The beginnings of the roof truss designs we see today, can be attributed to a need for a sloping roof that was better suited to shedding snow, water, and providing additional space for air to circulate, as well as adding volume to a building.
Within this context, the structural integrity of the building depends to a great extent on the roof trusses system installed. This includes stabilization of the walls, as well as holding up the roof itself.
Laying Out the Roof Truss Project
Since the strength of the roof trusses is vital to the building, it is a good idea to have a professional draw up the roof truss design. It saves a lot of headache, and will likely get past the building inspector a little easier. On that note, it may be required by local codes to have a professional contractor install your roof trusses. This is not the part of the house to practice your skills on.
Timber roof trusses will be preshrunk in a kiln to prevent swelling and shrinking as much as possible, and joined with galvanized steel connectors. Timber is still the best choice for value per dollar.
Steel roof trusses may be an option for owner-builders also, if it can be fit into the budget.
There are several advantages to steel:
-100% fireproof
-Resistant to mildew and mold
-Smooth handling and no splinters (but you wear gloves anyway, right?)
-Steel may be lighter and stronger than the timber you choose.
-Environmentally friendly-from the perspective of conserving trees that is.
-Eliminates the need for building code mandated sprinkler systems.
The roof trusses, either steel or wood, are held together with nail plates or connectors, respectively. The trusses are delivered and dropped on site, and should have detailed instructions to follow, or that can be pulled from the company’s website. These plans will show the location of the various connectors and components, which is valuable to owner builders and professionals alike.
Upon delivery, a crane will set the trusses on top of the shear walls, so securing the shear walls is vital in this step.
Gambrel roof trusses transfer lateral forces by redirecting them down into the side walls. To engineer a typical truss system usually takes up most of the volume added by the sloped roof. Gambrel roof trusses bypass the need for cross beams and post supports, and this additional space can be utilized to its full extent. Gambrel roof trusses are usually associated with barns, but architects today can use this design to create beautiful homes.
