How Long Does It Take for Concrete Sealer Smell to Go Away? 

 July 9, 2021

By  Dale Keese

Some types of concrete sealers emit toxic fumes. It’s fine if the smell dissipates within a particular time frame. But if not, it is a health hazard for those who are in and around it. Here’s what you need to know about that process.

The smell of concrete sealer will go away in a few hours to a few days at most when you apply the right amount of sealer in the right atmospheric conditions and ventilate the space well enough during the drying period.

Now, if you are planning to apply a sealer to your newly paved concrete surface, as you should, there are more than a couple of things you should know before you pick the right kind of sealer for the surface. While most solvents dry up in about one day, the smell lingers a little longer. Here’s the problem with it and how you can solve it.

How Long Does Concrete Sealer Smell

A sealer is applied to concrete after the concrete has dried up completely. That process, called "curing", usually takes up to 28 days although there are a few shortcuts that can help speed up the curing process.

Now, sealers are used to create a coating to protect the concrete from environmental factors like rain and expected wear and tear like traffic. This makes the concrete more durable. It is an easy way to help prevent cracks and stains in the concrete and increase the lifespan of the concrete.

Some of these sealers are also used for decorative purposes. They provide a glossy finish which gives the concrete surface a wet look. If you want a dry look, you can opt for matting additives so as to give it that kind of finish.

That is the function of a sealer. But much like painting a house, when you apply sealer to a concrete surface, it leaves a particular kind of smell.

Let’s talk about that.

Why Does Concrete Sealer Smell?

There are different types of sealers but they usually come in two forms—water based and solvent based. Unfortunately, both of them contain volatile organic compounds or VOCs to some extent.

The water-based ones have a relatively lower VOC count. They are also not hazardous or flammable. Their smell is tolerable and it feels, as mentioned before, somewhat like you painted the walls in a house.

Solvent-based sealers, on the other hand, have a higher level of VOCs and they also produce a strong smell that is bordering on offensive. These sealers are also highly flammable because some of them are petroleum based. This means, if you don’t take precautions, it can lead to explosions.

But it is not just about tolerating the smell and avoiding fire hazards. It is important to know that the smell emitted by some sealers is very dangerous. That is why those who are working on the site must use protective gear like respirators to protect themselves from the health hazards of this product. Make sure that your entire body is covered in cloth so that the sealer does not touch your skin which might crack due to dryness.

In case your skin does come in contact with the sealer, you must apply lotion or hand cream. If you happen to breathe in the fumes, you should get some fresh air right away.

And if things get so bad that someone accidentally swallows some sealer, make sure they don’t vomit and give them a good deal of water or milk. If the person happens to vomit, get them medical attention immediately. Yes, that’s how dangerous these fumes can be.

Now, if you are working in a confined space indoors, it is recommended that along with the gear, you ventilate the place both while the work is going on and afterward so that the damage is minimized.

Now, this foul odor comes from the fact that most sealers are made by mixing solid and liquid materials. And all of them need to dry for about 24 hours after they have been applied to a concrete surface.

While it is drying, which is technically called curing, the liquid material in the sealer evaporates and the solid material creates the protective layer. The liquid that evaporates is what causes that unbearable and probably dangerous foul smell.

This odor will linger for as long as the liquid is evaporating and the rate at which that happens is usually an indicator of how long the smell will last. Now, evaporation usually depends on factors like the temperature of the air, its movement, air pressure, etc.

But the amount of time it takes depends on the number of sealer coatings applied on the concrete. If you do too many layers and don’t air out the place, it will obviously take longer. Add to that, if the region is highly humid it takes a lot more time for the sealer to evaporate and the smell to disperse.

Concrete Sealer Smell in House

Now, when you apply a sealer in smaller places or inside the house, you need to be extra careful. But here’s essentially what you need to know about lingering of the odor.

The process of using ventilation, both natural and artificial, to quicken drying the sealer is technically called air exchange and the more it happens, the faster you will be able to get rid of the smell.

You can take some precautions—which we will talk about in a minute—but you are bound to smell the solvent anywhere from a few hours to a couple of days, no matter what. Two days is the worst-case scenario.

But even after that time frame, if you can still smell the sealer, well, then something has gone wrong. In any case, always read the instructions on the product so that you know exactly how long the air exchange needs to happen.

How to Get Rid of Concrete Sealer Smell

Now, let’s talk about the precautions one needs to take when dealing with the smell of a sealer and how to get rid of it.

The best way to control or get rid of this odor is to:

  • Apply concrete sealer when the humidity of the room is low.
  • Make sure there is cross ventilation in the room.
  • Get a dehumidifier for the room so that the sealer dries up sooner and clears out the air.
  • Make sure the fans are facing the floor and the windows and doors are open.
  • Get products that are only made of solids and no solvents at all. Eliminate the process of evaporation and dispersion altogether.
  • Make sure the right amount of sealer is applied so that the curing process does not take longer than it absolutely has to.

While you are learning about precautions, it is also a good idea to keep kids and pets away from this area. Some people are also found to be allergic to some solvents like petroleum in the sealer. Read the details on the product to make sure you go for water-based solvents and avoid such mishaps.

Frequently Asked Questions

Are Concrete Sealant Fumes Dangerous?

Not all of them are dangerous. Sealers made of water-based solvents have a low count of VOCs. They are also not flammable, unlike some solvent-based sealers which contain petroleum.

The fumes emitted by the second type of sealer are dangerous and also leave a foul smell. In order to escape these fumes, precautions have to be taken which have been mentioned above.

Is Water Based Concrete Sealer Toxic?

Water based concrete sealers do contain some amount of VOCs but they are not toxic. For instance, acrylic sealers are considered water-based sealers and they contain particles of polymer which are dispersed into the water in the sealer.

When the sealer is applied to the concrete surface and it starts to cure or dry up, the water in it evaporates and the polymer particles start bonding with each other. By the time the sealer is cured, these particles merge into each other and make a coating.

So what is evaporating is just water and a small amount of VOCs. This is what makes these solvents a preferred option not just for the sake of human health but also for the environment.

About the author

Hey, I'm Dale Keese.. thanks for reading.. hopefully this article can save you some time and trouble with your sealing job. I'm also in the process of making some video walk-throughs for youtube so check back soon! thanks

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