Performance

Question: 

We are finding it difficult to design permanent diagonal bracing for scissors trusses. The truss is often only a few feet in depth, which does not provide adequate room for diagonal bracing. Has SBCA come up with recommendations for permanent bracing of scissors trusses?

Question: 

I have a 29 x 72 mobile office with a 2-foot deep wooden truss above the ceiling that a client is required to sprinkler. Is there any way to avoid sprinklering above the gypboard ceiling?

Question: 

I would like to know the proper storage and shipping of wood trusses.

Question: 

Do you have sound rating information for floor truss assemblies (i.e., STC and IIC ratings)? We are looking specifically for ratings for 12 in. floor trusses, with 1 and 1/2 in. concrete topping and without the topping. We are looking to meet the minimum code rating of STC 45 and IIC 45.

Question: 

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

Question: 

I am a structural engineer designing pool cage structures that are typically attached to the house at the fascia board. Sometimes, the structure is attached where trusses are behind the fascia board and other times there is a framed gable end overhang. Do you know of any information concerning this additional load on the trusses or overhang under design wind loads? Is there a limiting distance on the amount of overhang? I know trusses are designed for certain uplift and the pool cage will add to this uplift at design load, but what about the gable end overhangs?

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 am looking for some information regarding black surface mold on lumber. Does it alter the integrity of the lumber stress values? I have a client who wants to use “all dry” lumber for his construction but I do not know if this is really necessary.

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: 

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?