I have a basic (obvious?) question about the proper way to measure the correct span I will need for some scissor trusses I will be ordering from a local truss co for a room addition. I have a short-wall foundation on one side of new room and post and beam on the opposite side (this was due to complications with getting heavy equipment to other side of yard...)
The room will be approx. 16' W x 28'L. I am assuming I measure the span starting from the edge of concrete wall where bottom plate is secured with J bolts and the other side where edge of 6x6 post will stand on footing (30" square pad) Is there and tolerance in case this is off by an inch or so or will the truss/wall tie-in be screwed-up?
My other option is to order the trusses a few inches shorter than 16' and let the carpenters figure out the beam placement for the floor since the pad/footing is so large. Am I missing something here?