Great Stuff spray foam OK in contact with copper hot water baseboard pipes?

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ort5

Member
Sep 1, 2009
33
MA
Hi guys,

I have an addition on my house from the previous owners. There is one section where the copper baseboard hot water pipes exit the building envelope and then poke through the addition floor. Not the way I would have done it, but it's there nonetheless.

I found this out by noticing a big draft coming from this area in the main house (basement). The access hole that was cut is quite a bit larger than would have been required for the pipes.

My question is this: can I fill the gap with spray foam? I'm worried about flammability mainly, but the can says do not expose to over 240 F I think. Surely the pipe temp is lower than that.

Thoughts?
Thanks,
Dave
 
I think most baseboard heaters are in the 160-200 range. Mine is right around 185 when running. I use great stuff in many of these areas, no problems.
 
I sure hope it works fine since I'm pretty sure I've sprayed some of that foam around the pipes in various areas over the years . . .
 
Thanks guys, I figured it would be OK.

Did I mention how much I love the spray foam!
 
i think its a great product, but i wish it came in smaller cans. I always find myself running around trying to use it up. Ive tried the whole cut off the straw thing, but it never works the same again.
 
Great point Eric, I do the same. I find myself saving up projects that need it before "breaking the seal". I also find myself running around the house looking for something to foam with the remaining product :)

Oh, and I've ruined plenty of clothes with it, and don't get it on your hands!
 
I keep a box of latex gloves on hand, use them all the time. Spray foam, unexpected car problem if not around a sink, pothole repair patch, septic effluent filter (my favorite)
 
Same but I use nitrile gloves. I bought a box of Latex ones by mistake once. I went through the WHOLE box in just a few days. Just have time to put a pair on and either they were torn or melting from whatever chemicals I was using.
 
How big is this area? Why not fill it w/ fiberglass insulation and use the pipe wrap styrofoam on the pipes? Or is it truly exposed to the outside? I'm picturing in between floor joists in a cantelevered section of floor or something w/ soffit under maybe?

pen
 
Right now it's totally exposed to the crawlspace under my porch addition. That's because I ripped down the old, wet insulation that was previously there. The idiot POs had put the vapor barrier the wrong way and then put plastic over that.

The foam is mainly air sealing, and there will be fiberglass batts over that for insulation. The total area of pipe exposed is only around 6".
 
If that pipe ever sees 240 degrees you'll have a bomb on your hand. It should be just fine.

pen
 
Packing these passages with fiberglass often works better. Copper pipes expand and contract as they heat and cool. If they are captive you can get odd noise as the system warms up or cools down. Harmless, but annoying to some.
 
ort5 said:
Thanks guys, I figured it would be OK.

Did I mention how much I love the spray foam!

You and my wife . . . although she usually just advises me where to spray it . . . and I inevitably get it all over me and end up spending the next two days picking off dried foam from my fingers.
 
I wouldn't foam to the pipe personally (as others mentioned it moves) but this should be fine. When the insulation contractors were sealing my place they foamed right over steam pipes before I noticed what they were doing :(

212F iron hasn't melted the foam so far.
 
EJL923 said:
i think its a great product, but i wish it came in smaller cans. I always find myself running around trying to use it up. Ive tried the whole cut off the straw thing, but it never works the same again.

They make the fire block foam too. I assume it has i higher combustion temp.

As for the reuse issue - try pulling the plastic applicator off, cleaning it out with a pipe cleaner or something else that fits, wipe the nozzle off and then reassemble and store. Works just fine if you clean them properly and really not that big of a deal.
 
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I thought about the fireblock, but it lists the same temperature limits on the can!

I'll check their website....
 
You can rinse the applicator tube in acetone to reuse it.
 
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