How To Use Flex Seal For Basement Walls

If you’ve never used Flex Seal for basement walls before, then you’re reading the right article.

I’ll be showing you how to apply this sealer and get the best results.

Does Flex Seal Work on Basement Walls?

It is normal for basements to have water problems, as they are located at the bottom of the house.

Water can damage your belongings and negatively affect the strength of the foundation, so it is a problem that cannot be ignored.

Luckily, Flex Seal for basement walls can help you keep your basement dry at all times.

As many Flex Seal users have attested to the fact that this line of products work as advertised, and have helped them maintain fresh, dry basements for many years.

How To Use Flex Seal For Basement Walls

Applying Flex Seal products is very easy and you don’t need a professional to do it for you.

Besides the steps I’ll outline below, you should also read and follow the instructions on the package so you can get the best results.

I also advise that you put on some protective gear while you’re at it.

It’s not like sealing basement walls is a matter of life and death, it’s just for the sake of saving you from the inconveniences of making contact with dangerous mold or other flying particles.

Put on a pair of gloves, a facemask, and a pair of eye goggles before you begin.

Now follow these steps –

  1. Find the Leak

You can’t begin to use Flex Seal to fix leaks if you don’t know where the leaks are. This means the first thing you need to do is to identify where the cracks are located.

This may involve moving some furniture away from the walls for better visibility. Once you have pulled the chairs, sofas, and wall ornaments away, you can have a better view of the entire wall.

Take a careful look and identify the cracks. Watermarks can tell you where the leaks originate from, as they will only start to drip from where the cracks are placed.

You have to be very observant during your search, because some watermarks on the wall may not even be as a result of wall cracks. Leaks in windows can also lead to the formation of watermarks along your basement walls.

Luckily, Flex Shot and Flex Seal spray are excellent for use around window sills and other spots you may not be able to access with the Flex Seal liquid.

Once you have identified where the cracks are, you have basically won half of the fight. Now you can move on to the next step.

  1. Clean the surface

The surface on which you plan to apply the Flex Seal product must be free of any obstacles. When I say obstacles, I’m talking about mold, spider webs, mildew, dirt, grease, or efflorescence on the basement wall.

You can scrub off grease with a brush and cleaning solution, while cobwebs can be removed with a broom.

As for mold and mildew, you can use a bleach solution to get rid of them. You can also use other commercial mold cleaners to do the job.

Remember to put on your protective gear when cleaning the mold. As I have mentioned before, mold is dangerous and can cause allergies and skin reactions.

After cleaning, ensure the walls are totally dry before applying the Flex Seal product. The sealer will not adhere correctly if the surfaces are wet.

To speed up the drying process, I advise that you leave your basement windows open so that some fresh outdoor air can come in. You can also turn on the fans for extra assistance.

  1. Apply Flex Seal Products

Now that your basement walls are clean and dry, you can begin to apply the Flex Seal product.

A quick tip before you begin applying the product – Spread some old clothes or old newspapers across the floor to collect all the droppings. This will make cleaning up after work a lot easier.

You can also move the carpet away from the walls so they don’t get hit with droplets of the Flex Seal liquid.

Flex Shot and Flex Seal liquid are great at sealing basement wall leaks. The Flex Shot variant comes with an extension tube that makes your job easier, as it can go into tight spots and corners.

Use the Flex Seal liquid for larger cracks, then use a paintbrush or roller to spread the product over more spacious areas on the wall.

Apply as many coats as required for best results. The coats should also be applied evenly across the surface for a better finish.

The manufacturer advises that you allow each coat 24 hours to dry before you apply the next coat. This further states the importance of ventilating the area during the sealing process, as it helps the sealer dry faster.

  1. Inspect the walls one more time

After applying all the coats, leave the last one to dry completely, then take a look at the wall again. If you find that the leaks in the walls have been completely sealed and that the Flex Seal has been evenly spread across, then it’s job done!

You can now return the carpet, chairs, sofas, and wall paintings to their former positions.

Flex Seal products have been tested and trusted to significantly reduce the amount of water seeping through basement walls, as several Flex Seal products are totally waterproof.

These include –

  • Flex seal spray
  • Flex glue
  • Flex tape

If you’d like to get your hands on these flex seal products, you can simply go online and place an order. They are also sold in many home improvement stores, so make the short trip down and make your purchase.

Can You Use Flex Seal to fill Driveway Cracks?

Yes, you can use Flex Seal products to fix driveway cracks.

As we all know, the winter can cause the already-existing cracks in your driveway to expand, and Flex Seal liquid is an excellent option for filling such cracks.

If you’d like your patio wood to retain its original color (which I’m sure you would), then I recommend using Flex Seal clear.

Is Flex Seal Permanent?

No product can last forever, as time and wear and tear will eventually weaken it. The same can be said of Flex Seal products.

However, they do have an impressive lifespan, as the Flex Seal liquid can last for as long as 2 years (24 months) if properly stored. You can check out the storage instructions on the pack.

Will Flex Seal Stop Water Leaks?

Yes, Flex Seal products can stop water leaks effectively. This has been attested to by thousands of customers who have used the product to waterproof their homes.

You can use Flex Seal products to fix leaks and seal your foundation in anticipation of heavy rains.

Flex Shot and Flex Seal spray are ideal for sealing cracked window sills and other areas that you may not be able to reach with the Flex Seal liquid. As for the liquid, it can be used to seal cracks in your basement walls and floors.

Can Flex Seal be Removed?

Yes, Flex Seal products can be removed. Although it would come off easier when it isn’t completely dried.

Remember, flex seal products are sealers, and their job is to block open spaces by hardening over a short period of time.

All the same, removing a flex seal product after applying it to a surface will require some effort.

You can use a brush and a damp rag to get it off. Just scrub as hard as you can and wipe up the loosened up sealer with the rag.

This is a continuous process, so you have to keep scrubbing hard until all the Flex Seal has come off.

How Much Do Flex Seal Products Cost?

Flex seal products vary by function and size. However, you can buy them starting from $14.99.

Go online to confirm the price of the specific Flex Seal product you are looking for.

What Does Flex Seal not Stick to?

Flex Seal is one of the best sealing products in the world. This is because it can adhere to almost any surface you can think of.

Among the many items, Flex Seal can be used include –

  • Vinyl
  • Cement
  • Rubber
  • Wood
  • Tile
  • Metal
  • Concrete
  • Fabric
  • Masonry
  • Plastic
  • Glass
  • Porcelain
  • Aluminum
  • Drywall

The multi-purpose use of Flex Seal is very impressive, but there are some rubbers, vinyl, and plastics that it cannot adhere to.

This is why it’s important to check Flex Seal’s compatibility with the material you are planning to sell before you buy.


Over the years, Flex Seal has become a popular solution for basement wall leaks. It can seal large cracks and can be used to guard wall surfaces from water that seeps through the pores.

For more information on Flex Seal products, you can visit the Flex Seal website and choose the product best suited for the leakage problem you are having.

Thanks for reading!

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