Roof Truss Spacing Requirements

The trusses should be a little longer than the exact width to allow for overhang and you will need sufficient trusses to mount across the length.

Roof truss spacing requirements. The live weight load of a roof basically comes down to the pressure. Minimum roof slope of 3 12. Most are spaced between 18 26 inches apart. Special inspection of the truss member bracing is also required where a truss clear span is 60 feet or greater 1705 5 1.

36 long garage with 12 bays. 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. This makes the roof ready for decking or sheetrock. There are also three things that will affect roof truss spacing.

Maximum ground snow load of 70 psf. Truss span not greater than 36 feet. Putting the trusses into place. Truss spacing the distance between trusses.

If your local building authority has a rafter spacing code you may not space rafters wider than required by code. The reality is there is no magic number. Once you ve calculated the number of trusses you will need you should purchase the lumber. Trusses spanning 60 feet or more require a registered design professional to design the temporary installation restraint bracing and the permanent individual truss member restraint bracing 2303 4 1 3.

If the overhang is more than around 2 6 it will require a 2 6 top cord for the tail section to handle that amount. Maximum roof slope of 12 12. Metal roofs and pole buildings. Building width not greater than 60 feet perpendicular to the truss span.

Maximum design wind speed of 140 miles per hour 63 m s exposure b or c. Rafter spacing rafters must be strong enough to hold the roof sheathing and the shingles. The dead weight load of a roof is all the different structural elements which can affect the amount of pressure that can be. Although the standard spacing of roof trusses may be the same as that of rafters with 24 inch spacing being a common option the design of a truss may allow for the use of a lower grade of lumber than would be required for rafters with comparable spacing and span.

The standard spacing is 2.