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Can Drylok Be Used on Wet Walls

Our basements form an essential structural part of a home, but they also can serve as your man cave or personal storage unit. Whatever you decide to use it for, it’s important to waterproof its walls and avoid compromising the home’s structural integrity. But the conundrum comes in when you are trying to waterproof your walls to stop them from getting wet, but they often have to be dry for the waterproofing to be effectively applied.

With the wide range of products out there, it’s easy to get confused. Let’s have a look at what Drylok products can be used for damp and dry surfaces. The dampness of the wall surface influences which Drylok product will need to be used.

Drylok’s Powdered Masonry Waterproofer and Fast Plug must both be applied to wet walls. Drylok’s Original Masonry Waterproofer, Extreme Masonry Waterproofer, and Floor and Wall Masonry Waterproofer can all be used on slightly damp surfaces, but it isn’t recommended. Drylok mustn’t be used on uncured concrete.

Don’t Apply to Uncured Concrete

Curing concrete involves controlling the rate of moisture loss, increasing the strengthening time for the concrete and preventing shrinkage. This is a little outside of the scope of this article, but you can read a bit more about curing concrete in this helpful data sheet.

So, while the concrete is curing, it will be losing moisture. If you apply a waterproofing agent, such as Drylok to curing concrete, then the water vapor escaping from the concrete will build up between the concrete and the layer of Drylok. The result of this is that the Drylok cannot properly adhere to the surface of the concrete, compromising it’s function.

The effect of this can be evident in bubble formations on the wall and the lack of adhesion between coats, weakening the strength of the coat and not allowing Drylok itself to fully cure.

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You should allow concrete to cure for 28-30 days before applying Drylok.

Dry or Not Depends on the Product

Ultimately, it’s not a question of if Drylok can be used on a damp surface, but rather which Drylok products are best suited to be used on damp surfaces. Luckily, there is an extensive product range that caters to both damp and dry masonry surfaces.

I also want to point out the operative word: DAMP. You cannot apply Drylok to walls that are very wet, it won’t bind properly to the surface.

Drylok Products That Can Be Applied to Damp Surface

The following Drylok products can be applied to surfaces that are slightly damp, but this will not yield the best results.

Drylok Powdered Masonry Waterproofer must be applied to wet walls. The product application instructions clearly state the following:

“The area to be painted must be thoroughly dampened with water prior to painting. Do not paint it until the surface water has been absorbed.”

Application section of the product page.

Drylok Fast Plug is a quick-setting cement used to fill cracks and holes. The chosen surface needs to be thoroughly wet for optimal adhesion as excess water strengthens the bond and it takes about 3-5 minutes to set.

Not sure about the amount of product you need? Simply use the Drylok Coverage Area Calculator to get an accurate measurement.

Drylok Products That Should Be Applied to Dry Surface

The listed products can generally be applied using a brush, spray (only select products), or squeegee.

If your basement walls are wet, you will have to figure out why before you can implement an effective solution. Sometimes the water is seeping up through the basement walls themselves, or it is condensing on the walls as a result of humidity and incorrect basement insulation.

Wet Area for Patching

When holes and cracks present themselves, the surface needs to be wet as that excess water allows for Drylok Fast Plug to effectively soak into and adhere within the pores of the surface, creating a stronger bond and creating a durable base for additional waterproofers to adhere better too when applied.

Interior/Exterior Brick Sealer, 1 Gal - Clear, Satin, Acrylic Sealer for Vertical Walls - Masonry Sealer for Reducing Brick Dust & Making Interior Brick Walls Easy to Clean

How Long to Wait Between Coats (Dry Time)?

The waterproofing range from Drylok suggests waiting 2-3 hours between new coat applications with a minimum of 2 coats each. However, the Drylok Powdered Masonry Waterproofer suggests a 12 – 24 hours wait between coats.

The sealers range, however, have more specific drying times, which can range from 30 minutes for Drylok Siloxane 7 Brick & Masonry Penetrating Sealer and up to 2 hours for Drylok Natural Look Curing Membrane & Penetrating Sealer.

You also need to consider that drying time/curing time may be influenced by surrounding temperatures. If temperatures are too low, certain chemical reactions within the product may not occur leading to a longer dry time. But warmer environments with hot, dryer air may speed up the process.


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