Concrete -PROBLEMS - Basement Floor New Const.

[NWOhioChevyGuy]

OK, my younger brother is building a new home and has the following situation.

9' basement ceilings with around 3200 square feet in the basement, poured concrete floor that yesterday we noticed was heaving. How we noticed, the rafters on the house were setting on an interior wall (non load) and lifted off the exterior wall. Doing some measuring the floor has moved up 1 3/4" under the central stairway in the basement, and pushed everything above it up around that same distance. Near the walls no movement, "heat" from the surrounding earth has kept it warm enough, plus alot more concrete in those areas.

When the basement was dug, this fall, they had a slight amount of moisture in the footers but nothing on the floor level. Well the sump they put in the floor never stops running so we suspect that with the VERY cold temps (negative double digits for several days) the moisture under the floor has froze and pushed up on the floor.

Well my brother called last night to bounce some ideas off of me for a "fix" A) will heating the floor / basement with a large portable heater cause the slab to relax back to where it belongs, melting the ice that heaved the slab? Mind you the house is just rough framed, no insullation, heat, electrical (other than temp. pole). B) will the concrete stay where it is and the walls that have been pushed up need shortened? C) what will I be left with for a basement floor now that its moved and cracked all to H?

Thoughts, Ideas? I know pictures would help, maybe later today if I swing buy that way.

 

[carcruse]

Sounds like you don't have a large enough sump pump if it is running continuously. It is not lowering the ground water around the walls and under the floor enough and the hydraulic pressure is causing the problem. The problem is most likely not caused by freezing that far down.

 

[walrus]

I had a friend who had the same thing happen, everything was ok until the carpenters shoveled the floor off and up it went. They put heat in the basement and the floor went back down. I'd get the plastic out and get the basement as tight as possible and throw some portable heaters in there.

Nations Rent or whatever rental place might have some ground heaters? Its a boiler on wheels with 2 reels of 3/4 hose, it pumps 180 degree thru the hose. You lay the hose down on the ground, cover with insulation blankets and with a day or 2 the frost will be out of there. Pretty expensive but a company I work with has one and I've seen it take 2 feet of frost out

 

[Wardster]

A) If you can keep the heat in, then maybe. The biggest issue is the fact that there is that much moisture beneath the slab in the first place. Considering the sump is always running, it almost sounds like there is a spring somewhere?

B) See answer A. If you can get ahead on the water coming in the sump (meaning it actually shuts off), then you may get settlement at the stairs?

C) You really won't know until after the ground is thawed beneath the slab. Worst case scenario, you replace the damaged area with new concrete.

 

[NWOhioChevyGuy]

Well the sump does not run all the time but atleast every 2-3 days he has to plug it in and pump out the water from the drains.

We spent this morning sealing things up and now have 470,000 btu's of heat down there warming things up. One of our brother in laws is part of a family Propane business so he has a large propane portable heater and mine and my fathers kerosene heaters are running down there to see if we can get enough heat into the slab to transfer down through.

Sat a 250 gallon propane tank, ain't gonna be cheap but hopefully the heat will thaw things and let it settle.

Talked to several concrete guys this morning and they say it should.

What a mess, hopefully he can get it fixed, then on to repairing the floor.

 

[Wardster]

Sounds like you got it under control.

We have had some heaving issues in the past and they all point to a trapped water source beneath the concrete that freezes. Once it thaws, I would not be surprised to see water making its way up through the new cracks. You get any pictures while you were there?

 

[NWOhioChevyGuy]

No, I was to damb busy and cold to remember to take any.

sorry, didn't even cross my mind while I was there.

 

[walrus]

If there is clay under the floor it won't take much water to get the floor to go up

 

[NWOhioChevyGuy]

Yeah that is part of the problem, the soil under the gravel fill is a clay loam.

I think if he gets it to settle back down the key will be to keep it protected / warm enough not to freeze again, as with it having clay soils it does not drain well so the moisture will stay.

 

[walrus]

With clay you'll get ice lense's(crystals of ice). They seem to grow right out of the dirt. When they do, up goes the soil and whatever is placed on the soil.

 

[Ray-CA]

First of all, who is the general contractor? He's the one who should be fixing this. If it's an owner/builder, then its on you. Sounds like the ground wasn't properly prepared before the concrete was poured and the slab needs to jackhammered out. After the ground is properly prepared the slab needs to be re-poured.

I would not think that the structure would pass inspection with that much uplift. Image what would happen with tile, wood flooring, plumbing etc. if this happens after the home is completed? Then, if you moved in and the insurance company found out that the owner knew of the trouble/condition before occupancy?.....So sorry, not our problem, see you later......

Ray