House Help - unique situation, trying to keep pipes from freezing

November 13, 2014 6:46 PM

Going internet on this one, need house help: Problem, cold temps coming, exposed pipes with water in 'em, want to avoid freezing/cracking.

...2nd floor of 3 family has been gutted (no insulation, no interior walls)
...main water stack goes thru and there's hot and colds for the ex-bathroom
...can't isolate direct water connection because it runs the laundry
...need to keep from freezing for a couple weeks until contractors can start

- space heaters won't work, cause the structure won't hold heat
- heat cable (thanks for the idea, mike) won't work because the non-stack pipes are too short
- i've heard it'll be too cold for too long to use conventional insulation wraps on the pipes themselves

Anyone know how to stabilize these pipes?

posted by Reasonably Everything Happens to Home & Garden (9 answers total)

I had some water pipes that ran into my house via underneath the barn which wasn't really well insulated. We wrapped insulation around the pipes--like wall insulation, the pink stuff--and then wrapped that in moisture barrier stuff to keep it pretty solid and held together. Really though even a 40watt light bulb in an enclosed space with the pipes should help it somewhat. Where are you and how cold is it going to get? I'm not sure why heat cable won't work? You just wrap it around the pipe, get like an extension cord type thing from the hardware store. You can also put a space heater in on a timer. All you need to make sure is that theh pipes don't freeze solid. Having them get really cold and then uncold at intervals should work okay as well. Or, honestly, just turn the water off most of the time and the turn it on twice a week to d the laundry and leave it off the rest of the time?

If this is your place and you're in a situation where you have contractors coming in that you are paying in a few weeks, ask them what is going to work for your climate and the weather you are expecting. If it's indoors and the upper and lower floors are heated, it shouldn't get too out of control.
posted by jessamyn at 6:52 PM on November 13, 2014

Any reason you can't just open the taps slightly to keep the water flowing at a slight trickle? If the sink/shower/etc have been pulled out you can probably just install a temporary flex tube to divert the running water into the existing drain pipes.

The open tap provides a release for the pressure caused by any water in the pipe that does freeze, not to mention that running water has a lower freezing point anyway because of the movement and turbulence.

I doubt the extra money you'd spend on the water bill would be any more than what you'd pay in supplies to implement another solution.
posted by trivia genius at 7:08 PM on November 13, 2014

Response by poster: Draining and then running for laundry is interesting.

This is near Boston, so it'll be sub-30 by Saturday.
posted by Reasonably Everything Happens at 7:10 PM on November 13, 2014

If it's 30 outside it should be fine outside if things are insulated and if you run a space heater occasionally. Heat tape really does work and you can use it on shorter runs of pipe. It's really when it's like 15-20 F outside for a week at a time that you really have to worry about things freezing so bad that pipes burst. Frozen pipes are just a pain because you can't get water out of them but they will thaw or you can thaw them. Burst pipes are what destroys your house, I had a house in Vermont and was forever having to deal with this sort of thing. Here is what the Red Cross has to say (they suggest leaving the faucet on at a trickle) and what Allstate says (suggest making sure bathroom cabinets are open if you have any). I'd also see what the window situation is and make sure you get maximum solar gain in rooms where there is water. Even if the room is 40F it will still be warm enough to keep pipes from freezing if the sun is out.
posted by jessamyn at 7:32 PM on November 13, 2014

Are the pipes exposed, or inside a wall cavity?

If they are exposed, could you build a small enclosure around them using foam insulation panels, then put a small heater inside the enclosure with a thermostat at its lowest temperature?

And if they're in the wall, could you make a hole in the wall and somehow heat just the wall cavity to 35 degrees?
posted by reeddavid at 9:59 PM on November 13, 2014

Heat tape under insulation should work, as should letting the water drip. As long as a small hole stays unfrozen, water will move through it and moving water will thaw any surrounding ice.
posted by summerstorm at 10:13 PM on November 13, 2014 [1 favorite]

When I was in college I lived for a couple of years in a trailer house, and the water supply was a hose connected to a faucet. In the winter, to prevent it from freezing, I had to use "heat tape". It has to be plugged in, but it doesn't really draw all that much power; all it has to do is keep the hose (or in your case the pipe) above freezing.

It worked fine. I never had a problem, and I didn't have to keep a faucet dripping or anything like that.
posted by Chocolate Pickle at 10:27 PM on November 13, 2014

Best answer: If the first floor is heated to human comfort levels, you're probably safe for the 2nd floor staying warm enough despite its lack of insulation. (I own a four-unit that derives almost all -- 80 to 90% -- of its winter heat from the lower level units.)

I agree with jessamyn here that just sub-30 is very low risk. Last winter we had a cold spell here that got me nervous about my crawlspace pipes, so I made sure that every unit had a drip going and put an oil-filled heater in the crawlspace. Everything was fine, though. (Most of the problems people had were actually in the underground pipes going out to the street -- the pavement gets very very cold because it's exposed, but the front yard in this case was insulated with a layer of snow.)

Thirding heat tape as another layer of risk reduction. It's very easy to install and won't cost anything significant to run, versus a frozen water disaster.

I know you say some of these things won't work but if you cobble them together in an appropriate way you can probably survive these two weeks. If you're really feeling like you need something more the best way to proceed might be to actually build an enclosure for the pipes using some 2x4s and drywall.
posted by dhartung at 12:13 AM on November 14, 2014

Our pipes froze a couple of times last year - due to the extreme temperatures, and what we suspect is a gap of some kind beneath the siding on the addition on the house, letting in air between floors. It's an impossible space to get to without some demo. I'm going to attempt some heating cables and pipe insulation in the furnace room, where the water line enters the house is, this year.

Even though the winter was extremely cold, there were only a few days we had to worry about. Leaving the faucets in the addition dripping did the trick. Just keep an eye on the forecast, and figure out the threshold for your pipes freezing.

If your pipes do freeze - turn off your water at the main valve into the house, and wait for them to thaw (crank the heat, pray for warmer weather etc).
posted by walkinginsunshine at 4:10 AM on November 14, 2014