What Are the Most Common Roof Truss Designs? The Complete Builder’s Guide
When you’re planning a new build or a major remodel, understanding the variety of roof truss designs available is critical to making smart, cost-effective construction decisions.
The roof truss is one of the most important structural elements of any building. The right design impacts everything from your project’s overall strength and safety to its aesthetic appeal and interior volume.
By exploring the most common types of roof trusses and their features, you’ll be better equipped to choose the best option for your upcoming projects.
What Are Roof Trusses?
Roof trusses are pre-engineered structural frameworks that use a combination of beams, struts, and ties to maintain the shape of the roof and transfer its weight safely to supporting walls or columns. Unlike traditional stick-built framing—where rafters and ceiling joists are cut and assembled piece by piece on-site—trusses are precision-fabricated in a factory setting.
This approach ensures consistent quality and dimensional accuracy. Trusses distribute loads efficiently, spanning wide distances without needing many interior load-bearing walls. They’re designed to handle specific dead and live loads while allowing for flexible interior layouts, higher ceilings, and creative architectural features.
The Most Common Roof Truss Designs
When evaluating roof truss designs for your project, you should consider:
- Building Type and Use: Residential vs. commercial, storage, living space, etc.
- Span Requirements: The distance that needs to be covered without interior supports.
- Roof Pitch and Architectural Style: Matching design goals and aesthetics.
- Load Requirements: Snow load, wind uplift, dead load from roofing materials.
- Budget Constraints: Balancing cost with performance and appearance.
- Local Building Codes: Ensuring compliance with safety regulations.
To help you decide, let’s walk through some of the most common roof truss designs, describing their structure, uses, advantages, and key features.
Flat Bottom Chord Truss
A flat bottom chord truss features parallel top and bottom chords connected by diagonal web members. While often used for floor framing, this design is also well-suited for certain roof applications where a level ceiling is desired.
It offers straightforward, efficient load transfer and is ideal when you need a simple horizontal span without changing ceiling heights. It’s particularly effective in commercial buildings or residential designs prioritizing a flat, consistent ceiling line.
Scissors Truss
Scissors trusses have sloped top chords (like most trusses) and also have bottom chords that slope upward toward the center, creating a vaulted interior ceiling.
This design is perfect for achieving dramatic interior spaces with a higher, cathedral-like effect. Variations of scissor trusses allow for different ceiling shapes:
- Parallel chord variations for maximum clearance.
- Offset scissor designs with flat sections transitioning into vaults.
- Partial scissor trusses that change slope along their length.
These are one of the most popular roof truss designs in custom homes, churches, and any building aiming for open, airy interiors without needing complex stick-built vault framing.
Cathedral Truss
A cathedral truss follows the steep, symmetrical pitch of the roofline directly, creating dramatic interior angles that mimic traditional cathedral ceilings. Both sides of the truss slope inward at matching, often steep angles, making them an excellent choice for creating a sense of spaciousness and luxury.
These roof truss designs shine in high-end residential builds, churches, and community spaces where visual impact is paramount. When paired with large windows, cathedral trusses can deliver breathtaking interior views and natural light.
Step Ceiling Truss
Also known as tray ceilings, step ceiling trusses are designed to create recessed ceilings with multiple “steps” or levels. These stepped recesses can be shaped in various forms—square, rectangular, round, or even octagonal—to match architectural preferences.
You can customize the number and width of steps (usually 6-18 inches) to suit room dimensions and budget. Step ceilings are ideal for:
- Adding depth and sophistication to interiors.
- Hiding lighting along the recesses or concealing speakers.
- Delivering high-end interior finishes without complex custom framing on site.
Room-in-Attic Truss
Room-in-attic trusses, or sometimes just called attic trusses, are engineered to include an open, rectangular space within the truss itself to create a usable attic room.
Unlike standard trusses that use a dense web of triangles throughout, room-in-attic trusses have a dedicated open area that can be finished as storage or living space. This can be a cost-effective way to add square footage to a property. It also eliminates the need for additional framing to build out the attic later.
Gambrel Truss
A gambrel truss features a double-sloped roof profile, steeper on top and shallower below. This classic barn-style roof maximizes headroom and usable space under the roof. It is popular for barns and agricultural buildings, sheds, and garages with loft storage.
