How To Measure Up For Roof Trusses

Pull a tape measure along the top plate of the house to determine the length of.

How to measure up for roof trusses.

Trusses are generally secured 24. Measure as precisely as possible down to the 1 4 inch 0 64 cm 1 8 inch 0 32 cm or 1 16 inch 0 16 cm. Trusses can be constructed with smaller sized lumber than rafters and often their cost is not significantly higher than normal rafters. Set two ladders at each end of the area to be measured.

For example if the pitch is 4 and the span is 9 feet 6 inches r 4 9 5 12 3 167 feet. Already having the rise will make it easy to determine the rafter length by loading the numbers into the equation chart. On a ladder beside the roof place the level a foot or so up the roof hold it level and measure from the 12 inch mark on the level s bottom straight down to the roof. How to measure roof trusses.

Use a level square and measuring tape. For a 9 m 30 foot long roof a total of 15 trusses are needed. In order to match up to an existing building there s a couple different measurements that are needed so that you will end up with a matching roof addition. Use a tape measure to measure the entire width of your building.

Step 1 find the total rise of the roof using the formula r ps 12 where r is the rise p is the pitch and s is the span. Measure out 5 to 6 trusses at a time. Pitch measurement method 1. Divide the length of the roof by two to determine how many trusses are needed.

Converting that to feet and inches the rise is 3 feet 2 inches. Starting at one end of the roof mark the first truss flush with the outside edge of a cap plate. C rafter length. 8 inches and you have an 8 in 12 pitch.

Overall span wall to wall bottom chord length if different than the wall to wall span overhang length. Use of manufactured roof trusses can dramatically cut labor costs when framing a gable roof compared to building rafters. Equation a2 b2 c2. For example a roof with a span of 20 ft and a rise of 7 feet needs rafters that are the square root of 400 49 21 2 feet.

If this distance measures 4 inches you have a 4 in 12 pitch.