outlets in fire rated walls and ceilings

[jdblasberg]

What are the requirements for lights and receptacles in fire rated ceilings (residential)? I have heard about special "dome" like covers for recessed fixtures and two hour rating for plastic boxes, but what else do I need to know? Thanks!

 

[Dennis Alwon]

If you add an outlet in a fire wall it must be securely fastened to the structure. Pop in boxes will not be allow. Also make sure the outlet does not occupy the same bay as the outlet on the other side.

 

[infinity]

Where are you installing these recessed fixtures and what is the required fire rating of the location? For recessed light fixtures there are 1-hour and 2-hour covers available for non fire rated lighting fixture assemblies. The 2-hour rated domes covers are up to 2X the price of the 1 hour rated covers.


Welcome to the Forum.

Here's a 2 hour cover:

 

[WIMaster]

The FR boxes I have seen were actually bakealight (sp) or fiberglass of some sort.

As for recessed fixtures you should contact your AHJ and see what will make them happy. You should contact both the biulding inspector and the EI. I have had issues were one says this is OK but the other doesn't. I had one that allowed a 5/8" drywall box around some cans, but I question how well this would do if there were a fire and law suit, as it is not a listed assembly.

There are also a number of stick on FR pads available for metal boxes. 3M etc.

 

[iwire]

I first recommend that you get your code book out and find out what that text says. If you do not own one then either buy the version that is germane to your state or check one out at the library. If you do not understand the NEC then you should consider hiring someone who does.

Interesting, the NEC has nothing to do with the question.

The answer to the question is contained in building codes and listing standards.

 

[raider1]

What are the requirements for lights and receptacles in fire rated ceilings (residential)? I have heard about special "dome" like covers for recessed fixtures and two hour rating for plastic boxes, but what else do I need to know? Thanks!

Welcome to the forum.

As others have already stated the fire resistance requirements come from the building codes and not the NEC.

For dwelling units that are stacked on top of one another the floor ceiling assembly will be required to have a fire resistance rating to create a "Unit separation" to separate the 2 dwelling units. The floor ceiling assmembly may on be penetrated by listed membrane or through penetrations depending if the opening goes all the way through the floor ceiling or just through the ceiling part.

For recessed cans penetrating this floor ceiling assembly there are a few options. You can box around the recessed can housing with sheetrock the equivalent of what the rest of the ceiling is made of, or you can use a fire rated can or rated dome cover or other listed product to maintain the required fire rating.

Most plastic boxes have a fire rating for both the wall and the ceiling so as long as the box has the required fire rating for the ceiling you can use the box without any other material.

Chris