Dual Pitch Truss
Dual pitch trusses, sometimes called dual slope trusses, have top chords with two different slopes—typically a steeper front slope and a shallower back slope. This versatile design is often used for sheds and can also work well for barns, warehouses, and other open-plan structures.
They can be especially valued for projects with large, open spans needing a simple but effective roof shape. The connected triangles distribute loads evenly while the web members add strength. Plus, the dual slope accommodates drainage requirements and creates dynamic rooflines.
Post Frame Truss
Post frame trusses are designed for installation on wider spacing, often more than two feet on center. This makes them ideal for agricultural buildings, pole barns, large garages, and commercial or industrial structures.
They’re a popular option for reducing material requirements for intermediate supports, faster installation times, and suitability for expansive, open spaces.
Sloped Flat Truss
Sloped flat trusses have both top and bottom chords sloped equally, maintaining consistent depth along their length. These roof truss designs are commonly used in warehouses, arenas, and churches.
This design supports large, open spans while allowing for sloped ceilings. They’re usually factory-prefabricated for accuracy and ease of installation on site.
Mono Pitch Truss
Mono pitch trusses are designed with a single slope in one direction. They’re frequently used to create multilevel rooflines, additions to existing structures, and modern architectural features.
Mono pitch trusses are especially handy for integrating new construction with existing buildings seamlessly while delivering distinctive, contemporary aesthetics.
How to Choose the Right Roof Truss Designs
Selecting the best roof truss designs requires close collaboration with your roof truss designers, understanding structural needs, and planning for the lifecycle of the building.
- Engage Your Structural Engineer Early: Your engineer can evaluate the specific load demands of your site and recommend roof truss designs that meet code while minimizing cost and complexity. Early collaboration avoids expensive redesigns.
- Think Beyond the Roof Line: Your choice of truss affects interior layout, mechanical runs, insulation strategies, and ceiling finishes. For example, a scissor or cathedral truss enables dramatic vaulted spaces but may complicate HVAC duct runs. An attic truss adds usable space but may need additional insulation.
- Evaluate Construction Logistics: Assess site access, crane availability, and crew experience. Some roof truss designs span long distances and require careful delivery planning and lifting equipment. Discuss with your supplier whether your job site has the space and access needed for larger pre-assembled trusses.
- Plan for Future Flexibility: If buildings might be renovated or expanded in the future, choose roof truss designs that allow for easy reconfiguration. For example, post-frame trusses reduce the number of load-bearing walls, making it easier to make changes.
- Partner with a Trusted Manufacturer: Work with roof truss designers and manufacturers who can custom-engineer trusses to your specs, provide sealed drawings for permit approval, and deliver on schedule. They should have a track record in relevant building types. At Standard Supply & Lumber, our team has extensive experience with multi-family, single-family, remodel, commercial, and agricultural projects. Our production supervisor alone brings nearly two decades of industry expertise, overseeing a well-trained team to ensure smooth, high-quality production on every order.
The Advantages of Manufactured Roof Trusses
Manufactured roof trusses are built off-site in controlled factory environments and delivered ready for installation. Compared to traditional stick-built framing, they offer significant benefits:
- No On-Site Cutting or Assembly: Prefabrication eliminates measuring and cutting on site.
- Uniformity: Computer-controlled fabrication ensures precise, consistent dimensions.
- Faster Installation: Many truss systems can be installed in hours instead of days.
- Structural Reliability: Consistency and precision enhance overall strength and load distribution.
- Lower Labor and Waste Costs: Fewer on-site hours and less material waste mean lower overall project costs.
- Design Flexibility: Complex rooflines, vaulted ceilings, and long spans are easier to achieve with factory-built trusses.
- High-Quality Materials: You get lumber that’s carefully selected and tested for strength.
- Weather Independence: Fabrication continues regardless of on-site weather delays.
- Cost Savings: Manufactured trusses typically cost 30-50% less than on-site framing.
Turn to Trusted Roof Truss Designers at Standard Supply & Lumber
Unsure which of these roof truss designs is best for your project? The Standard Supply & Lumber experts can recommend tailored solutions for everything from residential homes to large-scale commercial or agricultural structures.
Our expertly designed, precision-manufactured roof trusses will help you save time and money on upcoming builds. Reach out to our team today to discuss your needs, get answers to your questions, or to request a quote.