How to Fix a Leaky Basement Wall from the Outside

Fixing an interior wall of a basement appears accessible to most people. But only repairing from inside cannot give you a satisfying result. Moisture, rainwater, sewer water can pass inside the wall from the outside. Slowly, they will cause bubbles, cracks, and leaks on the wall.

Before your basement wall reaches this condition, you should try repairing the leaks of the basement wall. You can do it from both inside and outside. However, this article will teach you how to fix a leaky basement wall from the outside.

Fixing exterior wall means the “basement waterproofing outside.” The fixing project in such way consists of cleaning the area, sealing all the leaks, and finishing the stains. It may take only few hours to 2-3 days to complete fixing the exterior basement wall. If you are interested to know more about indoor and outdoor leaky basements you can visit Painters Villa for further information.Tools Required

You will need several tools for cleaning, repairing, and smoothening the basement wall surface. These are handy items you can pick from the local hardware or home improvement stores. These tools are:

  • Mortar mix
  • Water sealant
  • Notched trowel
  • Brick patches
  • Grout sponge
  • Plastic bag
  • Chisel or wire brush

Purposes of using these tools:

  • Mortar Mix

Mortar mix is widely applied to connect and hold the construction type blocks together. It turns out as a workable paste that sets hard later when you add some water to it. You should pick type S for the basement exterior. They provide heavy shields to the wall.

  • Water Sealant

Collect a quality water sealant from a nearby store. It is not a mandatory item. But it can save considerable money in a more through fix.

Notched Trowel

It helps to give the surface a smooth finish. You can alternatively rent an electric, brick-cutting saw for a heavy-duty project.

  • Brick Patches

These are extremely helpful in curing brick and concrete leaks. You can find them in variable shapes and sizes.

  • Grout Sponge

These sponges dissolve after saturating with water. You can use them for repetitive uses as they are easy to clean.  

  • Plastic Bag

You can use trash bags made of plastic to hold the mortar before applying it.

  • Chisel or Wire Brush

You can remove sticky or unnecessary stuff using any of these two items.

Once you have all the tools, you can prepare yourself to move to the next step. Ensure you put on rubber gloves, a hard hat, face masks for self-protection.

Steps to Follow

Follow these necessary steps to fix the basement wall exterior side:

Cleaning Up the Area

Take care of any nearby vegetation near the basement. It may cause redundancy during the applications of the patch. Also, they may get damaged when you repair the wall. Then, cover all the windows and doors with plastic sheets.

Remove all the grass, leaves, dirt with a chisel, knife, or shovel. It may provide you flat, smooth surface for working. Move out any materials properly from the area.

Pick a wire brush to remove any greasy stuff. Brush all the loose debris before patching up the foundation wall. Alternatively, a wire brush can scrape all the old adhesive from the tiles.

Setting Tile Against a Bumpy Surface

After cleaning the area, arrange an elevation system around it for flexible activities. Then, apply the mortar mix (or cement adhesive) to cover any bare wood or loose materials. You can use the notched trowel to fill any crack. In some intensive cases, you may need several coats of mortar mix.

You can put on water sealant to seal the minor holes or leakages. They fill the area and prevent moisture from damaging outwardly.

After drying the mix or water sealant, apply some quick set mortar mix again throughout the whole area to place tiles. These tiles will not move around when you use the adhesive. You can add a thin layer of mortar to any spot where you put the tiles.

Place the tiles against the wall firmly. You can add security to them with a thin-set adhesive to the edges by inside and out.

Apply mortal to surroundings around them till they appear to flush looking alongside the wall. Check out from different angles to make sure the surface looks even. Now, wait for 2-3 days to ensure the final judgment of the project.

Use a chisel or wire brush to scrape the extra dried adhesive around the edges. Then, wipe the area to get satisfying results. Follow the processes repeatedly to avoid any mistakes.


If you can follow the above steps well, the finished result will provide long-lasting results. Therefore, you can conduct regular maintenance to prevent any cracks, leakages on the basement walls. We hope you have found the solution of how to fix a leaky wall from the outside.