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SteveR177
Insulating a pipe that keeps freezing
SteveR177

We have a copper cold water pipe running inside an outside wall in a downstairs bathroom that keeps freezing. Finally this winter it burst.

It's a block outside wall with 2x4 studs, very little insulation covered by sheet rock. The pipe is now repaired. The question is how to insulate the pipe to keep it from freezing without ripping out all the sheet rock and starting over.

Should I cover the pipe with the circular foam sleeves used in A/C line sets? I could slide the sleeving along the pipe through the hole I cut in the sheet rock to repair it? Other ideas?

Thanks,

Steve

dj1
Re: Insulating a pipe that keeps freezing
dj1

A better idea is to run an electric heating wire along the pipe. Similar idea to an electric blanket.

Available at the big stores or on line.

bill
Re: Insulating a pipe that keeps freezing
bill

Yes install a heating cable but also insulate behind but not in front of the pipe.

SteveR177
Re: Insulating a pipe that keeps freezing
SteveR177

You can run a heating element buried inside a wall? Does code allow this?

Fencepost
Re: Insulating a pipe that keeps freezing
Fencepost

If the entire environment around the pipe is below freezing, and the water is not moving, then there is no amount of insulation that will prevent freezing. The thermal energy in the pipe will be lost through the insulation; the effectiveness of the insulation will determine how long it takes to get below freezing.

If the average temperature of the environment is below freezing -- that is, if the room warms up above freezing for part of the day and below freezing part of the day, but the average temperature (a function of both temperature and time) is below freezing, then the pipe will eventually freeze.

You need to apply heat in some manner. You could either use heat tape as previously suggested, though heat tape should not be enclosed in walls. Or your could insulate behind -- but not in front of -- the pipe and ensure that the interior space is heated well enough to keep it above freezing. Foam board is generally more effective insulation than fiberglass batts.

keith3267
Re: Insulating a pipe that keeps freezing
keith3267

You are going to have to rip out some sheetrock or you are not going to be able to fix this. Personally, I'd rip out all the sheetrock and insulate the whole wall, but do not insulate the pipes. Pull the pipes as close to the interior side of the wall as you can and run all the insulation between the pipe and the exterior side of the cavities. Put a steel band along the studs parallel to the pipe so that after the sheetrock goes up, you dont put a nail or screw into the copper pipes.

To just do the area around the pipes, set you circular saw to a 45 degree angle and set the cutting depth to just the depth of the sheetrock. Cut a few inches above and below the pipes with the bevel pointed to the pipe. This makes a V shaped or wedge shaped cutout. Put insulation between the pipes and the exterior side of the cavity. Use faced batts so the paper is on the exterior side of the pipes and you have an air gap on the interior side.

When you are done, you can butter up the beveled edges of the sheetrock strip you pulled out with joint compound and literally glue the strip back in place. After the compound dries, you can go over the seam with another layer of compound and paint, no one will know there is a repair there.

SteveR177
Re: Insulating a pipe that keeps freezing
SteveR177

Thank you all very much for your input. Let me throw one other idea out for consideration. Suppose I squirt expanding foam into the wall cavity keeping as much as I can between the pipe and the outside block wall. The foam will help seal up any cracks in the block wall that are allowing cold air in and by keeping an open space between the pipe and the sheet rock, this will help keep the pipe above freezing.

I can always cut away any foam that expands a bit too much. I realize I'll have to cut away sheet rock, something I'd really not want to do.

What do you think?

Steve

bill
Re: Insulating a pipe that keeps freezing
bill

it is going to cost a fortune I figure 3-4 cans at $10 per can equals 40 bucks. You can buy fiberglass for half that and do a much better job on the whole wall not just one bay These are the prices in my area they could be very different in yours. dry walling is a no brainer, taping is harder but you can sub that out.

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