Frozen Slab

[exploreparadise2]

I'll be inspecting a warehouse with a concrete slab floor and foundation next week. Half of the warehouse, or about 14,000 s.f., is refrigerated and kept at 13 degrees F (I better pack some mittens). The buyer says that the owner told him that he is keeping the refrigerated section, which is vacant, cold because the floor will buckle if it warms. The buyer will not be using the warehouse for cold storage.

I told the buyer that I don't foresee any issues with the floor, because warming it will only bring it back to the temperature it was when the concrete was poured and cured. Besides, it would be subjected to a far less dramatic temperature swing than any exterior slab in Minnesota would endure.

Do any of you concrete masters have an opinion on this?

[emalernee]

I think the problem is not with the concrete, but with the 3-4 feet of frozen soil, under the concrete, thawing. When that thaws the ground may shift or sink and cause the concrete to follow.

Read about a freezer storage building around here that was going through major repairs and the need to keep the floor frozen to prevent damage to the foundation and floor.

You may want to contact a contractor that works on that type of building and get his/her take on the subject.

Ezra Malernee

Canton, Ohio

[Darren]

Was the area designed for freezers & coolers.

If so, there shouldn't be a problem. Proper construction of freezers and coolers include insulation under them and a thermal break in the concrete surrounding them. A thermal break includes mesh & rods cannot be attached to the surrounding materials and some type of expansion (usually wood or asphalt) in the slab.

If this was not done, then I would expect to see some type of damage when the temperature is normal and the freezer is removed.

[Les]

You must know the composition of the concrete. It ain't all the same. If it were placed for a cold storage the mixture would have been quite different than a slab in Minnisota. You must know properties of concrete to make a "guess". My considered "guess" is the warming process is critical and there will be movement and resultant damage. Extent?