Fraud Blocker Is Polished Concrete Waterproof? Concrete Floor Systems

Is Polished Concrete Waterproof?

When it comes to indoor flooring, polished concrete floors can provide sturdy, easy-to-maintain, long-lasting surfaces. Its inherent strength and durability far outweigh those of tile, linoleum, and other flooring options.

To make a concrete floor more attractive and even more resistant to stains, we often treat them, which creates polished concrete floors. They look great, but is polished concrete waterproof?

Why Polish Concrete?

Some might wonder what benefits polished concrete brings since concrete on its own is pretty durable. However, concrete has weaknesses, and polishing it can help address those.

Most notably, concrete is a porous material. When it gets wet, moisture can seep into those tiny holes. In the case of an outdoor sidewalk, that moisture will usually evaporate quickly with few ill effects.

But an indoor concrete floor might not shed that moisture as fast. Depending on the space housing the floor, some possible undesirable outcomes from excess moisture might be worse than others, but none of them are good.

Fungal Growth

While some researchers have experimented with using fungi to seal cracks in concrete, a fungus still constitutes a threat to your concrete and the health of the people walking on it. Not only fungi but molds can grow in concrete pores on a wet area of concrete. 

A slab of polished concrete helps repel any water that might take long-term residence in the material’s pores.

Weakened Structure

Water, the only universal solvent, can eventually ruin anything, including concrete. It often ruins things through erosion, but unless you have moving water over your concrete, it probably won’t be an issue for you.

What can damage your concrete flooring is corrosion and other chemical elements and reactions. These can cause real problems and lasting damage. Water, left to stand on your concrete, can seep through until it reaches the rebar inside. Once it begins the oxidization process, the concrete structure’s support system becomes compromised.

Freezing and Thawing

While more applicable to outdoor concrete slabs, wet concrete is susceptible to cracks. When water freezes, it expands. When it’s in the concrete pores, that water has the potential to, upon expansion, damage the material from within. 

Even if one freeze doesn’t bring about cracking, repeated freezing and thawing cycles will stress the concrete floor, and cracks will eventually appear.


Sealed concrete differs from polished concrete. Sealed concrete has, as the name suggests, a sealant coat applied on top of the concrete. 

A floor with this sealant will be highly resistant to stains, but since the sealant itself is applied to the concrete and is, therefore, a separate part of the floor, it can pull away from the surface and become, for lack of a better word, unsealed.

Much of the stained concrete we find in residential applications is seal concrete, and the stain gets applied to the surface before the concrete sealer. The sealer, in turn, acts more as a protectant of the stain than the concrete itself.

On the other hand, polished concrete floors incorporate sealant into the concrete itself. An installer creates a concrete surface impervious to water by incorporating into the material a concrete densifier. 

By working the densifier into the concrete, the installer creates a polished concrete slab that is one piece rather than the two-piece construction of a concrete slab with a coat of sealer.

The floor then gets polished mechanically to even out the finish and, if you want, make it as shiny or matte-like as you wish.

Waterproofing the Concrete

Having waterproof concrete is more than a safety issue. Long-term exposure to moisture can cause several types of problems. 

So, is polished concrete waterproof? Yes, polished concrete’s waterproof nature is a critical tool for ensuring that your floor doesn’t crack or otherwise become compromised. 

Beyond the densifiers used in the installation process, installers can increase polished concrete’s waterproofing by adding material.

This involves installing two thinner slabs after surface preparation and can lead to even better protection for your floor. Installers lay concrete overlays that function as a foundation. 

Once it has cured, a waterproof membrane goes down before a second slab gets poured.

This second slab—the visible one—gets the densifiers worked into it and undergoes polishing so that the final product looks the way the customer wants it to look.

After Installation

While a polished concrete floor is a low-maintenance flooring option, as we all know, if you take care of your things, your things will take care of you. Flooring is no exception, so you will need some professional maintenance from time to time.

Depending on the amount of traffic your polished concrete floor sees, you may need to have it professionally resealed anywhere from every two to five years. 

A professional will identify and repair any stains that have set or chips in the finish or the concrete itself. After that, the application of a protectant follows to return the floor to the original stain-resistant state it was in before it underwent several years of regular foot and vehicle traffic.

This periodic refinishing does not replace the daily or weekly maintenance recommended above. You’ll still need to sweep, mop, and generally keep up with the floor if you want to get the most use out of it and keep it in good shape. 

Pros and Cons of Polished Concrete

While the pros outweigh the cons, polished concrete has a few drawbacks.


  • It’s affordable. Starting at just a few dollars per square foot, polished concrete can be a budget-friendly flooring choice. It can get pricier than that, but you’ll still incur savings by not having to redo your floors very often, if at all.
  • It’s durable. Polished concrete brings more durability to your flooring than other materials. We know concrete is strong, especially when standing up to foot traffic and even heavy equipment rolling across it. By the nature of its polished finish, it’s also waterproof and stain-resistant.
  • It’s easily maintained. With little more than a mop and a broom, you can properly care for your polished concrete floor. As a result, it’s easy to maintain, so you’ll be less likely to forget it because you don’t want to deal with the hassle. Since it’s no hassle at all, that solves that problem.
  • It’s long-lasting. Provided you take care of your polished concrete floor, it will last for decades. It may cost more than a roll of linoleum, but it will outlast just about any other flooring option you can think of.
  • It’s resistant to slips. Polished concrete can include texturing or even have non-slip compounds installed with the floor to keep the traffic area resistant to slips and falls due to small amounts of moisture. 
  • It’s waterproof. Since the concrete pores are sealed, the polished concrete floor is waterproof, which means it’s also resistant to chemical spills and other caustic materials that may come into contact with it.


  • Concrete in the winter is cold, no matter how well it’s been sealed or polished. A cold floor can result in higher utility costs. 
  • Hard surfaces mean two things: the polished concrete floor isn’t very forgiving, so it can take its toll on the bodies of people who have to walk on it repeatedly. It also has little to no acoustic dampening properties, so a large room with a polished concrete floor can be loud.
  • Incorrect installation can be disastrous. If moisture is present during the installation or polishing processes, the floor can be doomed from the start, so be sure you use a professional installer for your polished concrete floor.


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