Fire Testing

Question: 

I have been hired by an insurance company to determine the extent of damage to roof trusses exposed to fire. How much fire damage compromises the structural integrity of the truss?

Question: 

What is the life expectancy of wood that was used in an attic truss? Does fire retardant change the life expectancy?

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: 

What type of construction uses a fire cut truss? Could you describe a fire cut truss?

Question: 

I have recently heard of a problem with fire-retardant-treated wood (FRTW) trusses that were manufactured and installed in 1965-1980. I was searching for more information, since my job involves the protection of property in our member school districts. I had heard that the trusses make of FRTW during that time period can or will become corrosive to the hardware and the trusses will fail.

Question: 

In RC 2601, is RC-1 Channel used?

Question: 

Are there any published studies or guidelines on the fire rating of floor trusses built with 2x3 lumber?

Question: 

Is a Class A fire rating (provided by our liquid spray-on fire retardant) acceptable in certain situations?

Question: 

I am looking for a 1-hour roof/ceiling assembly for wood truss construction. I would like to apply the drywall directly to the bottom of the truss and also have insulation for sound control. Is this possible without using channels and what UL number would I use?

Question: 

Can a roof truss penetrate a one-hr. tenant separation wall without having a one-hr. rated ceiling? The building official insists that the 2x4 chords are combustible and nullify the integrity of the one-hr. rated partition that is constructed in an attic above an 8 in. C.M.U. bearing wall. The partition consists of gypsum board attached to 2 x 4 stud framing. The building official insists that a ledger must be attached through the gypsum board to support the trusses each side of the wall. This is almost saying that any rated assembly must have bearing only on other rated assemblies.