# Building during winter months



## concretemasonry (Oct 10, 2006)

I just saw a block basement (1500 sf) dug, footings, block work and protected all last week, so they could start the sills and joints this morning (-13F at 7:00 AM). The nail bender will probably not work until tomorrow.

It just takes a good contractor that can PLAN VERY WELL and get as much done once the ground is opened up and protect what is built (footings until backfilled, walls until 4 days old). Poured walls usually need mor protection since the concrete must cure. With block, the block are already cured and the morat does not need as much curing early.

Usually, once the foundation/basement is capped temporary heat will allow the plumbers to do the rought in.

The house is sold, so the builder will pay the minimal extra to get an early start.


----------



## Termite (Apr 13, 2008)

When the hole is dug, the soil must be protected from freezing. If you place footings on frozen soil, they'll settle when the ground thaws. Not good. Same for slabs. Insulating blankets are a must, or a lot of straw. 

As for concrete footings, they're pretty easy to protect from cold. Most crews around here spread a good foot of straw over them after pouring. Concrete generates a lot of heat as it cures, and the straw does a good job of keeping that heat in. 

Concrete walls are a lot more tricky to protect from freezing. Insulating blankets are about the only way short of building an enclosed tent around the entire thing and heating it with heaters, which I've never seen happen on a house. 

You're correct in saying that concrete that freezes will not hydrate properly and will therefore not develop its strength. Your concern is justified. There are admixtures that will help deal with it, but nothing is good enough to justify pouring in single digit temperatures. 

Having a home built "as soon as possible" scares me. I see this all the time. They pour the walls and strip the forms the next day. Then a day or two later they backfill around the foundation, which is something that ideally doesn't happen for three or four weeks. Concrete takes 28 days to reach its design strength in most cases, and stressing it early isn't good at all. The most consciensious builders know this and won't be pushed by a schedule set by an owner or a bank. You have to give some thought to the kind of product you'll end up with on a hurried schedule.


----------



## Marvin Gardens (Sep 30, 2008)

We poured concrete on the permafrost all the time. There had to be footers for sure and lots of rebar but it worked fine.

I have seen many of the basements we poured over 30 years ago and they are doing fine.

As long as your contractor has good solid credentials and is licensed and bonded I don't see this as a problem.

It is good to question things though as you have done here. I never trust anything unless I can back it up with solid science, experience and confirmation from others.

Independent thinking is a lost art. People just blindly follow along and never question anything.

Now if we would only start to question the lying media the corrupt politicians....


----------



## concretemasonry (Oct 10, 2006)

Perma frost is much different than normal freezing and thawing with heaving.

With permafrost, the problems are getting the concrete to cure before freezing and the problems way down the road if there is enough heat loss from the building to thaw it and make it unstable.

If you move fast and protect the exposed areas when needed, it is manageable.

I remember a big dirt moving job (earth dam) that was started in January after a few mornings of -40F to -50F weather. After probing through the undistubed snow, we found only 12" of frost over the clay deposit despite being in a 6' frost depth for code because it was protected. The snow and 12" frost was stripped and they hauled (2 mile trips) clay 24x7 for 4 weeks. - A lot of steam and they ran the strips east to west with the open face toward the south and the sun (you really only get cold weather in northern Minnesota when it is clear). After about 2 months, the work was done and local contractor that had a rediculous low price had one of his most profitable jobs ever because he had the planning and schedule. - Not a house building job, but an example that winter and cold weather construction is 50% physical, 50% psychological and 50% mental.


----------



## HandyPete (Mar 23, 2008)

STRAW and more STRAW! ..and a good propane space heater. Here in Northern Québec it's done a lot but, like everyone says, DO IT RIGHT!

On my big sites we use snow cannons to protect the earth but for houses straw is the way to go...it's place in the hole as we dig and we fill the basement, and foundation for at least a month. 

-pete


----------



## Termite (Apr 13, 2008)

Or do like Marvin Gardens says and buck the system, question the proven physics of moisture-laden soil expanding when frozen, and challenge mother nature by pouring on frozen ground. In this case, indepedent thinking is a bad idea...Lost art or not. :no:


----------



## concretemasonry (Oct 10, 2006)

Pouring on permafrost is well established as long as the soil below remains frozen. If it thaws, then it is a gamble on the differential settlement.

If you pour on frozen soil that you know will thaw, that is a real bad odds chance that only a fool will gamble one.

It is not that difficult to insulate and protect and provide some heat. Straw does work, but it is in predictable, uncontrolled, difficult to remove and can screw up a drain tile installation. A good contractor will use blankets.

In permafrost you insulate to prevent it from thawing.

Dick


----------



## Termite (Apr 13, 2008)

Agreed on the permafrost. For the record, there's no permafrost in Minnesota where the OP is located.


----------

