Freeze Protection for an Outdoor Faucet
I am one of many in Central Texas that had their pipes burst in the recent freeze. The outdoor faucet located in a unheated garage wall froze and ruptured. I had thought I had the situation under control after residing my house and upgrading sheathing to r-3 zip and insulating all walls (including garage walls), however forgot about the original construction that left a small section of water pipe outside of the slab foundation (see photo).
I’m looking into how to try to ensure this doesn’t happen again, and looking for advice. When we finally repair the faucet I will install a 4″ frost-free faucet with PEX connections, but the freezing is happening on the outside of the wall in the slab. My plumber suggested possibly jackhammering out the slab and trying to tuck the tubing back into the slab, but I’m really nervous about this as the tubing is already compromised and trying to work with tubing that’s over 40 years old scares me. My second thought is to install a 2″ or so veneer stone over the slab that would tie into a wash slab under the faucet. This would provide direct protection for the tubing and probably keep from freezing. Other ideas welcome.
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Sorry you had that problem.
Can you abandon that pipe, shut off at the source, and locate the new faucet on an outside wall of the conditioned space (not the garage)? For example, maybe it can come out from under the kitchen sink, if you have a kitchen sink against an outside wall?
Sorry to hear about this.
In places where it ordinarily gets below freezing, there are four ways to keep a pipe from freezing:
* Drain it.
* Run it below the frost line. If you can't run it below the frost line, the rule of thumb is that an inch of foam is worth a foot of dirt. Extend it for a foot horizontally.
* Run it through the heated part of a heated building.
* Heat it. There are thermostatically controlled electric heat tapes that only provide heat when needed. This might be the best solution for a spot that rarely sees freezing. Although it won't help if you lose power.
Since this is a rare occurrence, do you think you could configure it so you can drain it if frost hits again?
I think covering it with insulation would work better than covering it with stone. I'd add just enough concrete patch to ensure there's good contact between the floor and the pipe, then covered it with 2" of EPS, then the wash slab over that. This is assuming you are sure that the slab itself will never get to freezing temps.
A commonly used insulating product for outdoor faucets is this (or something similar):
https://www.homedepot.com/p/Frost-King-Outdoor-Foam-Oval-Faucet-Cover-FC1/100346042
These help to keep the heat from inside the home from "leaking out" through the faucet, which keeps the faucet a little warmer. The pipe suppling the faucet essentially carries some of the heat from inside the home out to the faucet. You only need a little bit of heat, since you only need to keep a little bit above freezing for protection. Using a product like this in addition to a frost proof faucet assembly should prevent further issues.
If that tubing in the slab is already compromised, then it probably is worth the effort to replace it. You don't want to fix one spot just to have the other spot fail next time.
Bill
Another way to freeze protect it is just to leave it running. Even a slight stream is enough.
One thing those in places where it doesn't often freeze may not be aware of is the existence of frost-proof sillcocks, standard issue in colder climates. The supply line needs to be in conditioned space, so it wouldn't help your garage situation, but if they are installed through a rim joist or wall they can handle very cold outdoor temperatures.
I have a frost-proof sillcock on order for when I can get a plumber back. I'll also have him replumb in PEX. We normally measure the Hours per year below freezing and that generally means maybe high 20's. 5 degrees and over 6 days without getting above freezing hasn't happened in my 40 years in texas. Think the last time it was this cold was 1897. We had a cold snap in 1989, where it stayed below freezing for 4 days, but the coldest it got was in the high teens, which was the high for about four days in a row
Thank you all for your suggestions. Let me clarify some points. The photo is the stem wall not the actual slab, so installation is not possible here. We could abandon the piping, but could only cap it off inside the garage wall, so the tubing still sticking out of the slab would still be exposed in we get another 100 year freeze. Capping it off lower would entail a pretty heavy demolition of the stem wall (pipe should have been just under the slab and not in the stem wall). Since this is the only outdoor faucet in the front of the house, and since it tee's off of the main line to the rest of the house, capping it is not the easiest solution. The garage is actually well insulated, with R-15 Rockwool insulation in the walls, a R-13 door and ceiling insulation. Eventually I'll add a mini-split to facilitate year-round woodworking. So the pipe is well protected inside the wall, just not here at the stem wall. Possibly just letting it drip or getting a heat lamp on it (assuming we keep power next time) is the best solutions. But still considering the stone veneer to provide some cover and protection to the pipe. Again thanks for taking the time to comment.
Here in North Georgia, it's common to have hose bibs on exterior walls. Similarly, it's common to have shutoffs for each bib, so the homeowner can turn off the water and drain the line. Maybe that's not possible here.
I also was going to propose a foam bib cap in combination with a hardwired electric heater in the garage, but I guess that wouldn't work if the electrical grid is so unreliable.
