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How To Fix A Leaky Crack In Your Basement Wall Or Pool‏

So you have a crack or old snap tie hole in your basement wall that is leaking water, or maybe it is leaking around the conduit coming through the basement wall to the electrical panel, what should you do? The best thing you can use is hydraulic cement.

Difficulty Level
3 / 12

Tools Required

Safety Supplies Required

Materials Required

It is different from regular cement in that it actually expands a little as it cures whereas regular concrete usually shrinks slightly. The fact that it expands makes it perfect for sealing water leaks in concrete basement walls or concrete pools because it really forms a tight fit.

Hydraulic cement is also a quick drying mixture so you need to only mix up as much as you can apply in about 5 minutes. The product comes as a dry powder and is mixed with cool clean water. Use a margin trowel to mix the powder while added enough water until you get a peanut butter type consistency. You can find hydraulic cement at most building supply / home improvement stores.

The areas that you want to patch should be free of dust and loose concrete before you start. With cracks smaller than 1/2" wide you will need to use a grinder with a diamond concrete cutting blade in it to actually make the crack larger. Use the grinder to make an angled cut along each side of the crack about 1/2" away and angling back into the centre of the old crack. Cut in to make the groove about 1/2" to 1" deep. This will produce some dust for sure so you may want to hang some poly up to confine the dust to one area, some ventilation will be helpful if doing a lot of cutting as well. Make sure to wear eye, ear and lung protection when making these cuts.

If you have other areas leaking such as around tie holes, conduit, pipes or window bucks, you need to do similar prep work . Make sure the area you want to fill is at least 1/2" wide and 1/2" deep and clean any dust and loose materials out as well. You may need to use a hammer and cold chisel to clean up these spots. On tie holes you may need to use a hammer and punch to drive the end of the metal still in the wall back at least 1/4" below the surface to completely cover it up. Be sure to wear eye protection and gloves when using a hammer and punch or chisel.

To fill the areas you need to fix, first mix up a batch of hydraulic cement then use a margin trowel, pointed trowel or your hands to press it firmly into the cracks and voids you are trying to fill. If you are using your hand I would recommend wearing rubber gloves to protect your skin. Work fairly quickly as the cement will set up pretty fast. Mix more batches until you complete the project and clean your tools as you go to keep them from becoming covered in dry cement.

This is not a tough job but can be dirty and time consuming but is well worth it to keep moisture out of the places you do not want it.