Fire Resistance

Sprinkler Loading

Question: 

Does the NFPA sprinkler standard address sprinkler loading? If so, how and where do I buy it? What other information do you have on sprinkler loading? How do other truss companies price jobs for sprinkler loading the plans do not include a sprinkler layout or even say what size/type of sprinkler system will be used?

Fire Damaged Trusses

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?

Penetration Of Fire Walls

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.

Fire Cuts

Question: 

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

Post Fire Retardant Treatment

Question: 

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

Fire Rating For Sloped Roof Truss Assemblies

Question: 

A question has come up concerning sloped roof trusses and fire assembly ratings. Some are reluctant to rely on test results from flat (parallel chord) trusses applied to sloped roof trusses. Do you have any information regarding the suitability of the fire rated ceiling assemblies for sloped roof trusses? Does the “minimum depth” requirement of the parallel chord assembly apply to the minimum depth of a sloped roof truss (i.e., heel height?)

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.

Metal Connector Plates In Fires

Question: 

I am thinking of using wood trusses for the roofing/ceiling structural systems on some houses I shall build. I remember, though, an engineer/volunteer fireman commenting back in 1989 that the connector plates are prone to expand and pop off, early on in a fire, causing catastrophic structural failure. Was this the case, and if so, has this problem been corrected?

Two Hour Assembly Ul Number

Question: 

We have a local builder wishing to use floor trusses with a 2-hour assembly. I have shown him the 2-hour design on pages 17-27 of the second edition of SBCA’s Metal Plate Connected Wood Truss Handbook. Is this assembly UL approved? If so, what is the design number?

Fire Damage Assessment

Question: 

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