Fire Wall pentrations

[inspector 102]

In a 3 story hotel the design calls for basically back to back outlet boxes in the room separation walls. Since these are 1 hour rated walls, outlet boxes are supposed to be separated by 24" when located in the same wall. How have people maintained the required separation if the spacing is less? Putty Pads in the electrical boxes? Fiberglass insulation in stud spaces? By the way, these are non-metallic boxes in wood framed walls.

 

[cowboyjwc]

Look for Allied boxes they have boxes where you only need 3" of seperation. They also have multi gang boxes that are 2 hour listed now.

Some jurisdictions might let you use the fire pads, but the problem is that you also need to install sound pads and you cannot stack these products. So you need a fire pad with a rating of 50 or more for sound and you will not find it.

 

[M. D.]

some stuff to read ,..if you'd like

5. Nonmetallic Electrical Outlet Boxes
Outlet Boxes and Fittings Classified for Fire Resistance (CEYY) includes Classifications for nonmetallic outlet and switch boxes for use in wall or partition assemblies. The information provided for each Classification includes the model numbers for the Classified products, a description of the rated assemblies, the spacing limitations for the boxes and the installation details. Nonmetallic boxes should not be installed on opposite sides of walls or partitions of staggered stud construction unless Classified for use in such constructions.

6. Metallic Electrical Outlet Boxes
Listed single and double gang metallic outlet and switch boxes with metallic or nonmetallic cover plates may be used in bearing and nonbearing wood stud and steel stud walls with ratings not exceeding 2 h. These walls should have gypsum wallboard facings similar to those shown in Design Nos. U301, U411 and U425. The metallic outlet or switch boxes should be securely fastened to the studs and the opening in the wallboard facing should be cut so that the clearance between the box and the wallboard does not exceed 1/8 in. The surface area of individual metallic outlet or switch boxes should not exceed 16 sq in. The aggregate surface area of the boxes should not exceed 100 sq in. per 100 sq ft of wall surface. The aggregate surface area of the boxes may be exceeded when Wall Opening Protective Materials (CLIV) are installed according to the requirements of their Classification.

Metallic boxes located on opposite sides of walls or partitions should be separated by a minimum horizontal distance of 24 in. This minimum separation distance between metallic boxes may be reduced when Wall Opening Protective Materials (CLIV) are installed according to the requirements of their Classification.

Metallic boxes should not be installed on opposite side of walls or partitions of staggered stud construction unless Wall Opening Protective Materials are installed with the metallic boxes in accordance with Classification requirements for the protective materials

.