prevent freezing basement

[ckr74]

I must question this, although what may be meant is that leakage may not occur until thawing begins, as the ice will seal the pipe.

Upon freezing, water expands by about 9% in volume (https://en.wikipedia.org/wiki/Properties_of_water#Density_of_water_and_ice). If the volume is constrained by an unyielding container, pressure goes up enormously. Copper usually cannot contain this pressure and can rupture. However, if the point of freezing is in an area with elbows or tees, the pressure of ice formation can simply pop the fittings open. I had this happen to me when I lost heat in a cottage for a day or so in bitter weather. When I crawled under, I discovered half a dozen popped open joints, one with a long tongue of ice protruding from it, but no actual pipe ruptures. The repair was easier, as no sections of pipe had to be replaced.

I questioned it too, but let it slide. Maybe right, I don't know. Begreen will know.

 

[prezes13]

Water reaches its highest density at about 39 deg f. That's why when you start thawing it and you do it too quick combined with the pipe frozen solid (water has no where to go)you will burst the pipe. When you are trying to thaw it you either open your faucet and start from that end or you start from the source(slowly) so that way water has a space to expend.

 

[Ashful]

Hmm, ok, shoot - even if it's a medium stove, and I insulate a bit?
I can always just throw a new thermostat in the basement and have the gas furnace heat that part, so I think I'm pretty set either way, but good to here more perspectives, thanks!

I'm not sure I understand the problem. One reply after the next stating your basement will hold 50F with a stove going upstairs, and your furnace not running, and you seem to indicate that is a problem. Yet, you stated in your OP that the only goal was to keep the pipes from freezing, not have a heated basement. Pipes will not freeze at 50F.

Simply ensure you have no massive cold air infiltration problem, and you should be good to go. With 75F floors above and 50F basement walls and floor (i.e. 4 ft. earth temperature) on all remaining sides, there is no opportunity to see temperatures < 32F.


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[xman23]

I believe I understand the basement is in the ground. The more the better. If so it's hard to freeze it.

 

[gloves12]

I'm not sure I understand the problem. One reply after the next stating your basement will hold 50F with a stove going upstairs, and your furnace not running, and you seem to indicate that is a problem. Yet, you stated in your OP that the only goal was to keep the pipes from freezing, not have a heated basement. Pipes will not freeze at 50F.

Simply ensure you have no massive cold air infiltration problem, and you should be good to go. With 75F floors above and 50F basement walls and floor (i.e. 4 ft. earth temperature) on all remaining sides, there is no opportunity to see temperatures < 32F.


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Sorry Ashful, I misunderstood someone's reply, I'm not the brightest bulb :D

 

[Ashful]

Sorry Ashful, I misunderstood someone's reply, I'm not the brightest bulb :D

No prob. Just wanted to be sure everyone was on the same page, or that the goal hadn't changed from preventing freezing to creating a heated / finished basement.

I can say, we see a few folks like you each year. Most of them become addicted to this wood heat thing, inside their first year. From the sounds of it, you may be able to heat your house 100% with wood, cutting off the oil man almost completely (excepting winter vacations, etc.). In my case, I run oil all year 'round (even a gallon per day all summer, for DHW), but cut my heating bill by more than half in the winter with the addition of my wood stoves.

 

[DickRussell]

Water reaches its highest density at about 39 deg f. That's why when you start thawing it and you do it too quick combined with the pipe frozen solid (water has no where to go)you will burst the pipe. When you are trying to thaw it you either open your faucet and start from that end or you start from the source(slowly) so that way water has a space to expend.

True, density is highest at 39 F. Density is mass per unit volume. Without flow, mass in the pipe isn't changing, but its volume is. A drop in density means an increase in specific volume, the volume occupied by a unit of mass. Density and specific volume are the reciprocals of each other. As you cool below 39 F, density decreases slowly down to the freezing point, then drops sharply. This means that the volume occupied by the water in the pipe is increasing at first slowly then dramatically upon freezing. Upon thawing, the volume shrinks, because the density is increasing. Expansion of liquid water is not a problem, as the expansion is slight and the water can back out of the pipe network into the air bladder tank (well system) or water main. If the piping is PEX, that will handle expansion. But too much ice forming in a run of pipe between fittings may not be able to expand lengthwise, and fittings pop or the pipe ruptures longitudinally.

