Injecting foam for freezing pipe in wall.


Old 01-09-15, 03:42 PM
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Injecting foam for freezing pipe in wall.

ok there's this bathroom that was added over a crawlspace. They barely insulated the walls when they built it and the crawlspace wasn't insulated. There's tenants living with the bathroom and complained to the landlord last year that it was too cold and they left a thermometer out and confirmed with the town that it's too cold for requirement.

I insulted the whole walls and ceiling of the crawlspace with r30 fiberglass, doubled up in some areas. Used caulk and great stuff on the mud sill, corners of masonry crawlspace corners etc. There's no moisture so I didn't use foam boards, I used the higher R value fiberglass. The crawlspace is adjoined to the main basement which has a bunch of boilers and is very warm, I'd say the crawlspace is at least 75 degrees in dead winter.

After insulating the crawlspace, the bathroom above it still didn't meet temperature requirement, so I cut holes high and low in the bathroom drywall and rented a cellulose insulation blower. Don't even bother with one of these because they clog very easy not only in the hose but also if you hit a horizontal wire in the stud cavity or a pipe or even just the build up of the cellulose, it will clog and be useless. I ended up just reaching my arm into the holes in each stud bay and putting in pieces of fiberglass. It met temperature requirement after this. This was last winter.

A few days ago, the tenants said the shower line is freezing and were late to work, made the landlord pay their lost wages, making the landlord pay for a space heater in the bathroom and possibly part of the water bill to keep the water trickling to prevent it freezing.

When I cut all the holes in the wall for the cellulose blower last year, I didn't in the shower because of the tiles. As I said, once I cut the walls open, I discovered the original builders barely insulated, it's like they just put a 2" piece of fiberglass in every third bay or something.

Ok, so the shower line runs through the crawlspace. I put foam pipe wrap and taped r30 fiberglass over the whole thing in the crawlspace last year.
In the crawlspace, the hot and cold shower lines turn and go up the shower wall which is uninsulated. This is an old building with wood clap board siding and probably doesn't even have plywood sheathing or possibly even home wrap or tar paper under the clap boards hence cold air is freezing the cold water line.

When I insulated the crawlspace, for some reason I think I was able to see up the stud bay where the shower lines go instead of the pipes going through holes drilled in the floor/sill how it should be. I think I stuffed as much fiberglass up there as I could reach which was only like a foot or two. There is a slow leak coming from these pipes since when I insulated the crawlspace last year. Could be from freezing and lucky it didn't burst.

Because of the slow leak, you'd probably say the best solution is to rip out either the whole tile shower wall or the exterior siding if that's less work than retiling and then fixing the leak and reinsulating.
But is there a cheaper way to inject insulation and hope it prevents the pipe from freezing or turning into a burst pipe and just living with the slow leak?

I'm thinking a DIY type injection foam, not the kind for spraying open work, the kind for injecting into bays. Where can I get that cheap? I do have access like I said from the crawlspace upward into this bay but is it even possible to inject insulation from the bottom up? Is the only option to cut out a few tiles in the shower and inject from there, or to take the clap board siding off and drill in from there and put home wrap/tar paper on before putting the clap boards back on since it probably doesn't even have home wrap?. It sounds easier to remove one or two tiles from the inside, but that would only be for one bay. Do you think if I inject only the bay with the freezing pipe and not the surrounding bays it will help much? Because maybe I should just remove the clap boards from outside (they will probably all crack and shjt though and need repainting and caulking etc) but this way I can have access to each bay on that wall (about 5 bays) and I can put home wrap behind the wood clap siding because air gets right through the clap boards. Also, if there is no sheathing under the clap boards, I can have a plumber easily come fix the leak from the outside. If there is sheathing, I can just cut a piece out and have the plumber fix it that way.

If it takes more than a day, I can get those plug-in wires that wrap around plumbing pipes and keep them from freezing because the whole wall will be exposed to outside, do you think those plug in wires will even prevent the liens from freezing if the whole wall is open to outside?

I could wrap the plumbing in the crawlspace with the plug-in wire heater wrap thing but I don't think the heat from it will travel all the way up the 8 foot wall to where the shower head is where freezing is happening.

maybe I can just attach a 6 foot tube to great stuff window and door kind that doesn't expand so much that it might damage the wall, drill a hole through the tile and spray it in and put a filler over the tile hole?
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Old 01-09-15, 03:54 PM
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OK, you said an awful lot in this post. But lets boil it down to what it will take to fix it once and for all. Remove outside clapboards and rebuild properly and have plumber fix leak (it will get worse as time goes by). Then remove inside tile and insulate accordingly. I see no short cut in this situation.
Old 01-09-15, 04:21 PM
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I take it that you are the landlord.

You did say a lot and you mentioned a lot of bandaids. One no-no is that electric heat tape doesn't go inside of walls.

