Tuesday, August 4, 2009

Foundation Repair One

The inside wall has always been bowed, but I'd always thought the form had blown out on whoever poured it. In fact I put in an extended window sill (like a shelf) to hide the curvature.

This winter though, we had a cold snap and the sheetrock began to crack quite a bit. Our housesitter told me that the wall downstairs was cracked... so I told her not to worry - it had always been like that. But, when I got home it was pretty bad. The window glass was flexed and so stressed that I glued insulation to it and double layered plastic over it inside and out in preparation for it shattering (which it didn't). It looks like it's moved in about 3 inches so I began to realize that the wall had failed.

The pour is a piece of shit - there is very little steel and ribbons of unmixed aggregate run though it. Either they did it in a couple pours or, more likely, they didn't agitate it well.

This is the major fault where the footer is broken.

This part is not structural so I'm not very worried about it, although it LOOKS pretty bad.

Big hole for a little loader...

It took quite a while to dig out, not least because I had to fix the loader a couple times... Either 2 hoses were leaking simultaneously or I changed the wrong hose the first time. I think the second hose was the leaker but had jetted through the casing on the other hose - making it look like it leaked. It's hard to troubleshoot because of the pressure, sticking your hand in there to see where the fluid is coming from is not such a hot idea. In the past I've had to section the hydraulic compartment off with absorbent, run it and repeat a couple times to narrow down the leak location. Of course, you've got to open it up and put it back together on each try - very time consuming.

The repair plan is to epoxy rebar into the existing wall and pour a new one outside of the failed one. Then, I'll cut the framed wall loose from the existing concrete wall, bang it back out to where it's supposed to be, Hilti it down again and then fair out the wall inside (which will still be bent). I'll have to custom rip each stud or maybe I'll just come out far enough to build a proper wall, but that would make the window and door openings about 10 inches thick. I'll have to see what looks good.

I'll also improve the drainage somehow. The ground has a lot more clay that I expected. I know it's glacial moraine down there somewhere and had always thought it was gravel just a few feet down, but this is pretty solid stuff so far. I had planned to just backfill with gravel, but I think I'll need to excavate (with a backhoe this time) for a french drain.

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