Roof Load Width Explained

Load limits on the roof of a building.

Roof load width explained.

Spacing should be interpreted as the centre to centre distance between adjacent parallel members. Roofs are under a lot of pressure. So consider a simple gable roof on a 24 foot wide ranch framed with 2 6 exterior walls and a 1 1 2 ridge. The snow load is treated as a live load when you use af pa s tables.

House roof framing loads. The roof of a house can t do its job if it doesn t remain where it s supposed to be and a variety of forces are always at work trying to make the roof fail to stay in. The north zone middle zone and the south zone are identified on the roof load zone map above. These diagrams may also be used to determine roof load width for floor joists.

To see how pitch impacts the look of a garage and changes cost click the design center button on our pole barn kits page. In order to stay intact and in place a roof must be able to resist loads both permanent and temporary that are pushing. Any areas between the wall corners that are not included within zone 5. Roof load width rlw and floor load width flw can be determined from as1684 or from the images below.

The north zone design live load equates to 40 pounds per square foot the middle zone equates to 30 pounds per square foot and the south zone equates to 20 pounds per square foot. This information is found in the code book. This zone accounts for about 5 of the roof surface represented the corners of the roof. Trusses struts and props.

Has the highest load. Used for roof overhang area along the perimeter of zone 3. Most commonly the roof s internal support structure is composed of a fairly complicated system of structural elements designed to manage the load from the roof. This downward imposed load on the home is also known as the snow load.

The entire roof load is supported by load bearing walls which in turn transfer weight to the foundations of your home. The span would be 11 5 3 4.