"There is no plate-to-plate wood connection anywhere in this building" between the fire-protected spaces, explains Rob Paisley. The truss hangers shown here provide a one-inch space that allows gypsum board to be slipped between the floor frame and the wall frame.
Ted Cushman/JLC "There is no plate-to-plate wood connection anywhere in this building" between the fire-protected spaces, explains Rob Paisley. The truss hangers shown here provide a one-inch space that allows gypsum board to be slipped between the floor frame and the wall frame.

A property in Portland, Maine, is under renovation as a new apartment building. The property is sited on a double lot, adjacent to an existing building that dates back to the 1800s.

A recent change in the neighborhood’s zoning allows the developer to build a new four-story structure directly abutting the older house, reports JLC's Ted Cushman. But when you do that, the new structure has to be completely isolated from the old one. To accomplish the required fire separation, the contractor and his framing crew built a typical two-hour firewall between the two structures as they framed the new building.

Framers attach a ledger for a stair landing to the stairwell shaft wall, after first fastening a strip of GP Gold Bond gypsum board in place at the ledger location. Framing multiple fire-protected elevator and stairwell shafts is tricky when no wood-to-wood contact between the shafts is allowed, observed contractor Rob Paisley. This staircase will help keep the shaft plumb and stable as the walls rise.This isn’t the only fire-rated wall in the building. The building’s two stairwells and its elevator shaft are each isolated from the rest of the structure with two-hour fire-rated assemblies.

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