Roof Load Width Formula
50 psf x 14ft 700 pounds per lineal foot.
Roof load width formula. Step 2 determine dead load by identifying the amount of each construction material used in the roof. Floor joists ceiling joists rafters snow load rafters roof live load deflection limit. This video looks at roof load width rlw. Rlw is used to calculate the sectional size of some roof members and supporting wall.
2x4 2x6 2x8 2x10 2x12. Snow load thickness density the result snow load or the pressure exerted by the snow has the units of kn m or lbs ft. Roof load area rlw u p span left u p span right or with fan struts. Measure the length and width of the carport to determine the area of the roof in square feet.
Load limits on the roof of a building. Roof load width rlw rafter span if placed at midspan otherwise span1 span2. 3 stud construction standard utility. If you want to calculate these values by hand use the following formulas.
910 pounds per lineal foot. Multiply the length by the width to get the measurement for the area. It is often compared to slope but is not exactly the same. This is the sixth video in the series on the timber framing code.
L 720 l 600 l 480 l 360 l 240 l 180. 15 psf x 14ft 210 pounds per lineal foot. The formula for truss loads states that the number of truss members plus three must equal the twice the number of nodes. In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches.
If the number of members is labeled m and the number of nodes is labeled n this can be written as m 3 2 n. For instance a 7 12 roof pitch means that the roof rises 7 inches for every. Both sides of the equation should be equal in order to end up with a stable and secure roof structure. In order to stay intact and in place a roof must be able to resist loads both permanent and temporary that are pushing.
It is important to list live load dead load and total load separately because live load is used to compute stiffness and total load is used to calculate strength. Roofs are under a lot of pressure.