Sweating basement wall -- fixes?

[szug-bot]

Originally Posted by stburr91

I agree with this, but I would also coat the exterior of the foundation with a quality waterproofer.

Check out this video.


http://www.youtube.com/watch?v=FqkK0LGqDD4

Interesting video. Can you answer a question? At 1:15 - he says "you can see the trench is well below the footer"....well, the footer continues deeper into the ground. that is what im seeing, correct?

and that is not what i would call a footer - that is concrete block. footers are usually poured concrete, and wider than the block, right?

[ditchdigger]

If you look closely enough you can see that that particular footer was trenched, rather than formed. The edges are real irregular, which makes it hard to pick out from the mud surrounding it and covering it. Actually, in the still shot shown just above, the worker's left foot is standing on the footer, right behind a spot where it steps down one course of block. The edge of the step stands out pretty clearly.

90% of the water problems I see can be fixed with a few tons of raw topsoil or cleaning downspout lines.

Sure. I've fixed more than a few myself. But for the purposes of this discussion, in the situation described, with the back of the foundation facing a hill of a size that we don't know, a groundwater problem certainly has to be considered as a possibility. That's one reason I always hated those jobs. You might go to all the trouble of compacting next to the foundation, and regrading to direct the water away from the wall, and still end up with the same problem. I speak from personal experience, because that describes the first house I ever owned...

[guy2073]

To answer the ? About weep holes in the block, I have broken the bottoms of block out to drill for vertical rebar before we grouted a shifting wall, the block drained water for a half hour, you could have ALOT of water in your wall. That is one reason why drylok paint is worthless

[szug-bot]

Originally Posted by guy2073

To answer the ? About weep holes in the block, I have broken the bottoms of block out to drill for vertical rebar before we grouted a shifting wall, the block drained water for a half hour, you could have ALOT of water in your wall. That is one reason why drylok paint is worthless

Sorry - I'm an engineer and have to sweat and understand all the details. So I have to ask...

what do you mean that you had to 'drill' for the rebar?
Why/how would grouting the wall prevent further movement?
And, can you explain the grouting - is that just filling voids in the block cavity?

[guy2073]

When a wall pushes there are a few options, one is the plates and anchors, another option is to install pilasters to keep the wall from moving more, if we excavate for an outside French drain, we will bust the block at the footer and at the top, we will drill the footer and install #5 rebar from the footer to the silplate. We then block the bottom of the wall and pump grout from the bottom to the top, this reinforces the cells and prevents the wall from moving.

When a wall is bowed and the outside is excavated and the force is off the wall the wall will sometimes move back to its original position, this is when grouting the wall is a great option. I have not done waterproofing and wall repair in years, there maybe better options now, but the old way would still work.

[alexernst]

I'd go with the diversion option at first. Get out in the rain (heavy rain) and just watch where it is all flowing. How soon after a rain event do you see leaks in the walls? Groundwater sources will be much slower. I doubt there is groundwater intrusion because it seems very unlikely for your basement to be below the water table if the hill continues well below your house.

With all of these issues you have to decide how much it bothers you and how much you want to spend. Perhaps some flashing/caulk and a dehumidifier will be sufficient. We have a 'sweating' wall too and the dehumidifier seems to do pretty well at extracting a lot of the moisture (so mold etc aren't growing).