Heat tape near insulation.

Old 05-17-18, 09:10 AM
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Heat tape near insulation.

Hey everyone, new to the forums here and looking for an answer to my problem. Right now I have a bathroom in the basement that receives little heat. The sink is on the outside wall and the pex piping runs along the outside. The previous homeowner did the basement himself and ran the pex piping inbetween the pink fiberglass insulation (IE tore the insulation in half and placed the two pipes in there.).

Over the winter the pipes froze and luckily no damage was done. However I'm looking at fixing this issue. Now I beleive I have two options. Option one is to re-route the piping to an inside wall away from the cold and insulate it as its still fairly close to the cold wall. This would require a little bit of work but not too much I believe. Option two is to run heat tape along the two pipes (about 10 feet worth). I'm just worried about running heat tape near insulation and causing a fire.

What is the best option here?

P. S basement is finished.
Old 05-17-18, 09:20 AM
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I don't think those tapes get hot enough to cause a problem with insulation, also I think insulation just melts as opposed to catching fire, when things get really hot. I think the heat tape manufacturers recommend insulation around them and the pipe and they never say what type of insulation so I suspect they are pretty confident that you would not have a problem.

Now it seems to me that a large part of your problem is that not only was the pipe insulated a little from the cold outside but it was also insulated a little from the warm inside. If you could remove the insulation around the pipe BETWEEN the inside wall and the pipe, it probably would never freeze again. Not sure how that would work for the overall insulation of that wall but for the pipe it would be significantly helpful.
Old 05-17-18, 09:21 AM
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Fiberglass insulation should not be a concern about catching fire, however your description points out a common mistake. By installing the pex in the middle of the insulation he inadvertently shielded the pipe from the heat in the basement. Rule of thumb is to insulate between the pipes and the cold but not between the pipes and the warm.

Not sure where you are located but must get pretty cold. In a cold climate it can be very beneficial to insulate the walls and air seal the perimeter house to foundation. Sounds like he insulated the cavities but typically they miss the air sealing which is what brings in a lot of the cold.


PS, I just noticed the Canada in your profile so that answers that question.
Old 05-17-18, 09:23 AM
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So which option is going to allow you and the family to sleep better?

Putting any type of electrical device or heat tape in a wall is never a good idea!
Old 05-17-18, 10:49 AM
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Welcome to the forums!

I always use heat tape as a last resort. A lot of it is manufactured cheaply/poorly, so there's always a bit of an overheating worry. Plus, most heat tape will only last 5-10 years max, so at some point, it's going to stop working, and you're not going to realize it until the pipe freezes and bursts. Plus, most heat tape you'll want to unplug over the summer and remember to plug it back in during the winter.

If it were my house, I'd rather try to get the pipe on the interior part of the wall. Also simply keeping the cabinet doors open during really cold weather can help.
Old 05-17-18, 12:59 PM
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Thanks everyone for the replies! I'm worried that putting the pipes inbetween the drywall and the insulation wouldn't fix the issue. As someone noted I am from Canada and it does get pretty cold up here (-30 isn't unusual). Not only that but the basement does also get cold (I like it, but I'm sure the pipes don't).

​​However what I will most likely do is reroute the lines like I said as that will bypass using heat tape.

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