Basement wall/floor joint leak - DIY Chatroom

fubar79 · 11-06-2009, 03:17 PM

Looking to start finishing my basement but I noticed a small amount of moisture coming up the wall along the concrete floor wall joint. No puddle, just darker concrete. Only in two spots a few feet from each other. ( 3/4 of the basemnt is still covered with builders insulation and studs.)

It's a three year old home with sub-pump that runs quite a bit. Run-off water is pretty well controlled. No problems with moisture through the walls or floors... just the joint.

I've read two ways to fix the floor/wall joint:

-"by opening it up and packing it with hydraulic cement "

"I would clean out the cracks and install a urethane caulk. That will allow movement between the surfaces but maintain a waterproof bond. Attepmting to seal that with a rigid material like cement will never work. Those surfaces move in different ways at different times. "

Pro's/con's/comments about either? Does opening up to use hydraulic cement mean cutting the floor slab a few inches around the perimeter first?

Any help is greatly appreciated!

fubar79 · 11-06-2009, 08:05 PM

Third option I guess is getting someone like Crack Doctor although it seems pretty minor. I think I'll head to the big box stores and see what they have on the shelves.

RobQuillin · 11-07-2009, 09:11 PM

I would first start by inspecting the grade around the fondation of the house. Also check the gutters and make sure that they are either draining into tiles or that they are discharging the water away fron the house. Also make sure that the grade is sloping away from the foundation and that there are now holes left from moving plantings or something else. Often if there is an area where the water is draining back toward the house, the water will find the easiest place to releave the hydrolic pressure, usually joints in the concrete are the weakest spot.

If the grade and gutters are fine, then I would concentrate on the Hydrolic cement repair kits.

fubar79 · 11-07-2009, 09:27 PM

Hey Rob, thanks for the reply.

The grade is fine. New home, and they have crazy swells away from the house. No plants, bushes or anything. On that side of the house, the drains run into a "big-o" that I burried, and drain at the end of the driveway.

Everything has dried up since I removed the studs/insulation/VB (24hours). I'm going to chisel out a bit of the cove, then fill it in with some hydraulic cement. Hopefully it's as simple as that and then i'm back to building as appose to ripping out. But i'm glad I found it now, rather then later!

RobQuillin · 11-07-2009, 09:33 PM

The main thing is to try to make the grove deep enough to give the hydraulic cement something to bond to. The cement expands as it cures, this is how it is able to withstand the pressure, so make sure that there is enough surface to let it get a good crip. When done correctly it has been very impressive fore me. Good luck.

fubar79 · 11-07-2009, 10:24 PM

Thanks for the advice. I will give it a try Monday when I have a few hours to tackle it.