An Expert Guide to Waterproofing Basement Floor

An Expert Guide to Waterproofing Basement Floor

Basements are notorious for leaks and funky smells, but the real issue goes beyond the stink. Without basement waterproofing, the entire foundation of a home can deteriorate eventually, risking the structural integrity of the house. 

Long-term water damage can also lead to costly repairs. Not to mention, the basement is an environment conducive to the growth of mold and mildew. 

Poor ventilation combined with a moist environment can quickly cause an infestation that leads to respiratory and other health problems for both people and pets.

To prevent problems and protect their investment, homeowners should waterproof their basements with a high-quality waterproof sealant like Liquid Rubber Foundation Sealant. We've put together a step-by-step guide to basement waterproofing, including applying basement floor paint.

Inspect Your Home Before Starting

Waterproofing your basement won't do much good if you don't deal with the causes of moisture in the first place. There are several reasons for leaky basements, and you or a professional must evaluate and fix each one before applying waterproof paint.

Ways to Avoid Water

  • Clear your gutters of debris regularly. Test the gutter water flow with a hose and make sure it diverts away from the basement. During a heavy storm, gutters can fill with debris, so keep them clean and clear.
  • Consider installing a weeping tile. This is a porous pipe that's used for underground water collection and discharge. 
  • Install a French drain. These drains help divert water from the foundation. French drains are trenches filled with rock or gravel that contain a perforated pipe that redirects surface water or groundwater away from a specific area.
  • Grade the soil. Ensure it slopes downward around your home to naturally carry water away from the house.

How to Prepare Your Basement for Waterproofing

The first step in basement floor waterproofing is to seal any large holes. You can repair large holes with brick and mortar or use spray foam if the area isn't saturated with moisture. 

You may opt for sealant & adhesive caulk, too, depending on the size of the hole, or a combination of all of these. Allow the repair material to dry and cure before you go on to the next step.

Next, you'll need to clean the surface thoroughly. This includes removing any dirt, mud, efflorescence, and debris from the surface. Power wash the area if it's especially dirty. This may be a good time for a mold and mildew inspection or professional mold remediation.

Allow the area to dry thoroughly before treating it. Many basements have cinder blocks or concrete walls, and while they may feel dry to the touch, they may not be completely dry. Use a large fan or other dryers to ensure the area is free of moisture.

Once the area is dry, it's easier to inspect it for cracks. Cracks may just be a natural effect of the building materials aging, or they can indicate a settling foundation. 

You can seal bridge joints, cracks, and any protrusions using our simple three-step method:

  1. Apply one generous coat of Liquid Rubber Foundation Sealant. Carefully follow the instructions on the product, using a brush or roller to apply the product with smooth, even strokes. Work in sections, from top to bottom.
  2. Then, apply one layer of Liquid Rubber Geo-textile while the sealant is still wet.
  3. Once the Geo-Textile is embedded, apply another coat of Liquid Rubber Foundation Sealant
  4. Check out our video “Liquid Rubber Sealant Applied 3 Course Method

Once the final sealing layer has dried, assess the coverage. Apply additional coats as needed to reach the desired coverage rate. This ensures that your seal is not only effective but also offers long-lasting protection against moisture.

Pro Tip: For the best sealant application, check the weather! Apply in dry, moderate conditions for faster curing and stronger protection.

How to Apply Waterproof Paint for Basements

The Liquid Rubber Foundation Sealant is an ideal product for basement waterproofing. You can apply this easily using a brush, roller, or heavy-duty paint sprayer. 

The first coat will take about four to eight hours to dry, so make sure not to apply additional coats until each layer is completely dry to the touch and uniform in color. Apply the product at temperatures above 10°C or 50°F, including overnight temperatures.

Benefits of the Liquid Rubber Foundation Sealant

  • Superior strength and durability 
  • 900% elongation to withstand expansion/contraction
  • Fast and easy to apply
  • Quick drying time
  • Eco-friendly and non-toxic
  • Safe for plants, animals, and children
basement laundry room

Preventative Measures for Basement Waterproofing

In addition to sealing your foundation cracks, there are other measures you can take to preserve the integrity of your foundation:

Gutter and Downspout Maintenance

Ensure gutters and downspouts are maintained and functioning correctly. Clean your gutters regularly, and inspect them for loose parts. Check if the spouts are directing the water away from your house and foundation.