 

[Ashful]

True, density is highest at 39 F. Density is mass per unit volume. Without flow, mass in the pipe isn't changing, but its volume is. A drop in density means an increase in specific volume, the volume occupied by a unit of mass. Density and specific volume are the reciprocals of each other. As you cool below 39 F, density decreases slowly down to the freezing point, then drops sharply. This means that the volume occupied by the water in the pipe is increasing at first slowly then dramatically upon freezing. Upon thawing, the volume shrinks, because the density is increasing. Expansion of liquid water is not a problem, as the expansion is slight and the water can back out of the pipe network into the air bladder tank (well system) or water main. If the piping is PEX, that will handle expansion. But too much ice forming in a run of pipe between fittings may not be able to expand lengthwise, and fittings pop or the pipe ruptures longitudinally.

Exactly. prezes13 is clearly not a student of physics.

 

[prezes13]

You are right that's why I ended up at where I am. Jokes aside increased volume has to go somewhere it's going to push its weakest point either push on the joint or split the pipe. It happened when it's thawing because it has nowhere to go because the rest is frozen. I am not a scientist and I never claimed I was. However I have experience in the field and I am the one who you call in the middle of the night complaining that you got no water. Trust me I know what I am talking about.

 

[tarzan]

Thawing frozen pipes always bring back bad memories.

I'm no student of physics either but always assumed the pipes burst while frozen but only showed up once thawed because the frozen water had difficulty with spewing.

 

[prezes13]

As I said do it slow. Start from the side that is not frozen so water has space to expand and you will be fine. Better yet insulate your pipes. Close your basement window. If the pipe burst when it was frozen you would see the crack in pipe before it started leaking. Anyways I rest my case. I have seen enough and quite frankly I don't really care if people agree with me or not. I am just trying to give a good advice.

 

[tarzan]

As I said do it slow. Start from the side that is not frozen so water has space to expand and you will be fine. Better yet insulate your pipes. Close your basement window. If the pipe burst when it was frozen you would see the crack in pipe before it started leaking. Anyways I rest my case. I have seen enough and quite frankly I don't really care if people agree with me or not. I am just trying to give a good advice.

Relax! I was not taking anyone's side, just stating what I have thought based on nothing but my own assumptions.

My pipes are insulated. I two thaw pipes for other folks if need be although it's not my occupation. I've yet to have one burst on me so maybe that's why I'm no expert on the subject.

 

[brenndatomu]

I have experience in the field and I am the one who you call in the middle of the night complaining that you got no water.

Sounds like we have the same job...

mass in the pipe isn't changing, but its volume is.

Start from the side that is not frozen so water has space to expand and you will be fine

Everybody is correct here...to an extent. Water expands both when it is heated...and cooled, pretty wild if you think about it.
Anyways, in my experience pipes frozen solid are almost always broken...but pipes that are partially frozen or barely frozen, are the ones that pop when you don't thaw them in the "correct direction"

To the OP, know that if you only heat the upstairs, the floor will be really cold...that may not matter to you, but personally I HATE cold floors. Just an FYI...

 

[Ashful]

To the OP, know that if you only heat the upstairs, the floor will be really cold...that may not matter to you, but personally I HATE cold floors. Just an FYI...

We have this issue. Warm house, cold wood floors. Not very comfortable, but we're paying the price for authenticity, I guess. Rugs help.



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[begreen]

We had a ventilated crawlspace up until the new foundation went in. Floors got quite cold in freezing winter weather. Now it is insulated and never gets below 60º. That has made a very nice difference in floor temperature and it also has stopped air leakage thru vents and cracks from the crawlspace on windy days.

If you heat with wood and are concerned about pipes freezing put a remote thermometer down there, preferably one with a settable alarm. And don't be afraid to cycle the central heating system a few times a day during a deep freeze.

 

[prezes13]

You could put a heated tape around it too. Tarzan I was not offended at all. I am pretty patient and it's hard to get me going. Two winters ago when it was a historic cold at least here in ct we had few water services frozen in the ground. That almost never happens.

