In Repair & Maintenance

Simple Tricks for Waterproofing Walls in Your Basement

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Some people are lucky and they live in a dry area where they never have to worry about waterproofing walls to keep the elements out of the basement.

For those less fortunate though, waterproofing your basement walls almost becomes a hated hobby. The only worse homeowner hobby is fixing a roof leak. Instead of trying the next greatest thing, why don’t you follow these simple tricks to get it right the first time?

Start with a Clean Slate and get Water out

sump pump

If you do get groundwater in your basement, your first step in waterproofing walls is getting the water out. Hopefully, there isn’t too much and you can mop it up or wipe it up without too much trouble.

If you do have a large amount of water in your basement, you’ll want to start your basement waterproofing by investing in a good sump pump and setting it up right to start by pumping all the water out.

A note…make sure that the pump is pumping water far away from the basement. Too many homeowners have had the pump send water too close and ended up with the water going right back where it started.

What Steps Should I Take for Waterproofing Walls

There is an important thing to note which is that your walls need to be waterproof, even if you don’t have a living space in your basement. If you have a crawl space that gets wet from water penetration, it will produce rot and mold that will destroy your home from the ground up.

Clean Gutters

Most of the basement flooding that occurs starts, to some degree, from gutter problems. If your gutters are clogged, water will flood over the sides and into the basement or foundation walls. Keep your gutters clean and in good working order to prevent most basement water problems. 

clogged gutters

Look for Cracks

The best waterproofing in the world will not help very much if there are large cracks in the walls. The more cracked the walls are, the worse they will repel water. Go over the exterior of your walls and look for large patches of small cracks or single large cracks.

Next, you’ll need to go over the interior of your walls with the same care. If you have a finished living area, this is obviously difficult but look for areas of damp drywall or flooring that would indicate water intrusion in that spot.

How do I Prepare to Waterproof my Walls

Waterproofing walls starts by making sure the preparation is done well. It is vital that the walls are prepped correctly in order for any waterproofing paint to stick well and for a sealed barrier to form.

Figure Out Where Water is Coming From–solve that problem

You absolutely have to figure out where the water is coming from so that you can give that area more attention during the repair process. Look for cracked or stained concrete. Stained concrete can be darker, if the concrete is currently wet, or lighter, if the concrete got wet and then dried.

If you have a finished space, look for damaged wall or floor coverings. If you have an unfinished crawl space, look for water on the home’s underlayment plastic or damp dirt if you don’t have plastic laid out underneath.

You MUST find the source of the leak before waterproofing walls in your basement or foundation.

Clean Off Anything Loose

Any areas that have loose concrete or dirt stuck to the wall will need to be wiped or cleaned off. You don’t need to get out the soap or the pressure washer. But make sure to get as much of the loose material off as possible before waterproofing walls.

Fix Cracks with Hydraulic Cement

If you have any cracks, especially large cracks, you’ll need to fill them with hydraulic cement. This is a special type of cement with a few key properties. Since it is cement, it will stick to the already cured concrete walls.

Hydraulic cement is also formulated so that it will set up even if water is still coming in through the crack. But probably the most important thing for waterproofing walls is that hydraulic cement expands slightly to fit the space it is put in. This means that you’re going to get a more complete seal throughout the crack.

What are the Best Products for Waterproofing Walls

concrete efflorescence

Waterproofing Walls with Efflorescence

Make sure before you apply any waterproofing product that you clean off any efflorescence. Efflorescence is a white salt deposit that occurs on the surface of concrete when the concrete gets wet and dries off. Efflorescence will prevent waterproofing products from sticking.

Drylock from UGL

Drylock is an excellent option for waterproofing walls. Not only can it withstand a future water intrusion but it also protects against radon which is beneficial in some areas. Drylock is also incredibly easy to use and is able to be found just about anywhere to purchase.

Watertite from Zinser

If you’re not entirely sure about your ability to properly waterproof your basement walls, Watertite is a decent option. Watertite has a heck of a lot of ability to withstand future water intrusion: up to 20 PSI. And, it prevents mold and mildew. So, for first timers, this is an excellent option.

