Roof Truss Support Walls

Gable trusses are more expensive than common structural trusses because more lumber is required.

Roof truss support walls.

Structural support usually a beam or wall that is designed by the building designer to carry the truss reaction loads to the foundation. 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. 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. 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.

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. You will need an engineer involved in this since many contractors will tell you anything to get the job. Nearly all types of trusses used in roofs from kingpost and queenpost to bowstring and cambered possess a central support beam. Roof trusses support a roof s weight by transferring the weight load downward and outward to the building s bearing walls.

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. Elements that make a roof truss bearing. Some roof truss types such as stub and dual pitch contain no center and therefore lack central support.

To hold them up until the decking of the roof is placed on top a 12 foot 1 inch by 4 inch piece of lumber is used. By eliminating interior bearing walls trusses also save the cost of interior foundation walls interior partition top plates and headers. A gable truss isn t structural and needs a continuous bearing support underneath such as a beam or wall.