Structural Residential Roof Truss Design

The chords are located at the top and bottom of the truss.

Structural residential roof truss design.

Roof rafters trusses and beams. Attic truss roof design is intended to provide a solution for additional living area within the roof space. Photo gallery video gallery residential steel trim selector post frame trim selector projects. The attic truss is able to support more load than a standard truss of the same span and pitch.

Typically the building designer or builder will contract with the truss fabricator who will supply a truss layout and a structural design of each significant element of the roof system. A mono truss roof allows for more sunlight and visual space proper drainage and relatively cheaper. A truss is a prefabricated wooden structure that integrates a triangular webbing of structural members to provide support for the roof above while tying the outside walls of the house together. Chapter 3 design loads for residential buildings typical load combinations used for the design of table 3 1.

The truss plate manufacturer s engineer usually reviews and seals the individual truss designs on behalf of the truss fabricator. Typical residential loading covers standard decking and shingles metal along with the sheetrock on the ceiling. A mono truss is a one sloped truss that forms a right angle triangle. In residential construction timber roof trusses have been used for decades to support floor and roof systems.

Shop roof trusses spacer floor truss. The long sloping beams extending to the top of the truss and the beam that runs horizontally along the bottom are called chords. Residential structural design guide 3 3. Overview building design truss design retaining wall design tall wall design requests.

Trusses have several key components. Structural model of truss truss girder self wt 4 05 k 4 05 k 80 ft x 25 ft 2 03 psf 18 03 psf bar joist wt 9 plf pd int dead load at an interior panel point 18 025 psf x 25 ft x10 ft 4 51 k due roof ceiling wt truss girder 9 plf x 25 ft 0 225 k due purlin wt 4 73 k pd. Roof and wall sheathing gravity and wind loads floor diaphragms and shear walls in plane lateral overturninand g loads 6. This is crucial for truss design because otherwise the trusses may not be built to handle the appropriate load.

This article will focus on timber roof truss design in residential construction.