How To Measure For A Roof Truss

Measure out 5 to 6 trusses at a time.

How to measure for a roof truss. How to measure roof trusses. 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. 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. If this distance measures 4 inches you have a 4 in 12 pitch.

Hook your tape measure on the king post to make marks at 2 feet 10 1 2 inches and 5 feet 9 inches on both the top and bottom chords. Trusses are generally secured 24. 8 inches and you have an 8 in 12 pitch. 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.

Position the truss on the floor with the bottom chord near you and the king post on the right. Trusses can be constructed with smaller sized lumber than rafters and often their cost is not significantly higher than normal rafters. Use of manufactured roof trusses can dramatically cut labor costs when framing a gable roof compared to building rafters. Hammer a nail in place to hook your measuring tape and space out the subsequent trusses every 2 feet or other designated spacing.

Most economical when the difference in slope between the top and bottom chords is at least 3 12 or the bottom chord pitch is no more than half the top chord pitch. Pull a tape measure along the top plate of the house to determine the length of. Depending on your roof slope add 4 to 5 inches for heel height. Be sure the tape measure is parallel to the bottom chord when measuring.

Divide the length of the roof by two to determine how many trusses are needed. Already having the rise will make it easy to determine the rafter length by loading the numbers into the equation chart. It will use the current cost of wooden rafters based on the average price found at home improvement stores. Starting at one end of the roof mark the first truss flush with the outside edge of a cap plate.

Use a level square and measuring tape. This online truss calculator will determine the all in cost of your truss based on key inputs related to the pitch width and overhang of your roof. Set two ladders at each end of the area to be measured. Equation a2 b2 c2.

C rafter length.