2 foot separation of receptacles

[mshields]

Our drawing notes cover the fact that receptacles on opposite sides of a rated wall must be 2 feet apart. But when challenged about this requirement recently, I was unable to find where this was required. So that's question number 1.

Question number 2 is; Is there anyway around this requirement such that receptacles can be installed closer together. i.e. perhaps through the use of a fire rated compound or material?

thanks,

 

[roger]

From Volume One of 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

 

[raider1]

The separation requirements for electrical boxes in fire-rated walls comes from the building codes.

The IBC section 712.3.2 deals with this subject.

Membrane penetrations of maximum two-hour
fire-resistance-rated walls and partitions by steel
electrical boxes that do not exceed 16 square
inches (0.0103 m2) in area, provided the aggregate
area of the openings through the membrane does
not exceed 100 square inches (0.0645 m2) in any
100 square feet (9.29m2) of wall area. The annular
space between the wall membrane and the box
shall not exceed 1/8 inch (3.1 mm). Such boxes on
opposite sides of the wall or partition shall be separated
by one of the following:
1.1. By a horizontal distance of not less than 24
inches (610 mm);
1.2. By a horizontal distance of not less than the
depth of the wall cavity where the wall cavity
is filled with cellulose loose-fill,
rockwool or slag mineral wool insulation;
1.3. By solid fireblocking in accordance with
Section 717.2.1;
1.4. By protecting both outlet boxes with listed
putty pads; or
1.5. By other listed materials and methods.

Hope this helps

Chris

 

[mshields]

Huge help!

Huge help!

Thanks to all!