hello! this is probably real easy but if comeone could tell me what are the correct requirements for fireblocking in residential house construction. Is it required in all framing member spaces ~ 8 feet or less? Also, if you pierce thru the blocking for plumbing vents, wire, etc., is expanding foam required?
thank you,sherndog
Replies
In my area, we need blocks at anything over 10 ft. In theory, the holes should be plugged with something.
I'm not so sure about it being fireblocking, though. If an enclosed wall cavity is sealed and no wires or sparky boxes, is fire an issue? I always attributed the blocks to a stud straightener/strengthener. At any rate, any holes in the cavity should be sealed at the top and bottom plates so plugging the block holes may not be so necessary.
Help at all?
Quality, Craftsmanship, Detail
In these parts they like to see it at ceiling level, with a maximum allowable stud bay height of 10'.
If you're a builder, refer to your IRC (International Residential Code) R602.8 or equivalent for your jurisdiction, or consult with your local building official.
It's not particularly complicated, but deserves more explanation than I'm willing to provide and besides, different jurisdictions may enforce their own interpretation.
The short side is that the purpose is to block firepaths between stories, in stair wells, in drop ceilings, in penetrations between plates (borings for wire, plumbing, HVAC, etc.).
Like most code requirements, the primary purpose is safety.
Excellent reply.
Only thing to add for sherndog is do not use expanding foam as a fire stop. It is a good air barrier but will readily melt in the heat of a fire, and the smoke rating is horrible. Use an intumescent firestop sealant for wire and plumbing penetrations.
Try looking at http://www.stifirestop.com for products to use. looks and guns like caulk, but designed for your application.
Dave
Edited 5/4/2005 6:09 am ET by DAVERICHESON
I've heard (but I don't know that I trust the source) that there is a fire stop rated type of expanding foam, but I've never seen it. Anyone hear of it or know a brand name?
I think that varies by locality. I've read from some people in this forum where they were required to put blocking in an 8 foot stud bay. Some times I just wonder if they know what they're talking about. I've never seet it done around here.
Check your local code
fireblock in 8' stud bays here
central fla
In many parts around here, all penetrations of fire-blocking now require fire-stop caulk. Same for any penetration through the plate.
Fire-blocking within individual wall cavities is generally not done in standard wood frame platform construction around here.
Some interior partitions may require fire blocking at the top, if there is no top plate. Balloon framed walls would require fireblocking between floors.
Edited 5/4/2005 1:04 pm ET by csnow
For us, all penetrations through either sole or top plate must be sealed. Either with foam or caulk. This is considered draft blocking not fire blocking. The inspectors are sticklers about it also.
I believe the fire rated caulk is needed in a rated wall.