One last thing for the OP, are you sure the pipe in the photo isn't polybutylene? Just asking.
No the whole house is copper plumbed and the faucet was covered and insulated. It froze just above the slab inside the wall cavity. I'm enclosing a pic of where the pipe was capped, just barely above the sill plate. If it had been much lower, it would have really been a disaster.
Looks like a shark bite cap save the day there :-) Those are probably the absolute best application shark bite fittings -- quick and foolproof when you need it to just work.
Regarding your semi-enclosed pipe, you could potentially insulate that part of the wall with some rigid foam to add some thermal protection for the pipe. I would try injecting canned foam around the pipe, trimming it flush with the wall, then adding some extra rigid foam over that to get up to whatever level of protection you desire. The canned foam will prevent air circulation around the pipe, and thus protect you from convection currents cancelling out the benefits of your other added insulation.
Letting water trickle is a good suggestion, but if you do that, you have to keep an eye on it -- sometimes it will freeze up enough where it's trickling to plug things up and stop the trickling, at which point you lose your protection. As long as the water is running, it has to get VERY cold to actually freeze. This is similar to how cement mixers keep the mxi from hardening in the truck.
A last option, but this requires electricity, is a heat cable. I like the so-called "self regulating" heat cables made by Raychem (and others). They are not cheap, but they are far superior to the heat cables that use thermostats.
A last option to consider for emergencies would be to keep some chemical hot packs on hand. You squish-mix these when you need them, then they stay warm for a while from a chemical reaction. You could stuff one alongside the at-risk pipe and then cover the entire thing with insulation to help ward off freezing temperatures. If the shelf life of the hot packs is long enough, you could keep a stash on hand for any other extreme cold weather surprises the future might hold.
Bill
I have an external waterline for a hose in NY where outside gets to freezing days every year. I put a shut off valve inside the basement, you can have it anywhere in your house just away from freezing temps. The first day I hear in year we are hitting freezing I shut off the inside valve and open it outside to make sure there is no remaining water in pipe or hose. If I need to turn on water at any point for a few minutes I just flip the valve open, use it, then close it. Once weather is above freezing I just leave valve open until next winter. You should be able to locate where the outside faucet is entering into main line and add a shut off valve. Any plumber should be able to do this inexpensively. I'm assuming that this is very rare where you are for freezing temps so it would be something you probably only shut off once a year at most. You can add insulation around pipes and it would probably make it easier to run warm water fast but if it's warm most days where you are it's going to be extra work I don't think you need.
Note that you can get ball valves with drain ports to use for the interior shutoff in situations like this. You shut the valve, then unscrew a little cap that lets remaining water in the outside line portion drain out. Just make sure to install these valves in the right "direction" so that the drain port is on the pipe that gets shut off, not the supply side :-)
Bill
Problem is that you can't shut off this faucet, as the line to the faucet is a tee off of the main line entering the home. I have plenty of insulation (zip r sheathing and rockwool insulation in the wall. So the part of the pipe inside the wall is pretty well protected. The problem is that the pipe is exposed on the outside of the slab stem wall. That is why I'm thinking of putting veneer stone over the stem wall (see original pic) to add protection to the pipe. This is all an artifact of how they build in central texas. No basements and all piping is under the slab so you can turn off all water to the house but can't turn off any specific water source. I am the only house in the neighborhood with insulation in the garage walls and the only home that has the exterior insulation, and I still froze because of original construction I can't easily fix without jackhammering up the entire stem wall and slab.
Your entire piping system is under slab? Def not use to that kind of construction
Under slab plumbing is fairly common with homes built on slabs. It's common in commercial buildings too. The big downside is that as Eric has mentioned, your options for future rework are very limited without doing a lot of major concrete work. With even the T's under the slab, you don't even have the option to isolate the one weak-spot faucet and back feed the rest of the system from a new tap somewhere else.
The only options I can see here without ripping out part of the slab to access the pipe is more insulation and a way to put some extra heat around that pipe in an emergency.
Bill
A previous house we built in the early 1990s had polybutylene under the slab. After about 10 years I began to hear a hissing noise under the floor, which probably indicated that one of the fittings had failed. (The fittings were usually the problem.) I was able to have the house replumbed in copper as part of a nationwide settlement with the pipe makers. Because we were in Zone 3A, the plumbers were able to run new insulated lines across the attic and down the walls. How well that would hold up in 5 degree weather I don't know.
I would venture that almost every slab house in this region has most of the water lines under the slab.
We have a lot of piping (and re-piping) run through attics here in Central Texas, lots of times because the in-slab plumbing has failed over time. And a lot of those people are now looking at redoing their piping again, and their ceilings, and floors and :( . Some R-6 pipe wrap in a vented attic, isn't much of a match for 5F temperatures