Landscaping Considerations

Avoid shrubs or small trees near your foundation, as roots can cause issues in the future. If you're concerned about existing trees or shrubs, consider moving them to a different part of your yard.

Land Slope Management

Check that the ground around your home slopes outward to avoid water collection. If you need to, consider having part of your lawn re-graded to ensure correct water run-off.

Exterior Waterproofing Measures

Consider implementing exterior waterproofing solutions, such as applying a waterproofing membrane or coating on the outside of your basement walls. This barrier combats hydrostatic pressure from outside, significantly reducing the risk of water seeping through your basement walls.

Drain Tile System Installation

Installing a drain tile system around your foundation can effectively manage water around your home. This system collects water and redirects it away from your basement, protecting your concrete floor from becoming a conduit for water ingress.

Sump Pump Utilization

A sump pump can efficiently remove water that collects in a sump basin, usually located at the lowest point of your basement floor. This is particularly effective in areas prone to basement flooding or where the groundwater level is above the basement floor.

Reinforcing the Concrete Slab

Seal and reinforce the concrete slab of your basement floor to prevent water vapor from seeping through the porous concrete. Use sealants designed for concrete floors that provide a moisture barrier and resist hydrostatic pressure.

Application Advice: Aim for thinner, even sealant layers for uniform drying and less risk of cracking or bubbling to enhance barrier durability.

Foundation Material Impact on Waterproofing

Different foundational materials can present unique challenges and require specific waterproofing approaches to ensure a dry and healthy basement environment.

To help you navigate these differences, we've put together a comparison of common foundation materials. The table below highlights each material's challenges and the strategies that are typically recommended.

Foundation Material

Waterproofing Challenges

Recommended Strategies

Poured Concrete

Minor cracks and pores

Epoxy injections, surface sealants

Concrete Block

Hollow spaces, mortar joints

Interior sealants, membrane installation


Irregular surfaces, gaps

Grouting, exterior waterproofing


Porosity, mortar degradation

Sealant coatings, external barriers

FAQs: Basement Waterproofing Insights

Got questions about keeping your basement dry? Below are answers to common questions, from addressing dampness to ensuring a permanently dry space.

How can I ensure my concrete floor stays dry and protected from moisture?

To keep your concrete floor dry, apply a high-quality concrete sealer. This will form a protective barrier that prevents moisture from seeping in, maintaining a dry basement environment.

What's the best way to address moisture issues on my basement walls?

Moisture problems on basement walls can be effectively managed by applying a waterproofing coating. This forms a moisture barrier that keeps the walls dry and protects against water infiltration.

Are concrete walls more susceptible to moisture, and how can I protect them?

Yes, concrete walls can be prone to moisture due to their porous nature. Protect them by using a waterproofing coating specifically designed for concrete surfaces, which seals the pores and prevents water entry.

What causes a damp basement, and how can I prevent it?

A damp basement is often caused by poor drainage or water seeping through the foundation walls. Prevent it by installing interior drainage systems that channel water away from the foundation.

How can I effectively waterproof a basement with a concrete foundation?

Apply a concrete sealer to the foundation walls and floor, and then install an interior drainage system to handle any water that does penetrate.

What should I do if I find standing water in my basement?

Remove it immediately using a sump pump. Then, investigate the cause, which may involve insufficient exterior drainage or a malfunctioning interior drainage system, and take corrective action to prevent future occurrences.

empty basement room with hardwood floors

Let's Get Started!

When it comes to protecting your home, interior waterproofing is something that you shouldn't neglect. Water seepage in your basement can damage your belongings and cause mold or mildew to form. Over time, this can damage the foundation as well and result in structural damage.

Liquid Rubber makes excellent products for waterproofing your basement, with proprietary mixtures that repel water and moisture by forming a seamless rubber membrane that's safe for people and pets.

Liquid Rubber is the preferred solution for many homeowners and DIY enthusiasts, with easy-to-apply products and video tutorials that will help you get the best results. Browse our online catalog to see our products and easily order all the supplies you need for your basement waterproofing project.