The US is known for heavily relying on concrete – although homes often include drywall instead of concrete only. However, commercial and industrial properties are often made entirely out of concrete to ensure code compliance. In 2021, approximately 109 million metric tons of concrete was used in the US. 

Concrete floors are often installed because of their general cost-effectiveness, long life, and smooth finish it offers. Furthermore, your concrete floor can also act as a great insulator with the right additives. However, one major problem people face when it comes to concrete floors is moisture seeping into them.

You may see damp spots on your concrete floor, which may eventually lead to depression in the floor and/or cracks. In this article, we will take a closer look at how to keep moisture out of a concrete floor, some common ways to seal the floor, and other important considerations. 

How Do You Keep Moisture Out Of A Concrete Floor? 

Keeping moisture out of a concrete floor is important when building or remodeling. Moisture can seep into the concrete and cause damage, rot, and even mold growth if it isn’t addressed properly. Fortunately, there are several ways to prevent moisture from accumulating on your concrete floors. 

The first step in keeping moisture out of a concrete floor is using a waterproofing barrier such as polyethylene sheeting or other waterproof membranes. There are also some sealants that you can spread on the concrete floor and wait for it to dry. Water will then bead off the floor instead of absorbing in it. 

Sealers should be applied after pouring to help prevent water from coming into contact with the slab and provide protection against staining.

The sheeting or membranes should be placed between the soil and the slab before the concrete is poured so that water does not come into contact with the surface of the slab. It acts as a moisture barrier, hence keeping your floor safe in the long run. 

Dealing With Moisture Seepage

If moisture seepage is already occurring, the most effective way to remove it is to use a dehumidifier and fans to draw out the humidity from the air. This should be done in conjunction with sealing the slab. Applying floorings such as tile or carpet can also help provide an additional layer of protection against moisture accumulation if used correctly. 

For existing concrete slabs that do not have any waterproofing barrier in place, using a concrete moisture sealer on top can help protect against water infiltration by forming a barrier between the soil and concrete slab as well as providing protection against staining from spills or dirt and grime buildup. 

However, if you need to install a barrier underneath, the best way is to reinstall the entire floor again. Products containing silicone or other sealants can help keep moisture from entering the slab from below. This should be done in areas where water may accumulate, such as near swimming pools and hot tubs.

Finally, a vapor barrier should be considered for any exposed concrete flooring to prevent moisture from seeping into the slab through evaporation. The best choice is using a porous material such as plastic sheeting that will trap any water droplets and prevent them from penetrating the slab. 

How Do You Dry Out a Concrete Floor Quickly?

If your concrete floor has been affected by moisture, getting it dry quickly is important to avoid further damage or mold growth. The most common and effective way to do this is by using a dehumidifier in tandem with fans to help draw out the air humidity and excess water quickly. 

Other common ways to dry out your concrete floor include, but are not limited to:

  • Using a wet vacuum to suck up excess moisture

  • Using an absorbent material such as kitty litter or sawdust 

  • Opening windows and doors to improve ventilation 

  • Covering the damp area with a tarp or plastic sheeting 

  • Applying calcium chloride to help draw out moisture 

Placing tarps over the wet area can absorb some of the water and speed up the drying process. If necessary, you may also want to consider renting a professional-grade boiler or electric heater that can be used to heat up the slab more quickly. 

Waterproof Existing Concrete Slab – A Quick Step By Step

The idea behind existing waterproofing floors is to avoid the risk of moisture seeping through the concrete slab. This can be done by following these simple steps: 

  • Clean the slab thoroughly to remove any dirt, debris, or material that could prevent the adhesion of a sealant.

  • Apply a concrete waterproofing sealer over the entire surface of the floor in an even layer and allow it to dry completely. 

  • Apply a second layer of concrete sealer to ensure maximum protection. 

  • Allow the sealer to dry for at least 24 hours before walking on or placing the furniture back onto the surface. 

  • Apply additional layers of waterproofing material, such as polyethylene sheeting or a vinyl membrane, to ensure long-term protection from moisture seepage. 

Following these steps, you can easily waterproof existing concrete slabs and prevent moisture from entering them. This will help keep your floor safe and free from damage caused by water infiltration and erosion over time. This will also extend the life of your floor and increase its aesthetic appeal significantly. 

Dealing With Damp Concrete Floor Under Carpet

Damp concrete floors can be quite a nuisance, especially when covered with carpet. Moisture can seep into the floor and cause damage to both the subfloor and the carpet itself. To prevent this from happening, it is important to mitigate moisture levels in your home or business. 

The best way to deal with damp concrete floors under the carpet is to use an appropriate vapor barrier, such as polyethylene sheeting, between the slab and the subfloor material before installing any type of flooring, including carpets. A dehumidifier near the damp area can help reduce humidity levels and quickly draw out excess moisture. 

Ensuring good ventilation in your home or business will also help keep moisture levels down and prevent dampness from forming on your concrete floors. You can also use other moisture barriers to ensure that it does not damage your carpet or the foundation and make removing moisture from the concrete slab easier.

It is important to note that these methods are dedicated to moisture on top of your concrete floor. In case of water seepage from below, you may have to install a barrier underneath, as mentioned in a previous section. 

Some of the best moisture barriers for the concrete floor (underneath)include:

  • A polyethylene film 

  • An epoxy sealer 

  • A waterproof membrane 

  • A concrete moisture sealer 

By using these materials, you can keep your carpet and foundation safe from any damage caused by moisture seepage. It will also help extend the life of your floor and make sure it looks good for years to come!


It is important to protect your floors from excessive moisture by using appropriate moisture barriers such as polyethylene sheeting, epoxy sealer, and concrete moisture sealers. Proper ventilation and dehumidification can help keep humidity levels low and prevent dampness from forming in concrete slabs. 

If you aren’t sure which is the best way to stop moisture in your concrete floor or have reason to believe that you have a concrete slab with no moisture barrier, it is best to consult a professional. They have several tools and techniques to minimize the damage or the time required to waterproof your concrete slab and ensure that your floors stay safe from damage caused by water infiltration.

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