Roof Truss Support Walls

Some roof truss types such as stub and dual pitch contain no center and therefore lack central support.

Roof truss support walls.

Elements that make a roof truss bearing. Roof trusses can span much longer distances than joists so if you have a gable roof there is a good chance that it can span between exterior walls and not require an interior bearing wall for support. A gable truss isn t structural and needs a continuous bearing support underneath such as a beam or wall. This means that at the top floor of a house the interior walls may not be supporting the weight of the roof structure and the weight of snow.

Gable trusses are more expensive than common structural trusses because more lumber is required. They do this by means of top chords which are sloping members that extend from the peak of the roof to the top of the exterior walls at the eaves. A gable truss sits on the end wall of a structure and has vertical studs every 2 feet or 16 inches. As each truss is put up on top of opposite walls it must be put up straight and supported while the next truss is put up.

Truss roofs are typically designed to use some interior walls as mid span support to save on costs associated with making the truss larger stronger. Nearly all types of trusses used in roofs from kingpost and queenpost to bowstring and cambered possess a central support beam. You will need an engineer involved in this since many contractors will tell you anything to get the job. Engineered roof truss systems may be designed to eliminate the need for load bearing walls or change where the bearing walls are located.

Flat the most economical flat truss for a roof is provided when the depth of the truss in inches is approximately equal to 7 of the span in inches. Roof trusses support a roof s weight by transferring the weight load downward and outward to the building s bearing walls. Usually trusses are put 24 inches apart.