How To Measure Roof Truss Size

Divide the length of the roof by two to determine how many trusses are needed.

How to measure roof truss size.

Trusses are generally secured 24. Starting at one end of the roof mark the first truss flush with the outside edge of a cap plate. 8 inches and you have an 8 in 12 pitch. Converting that to feet and inches the length of the top chord is 10 feet 3 16 inch.

Simply input the surface area of the roof choose from one of the available options and you will get your first roofing estimate. If this distance measures 4 inches you have a 4 in 12 pitch. Pitch measurement method 2 2. Obtain the height of the gable by finding the difference in height between the top of the roof and the top of the structure.

Next you will need to use a roofing materials calculator. 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. Check that your footage measurements are within this range so you can start off on the right foot. Divide this number by 2.

How to measure roof trusses. The important point to keep in mind when you use your truss calculator is that every truss calculation is completely unique and is based on the size of your roof and its specific dimensions. C rafter length. Equation a2 b2 c2.

Get the width of the structure you want to roof by measuring across the tops of the walls. Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter. Already having the rise will make it easy to determine the rafter length by loading the numbers into the equation chart. Measure out 5 to 6 trusses at a time.

Use a level square and measuring tape. For instance a 7 12 roof pitch means that the roof rises 7 inches for every 12 horizontal inches. These are the base boards of your roof truss. 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.

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. Set two ladders at each end of the area to be measured. Outside of the u s a degree angle is typically used. This sizing guide for roof rafters will help determine what you need for your small project.

Pull a tape measure along the top plate of the house to determine the length of. For example h sqrt 3 167 2 9 5 2 10 014 feet. The truss is a framework consisting of rafters posts and struts which supports your roof.