Roof Frame Spacing

Asphalt shingle can be installed on a pitch of 2 over 12 or greater.

Roof frame spacing.

A roof truss is a structural framework usually made from wood that bridges the space between the ceiling of the top level and the roof structure. And the line length measurement from the roof peak to the building wall is the hypotenuse. There are special shingles available for 2 12 but you re better off using other materials. The figures are based on quality materials.

Like wall studs and floor joists rafters and trusses are spaced every 16 or 24 inches from center to center. The framing of a basic gable roof is based on a right angle triangle and the various roof framing components fit the triangle. Designing roof trusses for proper placement on post frame buildings. As a general rule roofs that have a high human occupancy rate should be framed with rafters every 16 structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes.

The pitch of the roof determines the roofing material you can use. Stick framing combines roof rafters with ceiling joists. The typical spacing standards for residential and commercial buildings are about 1 to 2 foot. In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot.

For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet. For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap. Metal roofs and pole buildings. 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.

Most roofs utilize 16 inch spacings for strength and rigidity. Very simple trusses work on a principle of thirds. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. The rafters are usually positioned directly above the wall studs.

It must meet the local codes for thickness at least 3 8 which is also based on the rafter or truss spacing. The tables below give maximum spans for rafters and beams. The rise or height of the roof at its peak is the altitude of the triangle. The run or half the building span is the base of the triangle.

A super basic a frame roof will require anywhere between 4 and 8 depending on the size of the rafters with plumb cuts necessary for each angle in the brace. Rafter spacing depends on the roofing panel size.