We have an older 1950's home that had a exposed 4'x10' concrete slab front porch (4" thick). Below the porch is a small cold cellar. When we bought the home, there was a major crack and several small cracks, running out perpendicular to the house on the top of this slab. They had clearly been patched and everything was dry when we bought the home. However, it was not long before it started leaking water into the cellar.
Photo of the original porch attached, the crack patches are clearly seen.
This original concrete slab was not reenforced. The reason for the cracking is unknown. There is no evidence of movement or cracking in the foundation around the cellar or the house. At one point there was a low brick wall on top of the original porch slab which retained snow, ice, and water, and essentially crumbled when we dismantled it. We suspected that had caused the problem.
After multiple DIY and professional attempts to repair these cracks to stop the leaking, we finally had it torn out and replaced by a contractor with good references (specifically doing this exact type of work).
Our contractor poured a new 12" thick slab (to raise the entryway to be more in line with the front door) with a lot of rebar. The rebar is attached to both the porch/cellar foundation and the house, and goes throughout the slab. The slab is angled such that it drains away from the house. The concrete was sealed. Everything looked right.
That was in late May of last year. This week, after spring thaw, we have discovered the new porch slab is leaking into the cellar! There is a very fine crack going out perpendicular from the house. There is staining underneath inside the cellar along the same line. There is water dripping.
We had our contractor back and he could hardly believe there was a crack there. He is recommending a re-application of sealant.
Does this sound reasonable to anyone? I feel a quite lost here. I thought we had done the right thing with a full replacement and now here we are, thousands of dollars later, back at the beginning.
I was wondering if sealant was a good solution, since the rebar would keep the crack from widening? Should I demand a different fix?