I conducted a repair on my house this weekend for wedge crack - a common problem in south Texas. I chiseled out the crack a bit with my cold chisel - but didn't go all the way into it. The crack was quite small - but there was an area a bit deeper that had a 1/8" crack in it that I did not go deep enough to completely access. I was concerned about breaking the concrete corner completely off the foundation.
The crack is diagonal on both sides of the corner of my house. It starts about 10" from the corner and works its way to the corner edge on both sides. When I chipped off the cement overcoating, I found that the crack was very narrow - the cement was actually touching below the surface with no visible gaps...with the exception of the area with the 1/8" gap.
The larger area was at the very top of the crack on the side of the house that gets the most sun. I'd opened up the top of that crack area a bit (about a 1.5" wide x 1" deep section). The larger crack was visible from this area.
Once I'd verified that, with the exception of that larger cracked area, the cracks were present, but the concrete was touching, I attempted my repair.
First, I mixed up Quikrete vinyl concrete patching compound. According to Quikrete's website, this stuff has a compressive strength of 3000psi at seven days and 5000psi at 28 days. I packed it into the area I'd opened up at the top (and from where the larger crack was visible) to the point of refusal. That is, I couldn't stuff any more of the crack repair in. Whether it made it to the larger crack is unknown.
I then covered the rest of the crack with the the patching compound. The crack was covered in an area about 2" wide and 1/4" in depth.
For what it's worth, My house is a 1600 square foot, single-story home on a slab foundation. Three sides of the house are brick - the back of the house is siding. The foundation is coated in a stucco-like concrete parch coat. The house is located in north-central San Antonio where the soils are a combination of clay and limestone. The limestone bedrock is about 10 inches below the ground surface.
There is no interior damage to the wall or ceiling sheetrock, all the doors and windows function fine. The cracks in the corner appear to be limited only to the outside - I pulled up the carpet and found no cracking on the interior slab in that area. There are a couple of bricks that have cracked, but there's no deflection in them or separation. In addition, some of the mortar has cracked in various points near the same area.
Was this a decent repair?
Should I be freaking out about this type of wedge crack?
I've uploaded photos of the issue:
This is a house near mine that has the same type of damage. It could be called a "before" picture...although my cracks were not as significant.