Exterior Basement Waterproofing Process & Products For Outside Walls

In this guide, we will be discussing the exterior basement waterproofing process and products.

We will also explain the step-by-step procedure involved in waterproofing basement walls from outside.

How To Waterproof Basement Foundation Walls From Outside

Two of the major problems you will face with your basement are water and moisture.

Due to the fact it is surrounded by soil, and it’s at the bottom end of the home, it has the potential to attract water towards its direction.

Of course, there are steps you can take to get rid of basement moisture and flooding, but have you considered external waterproofing?

Home Exterior Waterproofing

Taking out the time to waterproof your basement from outside helps prevent water from getting into your basement, so you must do this to help you maintain a dry and comfy space.

Unlike interior waterproofing which is done to tackle internal moisture, the external approach spares you the headache of having entered altogether.

Thankfully, there are exterior basement waterproofing products you can use to achieve this. And we will be discussing them in this article.

Stay with us, as we look at waterproofing exterior basement walls.

About External Basement Waterproofing Process

The exterior waterproofing process has proven to be very effective. What’s more? It can be done on masonry block walls and basements with poured concrete.

The process may require that you dig out the dirt surrounding the basement walls. It also involves the application of a moisture barrier, as well as the installation of a drainage system to direct water away from your foundation.

Doing all these will prevent seepage right at the source, and it has become a popular approach among homeowners who believe in prevention rather than cure.

One of the biggest advantages of external waterproofing is the fact that it saves you from doing any interior waterproofing work. As long as it is done right, there is little to zero chance that you will ever have to deal with internal basement moisture.

Why Is Waterproofing Basement Exterior Walls Necessary?

Basements get soaked due to the water found in the soil that surrounds your home’s foundation. The water makes its way in through cracks and other porous parts of the structure.

It is typical of concrete walls to have small openings that allow water to pass through. These openings could have been created when the concrete walls were being poured.

The soil type around the foundation can also be the cause of internal moisture. As the soil absorbs moisture, it expands (the degree of expansion depends on the unique soil type around the foundation.

The expansion puts pressure on the foundation, thereby stretching out the small openings into larger ones, hence allowing water to pass through.

If your structure sits on clay soil, then you can expect a lot of moisture absorption.

Clay also drains poorly, so if this is the type of soil you have around your home, then you should seriously consider using external basement waterproofing products.

Advantages Waterproofing Basement From Outside

The major benefit of exterior basement waterproofing is quite clear – It prevents water from getting into the basement and saves you the trouble of having to deal with internal moisture.

A good exterior waterproofing approach or drainage will block water from flowing in and redirect it to the main sewer system.

The gravel used in the waterproofing system eases the hydrostatic pressure that would’ve been built up and ensures your basement stays dry at all times.

Another advantage of exterior basement waterproofing is that it spares your space of the unpleasant musty smell that is associated with dampness.

This makes your basement more habitable and increases the overall value of your property.

How Much Does Exterior Basement Waterproofing Process Cost?

The truth is, there is no fixed price for exterior basement waterproofing.

This is because the processes aren’t all the same. Furthermore, waterproofing basement walls from outside require different products and techniques, which also do not cost the same.

Another thing you have to keep in mind as far as basement waterproofing cost is concerned is the caliber of the contractor you are hiring. The more experienced or reputable contractors usually charge higher than the less reputable ones.

However, there are external basement waterproofing DIY methods you can employ to save cost.

Steps To Waterproofing Exterior Basement Walls

The external basement waterproofing process involves a few steps.

For best results, be sure to follow the steps below and execute them in the right manner.

First, inspect the walls for faults:

Before you head over to the home improvement store near you to shop for external basement waterproofing products, you need to do a little investigation.

This means you should first check the walls and identify as many faults as you can. After you are sure what the other causes of dampness are, you should get them fixed before you begin waterproofing.

These faults could range from internal condensation due to a busted pipe, or a simple crack in the wall itself.

Once the problem is fixed, you can then apply a waterproofer of your choice over the wall for the sake of prevention.

Prepare your walls for waterproofing:

After you have inspected the walls and fixed the cause of the original leaks, you should prepare the walls for waterproofing before you apply any sealant or waterproofing product.

You have to make sure the walls are free of dust and particles before you apply the sealer. If there are obstructions on the exterior walls, the sealer may not get the best grip on the surface.

If the walls have cracks or holes, then you must use a high-quality filler to patch them up before applying the sealer of your choice. Do not paint over the filler until it has completely dried.

As for rough and uneven areas, be sure to send them away until the surface is totally leveled.

After doing all the preliminary work, you can use water to wash off any particles of sand or dust that would be left behind. Once again, allow the wall to dry before you apply your sealer to get the best results.

Exterior Waterproofing Products

There are several exterior basement waterproofing materials you can use to seal your basement from the outside.

Here are a few you should consider –

The first is concrete waterproofing. This is one of the most popular external basement waterproofing products, as it is widely used by homeowners across the United States.

It is a cement-like product that sticks permanently to concrete and masonry. The good thing about it is that you can apply it on practically any surface, even on painted walls.

The second external sealer you should consider is the silicate-based concrete sealer. Just like concrete waterproofing, it is also a very common external basement sealing material and it is highly effective.

It reacts with the already-existing elements in masonry and concrete to create a reliable waterproofing coating.

While this remains a great waterproofing product, it has its minor downside. It can only be used on an unsealed or unpainted wall. This is unlike the concrete waterproofing sealer that can be applied to just about any surface.

The next external waterproofing product you should consider is waterproofing paint. It is almost the same as the traditional acrylic wall paint, only that this product offers a better waterproofing finish than the former.

Whatever brand of waterproofing paint you chose, ensure that it allows your walls some breathability. This means it should allow the walls to be able to get rid of moisture and not keep everything caged in.

The good thing about waterproofing paint is that you can apply it on surfaces that have been previously painted.

Use plaster waterproofing additive:

Plastering has been used in external waterproofing for many years. It doesn’t just improve on the aesthetics of your exterior basement walls, it also makes them more fortified and keeps them safe against moisture ingress.

Almost all exterior plasters have waterproofing capabilities, but that doesn’t mean you can’t add an extra waterproofing agent to the mix before you plaster.

This will only serve as a much-needed backup, and significantly reduce the chances of reoccurrence of leaks.

Applying The Waterproofer:

Applying the waterproofer isn’t a big deal and you can do it all by yourself. All you will need is a roller paintbrush and of course your physical energy.

Apply the first coat and allow it to dry, then take a look at what you’ve got. If you feel that you need a second or third coating, then feel free to do so, but make sure one coating dries before you apply another.

Don’t be afraid to make your coating as thick as it possibly can. The thicker the coating, the harder it would be for water to penetrate!

 Conduct a waterproof test:

After all the work is done, you would need to carry out a water-tightness test to be sure you have done a great job.

All you have to do is spray some water on the surface of the wall and wait for a few hours.

The basement moisture test is passed if your meter does not read any internal moisture.


That’s it guys, all you need to know about the external basement waterproofing process and products. Remember to follow the steps listed here to seal the exterior from water invasion.

Good luck!

1 thought on “Exterior Basement Waterproofing Process & Products For Outside Walls”

  1. my basement is roughly 1 meter deep water is getting into basement i believe the basement brick wall. What is the best product to use on the brick ?


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