Workaround To Avoid Frozen/Burst Pipes In Exterior Walls?

During the recent cold snap here in the western US, many homes in my area had water supply lines in exterior walls freeze and/or burst. All the plumbers within a 1 hour radius were rapidly booked out 10-plus days, leaving many folks here without running water for upwards of 2 weeks. In some instances, the affected supply lines were installed in exterior walls too thin (or in spaces too cramped) to insulate them properly. In others they were installed toward the outside of a stud bay (i.e. the colder side) with more insulation placed over the top of them on the interior/warmer side.

Here's my question for Permie plumbers:
In a location where water lines have been run through an exterior wall in such a way as to make the job of insulating them particularly difficult or impossible, is there a way to install shutoff valves in the lines prior to where they transit the exterior wall and then drain the lines in advance of cold snaps to avoid freezing/burst pipes?

Hi Donner;
Are you referring to an outside spigot? Or pipes installed on the cold side of a stud wall?
Outside spigots are normally plumbed with a stop and waste valve, which shuts off the water pressure and allows water to drain back away from the spigot and drain indoors.
Pipes being freeze-prone are a problem.
Opening up your interior walls and moving pipes to the warm side is a large messy, costly project.
Replacing old copper pipes that can burst with pex piping that can freeze and not break is another way to deal with freezing.
Using heat tape on any exposed pipes helps tremendously.
Moving your water pipes to be exposed on the inside wall.
Adding insulation to the outside wall to stop the cold from making it through the wall.
Plenty of options, most are not fast or cheap...

I had pipes inside a north wall, going to the shower.
They would always freeze.
I opened a hole in the wall and let warm air in. Sometimes used a hair dryer.
Sometimes let it drip and used the water for the toilet.
I eventually repaired the shower wall and moved the pipes outside the wall.
I live in a house that didn't have running water when built, 1860, so some of the pipes are outside the wall already.

I have seen PEX freeze and break.

I have encountered a variety of approaches. As has been mentioned, venting in the wall can help. Heat tape can be used.   I have moved the pipe closer to the interior of the house and added extra insulation to the exterior side.

To expand on the last item. I had a 6 ft piece of wall that was freezing. I opened the wall. Moved the pipe to the inside edge of the studs. I added  2x2 to the studs (making them an effective 2x6) , and I put insulation between the pipe and the outside wall.  Yes, I lost 2” of floor space.

To answer your idea, shutoffs would help, but I feel you would need a way to drain the water out of the pipe.

Donner MacRae wrote:Here's my question for Permie plumbers:
In a location where water lines have been run through an exterior wall in such a way as to make the job of insulating them particularly difficult or impossible, is there a way to install shutoff valves in the lines prior to where they transit the exterior wall and then drain the lines in advance of cold snaps to avoid freezing/burst pipes?

Well, there's a lot of complexity in that. No doubt shutoff valves could be installed to keep some "legs" of the water system active and isolate others. As John F says, there has to be a way to drain/push all water out of the isolated legs that are likely to freeze. Unless you have drain points for the vulnerable legs, the only practical choice is to purge all legs of water and then engage the shutoff valves.

Up here, we do this all the time. We purge seasonal water lines, sprinkler lines, and plumbing in seasonal cabins with compressed air.

Heck, I even had a Plan C in the last dangerous deepfreeze to do this for my entire house if I couldn't generate the heat needed to prevent freezing. I don't have any shutoffs -- it's all or nothing. But I have a compressor (and a little genny to power it) and a home-made gizmo to connect it to the outside taps on my house. Then I could open all indoor taps on each "leg" and blow out the water, moving to the next leg, and cycling through that a few times because residual water drains to the low point which is where damage would occur. And put RV antifreeze in all drain traps just to be safe.

Edit: It just occurred to me that I didn't have a plan for washing machine and dishwasher. The washing machine is in the well room, which would have a bit of heat hell or high water, as long as I had access to the property. Not sure how to purge/protect the dishwasher offhand. Hm.

craig howard said:

"I have seen PEX freeze and break."

Was the break in the PEX line itself, or was it an issue associated with one of the fittings breaking/leaking? If it was in the line, what were the conditions under which the break occured?

Douglas Alpenstock said:

"No doubt shutoff valves could be installed to keep some "legs" of the water system active and isolate others."

That's the notion I was getting at in my original post. Considering the length of time one can be without running water - either while waiting out a protracted cold spell with the water shut off at the main, or waiting for a plumber to arrive after the lines have burst - the idea of isolating the leg(s) that are in the greatest danger of freezing makes a good deal of sense to me.

OTOH, the more I think about the idea of ventilating wall cavities containing vulnerable lines to the inside of the home....I think that could be a good solution in some cases, too. If the vent could be hidden behind an appliance like a dishwasher (say) or inside a vanity cabinet, so much the better.

Great post, Douglas. =]  It's given me a lot to think about.

With regard to heat tapes, I'm not sure there are any listed for use behind sheetrock... Anybody have a brand/model number?

