Hi:

I have a slab floor under a bathroom that I had to bust open in order to relocate a drain for a new shower. The hole with the rebuilt plumbing is about 18" x 22" and about 10 inches deep, plus an adjacent hole about the same length and width, but about 3 inches deep. I now need to fill it so I have a flat surface for the new shower.

Calculations indicate that this will take about 5 80-lb bags of concrete mix. I've never enjoyed mixing concrete <grin>, so I was thinking of partially-filling the hole with gravel. The current slab is about 6 inches thick, so I was thinking of filling the hole so the gravel made the hole only 5-6 inches deep instead of 9. If I make it 5 inches deep, that makes it about 3 80-lb bags of concrete.

Am I making something out of nothing? Should I just grin 'n bear it and mix all 5 bags?

Thanks

Ron

You thinking is correct. Check the slab,likely only 3 1/2 to 4" thick and that's all you need to do. Compact the gravel and filll with crete

The most convenient way I have found to mix small quantity of concrete is with a dry wall bucket and a mixer chucked in a 1/2 drill. Pour water in bucket, pour about 1/3 bag of concrete in and mix, add another third and stir again, final third when that is all wet. Usually use 60 lb bags because I'm getting old.

That takes about 5 minutes a bag. Can be mixed right where I am going to put it.

Yes, you are making big thing out of nothing. Just like our Experts said, fill in the hole with sand or gravel and pour in 3 1/2" of concrete. You are done. Good luck with your project. Milo