Bricks, Masonry, Asphalt and Concrete - Cement floor woes

My husband and I have been remodeling our unfinished basement. The basement had a very low ceiling so we decided to jackhammer the floor and lower it at least a foot. We got the floor ripped out and then the problems started. We found that the walls have no footings and the foundation only goes to the bottom of the cement floor. And we found a big sinkhole on the north corner of the basement. The sinkhole starts at the corner of the house and then goes about 6 feet underneath the driveway. The basement is a daylight basement (only the south end is bellow grade). We have never have had a wet floor and are thinking of just putting some beams in the sinkhole to support the driveway and redo the floor at the same grade and forget about anything else. This is way over our heads and any help anyone can give would be great.

Thanks Jenny

Sounds like a permit probably wasn't taken out on this basement.

How old is the house?

You have been fortunate not to have any water. Wet soil could cause big problems because is weakens the soil and increases the pressures on the basement.

A proper reconstruction would be nice, but very expensive. If you have had a good history of no water or settlement you could try to put things back better than they were before you statred. It would be a good investment to get an engineer look at the sink hole and the foundation situation. My suggestions are more of a good "fix" and not a reconstruction. An experienced engineer on site may understand the situation better than you are able to relay to the forum, so he may have different ideas.

One thing to consider is drain tile believe it or not!!!
Since everything is open the cost would only be some additional work and the cost of plastic drain pipe and some rock. This would give you insurance in the case of changing conditions. It is only an option, but is standard on any decent home now.

Replacing the floor is good (4" minimum). When you pour, do not worry if you took out too much near the foundation base. Fill in with the concrete rather than using soil. Pour the floor before you do any work on the sinkhole. If you have any voids under the foundation, fill with concrete rather than trying to compact soil.

The sinkhole situation could have an influence on the repairs to your home, so make sure you have everything thought out before starting.

Good luck!

Dick

The house was built in the 40's

There is no way to extend the foundation or add footing to the existing walls to enable more clearance? My husband has an idea of digging beneath the existing wall and extending the fondation.

That would be a reconstruction and is not a DIY project. It can be very dangerous and you must support the house while you do it. To do a good job, you would have to go several feet under your existing floor for good footings and headrrom.

Going bit-by-bit slowly around the foundation is very unpredictable.

You really should get some professional advice since you have a big investment at stake and it will effect your resale price.

Dick

Heed Dick's advice. You've already ventured beyond a diy project. Soils and foundations are nothing to shrug off no matter how "easy" it looks. Get some professional advice before doing anything else. What's spending a couple thousand versus losing the house and possibly life and limb?

I've got some work to do in a 2 yo hose where even the experts erred. You and your husband have more knowledge?