How to Waterproof a Basement | A Full Step By Step guide


Articles, products, and services offered on this site are for informational purposes only. We are part of the Amazon Services LLC Associates Program, an affiliate advertising program. is compensated for sales resulting from links on our website.

Please review our disclaimer before acting based on anything you read or see.

The basement can hold many things, from entertainment centers and washing machines to winter clothes and holiday decor. On the other hand, stagnant water is something no one wants in their basement. Rain and groundwater can access your home in various ways if your basement isn’t waterproof, wreaking havoc on the structure and your property. It pays to watch out for the symptoms of excessive moisture in the basement and know how to stop it on the way. In this guide, I will discuss how to waterproof a basement.

Signs that Your Basement Needs Waterproofing

How to Waterproof a Basement

The first step in basement waterproofing is to know what to look for. Here are some common signs that could mean it’s time to control the humidity in your basement:

Mold or mildew

This can be caused by excess moisture in the air, even if standing water does not collect in your basement. Mold can also pose a health risk if left untreated. Using a dehumidifier is a great method to soften the mold.

Crushing paint

Paint can peel off walls for many reasons; it may be the wrong type of paint, or the surface is not properly prepared. However, there may also be excess moisture in the wall you are trying to paint.

Leaky walls

Basement bare walls can leak and occasionally create wet stains and condensation. This can be caused by pipes leaking behind the concrete or water penetrating the ground on the other side of the walls.

Dry rot 

This black-brown fungus usually appears as a by-product of the decay process and grows on wood. It can develop as a result of leaks and excessive moisture.

Flood or standing water

If your home is at a high-water level, water could penetrate the structure through imperfections in the floor or walls. Regular flooding can also result from problems with plumbing or drainage in the yard.

If you notice one or more of these warning signs in your basement, it may indicate a lack of waterproofing in your basement’s walls, doors, windows, or foundations.

On the other hand, if your basement is regularly flooded with standing water, your basement could have plumbing problems or various serious foundation problems. In this case, it is best to bring a professional plumber or foundation repair specialist who will inspect the space as soon as possible.

Environmental factors

The structural problems around the house and the environment around your house also play a role in water control problems in your basement.

If your home is located at the foot of a hill or a high-water level, there is a high chance that rainwater will collect on or around your property. It will increase the likelihood of basement flooding and important to plan these factors accordingly, carefully waterproofing basement walls and floors. It is also worth considering comprehensive flood insurance.

How to Waterproof a Basement?

How to Waterproof a Basement

Although foundation repair and remediation of soil damage should be left to trained professionals, there are several waterproofing projects you can undertake yourself to prevent basement flooding and reduce the risk of penetrating moisture. Keep your house dry and comfortable by using these basement waterproofing techniques.

Buy a dehumidifier

If your basement waterproofing efforts are focused on reducing mold, underground moisture, and condensation, a residential dehumidifier can do the trick. Dehumidifiers draw moisture from the air before moisten and damaging walls, carpets, furniture, and more.

There are many variants of dehumidifiers, but most plug directly into wall outlets and can be emptied regularly when their containers are full. Many can also be equipped with hoses to be continuously drained into a bathtub or floor drain, eliminating the need for manual emptying.

Choose waterproof carpet materials

Carpeted surfaces can be affected if your basement has water control problems. Fortunately, you can take steps to protect them from leaks and standing water. If you currently have bare floors or are in the market to replace your floor, a waterproof rug could be a good investment if your basement has already been flooded or has condensation problems.

You can also place a waterproof carpet mat to create a buffer between the floor of your basement and the carpet itself.

Apply waterproof sealant to walls and floors

Cracks can sometimes appear on concrete or brick walls, allowing water to enter from the outside. 

Don’t worry if you don’t know how to seal basement walls; it’s usually as easy as filling a crack with hydraulic concrete and painting the fractured area with waterproof masonry paint.

If the paint peels off, be sure to remove it first to identify leaks below. Before waterproofing basement walls, prepare the surface by thoroughly cleaning with a wire brush to remove stubborn deposits. Apply a solid coat of waterproof sealant and dry completely before attempting to repaint.

Keep wooden surfaces and water separate

Dry rot can occur if water or excess moisture comes into prolonged contact with wooden surfaces and structures especially support beams and floorboards.

To prevent the development of dry rot in the future, removing potential sources of excess moisture, such as leaking pipes that come in contact with wood, is an important step. The wood should also be separated from the soil surrounding the foundation to reduce the risk of dry rot.

Look for external problems

While problems like mold, peeling paint, and dry rot can occur indoors, external factors are often part of the problem. When waterproofing your basement, it is important to check that your gutters and drains are leaking, which can cause rainwater to flow directly into your foundation.

Contact professionals

If you find it difficult to prevent a routine leak or flood in your basement during a thunderstorm, there may be a variety of factors that may be beyond your control. Solving these problems with basement waterproofing requires professional training and equipment, so it is recommended that you consult an expert for advice or service.

Long-term damage control

The benefits of waterproofing go beyond preventing damage and costly repairs. It also offers peace of mind. In addition to the remediation and prevention projects cover here, there are other steps homeowners can take to better prepare for unforeseen water damage.

If the water level on your property is around or at the level of your basement, a trough pump can be a wise investment to divert water from the structure to prevent basement flooding. If you still worry about the flood, it can help you arrange the space so that the valuables do not directly contact the ground.

What to avoid doing on Waterproofing Basement

What to avoid doing on Waterproofing Basement

The following should be avoided when waterproofing

  • Do not use tar. The tar will become very brittle and will eventually crack.
  • Do not use plastic to waterproof basement walls. The plastic-like material will tear off, and moisture will penetrate inside.
  • Don’t use limestone for backfilling. Limestone will reduce the ability to drain and could clog any drainage structures. Use gravel instead.

Frequently Asked Questions

Can I waterproof the basement myself?

Apply a waterproof masonry product to the walls. Seal/coat the inside of the walls with a suitable waterproofing masonry product. When the paint dries, the sealant creates a tight bond to prevent water from penetrating. This way, you can waterproof your basement walls from the inside.

How can I waterproof my basement without digging?

Of course, there are times when waterproofing the basement from the outside is the best option and external waterproofing usually necessitates excavation.

How much does basement waterproofing cost?

According to estimates and online calculators, basement waterproofing can cost anywhere from $ 1,920 to $6,493 per square foot. The average price per square meter is between $3 and $10.

Is it better to waterproof the basement inside or outside?

Waterproofing the exterior of your foundation is the best way to strengthen your basement. Internal waterproofing can help avoid further water damage, but outside repairs correct the problems caused in the first place.

Can you waterproof the finished basement?

Water stains in the finished basement often cause despair of the homeowner, who immediately imagines destroying the beautiful living space to fix the leak. The best way for the homeowner that the finished basement can usually be waterproofed without pulling it out.

Is basement waterproofing worth it?

The main reason why basement waterproofing pays off for almost every homeowner is to strengthen your home’s foundation. While certain basement waterproofing methods use membranes to directly strengthen the foundation, any waterproofing system will considerably protect the foundation from moisture problems.


Waterproofing your basement is an important piece of the jigsaw to safeguard your house from water damage. But if your basement still becomes an indoor pool despite your best DIY efforts. You need to have a plan of action – this is important for the safety of your belongings and loved ones. With the call of an expert, learn what to do (and what not to do) when your basement flood.

Still, are you not done with the work on your basement? Consider completing the room with sealed insulation in addition to these basement waterproofing methods.

Comments are closed.