How do you fireblock a huge cavity in the middle of a house?
I was surprised that any fire blocking is required in single family residences. I had to look it up.
Section R602.8 requires it for “all concealed draft openings (both vertically and horizontally), to form effective barrier between stories, and between top story and roof space.” Also required at “openings around vents, pipes, and ducts at ceiling and floor level.
Approved materials are in Section 602.8.1 and includes: 1) 2” nominal lumber, 2) 2 layers of 1” nominal lumber with lap joints staggered, 3) 23/32” structural panels (plywood), 4) or 3/4” particle board, 5) 1/2” gypsum board, 6) 1/4” cement board, 7) batts or blankets of mineral or fiberglass is approved for compliance with the 10’ horizontal fire-blocking in walls constructed using rows of studs, but must be held in place. “
Also, Section R602.8.1.1 says “unfaced fiberglass batt insulation shall fill the entire cross section of the wall cavity to a minimum height of 16” measured vertically. When piping is encountered the insulation shall be tightly packed around the obstruction.”