Floor Trusses

Question: 

I have been told that the high temperatures and low humidity present in attics can cause deterioration of wood, leading to truss failure. Is this true? If so, what length of time are we looking at and can we see the deterioration in the wood by visual inspection?

Question: 

Are there any trusses that are supported strictly by the wood itself without any mechanical connections such as brackets?

Question: 

What tolerances are allowed for metal plate connectors in wood trusses? How do you take into account the possible presence of splits, waves and knots?

Question: 

How much OSB can be stacked on a floor deck without damaging the trusses?

Question: 

How often are trusses repaired?

Question: 

As a forensic engineer who has investigated numerous collapses of wood truss systems, I find your web site an excellent resource on the proper erection of wood trusses. What are your opinions on steel trusses, particularly with regards to installation and bracing? Do you feel that the installation and bracing techniques utilized for wood trusses are applicable to steel trusses? Do you know if that is the general industry standard or are there specific requirements and guidelines for steel trusses? Is there a particular guideline/commentary available for metal trusses?

Question: 

I'm looking for a book that will provide formulas and design criteria for trusses. Can you give me any suggestions of where to find a book or fairly inexpensive software?

Question: 

Some truss lumber repair nailing patterns call for 16d common nails. Most nail guns do not support 16d nails, but have an equivalent to a 12/10d nail. Is there a substitution guide or ESR report that could help us?

Question: 

When you’re selling trusses through a lumberyard and the contractor calls to say that the “trusses don't fit correctly,” who has the ultimate responsibility for the trusses? I argue that the lumberyard is responsible since we have provided them with all the information on how the job was designed, even though they may or may not have passed this information on to the contractor.

Question: 

Is finger-jointed material allowed in the manufacturing of trusses?