Need firestop info

[Denray]

Looked at a 1973 triplex today where the attic was continuous all the way down the three side by side units. How long has that not been allowed? It's the same in the crawl space.

[Douglas Hansen]

At that time I think the building code in your area would have allowed it. Assuming that Humbolt County was using the 1970 UBC, section 3204(b) would have allowed a common attic up to 3,000 square feet.

Today it would require a rated fire partition. As to "how long has that not been allowed?" it looks like a requirement for a draft stop separation went into the 1982 UBC, and the modern version of this (requiring at least a one-hour separation) would have been in place starting in 1994.

Aside from the fire spread issue, it could also be a security issue for the tenants.

[Denray]

Thanks Douglas. That was a pretty good lecture from Joseph Lstiburek last Saturday, eh.

And in the crawl space it's no big deal to have access to all of them from one entry?

[Douglas Hansen]

I wouldn't be as concerned about the open crawl since fire usually goes up, though if there were gas-burning appliances down there my opinion would be different.

Saturday didn't meet my expectations, and my specific questions at the time went unanswered. At least I got to check it off the list of things I thought I wanted to do someday.