Home>Discussions>EXTERIORS>Leaking foundation wall
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keith3267
Re: Leaking foundation wall

According to Clarence, some epoxies are designed to be used under water. That is true, but the under water side of your basement is on the outside, not the inside so any repair on the inside is a bandaid. Also, even if the repair does hold up over time, there will be new cracks, so you will always be chasing cracks, especially if you live in and earthquake prone area.

The best way is to have the perimeter of your foundation excavated and the exterior of the basement walls waterproofed. You need a flexible membrane type water proofing system so that any movement in the basement walls will not introduce new leaks.

But, once waterproofed, there is still the issue of the structural integrity of the basement walls. You should have the cracks inspected and there is the possibility that the cracks may have to be addressed anyway.

Mastercarpentry
Re: Leaking foundation wall

Get a structural engineer out there to check things- the earthquake could have cracked more than that wall and in that case no wall repair will hold long as things keep moving. Even if epoxy holds that crack another will appear as long as movement continues.

As always, the best place to stop water is before it touches the structure. An outside waterproofing membrane is the best way to go but it may require a lot of excavation and re-landscaping to do. No interior-applied waterproofing method really works well over time, and only those that include drainage are guaranteed to last- now if there isn't any water getting in after they 'waterproofed' why must they allow for drainage of water out afterward? Think about that, and always apply waterproofing outside the structure where it belongs.

canuk
Re: Leaking foundation wall

I don't believe in trying to keep a basement dry by simply patching all the cracks in a wall from the interior.

First thing, consider the fact that around 80 percent of all basement water leaks can be handled by getting outside water away from the foundation --- rain gutters to collect the water flow from the roof, downspouts set up to get it at least 5 feet away from the foundation and landscaping that stops run-off from flowing towards the house -- especially in the spring while the ground is frozen. Those three efforts are critical because even if we do manage to perfectly seal a crack, if there is a lake outside that wall, the water will just move down the wall until it finds another crack. Often if we remove the water, we don't even need to seal the crack.
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Epoxy is a good adhesive and a good sealant but it has the one major drawback that it cures very rigid. If there is any vibration or movement in the wall, the concrete will easily crack again, right next to the epoxy repair.
Polyurethane is a more flexible material that can handle vibrations and a little growth in the crack. Neither system is any good on cement block foundations because of the hollow cores in the blocks. They require repointing the mortor with cement based products.

With either material if they are not fully injected into the crack ( from interior to exterior ) then water will still enter the crack and cause further issues -- especially if the temperatures get to freezing .
The same applies to a topical application of hydraulic cement.

Hence --- the band-aid analogy.

I echo the comments made by keith3267 & Mastercarpentry in that repairs and waterproofing the exterior foundation wall is by far the superior way of doing things. This is the preferred method by many professionals ( engineers and the like ) if the simple steps mentioned above don't resolve the water infiltration.

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