Concrete pad

[6sunset6]

Spring 2014 poured a concrete pad in front of my barn. It replace a pad that was left over concrete from the house floor pour in 1995. no wire or rebar in the original and it was 4' from the barn floor.. There was probably 24 inches of bankrun fill in the area . Well tamped after 19 years. The new pad has plenty of rebar in it and is at least 5.5 inches thick. Well we had some cold this winter minus 15 d F a couple of times tonight as well I think. The slab, the whole thing I think 32 wide 20 deep lifted It is 2.5" above the barn floor. Really trips the snow plow blade when I forget to lift it on the way out. Bummer. It seems when water freezes there is 9% expansion so there must be water down there and it must have froze solid at least 24" to lift 2.5 . Anybody else seen this? Does it go back down? If I was doing it again I would put foam boards under it so its like a cap on a root cellar. That's what I did when I poured the barn floor but that was to keep the barn warmer. The barn floor has never moved. I never thought about it for an outside slab.

 

[PILOON]

It should go down some but not always judging by stones that pop up in the streets and drives.

 

[s219]

I just started a thread about the same problem, though my skirt is a lot smaller, and mine has only lifted about 1/4" (likely because we're not as cold as you).

http://www.tractorbynet.com/forums/rural-living/331819-frost-lifting-barn-skirt-slab.html

 

[EddieWalker]

When the ground dries out, it will settle. No telling how much, but when it's starts to settle back down is when concrete usually cracks. Did you anchor it to the existing slab with dowels? How deep did you go on your footings around the perimeter and what is the normal depth of for footings in your area? You might be able to anchor it in place once everything dries out, but I couldn't imagine anybody guaranteeing the work.

Eddie

 

[mikefromnh]

I have asphalt driveway that does the same thing. It will go back down but less and less every year.

I the spring you could try digging around the perimeter of the apron and placing foam insulation... Until then leave as much snow as possible on the slab to keep the frost from going deeper.

 

[joeyd]

I have the same problem with the apron in front of my pole barn also although mine only rises about 1.5 inches. My biggest gripe is that when the snow on my tractor melts the lip holds the water in the barn and I have to use a squeegee to remove it. The apron recedes back to normal but it has cracked the concrete and since the concrete is under the bottom edge of my front wall it has also buckled the siding slightly. The front apron was not pinned to the slab.

 

[Egon]

Google "Frost Heave". That should explain your problem and give the solution.

You have frost/ice lenses forming when capillary action brings water to the surface.
You'll have to get some drainage and coarser material under the problem area. Tying in to the main floor will not help.

 

[FTG-05]

Google "Frost Heave". That should explain your problem and give the solution.

You have frost/ice lenses forming when capillary action brings water to the surface.
You'll have to get some drainage and coarser material under the problem area. Tying in to the main floor will not help.

So basically digging a hole next to and under the concrete, filling it with gravel, then make sure it drains to daylight?

 

[Egon]

That's about it. Just make sure the gravel can't wick water. That is what allows the ice lenses to grow.

 

[Zick]

That's about it. Just make sure the gravel can't wick water. That is what allows the ice lenses to grow.

I keep hearing you say this but I can't seem to understand it. How exactly do you make sure gravel can't wick water?