Engineering

Question: 

What are the requirements for installing valley sets over roof trusses? I am interested in nailing and support conditions. Some engineers ask for the bottom chord of the valley truss to be ripped to match the roof pitch of the underlying trusses. Is this necessary? How can I calculate values for uplift resistance for the building inspector?

Question: 

In RC 2601, is RC-1 Channel used?

Question: 

In a hip roof application where jack trusses connect to a girder truss using pressure blocking (power blocking), what is the proper installation and the span that is acceptable before a hanger is required?

Question: 

How do you evaluate whether a metal plate connected truss is still usable after exposure to fire? Are there any recommended tests?

Question: 

Are wood trusses designed to be fall protection anchors that would support a worker should he fall?

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: 

We are having a house built and on a recent visit we brought along a friend who builds houses for a living. He noticed that the trusses were wet and a bit moldy. The wood seemed warped, brown, and had white splotches on it. We are worried that it would later make the roof uneven. How could we tell how long the trusses have been exposed to the elements? What options do we have from here? Do we request new trusses, or can these be repaired?

Question: 

How important is continuous lateral bracing in roof trusses? Is it detrimental to the roof integrity if it is missing?

Question: 

I am trying to develop a guideline for my firefighters regarding initial fire attack in buildings with light-weight trusses. My concern is truss failure, especially when exposed to fire. Is there any information on failure time related to flame impingement? Any information about truss failure – especially in a fire condition would be helpful.

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?