How to seal & waterproof a basement wall from the inside & outside

If your basement is leaky, waterproofing seems like the best solution. But before you start doing that, you should figure out and understand the potential causes and why this happened. Since basements are below the surface, they are more likely to accumulate too much moisture and excess water. 

Here are the most frequent causes of why basements get water damaged:

new basement

Water will almost certainly leak if your walls and floors are cracked. Inadequate drainage will lead to excess water. Rainwater will collect at your home’s foundation and damage it if it’s not properly channeled away from the building. 

Drainage systems that are not constructed correctly can get clogged. If the land is facing towards your home, water will tend to flow and accumulate around its foundation, damaging your basement’s integrity. 

Now that you know why there is excess water, let us show you some reasons why you should waterproof your basement and how to seal them from the inside.

Reasons to waterproof

Your basement is a great storage space where you want to deposit items unwanted or unfit for your house. Additionally, it serves as your home’s structural base, so its integrity should be important. While this reason might be just enough to waterproof your basement, we’re going to give you many more below:

Waterproofing prevents flooding

Since most of the basements are located underground, they are at serious risk of flooding when severe weather. Regardless of the weather, waterproofing can help shield your house from water damage that might damage your belongings stored there.

Prevent cracks in the foundation

When temperatures fluctuate, moisture that is trapped in your basement’s foundation can expand and contract. It causes fractures that might be dangerous to the structure of your home. Fixing these leaks and waterproofing your basement will help you in the long term, eliminating any possible damage in the future. 

Reduce Energy Costs

During the hot summers, the humidity in your basement will increase significantly. Therefore, you’ll have a higher energy cost when you try to cool it. As an opposite effect, your house might get cold air coming in from the foundation cracks during the winter. Your house will have better heating and cooling efficiency if you decide to waterproof your basement.

Products you will need

Before you begin the waterproofing process in your basement, ensure you have the right tools for the job. Some of them include:

Drylok Fast Plug

This quick-setting hydraulic cement hardens in 3 to 5 minutes and stops water from flowing, even under pressure. It is the perfect material to fill cracks and holes and seal floors and wall joints. The key feature of this product is how fast it hardens, making the job quicker. 

DRYLOK Concrete and Masonry Liquid Etch & Cleaner

While most of the products used for cleaning metal surfaces are hard to use, this product is much easier to apply. There are no dangerous odors either, as Drylock ensures both safety and efficiency for their products. 

Sikaflex Crack Filler

You can use this product to seal waterproofed cracks in the walls and floors. This substance is non-flammable, making it safe to use in any environment. After applying it to the cracks, it will dry and harden into the concrete color without changing the aspect. Cleaning is easier, as it is done with just plain water and soap. After you finish waterproofing operations, you can apply paint over it to mask it with the wall or floor.

INSL-X Aqua Lock Plus 100% Acrylic Water-Based Sealer

This popular product is a high-end interior coating that was specially created for bathrooms and spas with high humidity levels. Due to its resistance to humidity, it is ideal to use it in your basement too. It provides incredible durability and great color with the additional advantages of safety features and long-lasting effects. This paint was made for such conditions, and your basement will look much better after you finish painting it.

DRYLOK Clear Floor & Wall Masonry Waterproofer

This waterproofer created by Drylok is guaranteed to stop leaks. It is ideal for protecting existing structures or safeguarding the newly built ones. It enters the pores of a surface, forming an impenetrable barrier and ensuring the high resistance of your basement’s walls. 

Best basement sealer

standing water in the basement

After comprehensive research and comparison of what the market currently offers, we picked the Siloxa-Tek 8500 by Ghostshield as the best performing and long-lasting sealer. It is a high-quality product that will repel nearly all of concrete’s enemies, such as water, salt, or oil. 

That’s why the Siloxa-Tek 8500 will be the best choice for your basement sealing project. Water will no longer threaten your walls since it will be protected by the most powerful sealer made by Ghostshield. You don’t have to be an expert in construction and know the composition of your walls to apply this product. Applying directly to concrete using a low-pressure sprayer or a brush is easy.

Aesthetics matter even in the underground basement, which doesn’t get many visitors. But every time you enter yours, you will be pleased to find out that this sealer maintains the original design of your walls while also making them strong and durable. 

Below we will show you the benefits of applying this product to your walls and floor:

  • Superior waterproofing – This solution penetrates deeply into the concrete and creates a chemical interaction in the pores of your walls to produce a durable surface that easily repels water.
  • 100% breathable – The air circulation process is undisturbed, making it easier for the internal moisture to evaporate without harming the sealer.
  • Resistant against oil and other substances – It will be simpler for you to clean up such stains from surfaces sealed with this product, reducing maintenance requirements in the long term. 

After application, the drying process will usually take 4 to 6 hours at a temperature of 70 degrees Fahrenheit. It might take longer in cooler temperatures with higher relative humidity, but the surfaces will become durable and resistant after the solvent has dried. Within 7 days after application, the ability to resist water will continue to grow constantly. 

