Shimming Or Shaving Variances In Truss Dimensions
Question:
If you have the condition where you are out by the max tolerances of 1/2 in., how do you correct the situation? Do you shim the truss from the bottom? Shim from the top? I will assume you do not shave the truss off. What is the published corrective action for situations that cannot handle the variation in truss height?
Answer:
If all the trusses are higher or lower than the tolerance limits and the truss still meets the engineering requirements based on the actual depths that exist, then the situation probably does not need correction.
If there are variations among the trusses, then shimming would be the natural solution either at the bearing or at the sheathing side. The shims need to have solid bearing or a way to provide a solid nailing surface for the sheathing.
Clearly, shaving a truss is not the way to go as it will change the properties of the lumber, reducing its strength depending on how much is removed.