Question

how to determine truss depth?

Answer 1

They are a lot of factors to determine how high a truss is. First is this a floor truss (flat) or a pitched roof truss? How much load will the truss have to carry? What lumber grades are available for the truss? What are the code requirements? So, you can see there are a lot of factors that would determine the height of a truss.

Here is an example of how to calculate the height of a common shaped pitched roof truss. An approximate height of a pitched truss can be calculated with the following formula: take 1/2 the span and multiple it by the pitch. Then add about 4 in. for the top chord lumber. For example: a 33-9-0 (33 ft., 9 in. and zero 16ths) truss on a 4/12 pitch would be 33.75 ft. times 0.5 times 4 = 67.5 in. plus 4 in.= 71.5 in. or 5-11-8 (5 ft., 11 in. and 8/16ths).