 

[Handsonautotech]

Guys I am really confused by this thread. I live at 7600 feet in CO. My basement is not insulated. My wood stove is up stairs. Are you all saying my pipes will be fine as is? I was assuming I was going to have to insulate the basement and install electric heat down there. The first few replies in this thread seem to suggest that i will be fine with out this extra work. can you all please clarify?

 

[firefighterjake]

Guys I am really confused by this thread. I live at 7600 feet in CO. My basement is not insulated. My wood stove is up stairs. Are you all saying my pipes will be fine as is? I was assuming I was going to have to insulate the basement and install electric heat down there. The first few replies in this thread seem to suggest that i will be fine with out this extra work. can you all please clarify?

Not sure if it makes a difference or not with the difference in altitude . . . but here in Maine you get enough heat from below the frost line (most basements are installed below the frost line) that it will keep the basement/cellar temp's above freezing. In my own case, my domestic hot water lines also run through the basement so I suspect the residual heat coming off those pipes also helps . . . and when it's wicked cold for an extended time (sub zero) I will fire up my oil boiler and run it for a few minutes to bring a little more heat (and move the water through the pipes.)

My basement -- really more of an over-sized crawl space (frost walls with footings and a ledge/stone floor) as it is only about 4 1/2 feet high -- is not insulated other than insulation in the 1st floor joists right above the sills.

 

[Ashful]

Guys I am really confused by this thread. I live at 7600 feet in CO. My basement is not insulated. My wood stove is up stairs. Are you all saying my pipes will be fine as is? I was assuming I was going to have to insulate the basement and install electric heat down there. The first few replies in this thread seem to suggest that i will be fine with out this extra work. can you all please clarify?

This depends on many factors, the two primary being:

1. What fraction of your basement is above/below ground or frost line.
2. How well sealed your sills are.

I don't live in CO, but I can't imagine any full basement in the lower 48 states with less than 2 feet above grade and well-insulated sills freezing. If you have a standard submerged basement without walk-out, I'd spray foam the sills and rim joists to 4" or better, and just monitor the temps for your first year. If you see it heading toward the freezing point, you can always fire up your traditional heat, until you find a solution. I'm betting you won't see it dip below 50F, though.

 

[sportbikerider78]

Water expands both when it is heated...and cooled, pretty wild if you think about it.
Anyways, in my experience pipes frozen solid are almost always broken...but pipes that are partially frozen or barely frozen, are the ones that pop when you don't thaw them in the "correct direction"

That didn't sound right (and we didn't cover that in heat transfer or fluid dynamics in engineering school),,,so I looked it up. Water expands on heating only.

If it expanded when cooled or heated this graph would look like an upside down "U" for specific volume. This is for water only, not steam or any other phase change.

 

[Handsonautotech]

My basement is a walk out.

 

[MAD777]

Actually, water does expand just before it freezes. That graph starts above freezing. As water drops to near 33 degrees, it reverses the contraction (yes, a U-shape) and expands at the last minute before freezing.

Think about it. Does ice form on the bottom of a lake? No, that expansion near freezing is what lifts the water to the top as it is freezing. Life on earth wouldn't be the same otherwise.

However, in the confined and pressurized space of a water supply line, maybe this isn't applicable, I don't know.

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[Ashful]

My basement is a walk out.

Then the chances of it freezing are a little higher. A lot depends on fraction of exposed wall vs wall buried below frost line.


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[sportbikerider78]

Actually, water does expand just before it freezes. That graph starts above freezing. As water drops to near 33 degrees, it reverses the contraction (yes, a U-shape) and expands at the last minute before freezing.

Think about it. Does ice form on the bottom of a lake? No, that expansion near freezing is what lifts the water to the top as it is freezing. Life on earth wouldn't be the same otherwise.

However, in the confined and pressurized space of a water supply line, maybe this isn't applicable, I don't know.

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Ice isn't on that graph because its not water. Not trying to sound like a smart a$$. LOL
Take a look at this chart and let me know what you think. http://www.engineeringtoolbox.com/water-thermal-properties-d_162.html

Ice doesn't form on the bottom of the lake because as it freezes it expands and becomes less dense..and therefore floats to the top. That and because it is warmest at the bottom of the lake.

 

[brenndatomu]

Water expands on heating only.

It expands when it gets cold too...I just never specified how cold...you may say it is ice at that point, but I say it is frozen water