Basement & Masonry Waterproofer from Kilz

Kilz makes an excellent product by all reviews and standards. This coating provides a durable coating that will last a long time if applied over properly prepared walls. It dries very fast so you can recoat quickly and build up a protective barrier even faster.

How do I Waterproof an Exterior Wall from the Outside

Waterproofing walls from the inside is sometimes the only option. But for a great waterproofing job, you may want to consider waterproofing the outside of the walls as well. Of course, this is going to add tens of thousands of dollars to the cost. But sometimes, it can be worth it.

7 steps for waterproofing walls from the outside

Clear off Dirt

The first step to waterproofing walls from the outside is to excavate the dirt around the foundation walls. This is usually done with a backhoe, not a shovel. You will need to dig down several feet deep and as long as the wall where the leak is occurring.

Clean Wall

Just like when you waterproof walls from the inside, you need to clean the exterior wall in order to get a good seal. Start by using hands and a broom to brush off any large chunks of dirt and debris. You can use a pressure washer but only on the 40° setting. Otherwise, you could end up doing more damage to your wall.

Chip off Loose Material

If you do have any large chunks of concrete that are spalling off, make sure to chip them away. But be gentle because you don’t want to chip off more than you have to and you don’t want to damage the wall by being too aggressive.

Fill Cracks with Hydraulic Cement

Any cracks that you see or large patches of concrete that came off will need to be patched with hydraulic cement. Remember, waterproofing walls is all about having a good wall to start with. Apply the hydraulic cement and allow it plenty of time to cure before applying the sealer of your choice.

Apply Waterproofing Sealer

On the exterior wall of the home, you can consider more substantial sealers than on the interior wall of a home. There are several tar based sealers that you can use but there are also self-adhering membranes from companies like Henrys that can offer a simple solution.

Fill the Bottom Part of Hole with Gravel

Once you have properly waterproofed your walls, you want to give them the best chance of standing up to water intrusion. Fill the bottom of the hole with gravel to help with drainage if water does ever leak into that area again. Especially if you live at the bottom of a hill or in a wet area, this will be invaluable.

Backfill with Dirt

Once the bottom third of the hole is filled with gravel, backfill the rest of it with dirt and topsoil. Compact them down as you fill in the hole because otherwise it will compact down over time. This will leave a low spot right next to the foundation and water is more likely to intrude again.

Waterproofing sealers are designed to be put on bare masonry. Do not apply them over paint.

Can I Waterproof a Painted Wall

If you have a living space in the basement, you may have to waterproof a painted wall. You will not be able to waterproof an interior wall properly with the drywall and paint on it. There is always the possibility of waterproofing the wall from the outside.

But again, that is the more expensive option. To waterproof the wall correctly from the inside, you will have to take down the painted drywall and any framing the drywall was connected to. Then you will need to waterproof the wall according to the instructions above.

How can I Prevent Water from Getting Back in my Basement

graded yard

Grade your yard away from the home

Another thing that will assist in your basement waterproofing efforts is to make sure that your yard is graded correctly. What that means is: which way does the ground slope?

You want your yard to slope away from your home, with your home basically on a small hill. This way, any rainwater will tend to go away from your home. Again, water follows gravity and you can use that to your advantage.

If your home is at the bottom of a hill, you can always install a French drain to help funnel water around your foundation rather than through it.

Direct any water that does get in to a way out

If there is no way to successfully waterproof your basement and you have to accept groundwater within your basement, there are still methods of dealing with it.

You can always give that water a channel to flow through that eventually reaches a sump pump that pumps it back out again. This way, it at least keeps the water away from any appliances and possessions within the basement.

For homeowners planning on finishing their basement as a living space, they actually make some floor underlayment that help water channel beneath the floor to protect the living space. For homeowners that don’t plan on finishing the basement, it can be as simple as a low lying channel of concrete leading to a drain.


If you follow a few simple procedures, waterproofing walls can be successful and simple enough for most homeowners. For people with a small water intrusion, waterproofing walls from the inside is probably enough. If you have a bigger problem, consider waterproofing the interior and the exterior of the wall.