How to seal exterior foundation cracks above ground

Here is how you can seal minor exterior foundation cracks above ground. Finding cracks on exterior foundation walls can be dreadful for first time home owners. Its much worse when you come to know that water leaking through this crack has been the reason for the mold growth on the basement wall. The good news is that you can fix it yourself without calling a contractor. But you have to first figure out how big the problem is. Below fix is only for small cracks like shown in below picture.

Note: This is by no means a professional opinion. We are not experts. We are only posting based our own experience. Just so you know, sealing the crack alone on the exterior wall will not fix the water leaking into the basement. In order for it to work, you should find if there are any other issues that lead to water leak. In our case, we had negative slope all around our house. So, when it rains the water drains towards the house.

Now, lets get into the steps.

Identify the crack:

First and foremost thing is to identify the type of crack you have. Check out this link here and understand what are you dealing with.

Items you need:

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How to seal exterior foundation cracks above ground

This is the crack we found on our foundation wall. As you can see, Its right next to the rain water drain pipe and luckily crack is not too wide.

There was also a gap in the drain pipe that made the water to spill out whenever it rained. The soil was damp here most of the time due to the way the slope was towards the home. So, we first fixed it by adding a connector to fix the drain gap. The above picture was taken after fixing this.

Once drain was fixed, we started digging the ground to see how deep the crack went. Luckily it was not too deep.

Then, we cleaned in and around the crack with a wire brush. Hand brush can reach tight spots, but we also used a wire brush attached to our power drill. This made the job much easier!

Now comes the important part of this DIY – applying the sealer. We used this DAP waterproof sealant used for concrete and masonry.

Cut the nozzle 45 degree angle on the tube and apply slowly. Then use your finger to push the sealer into the gap and apply one more time if needed. This sealer dries in an hour. So, came back later to fill the soil back, level and grade the soil away from the house.

Just remember that this solution works only for small cracks and provided you also fix other issues related to this crack. In our case, we had negative slope and drain water leakage along with it. We fixed our drain, filled soil, fixed the negative ground slope and remediated the mold growth inside the basement.