Standard Wood Roof Truss Sizes

Girder trusses are designed to carry additional loads other than standard roof loads.

Standard wood roof truss sizes.

A truss of this size and larger usually runs a higher figure of around 4 to 4 75 per foot of truss. Common or standard trusses are symmetrical and have standard four inch heels. Spaced sheathing or 1x boards may be reduced slightly. Essentially a roof truss is a prefabricated frame of supports designed to go on top of a building as it s being built.

Spans for 2x4 top chord trusses using sheathing other than plywood e g. 0 250 kn m ceiling live load 0 250 kn m tank load 0 450 kn max tile batten centres. The truss is a framework consisting of rafters posts and struts which supports your roof. This truss has a 30 span which is only 4 more than 26 but look how much more webbing there is.

The webbing is necessary for the strength of the truss and it is needed in a truss this size. Easily attached to the rest of the building s frame they circumvent the complicated expensive nature of from scratch roof framing and can be purchased in a wide variety of designs made from either lumber commonly used for homes or metal primarily used for commercial. The standard roof truss spacing is 2. A truss with the same pitch and heel on both sides and a peak at the center is called a common truss.

The important point to keep in mind when you use your truss calculator is that every truss calculation is completely unique and is based on the size of your roof and its specific dimensions. Standard framing details for use in preliminary design. 0 785 kn m snow load. Trusses must be designed for any special loading such as concentrated loads from hanging partitions or air conditioning units and snow loads caused by driftingnearparapetorslide offfromhigherroofs.

You can use sbca s span charts to roughly determine truss sizes available. Standard roof truss general load settings. The steeper the roof the more expensive the trusses get because the longer the boards get and the more roof area increases. This is the distance between trusses.

360 mm general truss information. Included are a series of representative roof truss span tables that will give you an idea of the truss spans available for a particular load condition load duration lumber type and truss configuration. You will also incur additional costs because it is much harder to deck and shingle a roof that is 12 12 pitch versus a 4 12 roof. 0 524 kn m ceiling dead load.