fire rated walls

[sminor]

I need to know if there is a code section or other info to explain 4s boxes in a fire rated occupency seperation wall, that is, two fire rated walls with 1 inch seperation between them, as in multi-unit dwelling units. I understand that fire putty pads are required on all 4s box penitrations, including boxes less than 24 inches apart and no "back to back" boxes allowed. I would love to see a web site with pictures showing the walls with space between. thanks for any help!

 

[cowboyjwc]

You can look at some of the UL tested assemblies and also check the Gypsum manuel

 

[roger]

I agree with John, you will find this information in other codes and standards, below is from the UL Fire Resistance Directory.

WALL AND PARTITION ASSEMBLIES

Metallic Eletrical Outlet Boxes

Listed single and double gang metallic outlet and switch boxes with metallic or nonmetalliccover plates may be used in bearing and nonbearing wood stud and steel stud walls with ratings not exceeding 2h. These walls shall have gypsum wallboard facings similar to those shown in Design Nos. U301,U411, and U425. The metallic outlet or switch boxes shall be securely fastened to the studs and the opening in the wallboard facing shall 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 shall not exceed 16 sq in. The aggregate surface area of the boxes shall not exceed 100 sq in per 100 sq ft of wall surface.

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

Metallic boxes shall not be installed on opposite side of walls or partitions of staggered stud construction unless "Wall Opening Protective Materials" are installed according to the requirements of their Classification.

Roger

 

[e57]

Some white paper on puddy pads have alot of usefull info...

Or the product guides for what ever product you use....

If you start looking through them all - you might find a picture you're looking for - I have seen them before - I think I know what you're looking for.... I keep a bunch of these type of things in my truck to show people when clarification comes necessary....