A scissor truss creates dramatic interior ceilings and provides support and stability to buildings, especially for roofs that are exposed to extreme weather or houses located on lots with shifting soils.
What is a Truss
Trusses are essentially roof frames. Creating roof frames with trusses is superior. An interlocking sequence of rafters, joists, and jacks is installed, generally off-site, to build a trussed roof. With these, A-frames are constructed with far more strength and durability than cut roofs.
What is a Scissor Truss?
A scissor truss, also known as a cathedral truss, is constructed with double bottom chords that meet in the middle, forming an inverted-V shape underneath.
A scissor truss supports scooted ceilings or high vaulted roofs as high as 78 feet in residential buildings.
The Cost of a Scissor Truss
Scissor trusses cost more than typical trusses—they can cost 15% to 30% more than the average truss price.
The Pros and Cons of Scissor Trusses
Like all roof trusses, scissor trusses come with advantages as well as disadvantages.
Pros of a Scissor Truss
Low Installation Cost
To maintain the pitch of a roof truss, framing support may be necessary. Scissor trusses do not need any additional support, so there can be significant savings as a result.
The vaulted ceiling provides extra headroom and gives a sense of openness to your home.
Easy to Install
Because they are prefabricated, scissor roof trusses are easy to install.
Scissor Trusts are Customizable
Most truss or roof fabrication manufacturers offer customized designs to increase or decrease the size or slope of a scissor truss to perfectly fit the specifications, which can be installed with barely any modifications on-site.
Easy to Maintain or Repair
Water damage is the most likely issue, but a typical scissor truss prevents water from accumulating and causing damage or mold, making it less susceptible to structural damage over time. Not to mention, scissor truss roofs are easy to maintain because they have fewer structural components than other truss types.
Cons of a Scissor Truss
Difficult to Insulate
Scissor trusses are more challenging to insulate than any typical roof truss because of the tight access at the narrow end of the truss. That makes it hard to air-seal the ceiling near the outside wall. It also restricts the available space to add effective insulation and attic-venting detail at the roof’s edge.
Tight Access to Eaves
Compared to typical roof trusses, scissor trusses provide narrow access at the eaves. Construction workers usually find it hard to crawl to the edge of the attic to perform work. Even inspection for potential problems won’t be as straightforward—consult with a roof inspector to conduct a roof inspection near you for more information.
How Are Scissor Trusses Made?
In constructing a building’s ceiling, trusses transfer the weight to walls that support weight. Almost no on-site alterations are required by the truss engineers as they can create customized trusses to fit your design.
Factories that manufacture prefab trusses use advanced software to design the trusses. They provide the span of the roof and the desired roof pitch, leaving the software to do the rest automatically.
Can You Mix Scissor Trusses With Other Trusses?
Roofing contractors often use different truss types to cover more roof areas. You can install a scissor truss in one part of your home and use other types of trusses in other areas.
Despite one area having high ceilings, your roof will look uniform from the outside, but different trusses will make the structure more challenging and will cost more than usual truss installation. For more information, contact a Collin County roof installation professional.