Frozen pipes in unheated space

WhirlingD

Hi everybody…

I’m trying to find answers to a problem I’ve been having for years with water pipes running through this space that is inaccessible in my 250 year-old house.

The pipes go through a closet and then down below the floorboards and then take a right hand turn and go through the rock wall foundation into the basement.

The pipes freeze as they are under the floorboards and before they go into the basement. Under the floorboards is basically dirt probably a foot and a half down… And that part is not part of the original footprint of the house, and has no heat. It gets some mighty cool down there.

Now, on the floor of the closet, there is a little trap door about 12“ x 6“, and it’s enough to reach my hand in there and do what I need to do if the pipes freeze. But it’s so annoying.

I’m trying to keep that room relatively warm, and I leave the trap door piece off so that maybe somehow the warm air from the room may migrate down into that cavity below the floors.

so, my question has multiple components… First the science. If hot air rises, is there any chance that the warmer air from the room is even going to descend down into that hole and perhaps keep the airspace down there from preventing the pipes from freezing?

What other solutions could I be considering in a space like that? There’s no way to get down there any other way other than this little cut out hole in the floor of the closet.

What can I be thinking about to keep that space warm enough to prevent the pipes from freezing?

Any brilliant?

Big Ed_4

If the system is non accessible , you should add glycol to the system …

DCContrarian

Heat flows in all directions. If you were to insulate below the pipes and not above, the pipes would likely stay near room temperature. I imagine the floor of that room is cold too? Insulating would help with that.

There has to be some way of getting down there. How did the pipe get there in the first place? They didn't put it in 250 years ago. Could you cut a bigger hatch in the closet? The real fix is to go down there and insulate the underside of the floor properly, if necessary moving the pipe up so it's about 1-1/2" below the subfloor. Alternately, you could insulate the walls of the crawlspace and make it part of the heated part of the house. If the walls are rough stone spray foam is a good choice for that.

This article has good information on how to insulate a crawl space:

https://buildingscience.com/documents/insights/bsi-009-new-light-in-crawlspaces

EdTheHeaterMan

What is in the pipe that freezes? is it potable water or a closed heating system water pipe? Antifreeze is not the answer for potable water. Antifreeze might be the answer for a closed heating system pipe.

You said the space is not accessible. If I had a chain saw I could access that area. What you mean to say is that it would be expensive to access that area, or you don't want to rip up the floor above that pipe to access that space and properly insulate it so that space is no going to be easily frozen.

If that space was created by a human being that space can be accessed by a human being. Once you decide to access it by removing the floor above that space, you will have more options.

Larry Weingarten

Hi, An inexpensive, temporary fix could be to use some small flex duct on a fan, which lives in the warmed room. Insert the duct pretty deep into the crawlspace, so it warms the pipes, and leave the hatch completely off, so it's easy for air to flow back into the room. As long as you have power, it could do what's needed. 🤞

Yours, Larry

WhirlingD

Unfortunately, I don’t think it’s at all practical to consider ripping anything up to get down there.

There is no easy way to get there other than demolishing the whole closet, which includes a wall to the opposite foyer, which is pretty much where the pipes run. There is no other access.

I like the idea of having a fan with flexible duct, but where would one get a fan that could work easily with flexible duct?

pecmsg

WHEN a pipe bursts you’ll find out how practical it is.
closet floors are easily repairable, large sections of flooring and walls are not.

Open the closet

Rerun the pipes in pex and insulate hot and cold together.
Heat tape with self regulating tape and plug in as needed.

WhirlingD

I appreciate what you are saying, but getting the walls and floors out that would need to be removed would destroy them, so it’s probably more practical to find a solution other than that.

I don’t hate the idea of trying pex, but even getting into where those things are is challenging.

I had other pipes down there in a different area of the house freeze this past spring, and the heating guys that were down there were very unhappy to try to replace those particular ones, and I had those replaced with pex.

They didn’t even wanna have to consider replacing those heating pipes which run along side of the onesI’m referring to now, even though I said to them, I kind of wanted them to do that. We put that on the back burner, and it’s still on the back burner.

DCContrarian

How big is the closet? You could cut out the entire closet floor with minimal impact on the rest of the house.

PEX can be "fished" — pulled through hidden areas. If the spot where the pipe comes through the wall can be reached from the hatch in the closet floor with a stick, you could use that to fish a piece of PEX. Before fishing it you could insulate it and attach a heat tape.

People are often intimidated by the idea of making holes in their house. It's how plumbing is done, most plumbers consider drywall a temporary covering.

pecmsg

The OP wants an easy solution……………Sometimes that just doesn't happen!

As I said WHEN it bursts, he'll learn.

WhirlingD

of course I want an easy solution.

Someday, when you own a 250 yr old antique house, you can come back here and tell me that you’re eager to rip out parts of the house that have likely been there for centuries. Right.

Jamie Hall

There are several unknowns here. First, just how big is this closet, and how big is the area under the closet? For instance, I kind of like the idea of spray foaming the foundation walls — but if they are more than a few feet from any usable opening, that might be difficult without access. Second, how long is this run of frosty pipe? I also like @DCContrarian 's idea of fishing PEX through there. I've fished PEX through some pretty gnarly spaces, and it's just not that hard to do, given a little ingenuity. Third, though — and this goes back to "how big" — a good carpenter can take up a piece of floor and do it in such a way that when it's put back you'd have a rough time knowing, unless you knew what to look for.

Or a combination of the three above… !

WhirlingD

https://forum.heatinghelp.com/discussion/comment/1829799#Comment_1829799

think of like a closet/China cabinet. I’m going to guess about 2 feet wide maximum. The standard size door on the front of it is really about the width of the entire closet.

The area underneath the closet runs the entire length of the house, so saying probably 25 feet.

I am guessing it is a foot or two down to the ground, but it’s been a long time since I’ve had a good look down there.

There is an opening into that crawl area, a good 10 feet away, which is where the kitchen pipes go through. I think it might be the original window opening to the outside, before the kitchen section of the house was added.

The heating guys attempted to see what they could get through from that opening to the closet opening, and they said there was a beam down there… And they couldn’t get a direct line to fish a pipe through there for heat appliance that is on the other side of the wall from that closet. I’m sure they could, but they had no interest in doing it during that visit. They just said, no way.

I suspect that heat appliance was also burst during a freeze down quite a few years ago, and it has sat shut off since.

Jamie Hall

I think I need some pictures…