Construction over the winter
Good day folks, wondering if anyone with experience constructing over the winter has advice they’d like to share.
We’re building a house up in Canada in climate zone 6. When I look at my construction schedule the house won’t be done until the spring; and heat won’t be available until then as well.
Before the frost sinks in, the plan is to have the foundation in, house framed and wrapped, windows, doors and roof installed…basically weatherized.
Now, I’ve asked for advice locally and responses have ranged from “don’t do it, the foundation will crack and windows will break” to “it’s done all the time…no worries”.
Builders in the region seem to build year round so I’m guessing I’m probably fine. But if you have any tips or advice, I’d certainly appreciate any feedback.
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In related questions I see many are advising to throw down some straw/hay to protect the foundation. To clarify, people are doing this to protect the footings right? So if the basement walls are sprayed with 2" of foam, I am assuming it would still be desired to lay down stray/hay around the perimeter of the inside wall.
My guess if you want the house under roof by winter, your foundation would have had enough time to cure, not a concrete guy maybe there is some issue I don't know about.
For the house there are absolutely no issues with working through the winter, windows will definitely not blow up. One annoying part was trying to wrap up siding/trim towards the end of November and having snow melt drip on your head. Cold is fine, snow is fine, but water dripping on you in -5C is awful.
Once you get the house outside is wrapped up, it is great to work inside, much more pleasant than running wiring and plumbing through rough framed house. If you can have the main panel in earlier, a couple of larger space heaters really help to take the edge of in Jan/Feb.
Try to get all your roof and wall penetrations done beforehand. For example you can have a small stub of 3" pipe for your vent through the roof and connect the stack afterwards to it.
Wintertime spray foam has a lower R value per inch, probably best to get any spray-foaming done before it gets too cold.
Eric,
Yes, it's just the threat of frost-heave that leads to the suggestion that you insulate your footings. Given that you will have the house to lock-up, perimeter drains installed and the foundation backfilled, it isn't necessary to add straw.
We've done several that we did foundation and slab and backfilled in fall and framed in spring. We use 100% gravel to backfill with tarpaper on top followed by straw
Frost heave acts in the the direction of heat flow. So, if the basement is colder than the soil, the walls get pushed in. If you keep the basement warmer than the soil, no problem. Include space heaters in your plan and it won't be an issue. You don't need much space heat - just keep the basement above freezing. If you're using fuel-fired space heaters, condensation and carbon monoxide can be issues, so plan accordingly. Otherwise, once you've got the place air sealed, life is not so bad.
There's also frost adhesion which can also damage foundations. If the surface soils freeze and adhere to the foundations, then the subsurface soils freeze and heave later, they lift the whole foundation away from the footings. This doesn't happen if you've got any sort of exterior insulation, drainage board, or any other sort of slip sheet between the foundation walls and the soils. Even a very smooth foundation is unlikely to have this problem.
My house was built in the winter. (Zone 6)
Definitely make sure insulated blankets cover your footings. I would avoid pouring the basement slab until spring. Otherwise, make sure you cover it with insulation or a really thick layer of straw. Or get the walls up and turn on the heat.
I just saw a slab last weekend that was poured in winter and never protected. The surface is chipping away and it looks terrible. Such a mess...
Also, if you live in snow country like me, get the roof on as fast as possible! (See attached)
Mostly just make sure your foundation is done and cured before temperatures start going below freezing. That’s the big thing. Once the concrete has cured, freezing doesn’t matter. The other big thing to get done is ANY digging in the ground. It is MUCH harder to dig after the ground freezes. That means run all your underground utilities before freezing temps set in.
Personally, I’d like to have enough framing up to provide a bit of shelter for the crews so they aren’t working full days outdoors in nasty winter weather. It’s more dangerous to do things like roofing in winter weather, but it gets done all the time. Once you’re done framing and you have sheathing up so you have a shell, portable heaters can take care of interior finish work.
Bill
Zephyr / Bill,
You wrote, "Once the concrete has cured, freezing doesn’t matter." That's not quite true. You still have to worry about the soil under the footings. You certainly don't want the soil to freeze.
In Comment #1, Eric wrote, "I see many are advising to throw down some straw/hay to protect the foundation. To clarify, people are doing this to protect the footings right?" No. The hay is there to protect the soil under the footings. The whole point is to ensure that the soil stays frost-free.
I was assuming the footings were down to the frost line and backfilled where they’d be protected. I probably should have been more clear.
Basically my point is to make sure any work in the ground is done, completed, before freezing temps set in. Most of the significant issues with wintertime construction work involve work in the ground.
Bill
Thanks for all the replies folks. Based on everyone's feedback I'll either run some heaters in the basement or throw down some hay/straw depending on how the schedule progresses.