Replies

1. 
   IronHelix | Dec 29, 2007 04:27pm | #1

   The green capped Great Stuff is listed as fire-resistant, but not an intuminescent.

   The rating for the red can...?  Go to the Great Stuff web site and look up specifications.

   Nice way to reduce air infiltration....but what a pain for any retro-work!

   ...........Iron Helix

2. 
   davidmeiland | Dec 29, 2007 08:21pm | #2

   The insulators around here usually dab a bit of foam on the KOs where the wires enter plastic boxes. Filling the box with foam sounds heinous, something a run-amok DIY would do.

1. 
   Gunner | Dec 29, 2007 09:25pm | #3

      I dabbed a little fire resistant foam in all my electrical boxes after they were roughed in. I wouldn't want to dig a box full of it out.

    

    

    

   http://www.youtube.com/watch?v=ChIdFwQwoYM&feature=related

2. 
   CAGIV | Dec 29, 2007 09:36pm | #4

   ran into a few filled boxes on one project last year....

   Was a royal PITA and ended up replacing the devices we had to access.

   Electrical company we use said wasn't a fire hazard though....  Not sure I buy it, and the h.o. did own up to it.

1. 
   davidmeiland | Dec 29, 2007 11:16pm | #5

   There are clay sheets that are designed to wrap around the outside of electrical boxes for air infiltration and soundproofing.

1. 
   fall50 | Dec 30, 2007 01:37am | #6

   I have a take off question ......I have project where some copper pipe runs parrllel at grade in a basement with 2'' of Extruded Polystrene behind it.   The copper is    cut-in running parallel through the studs  I have 1-1.5'' gap  bewteen the XPS and the copper where I could stick some more foam behind it or fiberglaass.  Does anyone know if spraying Great Stuff Foam around these pipes would be a good idea?

   I have read conflicting opions on this.  Some say to insulate behind the pipe  or box it in with XPS foam leaving 1 side open which faces the drywall so that heat can transfer easily into the box and stay trapped in the box effectively keeping the pipe fairly close to room temp/

   When the inspector did his walk through he suggsted the spray foam, however I wanted to get a second opinion.  

   Again this is a basment wall with 2'' of XPS with the rimm joists sprayed with 2 part closed cell SPF.  In other words the wall is farily well insulated to begin with.  My climate is COLD  Minneapolis.  The basement is heated via forced air.

1. 
   davidmeiland | Dec 30, 2007 02:11am | #7

   I would use pipe insulation... the stuff that's like a giant drinking straw made out of grey foam.

2. 
   DanH | Dec 30, 2007 06:25pm | #11

   If you're trying to prevent freezing pipes, only insulate on the outside. The pipe will stay twice as warm as it would insulated on both sides.
   If your view never changes you're following the wrong leader

3. 
   fall50 | Dec 30, 2007 07:06pm | #12

   So essentially box it in leaving the warm side open so heat can transfer into it.  What about putting pipe insulation around the pipe still?  Seem liks if you box it in (leaving warm side open) you will capture the heat within the space

   Edited 12/30/2007 11:26 am by fall50

4. 
   DanH | Dec 31, 2007 01:36am | #13

   Any insulation on the warm side will only make the pipe colder.
   If your view never changes you're following the wrong leader

3. 
   BUIC | Dec 30, 2007 06:51am | #8

     Take a piece of foam out and take a match to it?

4. 
   IronHelix | Dec 30, 2007 02:46pm | #9

   Yesterday..........

   Had to help my SIL put a downdraft vent through an 8" concrete wall.....he handed me a can of Great Stuff to finish the fill around the 8" vent pipe.

   So....I read the label to see if it had the answer to your question, and it did on the second or third line.

   FYI....   "Cured foam is combustable."

   With that fact, one might consider using this Great Stuff (RED CAN) in an electrical box a potential fire hazard. 

   If I were doing on-site observations I think I would call this out to the GC/electrician  and request the foam removed, unless the empty cans laying in the floor were Great Stuff (GREEN CAN).

   Rethink the situation!

   .............Iron Helix

    

   
   

   ---

   Edited 12/30/2007 6:48 am by IronHelix

5. 
   edlee | Dec 30, 2007 03:48pm | #10

   We use box-fill calculations regarding the maximum number of conductors that are allowed in an electrical box. One of the reasons for this is to allow heat to dissipate from conductors under load. 

   Filling them with thermal insulation would violate the intent of this requirement.

    

   Ed