Concrete sealer protects concrete from water damage and spills. But, to get good protection, you need enough coats of concrete sealer. So, how many coats of concrete sealer should you apply?
You should apply two coats of concrete sealer on a concrete surface. The first coat serves as the undercoat or substrate to seal the concrete surface. This coat will most likely disappear into the concrete and you’ll need the second coat to provide the finish and cover the first coat.
It’s not recommended to apply more than 2 coats of concrete sealer to prevent the finish from developing bubbles and turning tacky.
This post reveals more about the required number of concrete sealer coats including the number of coats needed for different types of concrete sealers. Let’s dive in.
Why Does The Number Of Coats Matter For Concrete Sealer?
The number of coats matters for concrete sealers because it determines the type of finish you’ll get and how well the concrete sealer will repel moisture from the concrete surface. It also determines how long it will take the concrete sealer to dry and the color shade you’ll get when it’s dry.
The number of coats determines how well the sealer finish will protect the concrete against moisture. More coats of the sealer equal more protection against moisture while fewer coats equal less protection against moisture. Also, more coats of concrete sealer will take longer to dry than fewer coats.
If you are working with a tinted concrete sealer, the number of coats also determines the color shade you’ll get when the finish dries. Tinted concrete sealers contain a color pack to give the sealer finish some color.
More coats of a tinted concrete sealer will give you more color than fewer coats. Even if you use a transparent sealer, more coats mean that the finish will be less transparent and blurrier. On the other hand, fewer coats of a transparent concrete sealer will be clearer and less blurry.
So, you see that regardless of the type of concrete sealer that you use, the number of coats will always matter, and when it comes to sealers, applying more coats is not always a good idea.
How To Know If You Need A Second Coat Of Concrete Sealer?
To know if you need a second coat of concrete sealer, you should inspect the first coat after it has dried. Usually, the first coat of concrete sealer is absorbed into the concrete surface after application. If this is the case, then you need a second coat to provide coverage over the concrete surface.
If you are using a tinted concrete sealer and the first coat turns out lighter than you want, you should apply a second coat to give more color. More coats of tinted concrete sealer give more color. You can check the user’s guide or manufacturer’s instructions for whatever concrete sealer you are using to know for sure if a second coat is recommended.
You can also try out the water test. For the water test, sprinkle some water directly on the first concrete sealer coating when it has cured. Usually, this takes 24 hours. If the water is absorbed into the finish, then you need another coat because the surface is still porous. However, if the water doesn’t absorb or affect the concrete in any way over a few hours, it means the one coat is perfect.
However, you should know that most concrete sealer manufacturers advise DIYers to apply 2 coats of the sealer for good coverage, waterproofing, and concrete protection.
What Happens If You Apply Too Many Coats Of Concrete Sealer?
Applying too many coats of concrete sealer will result in a blurry or whitish appearance. Over time, the concrete sealer will detach from the concrete surface and peel off gradually. When this happens, the concrete surface will have no protection against moisture stains.
Cconcrete sealers are thick and sometime paste-like in texture. What this means is that each coat you apply is or almost equivalent to two regular coats. This is why manufacturers recommend you apply only thin coats of the concrete sealer.
If you apply too many coats, it will result in the sealer being too much on the concrete surface. What follows is the thick coats will not dry properly. Instead of drying, the coats will trap moisture between them.
The trapped moisture causes the sealer to swell gradually and allows air to get in. The presence of air and moisture in transparent sealers will make it turn whitish or blurry while in tinted concrete sealers, the colors will appear messy or wet.
Over time, the sealer will detach from the concrete surface due to a lack of proper adhesion and peel off. At this stage, your concrete slab or floor is no longer protected from water damage or discoloration.
What Happens If You Don’t Apply Enough Coats Of Concrete Sealer?
When you don’t apply enough coats of concrete sealer, the sealer will not be waterproof when dry. Also, if you used a tinted sealer, you will not get enough color on the sealer finish. This is because the sealer will be absorbed in the concrete surface.
Usually, the first coat of concrete sealers is absorbed in the concrete surface. This is the substrate or undercoat that goes into the concrete to seal it from the inside. This first coat is usually unnoticeable since it penetrates the concrete so you usually need at least a second coat for good sealing, coverage, and protection.
If you don’t apply enough coats, the sealer will not protect the concrete from moisture completely and you won’t get a finish on the concrete. It will also take little effort to dent the concrete surface.
How Long To Wait Between Coats Of Concrete Sealer?
It’s advised to wait 2-6 hours between coats of concrete sealer. However, topical concrete sealers (concrete sealers that don’t penetrate) often take a few more hours to dry between coats.
To be sure how long to wait between coats, check the user’s guide of the concrete sealer that you are using. Manufacturers often indicate the dry time between coats on the user’s guide.
If you don’t have a user’s guide, you’ll need to keep tabs on the first coat to know when it is dry enough for a recoat. When you notice that the first sealer has been absorbed, you can apply a second coat.
Also, if the first coat is dry and hard, you can apply a second coat of the sealer. However, the best way to get a perfect finish is to wait before applying the second coat. You can’t go wrong even if you wait more than 6 hours between coats.
In summary, 2 coats of concrete sealer are enough on any concrete surface. You should always check and follow the manufacturer’s instructions when applying concrete sealer so you don’t mess up the finish.
Also, always leave enough dry time between coats of the concrete sealer. If you aren’t sure how long to wait between coats, just wait 6 hours.