Engineered Wood Products

Bottom Chord Live Load Concurrency and Truss Design - Educational Program

This presentation seeks to explain how to correctly apply live loads to the bottom chord of trusses for uninhabitable attics in accordance with IRC Table R301.5 and IBC Table 1607.1 and ASCE 7-10 Table 4-1.

Fire Assemblies: Performance and Application Using Wood Trusses - Educational Program

This presentation provides an overview of fire-rated assemblies that include wood trusses. Topics covered include assembly testing, Harmathy’s rules, and an examination of fire performance in the field. 

Installation Guidelines

Question: 

Are there any associations that have recommendations for the installation of wood trusses?

Charring Of Trusses

Question: 

Our home caught fire last month and burned partly through a tongue and groove ceiling to the trusses. Some are charred. Our contractor did a moisture meter test. An engineer for the insurance company said the trusses were only smoke damaged & the moisture meter test is invalid (it can be set to read anything). I found one article on charred trusses, but it’s pretty vague. We do not feel safe with the insurance engineer’s assessment because some of the trusses are obviously charred. We hired an engineer who agreed with us.

Floor Performance

Question: 

How do you avoid floor performance problems?

Information On Truss Fire Issues

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.

Sprinklers Above Gypboard Ceiling

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?

Duct And Light Penetrations Of Fire Rated Assemblies

Question: 

In a small scale multi-family residential project, I'd like to use a wood truss floor-ceiling assembly to achieve a one hour separation between units. I'd like to directly attach the drywall to the underside of the trusses & use the truss space for ducts & lighting (the floor above will be lightweight concrete on plywood sub-floor). UL assemblies do not seem to address the duct/light penetrations in such an assembly. Can I achieve a one-hour rating in such an assembly and how are penetrations addressed? Can the ducts in the truss space serve both units above and below?

Wood Three Hour Fire Assembly

Question: 

Is it possible to construct an assembly for ceiling between first and second floors using 2x with few layers of gypsum to obtain a 3-hour fire rating?

Sloping Floors

Question: 

In our one-year-old home, as you approach the hallway, the floor slopes downward. Our home inspector said that this was most likely due to the fact that the walls were resting on the floor as opposed to being load-bearing walls. What has been your experience with sloping floors in a new home? The floors are very flat elsewhere until the walls start. Do you think this sloping could turn into a structural problem eventually?