Can we backfill a basement and then do slab on grade?
We have significant water issues, and would like to 'get rid of' our basement. We wondered about 'backfilling' our basement, raising the house to second story height, and building a new ground floor on a slab on grade foundation, so to speak. We live in a high ranch, with the front door cut into the existing foundation, so the idea would be to bring the foundation to "level" (tying in door, window spaces) and then having a slab at that height, which would put us well above water. Of course this would need to be engineered. But, going into the process, could you offer insights or advice about this potential approach? Would we be better to just dig the basement up and try to bring the grade of the entire property up?
Yes, you can jack the house up and build a slab on grade then drop the house back down, or build an entirely new level underneath. You would need to cut the foundation down and and be sure to compact the fill at intervals as you raise the level inside the foundation, so it must be done with due diligence, and it would most definitely need to be engineered, In a situation like that with disturbed soil and an infilled foundation it may not be every engineer that will want to stamp such a job but here is a company that designs raft slabs, which distribute the weight over the entire surface rather than resting on a footing so soil compression is much less of an issue.