Concrete slab question

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Oct 21, 2006 | 08:03 AM

CowboyBilly9Mile

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From: Eastern WA

Concrete slab question

I need to pour a concrete slab (monolithic foundation) for a pump house I'm going to build and with the weather here getting down to 22-25 degrees at night I'm wondering how to protect it from freezing. I don't have power turned on at the property so heaters are not an option. Should I just lay a tarp over it and spread out a few bales of straw? And for how many days do I have to worry about freezing damage? The outer perimeter of the foundation will be 8" x 8" with a 2 - 3" floor. Thanks in advance.

**I have to wonder if the deer and elk will munch on that straw and leave little footie prints in that new concrete............

Oct 21, 2006 | 08:09 AM

lenny1carl

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From: in the adirondack mts

tarping will help as crete generates heat as it cures. get past the 1st 24 hrs you should be gold. they sell a cold mix here (no i don't recall the name) that cures faster but still need tarping

Oct 21, 2006 | 08:12 AM

tjc transport

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From: Marlboro Mental Hospital.

are you going to mix it yourself, or have it delivered??
pouring concrete in the winter requires calcium chloride being added to the mix so it will not freeze as it sets up. it will still need to be covered to retain the heat the curing process generates.
if you are pouring over a sand bed, you should be able to uncover it after 4-5 days. if your are pouring over a plastic sub strata or something that will hold in the moisture, it will take allot longer to setup.

Oct 21, 2006 | 08:30 AM

lariat97

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From: North west La

Covering it with hay will help. Like said above the winter mix should work fine. I've poured slabs in freezing weather before & they did ok.

Oct 21, 2006 | 03:18 PM

Mil1ion

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span some 2x4's arcoss the slab to the top of 5gal pails or the like and lay the tarp across then secure it against any wind by laying 2 x 6's along the edge of the tarp.

seal off all the edges and place an in-car heater or small fan style electrical heater to keep the air moving around during the time the outdoor temp is lower than 34*F.

The pour:
Use a 2% calcium chloride mix (to speed up the curing effect) and make sure there is a a 4-6% air-entraining agent in it as well.

72 hours is long enough to remove the moisture from the concrete.

So as long as the ambient temp outside is higher than 34*F you should be fine without the heater.

I assume you have electrical power at the site