Can someone explain what is meant by Stiffening on this truss drawing? Is a floor required along the entire span 1-11 to achieve stability? (I was thinking of delaying the floor installation...)
Even more difficult to interpret is what 800mm means? If we use raw tongue and groove, is it sufficient stiffening?
Stiffening usually means that there should be boards running in the longitudinal direction of the roof to prevent the pins in the truss from buckling. I guess 800 is a cc measurement. For the outer roof, the tongue-and-groove wood will suffice. The collar beams are stiffened by the sparse paneling. In any case, it might be a good idea to screw in some walkways so it's easy to move around up there before you furnish.
