Concrete sealers are used to protect areas from water damage and staining. They can make a place pop and even look glossy, if that’s the kind of sealer you pick. But a little bit of rain while it is still curing or drying can literally put a dampener on the party.
If you know your sealers well, you will know exactly the kind of weather for the project to take off smoothly. Otherwise, you will have to add a second coating and wait the same number of days to finish the task at hand. Here’s what you need to know about the different varieties on the market.
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How Long Before It Can Rain on Concrete Sealer
We look at the most popular choices and discuss how long it takes for them to dry on the surface and finish the curing process entirely. Take a look.
Penetrating Concrete Sealer
There are different types of penetrating concrete sealers like siloxanes, siliconates and silanes in the market. They are called so because they penetrate the concrete to form a shield that protects the surface from moisture. But they are also breathable materials so that the vapor can escape the surface.
Now, they are used to prevent discoloration when water is absorbed. And these sealers work quietly under the surface level. After a penetrating concrete sealer is first applied, the surface might dry up in just about 30 minutes but remember that underneath the surface, the sealer is still doing its job for at least the following 72 hours.
If you have one of these, you can walk around on the surface within a few hours after applying it but the concrete must stay dry for a little over a day. Let’s say that is about 36 hours just to be sure that the sealer does its job without interruptions.
The surface of silicate concrete sealers, on the other hand, also dries up within 30 minutes but the work underneath goes on for about 90 days. And this is faster than some other varieties that are water based because this is a solvent-based sealer.
Acrylic Concrete Sealer
Speaking of water-based sealers, this is one. So, for starters, be prepared to give it more time. That is because the drying process, called coalescence, is a bit more complicated with this variety. Temperature and humidity play a huge role in the drying of acrylic concrete sealers.
With these sealers, the water and coalescing solvent evaporate and merge with the acrylic particles. This creates the sealer film. If this happens when the temperature is too low or the humidity is too high, the solvent will vaporize before the water. The latex particles are left separated before the drying and you will notice that the sealer becomes dry and powdery.
You will see a similar result if you use these sealers on a pool deck or other areas with water puddles. This can cause blushing because of the high levels of moisture. It is important to read the product specifications of a water-based sealer.
Typically, these are great for interiors and exteriors because they make the surface look glossy and polished. The process of drying takes anywhere between four and 12 hours on the surface unlike penetrating sealers which take only about 30 minutes. You can walk on it after a few hours but expect it to take about 48 hours to harden. If your sealer is new, make sure it does not get wet for the first 36 to 48 hours.
Stamped Concrete Sealer
Stamped concrete sealer is a variety that thrives but under specific weather conditions. When it is first applied, you cannot walk on the surface until it is completely dry and hardened. Obviously, placing objects on it and driving is a complete no-no. And rain can be a total buzzkill when the surface is still curing or drying.
So, a smart move is to check your weather forecast before starting the project. Pick a sunny day to pour and stamp the concrete. And make sure the following few days are also sunny.
Stamped concrete drys well in 3-5 days but for it to fully cure. If there is even a drizzle in the first 36 hours, you are in trouble. After that time period, it can handle some amount of water. But that is just the surface.
Now, if you are not sure about the weather but need to go ahead with the project, there are some precautions you can take to protect the surface while it is drying. Plastic sheeting would be an obvious choice to cover up a curing surface.
But remember that plastic collects little puddles of water which can cause problems if it gets into the surface. It also stops the moisture from escaping through the surface and ends up causing discoloration and leaving blotches on the surface.
You can put a straw on the surface before going forward with the plastic sheeting. If you can, go for a tent over the structure to prevent discoloration and blotching on the surface.
If you have backwash from a swimming pool or sprinklers, you might want to make sure that the concrete surface is protected from these structures during the drying period. You might see some discoloration while it is drying and that is natural as long as you are sure the surface was not exposed to rain.
Concrete Driveway Sealer
There are different types of concrete driveway sealers, from penetrating sealers to acrylic-based sealers to epoxy sealers.
For the pricing, acrylic sealers are the best performers. Typically, you will find them blended with polyurethanes or epoxies for water resistance and improved durability.
Epoxy sealers are costlier than acrylics and are more slippery too. If they are not allowed to dry properly, you will notice fogging or white hazing. There are different types of epoxies and the drying time varies for each but you must let it dry for at least 10-12 hours before you consider walking on the surface. Underneath, it will still be drying for 36 to 48 hours.
What Happens If It Rains on Concrete Sealer
This result is strictly specific to the type of sealer used. But every sealer works best when the weather is moderately warm. A sunny day with a temperature ranging between 60 and 70 degrees Fahrenheit is a good day.
If it rains before the sealer has dried, some varieties look cloudy. This is particularly true if you were aiming for a glossy look. Prepare to take up this project when you see there are at least 14 dry days which gives the moisture time to escape before the sealing begins.
Frequently Asked Questions
Can concrete sealing be done in the rain?
Definitely not. It will cause the sealer to blister and bubble, especially if it is newly sealed. You must do this when the weather is rain-free for at least a day.
How long after rain can I apply concrete sealer?
There are some water-based acrylic and polyurethane hybrid sealers that can be applied on damp surfaces. These are non-hazardous and do not produce much odor either. So, check the specs to avoid spotting.
Can I fix concrete sealer that got rained on?
Thankfully, yes. And it is not very complicated either. It will look stained but you can fix the sealing issue by applying a second coat that will melt the first one. While the sealer is wet, back roll it to clear the blisters and bubbles.