Do you have to put heat in a bloch basem
Shaddy
| Posted in Construction Techniques on
I am wondering if a new basement has to have heat in it during a southern Ontario winter during construction. The basement walls are 12″ block with conventional framing on the walkout side. What are the dangers if I do not put heat in it? I’m close to being closed in but there is 10 cm of snow on the groud today and it looks like the winter weather is coming sooner then usual here in the north..How much of a pickle am I in?
Replies
Ahoy Shaddy,
Been there done that. Under no circumstances should the foundation be unheated over winter. I was in this same situation as you, when winter arrived way to early, and a hard freeze followed a wet mild spell. The outflowof the weepers froze up and the frost penetrated and froze up the water in the back filled excavation. The results were not pretty. three of the walls buckled from the frost heaving. with a sub floor on it. The blocks were bowed in about 6" over 36'. Come spring it all had to be dug out, and the sub floor jacked up and the 10" block removed, and new walls laid up, parged and waterproofed again. That was my experience with unheated, foundation walls an Southern Ontario, (Meaford area.) The BI at the time was close to condemming the project, but I perservered and salvaged it. The house lives today. Today there's way more construction heating options available than there were in 1976 when I built this.
"The only new thing under the sun is history that we haven't read yet."
Harry S Truman
I'm in south Texas, and we think it gets cold here, but you'd probably think it's balmy. And we don't have basements. So I may not have a clue what I'm talking about. But ...
If I read your post correctly, it sounds like your basement walls buckled becasuse of frozen water in the excavation area. How would that have been prevented by heating the basement? Sounds like if you had managed the excess water properly, nothing severe would have occured.
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
He did manage his excess water properly - had drain tile around it. If it gets sort of warm (about freezing) and rains a lot or melts a lot, the drain pipes fill up with water but maybe can't all drain out 'cuz of ice at the daylight outlet or something like that. Then let's say it gets real cold - like -20 for a couple of weeks. The foundation freezes. The drain pipe freezes. The water in it freezes. Then let's say it gets real warm - something above freezing but just for a couple of days. Maybe some rain. Maybe some surface melting. Water in the excavation area fills in around the pipe but can't get through it 'cuz it's still froze full of water from the first round. Then let's say it gets real cold again. Everything freezes. Wall buckles. Bad news. Always heat the basement, no matter what. btw - there's a reason only 30 million people live in this huge country. it's a lot of work being cold all the time :)
So you're saying that heating the basement will allow enough heat to escape through the foundation wall to keep the groundwater from freezing?
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
"So you're saying that heating the basement will allow enough heat to escape through the foundation wall to keep the groundwater from freezing?"Right. The only reason the groundwater would freeze that far down in the first place (in that part of Ontario, anyway) is because of the big concrete hole in it. In theory, a fully insulated basement which included insulation under the floor and around all the walls wouldn't need to be heated during construction because the ground would keep itself above freezing below the frost line, but that's a lot of faith in the foam. I've never tried it.
Quote: "In theory, a fully insulated basement which included insulation under the floor and around all the walls wouldn't need to be heated during construction because the ground would keep itself above freezing below the frost line, but that's a lot of faith in the foam. I've never tried it."
That will work at least in 8,000 dd F locale like southern NB. In 1983, I put a heated 8' concrete basement under the 200 year old house I bought in 198O. The house sat through one winter with no problems using just a 5 KW commercial electric heater in the unisulated basement.
The next year I decided to re-attach rather than tear down the 16'x24' 1+1/2 storey shed and place it on a 7' unheated foundation. It was to be unheated for dry storage of firewood, etc out side the heated area of the home. Placed 1+1/2" of extruded foam under the slab/over the inner footing extension and the same along the outer wall from grade down to footings. I still drive by it occasionally and its still straight as can be. I know the owners as I bought it from them originally and they claim still no problems.
Sh...t!! just lost a full post due to the crazy system used here for word processing!! Again:
Install fiberglass in the main floor joists. Cover it with fairly airtight poly. Use electric heat set at about 40-45 degrees. The batts will help keep heat costs down. Did this in may first house in NB in 1983. Use the batts later in the upper walls.
Since you're in a colder locale and the block walls are not as strong as concrete, I would suggest moving snow back from the block walls and installing sheets of 2"x2'x8' extruded polystyrene horizontally (SM, Protec, Codebord) all the way around and then cover with snow/dirt/rocks for ballast weight. This will stop/reduce frost penetration downward along the wall /dirt where it may push blocks inward. Hopefully there will be a deep snow cover this winter as this insulates and lessens frost depth also.
Good Luck!!!!
Edited 11/29/2005 7:58 am ET by experienced
I used to lose a lot of posts when I had a poor operating system and was on dial up. I got into a habit of copying my post to the clipboard before I'd hit the "post" button because I lost so many. Then, when something would fizzle out, I could just "paste" the material back into the window. When my operating system got real, real bad. I used to cut and paste and save the long posts to a document file. Then if my computer froze while trying to post, I could retrieve it later after a reboot.
Thanks goodness for Windows XP.
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Thought you were in northern Ont. Well I guess I always think of Ont being colder than here in Halifax!! Maybe you don't need the exterior foam. But do the other in case you get a cold open winter with deep frost penetration.
Been there, done that, doing that in Ottawa ... this is my second winter heating just the basement. You need heat but not as much as you might think. I'm heating about 1000 sq ft, very little in the way of penetrations from the basement to the main floor. All I have is the main hot and cold air plenumns hooked up to the furnace and set the thermostat to about 8 º C. All that's between basement and fresh air is the old 3/4 diagonal plank, roofing felt, 5/8 t&g plywood. Pulled a sheet of ENERMAX over stair opening, but you definetly have to heat it to keep the weepers open and the soil from freezing to the foundation ..
That how they do it around here. They just seal off the stairwell opening and fire up the furnace. I've seen them do that and melt piles of snow and ice that were six feet tall.
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