How should I fill a deep hole next to my foundation?

Question

We dug a large hole on the outside of our basement foundation. Our plan had been to enlarge the small existing window, but the discovery of a water main has changed that plan. Now we have to fill the hole back in. The hole is 6' deep, and fills with water when it rains, and the water seeps into the basement at the seam where the wall meets the floor. Should we use regular topsoil and tamp it down? Should we use gravel? Should we use a combination? The original soil/clay is no longer available.

Answer 1

i assume that you are going to have to have soil of some sort brought in for this if the original soil is not available. In that case, i would simply ask whomever you are getting it from for "fill dirt" and tell them what you are doing, they should be able to supply you with the appropriate mix of soil for your needs. If you are going to be harvesting fill from your own property however, any dirt that appears similar to that around the hole you are filling will work fine. you should tamp it as you fill, so that it does not collapse into itself later and require more fill which can be a pain if you put sod or grass over the spot. Be careful tamping, do not drive over the spot or press on it with a back-hoe head, as this could be to much pressure, and damage your basement wall, or even break through it if you're really un-lucky.

Answer 2

What I would be inclined to do in this case would be to first of all empty the hole of water. I would then make waterproof all along the area of the foundation where the water is seeping in. I would do this with a good mortar mix, say 3 parts sand, 1 part cement with a waterproofing agent added. If you could manage to keep the hole dry for a couple of weeks, I would then apply a coat or two of tar or bitumen

If you fail to do the repair, it will not matter what you backfill it with, the water will now continue to seep through. Once repaired you can fill-in with whatever you like. Water wiil only drain away in PERVIOUS soil, but you have Clay which is IMPERVIOUS, so gravel will make the matter worse. Good luck with the job.

Answer 3

You need to get the remaining water out of the hole. fill it with dirt compacting like mad as you fill it but BE CAREFUL!! as you work around the water line so you don't break it.

Do not use any gravel because this will allow that area to be porous and as you saw (water coming in by the footing/floor) would allow water to continue to seep in the home.

Sounds like the footing and wall joint has lost is water shielding ability. Make sure the ground (grade) all around the foundation is sloped away from your home and all downspouts from the gutters carry the water as far as possible away from the foundation. If you dont; down the road you might be back on here finding out why you have a wet floor ;)

Answer 4

you can take sand and cover your water main with at least a foot of sand, after that you can use fill dirt or top soil.

Answer 5

I would fill it with clay if possible that would reduce the water penetration. Gravel would allow water to drain to the bottom of the hole and seep into your basement, and topsoil may as well. You could fill 4 feet with clay and the other 2 feet with topsoil.