interesting video;
http://www.youtube.com/watch?v=Jo5ZtBXJiHo
http://www.youtube.com/watch?v=Jo5ZtBXJiHo
I could be wrong Ian, but I would think that "Stick Build" would be closer to "Timber Framed"
If a fire gets to that point, does it really matter??
I'm with Jeff, it really doesn't matter at that point. If a fire gets to that stage there is little chance your going to rehab the building, it'll need to be demolished any way. Personally, If it was my house and it's not a minor fire, then I'd prefer it burned right to the ground. Less clean up and disposal costs.
Mike
Thanks for the update. I guess the roof trusses are only one part of the overall problem. For example, those engineered wooden I beams with the thin center section will burn through long before the roof trusses give out.I don't really know why gussets are made as flimsy as they are with relatively short "teeth". My guess would be that they are engineered for efficiency in ideal conditions - not fire. If the fingers were longer, you'd likely need a thicker plate of metal to give the teeth sufficient stability. The more steel used, the lower the efficiency of the connection. It's probably a few bucks per house to make the gusset plates more substantial, but truss builders are focused on economies of hundreds or thousands of homes per year.
A change like that would likely need to be regulated through a change in the code requirements. It's the classic conflict between business (seeking to optimize efficiency) and government (needing to regulate for health, safety, and welfare).
Most houses now are built to burn, as long as the occupants have a reasonable chance of getting out unhurt. Rebuilding those homes that do burn is cheaper than requiring non-combustable construction for all homes. That said, charred roof framing is one thing - structural collapse is something else entirely.
If a fire gets to that point, does it really matter?? I would assume in most cases i's going to have to be torn down anyway to repair or replace it. Just as long as no one is inside, and suspect at that point they wouldn't be alive anyway.
Mike, Jeff
I think if it matters then it matters to the firemen risking their life.
Absolutely. I would think they wouldn't be in a building that was that bad engulfed.