# Caulking a copper pipes



## Vic99 (Jun 19, 2011)

As a back up to wood heat, I have forced hot water baseboard gas heat.  

Will I risk fire or strong odor if I caulk the gaps in the basement ceiling that the copper pipes pass through to get heat to the living space?  Will standard 35 year caulking be able to take any expansion and contraction that comes with pipe heating and cooling?  I'd like to do this job just once.


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## North of 60 (Jun 19, 2011)

No fire, thats for sure. As for smell and expansion and contraction, that will depend on the caulking.  Odors would be gone once the caulk has cured.  I would insulate your pipe with pipe insulation at the penetration. Make the hole bigger to make it fit if need be, then caulk around the insulation to seal it.  That way the pipe can move in the insulation without disturbing and moving on the sealed joint.


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## fishingpol (Jun 19, 2011)

I'm going to go the other way on this.  First, the insulation will probably not give off an odor.  The temps on baseboard heat are just not that high.  I would then buy a pack of suspension clamps that wrap around the pipe under the floor or where a pipe passes under a joist.  Screws are put through the wings of the clamp to hold it tight to the subfloor or framing.  

If average subfloor is 3/4" if you have hardwood floors, you are looking at 1 1/2" of floor to insulate.  Go with minimal expanding blow-foam.  Regular caulking will settle and fall out if no means are used to keep it there.  Blow foam can be sprayed in a little circle around the pipe and you are done.  It is a sticks tenaciously once applied.  If had enough of it on my fingers over the years to know.  Prep all the penetrations and go around all at once.  Go and do any gas, electrical and other plumbing penetration through the floor at the same time.  It is a worthwile project.


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## Vic99 (Jun 20, 2011)

Thanks guys.  In my 1920 built home every year I find more holes to seal up.

All the the basement piping has grey foam piping insulation around it.  I'll then add that insulation where it penetrates the floor.  Next I'll use a can of spray foam in the gaps through the floor.  Finally, I'll replace my basement ceiling fiberglass batts.


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## Adios Pantalones (Jun 20, 2011)

You must be getting extra bored there, gimpy


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