Although stains are not a permanent problem, spills are not recommended to sit for extended periods. When accidents happen, make sure to clean your floors and walls quickly. They will disappear easily.

When applied properly, the Ghostshield Siloxa-Tek 8500 will do wonders to your walls, sealing them for a long time. It is the perfect sealer for your basement, ensuring high resistance and water repellence. 

Before you begin the DIY sealing process of your walls, it is important to clean the place first. Do it thoroughly so no external materials or residues are present. You want this process to be perfect. Remember, waterproofing your basement will bring you benefits for many years. Preparation steps before executing this process are necessary.

Substances used for waterproofing and sealing may only be applied directly to the surface. Otherwise, they won’t be effective. If your walls have old paint on them, use a brush or other tools to remove them. This process might be easy for some people, it is always essential to wear the appropriate safety gear while removing paint and cleaning the walls and floors of dust and debris. It includes coveralls, a respirator, and gloves.

Maybe all surfaces are clear and you have all the necessary tools and products available. Then we’re ready to begin the waterproofing process of your basement. Start by following the instructions below:

How to seal & waterproof a basement wall from the inside

  1. Eliminate standing water

    Make sure to eliminate any standing water in your basement before starting. You don’t want your sealing procedure to be incomplete because of external factors and elements which can ruin the process. 

    To stop a water problem, the water must be directed away from the home’s foundation. That’s why gutters are beneficial because rainwater is collected in them and transported away. If your home lacks gutters, you should consider getting them since they are vital for the future protection of your basement.
    If your home is already equipped with gutters, clean them regularly. Gutters overflowing with leaves and branches won’t function properly, and water might get directed elsewhere. This often occurs during autumn when leaves fall. That’s why during this time, the cleaning process has to be done more often. standing water basement

  2. Patching and waterproofing the walls

    It is unlikely that patching the leaks and cracks in your foundation will completely prevent water from entering the basement. However, it is an optional step that can be conducted for better results. However, you will need hydraulic cement to accomplish this since this product will stop water from entering the walls. 

    15 minutes after mixing, the cement is ready for use. Make sure you are prepared to apply it before you start the preparation. Hydraulic cement can harden rapidly, so it’s essential to complete this step quickly.

    Your walls can also be waterproofed, which is a much more effective process. The goal is to apply enough waterproofing to the walls such that it penetrates their pores and cracks. Chemical reactions will create the blending process, and the cracks in your walls will be filled instantly.

    Such products can be applied using a variety of brush strokes. By doing this, you will apply the solution exactly where it is needed while also ensuring it fills all the cracks and not only the surface. A second one can be applied as soon as the first layer has dried. Right at the end, multiple layers of paint can be applied thinly to mask the changes in your basement’s walls when the waterproofing process is finished. basement waterproofing

  3. Control condensation and humidity

    Condensation occurs when pipes are cold while exposed to warm air. Insulating these pipes can prevent condensation from accumulating, and it is affordable and simple to install. Such insulations are specifically made for pipes, and you’ll successfully get the job done with just a pair of scissors. 

    If you live in a colder climate, insulation will prevent the pipes from freezing by keeping them warm. This is an added benefit to condensation control. Also, insulation of the walls is beneficial since it helps protect against moisture. Installing wall insulation is easy since it comes in panels specifically designed and created to your preferences. 

    Beware not to insulate in places where water is currently leaking because you will provide a favorable environment for mold to form. That’s why you need to fix the leakage and cover the cracks with the products shown in this article. Insulation is a late-stage step that will extend the results of your work. 

    An additional problem is humidity. There is nothing you can do to control the humidity outside. But by utilizing a dehumidifier, you can control and lower the one present in your basement. While some dehumidifiers require draining once they are full, others will let you connect a hose to drain the water in a designated space. 

    If you decide to purchase humidity reduction equipment, seal tight the exhaust line from your dryer. Overall, waterproofing your basement is not difficult. However, it will provide long-lasting durability and results that you will be satisfied with. A basement with a water problem should never be ignored. 

    While reparations and waterproofing are required immediately, make sure to thoroughly follow the instructions and finish every step as efficiently as possible. basement that has been waterproofed


Can I waterproof my basement myself?

Waterproofing your basement is not difficult, and you don’t need to be an expert in this subject. Even if you don’t know about the complicated details of construction and the fundamentals of structural integrity, all you got to do is follow the instructions carefully when you seal. If you do it correctly, you will get exceptional results. 

What is the best way to waterproof your basement?

The most efficient way to waterproof your basement is to follow the instructions in this article and apply hydraulic cement to fix the damage to your walls. 

What is the cheapest way to waterproof your basement?

If this method is too time-consuming or expensive for you, installing an interior drain system will also help reduce water. It is much cheaper and can be done quickly, although this is not a permanent solution. 

How much does it cost to waterproof a wet basement?

Depending on which product you use and the size of your basement, a waterproofing operation will cost you between $1,920 and $6,493. Usually, the average cost per foot ranges from $3 all the way to $10. While this might be a significant investment, you will get results for years to come and prevent your basement from being damaged by floods or excess water.