There's also such a thing as "frost free" hose bibs, which are exterior water faucets whose opening and closing mechanism, while controlled by a knob at the outside faucet like normal, opens and closes a valve that is inside the conditioned envelope of the house. These typically also have a vent to drain water left in the "cold" portion of the pipe once the valve has been closed.

I don't know if installing these is easier or harder, cheaper or more expensive, than installing inline shutoff valves just to the warm side of each external fixture, but it's worth looking into.

Oh one other cheap/easy action you can take to mitigate the problem is to put Styrofoam covers over your exterior fixtures during the cold seasons. Not 100% effective but in my experience way better than nothing, and for $3 or whatever why not.

We're pretty temperate here but will occasionally have several days of below freezing weather. Our water supply has two legs, one to the kitchen and one to the bathroom. If we're going to be below freezing for more than 36 hours or so I shut off the leg to bathroom and evacuate the line with an air compressor. You can get a valve with 1/8" drainage port on it (See picture below). We have a compost toilet so cutting off water to the bathroom isn't as big a deal.

If we lived in colder climate I would come up with a better solution but it works for our 3-7 freezing days a year. Our cabin is on pier and beam foundation so its plumbing has an inherent weakness to sub freezing weather. If we had a ground contact foundation and plumbing in the exterior walls I would add exterior insulation and/or exterior enclosed storage areas attached to the house along the water line route.      

My current house has the frost-free hose bibs. They work fine and require no actions on my part.

My old house had standard taps on the outside, but inside there was an isolation tap with a little drain port that let me drain the short line segment that was vulnerable to freezing. This also worked well enough, but I had to be on top of it every fall.

Douglas Alpenstock wrote:
Heck, I even had a Plan C in the last dangerous deepfreeze to do this for my entire house if I couldn't generate the heat needed to prevent freezing. I don't have any shutoffs -- it's all or nothing. But I have a compressor (and a little genny to power it) and a home-made gizmo to connect it to the outside taps on my house. Then I could open all indoor taps on each "leg" and blow out the water, moving to the next leg, and cycling through that a few times because residual water drains to the low point which is where damage would occur. And put RV antifreeze in all drain traps just to be safe.

What pressure to you set your compressor to? I've only evacuated my water lines a few times. I dialed my air compressor pressure down to around 50 PSI to be safe since that's about what my water pressure is.

Donner MacRae wrote:is there a way to install shutoff valves in the lines prior to where they transit the exterior wall and then drain the lines in advance of cold snaps to avoid freezing/burst pipes?

If you know that a cold snap is coming, and you are at the property, it would be easier to just let the line drip to avoid freezing.

We had a friend with a similar problem.

They cut a hole in the wall where the pipes were and installed a decorative ven to let warm air in:



source

Aaron Yarbrough wrote:What pressure to you set your compressor to? I've only evacuated my water lines a few times. I dialed my air compressor pressure down to around 50 PSI to be safe since that's about what my water pressure is.

Agreed, it shouldn't be more than the normal water pressure. I do about 40 psi (less than my water pressure) because I will pulse it the second time around and that increases pressure momentarily. The volume of air is the most important factor.

Frost free tap

Donner, like others have mentioned there are fixes to correct the problem, and then there are remedies to get you through now and then.

Probably the least expensive remedy is to run the water, either open a tap to a trickle, or adjust your toilet fill valve "wrong" so the toilet runs. Bonus points if you can reuse the water by capturing or redirecting? (but I wouldn't sweat it.)
The next remedy is to adjust your heat higher ahead of and during the cold snap, or possibly a space heater in the affected room even blowing at the wall in question, and open vanity/kitchen cabinet under the sink... This remedy is also insurance against a power outage that might shut down or limit your heating capacity, you will have longer before the house gets too cold.
Adding a vent in the wall is a bit like the open cabinet doors approach, but again you need to get some heat in there and extra heat helps.

Renovating the plumbing is a fair bit of work, however, if you do it in advance it will cost less than repairing a burst pipe and you get no water damage! You can also probably even save more by not having an emergency call, and only be without water for an hour.

Where I work we have two bathrooms that have frozen up BUT NOT BURST in the past. We had a recent cold snap we used the high thermostat trick and it worked for us, when the trickling tap had been hit or miss before.

Not much of a work around but a method we use. I'm in Texas, might not be possible in colder climates. When we are expecting severe cold, we fill containers with water for drinking, fill tall buckets for toilet flushing, then turn off water and empty all valves to clear out water in the pipes. Pipes can't freeze if there is just air in them.

No this isn't convenient but we were without power fo 8 days with temps in the 20s and lower. Handwashing was clumsy... we had a container with a ladel and you would have to have someone ladle water over your hands to wet them and then to rinse them

We survived with no broken pipes. Again not a solution for a northern climate where it is cold for months.

rain water wrote: Handwashing was clumsy... we had a container with a ladel and you would have to have someone ladle water over your hands to wet them and then to rinse them.

If this is something that's likely to happen periodically, I have some large camping water jugs which have a spigot on them. Yes, you would want to be careful not to use too much water for hand washing, but at least it can be done without 2 people.

