the specified assembly. Placing the plies side by side does not complete their connections. Multi-ply terminology
Ask the supplier to identify girder locations and the framing they support. Ask the building designer to confirm reactions, the supporting structure, and connections. Keep those answers with the drawings delivered to the crew.
TPI establishes design, construction, quality-assurance, and testing methods for metal-plate-connected wood trusses. Use its standards with the project drawings, which define the specific component and assembly. TPI standards development
Do not substitute a common truss for a girder because the outside profile matches. Obtain a reviewed change through the responsible design parties.
Scissor trusses change the ceiling profile
A scissor configuration uses sloping bottom chords to create a vaulted interior. The outside roof pitch and inside ceiling pitch remain separate design questions. Manufacturer illustrations help show the distinction, but they do not fix the dimensions for your house. Scissor profile example SBCA configuration examples
Before approving the package, ask for the interior height and slope shown on the current design. Coordinate room finishes, partitions, insulation, ventilation, and service routes with that profile.
Do not assume a vaulted room has the same usable cavity or mechanical route as a flat-ceiling room. Ask the designer to resolve room and service-route conflicts before release. Do not leave the framer to cut around them.
BCSI addresses installation and stabilization of trusses. A scissor shape still needs the applicable handling, restraint, bracing, and connection plan. Follow those installation requirements regardless of the room profile. BCSI guidance
Specify the room use and loads for attic trusses
An attic truss arrangement reserves a space inside the roof profile. The manufacturer’s guide describes components designed for both roof and floor loads where an attic room is intended. State the intended use in the design brief. Attic truss example
State whether you want a habitable room, limited storage, or service space. Ask the building designer to coordinate floor loading, access, headroom, openings, and the enclosure for that use. An open rectangle on a drawing does not mean the space is approved for occupancy.
Use the supplier’s actual room dimensions when comparing options. Label the finish buildup and any constraints the designer identifies. Record the agreed use in the production-release documents. Check later changes against that use.
Builders FirstSource describes roof-truss and engineered-wood layout support. Ask your supplier what is included in its review and how it receives the building designer’s requirements. Confirm the scope with your supplier. Suppliers may offer different services. Supplier design services
Check hip sets, gable ends, and piggyback assemblies
SBCA describes hip sets as coordinated step-down components forming end slopes. It separately defines a gable-end frame with continuous support from the end wall or beam. That support condition matters when reading the roof layout. Hip-set and gable-end terminology
Piggyback trusses consist of a supporting component and a cap assembled at the jobsite, often because manufacturing or shipping limits constrain height. Give the crew the assembly and stabilization documents for those pieces. Do not treat the delivered pieces as complete without the specified site work. Piggyback definition
Ask the supplier to mark components that differ from the repeated interior trusses. Review those special connections with the framing lead before delivery. Put their marks and locations into the installation packet.
Who chooses the type
The owner and building designer define the spaces and building requirements. The manufacturer and truss designer develop the components within their assigned roles. SBCA’s delegated-design discussion distinguishes individual truss design from overall building-system design. Design responsibility boundaries
Use order roof trusses to turn the design conversation into a reviewed release. Compare roof trusses and rafters only after both options answer the same room, support, load, and scope questions.
Before fabrication, ask the supplier:
- Which component types and structural roles appear in this roof?
- Which room uses, loads, bearings, and openings form the design basis?
- Are ceilings, eaves, and service routes coordinated with the current plans?
- Who reviews revisions and authorizes production release?
- Which installation and special-assembly documents reach the crew?
- Who answers field damage or conflict questions?
SBCA’s jobsite packages supply handling, installation, restraint, and bracing information. Retain that guidance with the current drawings and accepted revisions. Jobsite documentation
Use the trusses and engineered-wood supplier page to prepare the first inquiry. Obtain the actual quote, documents, and delivery commitment from the supplier.
Where Cercha fits
Cercha supplier profiles show carried brands, and portfolios help you review relevant framing work. Search narrows the trade and location, while Messages supports the first conversation. Component selection and structural acceptance stay with the responsible designer, manufacturer, and installer.