You could really do all the work from outside and not mess with the tile.

You mentioned you insulated the crawl space. Maybe you should allow some of the warm air up the walls for now.
Old 01-09-15, 04:41 PM
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yes hopefully that's the longest post I'll ever have to write.

im not the landlord. I said I would make it meet temperature requirement last winter which I did and still is but that pipe is freezing. I knew once the cellulose jammed while blown that I could have called an insulation injection contractor but all it needed was like 2 degrees so I saved the landlord a lot of money and just stuffed the holes with cellulose and fiberglass. There were no holes in the shower tile though anyway to insulate them. The shower has a drop ceiling and there's no area on the shower walls that have just drywall and no tile. it should be injected from outside.

I think you're right, easiest smartest thing would probably be remove the clapboards and the sheathing and homewrap if it even has those. Then get the plumber to fix the leak, insulate and put the clap boards back up. I wouldn't have to take the tiles down like norm said to insulate because the whole wall will be open to outside. that's why I said maybe wrap the pipes with heater wire if this takes longer than a day, just a temp fix, and if I installed the wire wrap on the pipe permanently it would be in the crawlspace but I doubt the heat would travel all the way up the 8 foot wall and prevent freezing anyway.

If I go from outside I have to worry about the elements but I can install new building paper since it might not even have it or is all damaged. But a few coats of good paint and caulking all the clap board joints might be as good and then redo the tile wall from the inside without having to worry about the pipes freezing over night. I'm not sure.
Old 01-10-15, 02:43 AM
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Here's what I'm pretty sure is going to happen: Instead of taking the whole siding clap board section off, I think we'll just drill hole saw right through the clap board and inject the foam through there and then plug the holes and put a bunch of paint layers over to hide the plugs.

The slow leak in the plumbing might just have to be for now. Because the only way to address that is to remove all the exterior siding and then cut away a section of sheathing (if even installed) and then fix the pipe from there or from inside by taking the tile wall down. Most likely it would be done from outside and would be a race against the freeezing to get the wall put back together after the plumber fixes the pipe. If done inside, there'll be no shower and thus possibly pay loss deductions or something from the tenants. Fixing the pipe can be done after the foam, just the bay with the burst pipe, if it ever bursts, the foam insulation will have to be picked out of there and then reinsulated after the pipe's fixed.

Where can I even get the injection foam? Online or have to have to be certified and buy a big truck load at a time? Because all I think really needs it is the bay with the frozen pipe and the two surrounding bays which I can do no problem, and to get an injection contractor for just that small job, they'll probably charge for the day and this is on a budget. But if they do charge for the day, there's at least 8 other bays they can do on the other side of the shower around the corner of the wall even though the bathroom already meets temperature code, the shower walls have possibly zero insulation in them so it's good to be safe and insulate those as well.
Old 01-10-15, 06:59 AM
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If you inject the foam it will make plumbing repair a nightmare. It will encase all of the pipes. It's a bad plan. Take everything off from the outside. That is the smartest thing to do. If it takes more than one day to finish putting the wall back together, attach a piece of rigid foam over the outside.

The landlord is not responsible for lost wages because of the shower. If he was, it would be cheaper to put them both up in a hotel for a night. The landlord won't need to compensate them for anything if he fixes it in a reasonable amount of time. They can also just take a sponge bath if the sink is working and they really need to get clean. Plenty of options to deal with the shower not working for a couple days.

You can buy slow rise foam online. The stuff isn't cheap. I have purchased spray foam from Foam it Green Spray Foam Insulation Kits and have been using it in my house. There are others out there.
Old 01-10-15, 08:57 AM
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My apology for not reading your post (too long) so disregard this if not applicable or a repeat.

When insulating over a unheated space while trying to protect water pips it is important to insulate and air seal between the pipes and the cold while not insulating between the pipes and a source of heat. An example would be to insulate below the pipes while keeping the above area open to a somewhat heated basement space.
From above, the heat (warm air) tends to migrate upwards while any cold flows to the floor.
Air leakage during the colder months flows up through any path it can find on its way into the house and up and out a similar leak up top.

A layer of house wrap well sealed within the bottom layer would act as an air barrier, yet avoid some of the moisture issues related to vapor barriers.

I did see the mention of leaking pipes, which obviously must be fixed, and the reminder to not bury heat tapes inside walls or cavities, so look for a path from basement to this cold area that you can leave open. On the warm side of the insulation you install you will want a vapor barrier so the moisture in the warm air doesn't reach a cold place to condense.

