What is a truss?
A truss is a building component comprised of at least one bottom chord, one top chord and a web piece joining the top to the bottom. Generally speaking, trusses take advantage of the natural strength of the triangle. Loads are controlled and transferred from the top chord to specific bearing points where the load is transferred to the ground.
There are two basic types of trusses. The pitched truss is easily recognized by its triangular shape, and is mostly used for roof construction. The parallel truss is flat on the top, and usually used in floor construction.
What kind of materials go into a truss?
Trusses are generally made from #1 and #2 grade southern yellow pine. Each piece is chosen specifically for its role within the truss. The pieces are clamped together by cleated metal plates. The plates are designed to transfer maximum loads through each piece of the truss to the bearing points. Most of the strength of a truss is due to the metal plates.
Why can't I just build a truss out of materials on my jobsite?
The metal plates in each truss are pressed into the wood in a computer-controlled manner, much like a set of bearings is pressed onto a shaft. Beating the plates into the wood onsite would destroy the strength rating of the plates. Without this rating, the trusses cannot be reliable.
Why can't I build trusses without metal plates?
You can, but there's no guarantee your loads will be properly transferred to the ground. Truss design requires that the loads be concentrated at the connectors. You'll need to provide certified engineered drawings showing the load carrying capacity of each part of the truss, including the connectors to get your inspectors' approvals. These drawings are always a part of the Total package.
Can I build a whole house out of trusses?
It's possible to build a livable structure using only attic-framed trusses set on a foundation. This doesn't allow for much customization and it's seldom done.
I have a roof design that's too tall to make shippable trusses. How can trusses make sense for me?
Piggyback trusses are the answer to your needs. Piggybacks are designed and manufactured in sections, then joined on the jobsite. Using piggyback trusses, tall roof lines are no problem at all.
What special tools will I need to install my trusses?
No special equipment is needed at all. If you have the tools to frame the roof, you have the tools to set the trusses. For larger trusses you might need a crane for a few hours.
How much will I really save if I use trusses?
You should expect a time savings of about 30%. Your waste will be cut to practically nothing.