The lack of "running" water was bugging a friend several years ago when the pipes froze before getting to her house (so at least she didn't have water damage). I loaned her the jug and it worked really well for her for the few days before things warmed up enough that the water started flowing again.

rain said:

"When we are expecting severe cold, we fill containers with water for drinking, fill tall buckets for toilet flushing, then turn off water and empty all valves to clear out water in the pipes. Pipes can't freeze if there is just air in them."

How did you clear out the water in your pipes?

We try to keep at least 14 gallons of drinking water in reserve for each person in the house in case of extended power outages, etc. For us this seems to be about 2 weeks' worth (*IF* none is being used for coffee-making). I've also been in situations where I had to gather snow for washing and utility water needs. I'd refill the toilet tanks from 5 gallon and 15 liter buckets I'd used to gather snow the previous day and which had been set in an unused room to melt overnight. (Tip: Even the wettest snow will reduce to less than 50% of it's initial volume once melted.)

The snow that was used for dishwashing, hand-washing, etc. was first boiled to eliminate the risk of Listeria and other pathogens.

I have a trailer house that has constant problems with the water lines in the floor and outside walls freezing.  My plan is to move all the fresh water lines into the heated envelope of the house this summer.

The way the water lines are now it is very difficult to drain them(even with an air compressor) so my plan is to simplify the plumbing as much as possible by getting rid of lines that we don't use(dish washer and fridge ice maker).  I will also be sure to put shut off valves for every appliance and spigot and put drain ports to make draining it easier.

The pipes run inside may look tacky but prefer tacky and running water compared to no running water, burst pipes and water damage.

J Hillman wrote:The way the water lines are now it is very difficult to drain them(even with an air compressor) so my plan is to simplify the plumbing as much as possible by getting rid of lines that we don't use(dish washer and fridge ice maker).  I will also be sure to put shut off valves for every appliance and spigot and put drain ports to make draining it easier.

This!!! One of the first things I look at in houses, is whether the plumbing "makes sense". Many modern houses have a en-suite bath for every bedroom, and the plumbing must be crazy long. The first house I bought had the upstairs bathroom directly above a main level 2 piece bath which shared a wall with the kitchen. The only plumbing on an outside wall, was the kitchen sink, and if I knew then what I know now, I would have made sure the shut-offs for it were in the basement with a drain port - live and learn.

So what have I learned???
1. Slope is my friend - there's a place for level, but not in pipes you want to have easy to drain!
2. Design for efficiency - keep all the water clustered as best possible. Consider two separate systems if that's the best approach for reasons.
3. Document - take pictures, write notes, and don't assume that 20 years later you will remember what you did.
4. Don't accept the modern attitude that every human in North America needs his/her own private bathroom. Teach people to be respectful of shared spaces and to clean up after themselves.
5. Take a page out of the Japanese playbook and have the bath/shower separate from the toilet room.

And for J Hillman, make the pipes look like they're part of the decor - paint them likes snakes maybe? Stick some out from the wall to be towel holders? Think outside the box, and if that's a struggle, post pictures here and ask for ideas - just be warned - a lady who did that thinking she wouldn't get anything useful, had to sit down and choose between 5-6 ideas she liked that us creative permies had thought up or done ourselves in our pasts.

Hi Jay,

Loved your list. Many years ago I flipped houses before flipping was a term.  I would buy condemned houses and have fun.  By any means, I developed a number of practices.  One was to make relevant plumbing and electrical diagrams on the inside of related pieces of molding.  Sometimes I would spell out the logic of what I was doing.

For example, my wife and I debated installing an en-suite bath in one house;  there was space, but the potential sale price of the house wouldn’t support it. So, we installed plumbing and wiring through the walls. We attached a couple of notes in the basement, written on joists,  explaining why the plumbing and electrical to and from nowhere was there.

You don't need to drain the line if you put in a shutoff, just open the tap. The lines might freeze but pipes won't burst.  
As others have said, put the insulation on the cold side. Let it get some heat.

FarmerMike OnTysonRd wrote:You don't need to drain the line if you put in a shutoff, just open the tap. The lines might freeze but pipes won't burst.  

I respectfully disagree. Pipes can and do burst due to the 9-10% expansion that occurs when water fully freezes. The type of pipe and the way it's laid out are factors in this.

That said, I have found releasing the pressure off garden hoses makes them less likely to burst. Even then I try to drain some water out, and open both ends; good hoses are not cheap.

FarmerMike OnTysonRd wrote:You don't need to drain the line if you put in a shutoff, just open the tap. The lines might freeze but pipes won't burst.  
As others have said, put the insulation on the cold side. Let it get some heat.

That is very risky advice.  Depending on the material of the pipe , how much water is in it and how fast it freezes it may not burst the pipe.  But there is also a very high chance that it will and will do large amounts of damage.

There are many ways to keep the pipes from freezing that rely on electricity.  But you should also have a back up plan because often cold weather comes with power outages.  Last year a neighbor had to move out of his brand new house(built that summer) because of a 4 or 5 day power outage and sub zero weather.  

With no power he couldn't run his furnace so had no heat.  Without heat his pipes froze and some broke.  So he moved out until he could get everything fixed.