Fire/Smoke Damage to wood structural members.
Fire/Smoke Damage to wood structural members.
(OP)
What is the overall consensus on fire/smoke damage? I am often consulted to evaluate fire damaged roof members when the insurance company does not agree that the roof should be replaced. Charring is obvious, but smoke damage is difficult. Do any of you know of a resource that outlines the levels of fire/smoke damage to the decrease in strength of the member? In my opinion, the exposure to extreme heat leaves the members brittle. NDS notes that prolonged heat exposure above 150F can cause permanent loss of strength, but the percentage of loss and the definition of "prolonged" are left to interpretation.
Obviously, the CYA approach is to say that all members should be replaced. This is actually the request of the contractor and homeowner. However, the insurance company shouldn't have to pay for un-damaged, or lightly damaged members (I guess?).
Any opinions/suggestions?
Thanks!
Obviously, the CYA approach is to say that all members should be replaced. This is actually the request of the contractor and homeowner. However, the insurance company shouldn't have to pay for un-damaged, or lightly damaged members (I guess?).
Any opinions/suggestions?
Thanks!





RE: Fire/Smoke Damage to wood structural members.
RE: Fire/Smoke Damage to wood structural members.
RE: Fire/Smoke Damage to wood structural members.
This particular house is fairly old and the county is requiring the contractor to bring it up to code. It is located in a coastal region of Florida, therefore uplift connections have to be made. A daunting task even with a new roof, but to have to work with a weakened roof system is the last thing I'd like to have my name on. My concern is that the rafters have lost a significant amount of their original (in place) moisture content, more so than would be expected with new construction. This would cause the members to shrink and consequently have the nails attaching the roof sheathing to loosen. I could have them re-nail the sheathing, but likely the rafters will regain moisture and swell causing the fasteners to loosen once again.
To put it in perspective, if you have a house fire and your window curtains receive smoke damage, the insurance company will replace them. However, if your roof system has smoke damage, they want you to paint them and everything is OK???
RE: Fire/Smoke Damage to wood structural members.
Your points are well thought out. In order to meet FL code - it may well be easier/cheaper to remove and replace the roof. Smoke and moderate heat will not hurt the rafters/trusses - if short term. However - any charring should call for replacement.
RE: Fire/Smoke Damage to wood structural members.
1. to replace the whole roof
2. Outline the investigative work required to justify keeping the existing roof along with any work that has to be done anyway. Also state that there are no guarantees in this option.
get quotes for the investigative work and get the contractor to do an estimate for each - I am sure that replacing it will come out cheaper.
RE: Fire/Smoke Damage to wood structural members.
Make an assesment of the reduction in cross-section due to charing and reduce the member capacity accordingly. You can always reinforce it.
Just painting is not enough to cover smoke smell, it should first be sealed with a product similar to "KILZ" and then the finish coat of paint.
RE: Fire/Smoke Damage to wood structural members.
Dik
RE: Fire/Smoke Damage to wood structural members.