We live in a house with a full height basement. The basement has an exterior entrance via concrete steps from ground level to a landing where the basement door is. The steps on one side abut the exterior basement wall. The steps are bounded on the other side by a 6" thick concrete wall.
During & after heavy rains I would notice dirt on the steps themselves. I could not figure out where the dirt was coming from. The ground slopes away from the house at the top of the steps and around the house (and there is no dirt missing on the surface). I attributed it to topsoil being washed away from a garden I had years ago nearby. Unfortunately after the garden was replaced with grass, this no longer explained continuing dirt, almost silt like on the steps after rains.
During a recent heavy downpour I watched water coming over the basement door threshold. I knew the drain in the landing of the basement steps was blocked. I opened the door and saw the drain was clogged with leaves etc. When I looked "up" the steps I saw water spouting out of the exterior block wall of the house! (See picture picture here
and another picture here
). I later figured out that it was actually coming from behind the stucco veneer and not from behind the wall itself.
After the rain, I probed around the top of the steps as there was no way the water streaming down the steps was just from the rainfall on the steps and it didn't explain the dirt on the steps themselves.
A 6" area of grass and dirt "fell in" beside the cement pad at the top of the steps (see pic of the hole before I dug it out
) and looking into the hole
but not much too see as I didn't want to drop my phone down the hole.
I opened this area up with a shovel and discovered that there is a void underneath the steps, and between the exterior wall of the house and the wall adjoining the steps approximately 1.5 - 2' below the steps and going down the steps at least 8'. The steps are 4' wide. I can actually put my arm in the hole, and see the bottom of the rebar of the steps, the rebar in the outside wall, and the exterior wall of the house. It's a big area. I can't really figure out where the dirt was going except that it was filling with water and being pushed out through the stucco (and I remember repair a large crack in the stucco a few years ago now).
How do I repair this? Obviously I need to get something under the steps to keep them from caving in. But this is a much bigger job than filling with bags of Quikrete.