I’d be grateful for any advice on this.
I recently noticed cracks in my foundation. They’ve been there for a while, I just noticed them while walking around the perimeter. It is not hard to see the cause: they emanate from a dryer vent put in the wall. We had a handyman put the duct to the vent in about 3 years ago, my wife claims there was already a vent there, and it does look like it preceded a paint job on the foundation about 4 years ago.
In any case most of the cracks are hairline but one is going up vertically along the lines of the foundation blocks and is a millimeter or two wide in places. It is clearly widening from the outside in as weather wears away the edges. The whole area around the dryer vent and main crack spreading from it (horizontally at first and then going up along the line between cinder blocks) has been patched with concrete, and sure enough the handyman billed us for a bag of concrete although this patch was never mentioned.
The upper part of the patch has broken off exposing the crack, perhaps this is why I didn’t see it earlier. But all of the patch is now flaking off and looks like a couple of good rainstorms will wash it away.
What course of action can people recommend? Reapply concrete every couple of years? Epoxy? Lift up the house and replace the foundation? It is certainly wide enough along the main crack to let insects in, at least on the outside. The internal space is a crawspace added during a kitchen extension by previous owners. We are planning to have someone insulate the crawlspace sometime this summer, and after that of course there will be nothing more to do from the inside.
I would really appreciate suggestions. I made the mistake of reading a book about renovating old houses, a whole chapter about jacking up houses to repair or replace foundations….