Old 01-10-15, 09:30 PM
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the crawlspace under the bathroom was 40 Fahrenheit while outside was 15. So, the fiberglass on the crawlspace ceiling is only making the bathroom colder, correct? Because ceiling insualtion is stopping the hot crawlspace air from rising though the bathroom floor, yea? Also as I mentioned in the first wall of text, in the crawlspace, if you look up in the corner you can see up in the bay where the copper pipes go to the shower, the same pipes that are freezing. I should remove the fiberglass insulation plug that is there also, right? And then try and fish insulation up the 8 foot wall bay but only on the side of the pipe that faces the outside, yea?

I wish I could get foam board up there but it's like a 3' crawlspace so I think the only option is to fish a small piece of fiberglass up at a time with a telescopic stick or something until the whole thing is filled with fiberglass but not compressed fiberglass which lowers it's R value.
Maybe this will be enough to keep the pipe from freezing and also make the bathroom warmer.

One last thing.. hopefully, if someone ever finds themselves in this same situation where the original builders just skipped insulating the bathroom and shower, and if you don't want to pay for an injection foam company or buy the DIY kits but want to insulate the walls behind the shower and possibly fix a slow leak, then instead of taking the whole exterior off, knock the tile shower walls off, fix the pipe, insulate with foam boards and caulk the perimeter (possibly only insulating the half of the stud bay which is between the pipes and the exterior wall so that the hot air from the bathroom passes through the pipes hotter than if the half of the stud cavity between the drywall and the copper were also insulated), and then instead of having to retile, just get one of those plastic bathfitter type solid plastic walls, maintenance-free easy to clean etc. You can install a fancy marble counter or something to counter balance it if you think the plastic tiles look cheap or something but I think they're great.

Last edited by gunner666; 01-10-15 at 10:08 PM.
Old 01-13-15, 12:29 AM
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well one more note, sort of talking to myself in this thread, but in case it helps anyone:

Always check the obvious. After all this, I just remembered seeing broken glass outside this bathroom's window last year. I'm pretty sure they just replaced only the glass with plexiglass after it broke, and this is one of those double pane windows with the sealed insulating gas in between the panes. Of course just putting a regular piece of glass into it will greatly reduce the temperature. This could be the main culprit.

Tonight, I went to try and stick insulation up into the bay where the frozen pipe was (because you can actually see up the bay from the crawlspace...). I forgot I already stuffed the bay with fiberglass last year. The bay is also already insulated with batts but it's very drafty and is like a 2x6 stud with 2x4 sized batts so there's a lot of dead space that could be insulated. I pulled the insulation out because having it on the side of the pipe that faces towards the warm bathroom is only slowing the transfer of heat from the bathroom into the pipes, you only want the colder side of the pipes insulated (of course this and some of the other methods described are only good for maximizing heat and will lower the insulating affect when trying to keep cool in the building in summer).

I also discovered the slow leak is likely just the trap from the shower PVC and probably easily fixed from the crawlspace, so that's good.

The crawlspace was supposedly 25 degrees F while it was 9 degrees outside. I checked and it was 59 while 36 outside. Which isn't as warm as I thought it would be, so I didn't remove all the insulation from the crawlspace ceiling to allow the crawlspace's hot air to rise and help heat up the bathroom, instead, the insulation will stay there and slow the transfer of the bathroom heat being lost to the colder crawlspace. The only part I left open was the bay that can be looked up into from the crawlspace which has the frozen pipe. Because it's better that the warm air of the crawlspace can go up in that bay instead of it being blocked by insulation. Because heat always migrates towards cold, so if it were insulated, it wouldn't do any good because that stud bay is colder than the crawlspace.

the only options I see left are remove the r30 fiberglass from the walls and spray insulation on them and the rim joists. I have never installed anything but fiberglass in many inspected basements finished but I think there's some draft coming through the fiberglass even though I caulked every crevice. Maybe plastic sheet can be put over the cement and then caulked all along the perimeter to stop draft but the crawlspace is so dam small with so many obstacles that it would make sense to just shoot everything with foam, even if it's that $400 foam it green kit you buy in the mail or something. The foundation walls are so bumpy and stuff that foam boards would have big gaps behind them and might not be able to seal and caulk the perimeter backing so I would say just shoot foam instead of that too. And then put the r30 back over the foam because it has so much more R value than the foam. Or maybe there's something you can shoot on with a compressor that just seals everything but has no insulating value but then install the fiberglass over that.

but the main problem is the drafty bathroom walls and of course the broken window. The only way to address that is with the injection foam I already mentioned or to take the whole tile wall down from inside and use non-injected foam boards and then replace the tiles with a plastic shower wall just because it's a lot easier and less problematic than redoing the tiles.

can also wrap the pipe in the crawlspace with a plug-in water pipe heater.
Maybe you can gain a few degrees by using some special exterior paint on the wood clap boards but it's probably just a waste of money that can go towards injection foam.

There's a small baseboard hot water heater in the bathroom this whole time. that should be inspected to make sure it's working right.

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