How do you determine the number of trusses needed for a building?

To determine the number of trusses needed for a building, it is essential to consider the spacing of the trusses and the total length of the building. The correct calculation involves taking the length of the building and dividing it by the on-center (O.C.) spacing of the trusses, and then adding one additional truss to account for the starting point.

The formula involves the relationship between the total length of the building (which provides the overall span that needs to be covered) and the distance between each truss (the O.C. spacing, which dictates how trusses are placed along that length). By dividing the total length by the spacing and adding one, you ensure that you have enough trusses to cover the entire length of the building, including the truss at the end.

For example, if a building is 30 feet long and trusses are spaced 2 feet apart, you would divide 30 by 2 to get 15, and then add 1 to determine that you need 16 trusses in total to cover the length appropriately.

This calculation is critical for ensuring the structural integrity and proper load distribution for the roof system. Understanding the correct formula allows for accurate planning and resource management during construction.