Can You Use AquaDefense On Concrete Floor? (Explained)

AquaDefense by Mapei has already established its name as a leading waterproofing and crack isolation membrane.

This quick-drying and advanced liquid-rubber formula does a marvelous job of preventing moisture from passing through and the development of cracks on tiles.

After application, AquaDefense dries into a thin barrier that protects floors located below from water damage.

Mapei AquaDefense is a highly effective waterproofing membrane that professional contractors and DIY builders use.

Though highly beneficial, AquaDefense is designed to be used on a particular set of substrates. Is concrete one of them?

If you want to waterproof and tile over a concrete floor, it’s crucial to determine whether AquaDefense is recommended for use on concrete floors.

Concrete floor

Can You Use AquaDefense on Concrete Floors?

Concrete is one of the ideal substrates recommended for AquaDefense use by the manufacturer, Mapei.

They mention this on their website and explain that besides concrete, AquaDefense can also be used on ceramic and plywood finishes. Therefore, if you were considering using AquaDefense to waterproof a concrete floor, this is a green light.

Even though concrete floors are a suitable substrate for AquaDefense, you need to know a few things.

Tips on Using AquaDefense on a Concrete Floor

AquaDefense will adhere to a concrete floor, waterproof it, and prevent cracks from forming on tiles. However, there are a couple of things that can go wrong. And before you embark on your project, it’s worth noting these things.

First, AquaDefense should be applied over a dry, stable, solid, and structurally sound concrete floor. This is as per the guidelines provided by Mapei.

Secondly, you should not apply AquaDefense over a new concrete floor. Give it at least two to four weeks, so it fully dries before applying a layer of AquaDefense. When concrete dries, it shrinks.

Therefore, the layer of AquaDefense may shrink alongside it. In case there are tiles on top, there is a good chance that the tiles will crack. Avoid applying it on new concrete to prevent AquaDefense failure.

AquaDefense must be applied to dry concrete. If there is a lot of moisture within the concrete floor, the AquaDefense may take longer to dry. When that happens, the risk of efflorescence is high.

It’s a good idea to ensure any drains near the concrete floor don’t leak. If this project is being done outdoors, you can wait for the dry months when it rarely rains.

For outdoor concrete floors such as balconies or driveways, you should use a more durable waterproofing product such as Mapelastic Smart. This is a two-component cementitious mortar that has better waterproofing abilities than AquaDefense.

Do not apply AquaDefense over damaged or cracked concrete floors. Understandably, a lot of DIY builders prefer to take shortcuts. But using AquaDefense over cracked concrete floors is a shortcut that will come to haunt you a few months later.

If the concrete is damaged, plan how you will repair it. If cracks exist, fill them in first and let them cure before laying AquaDefense.

Always clean the concrete before applying AquaDefense. Concrete floors that have been around for very long may have accumulated contaminants such as adhesive, grease, oil, and a wide range of substances. These contaminants can affect the adhesion of AquaDefense to the concrete floor.

You should also ensure the concrete floor has enough surface profile (CSP). A CSP of 1 to 3 will bond better to AquaDefense and tiles.

If the concrete floor isn’t flat, you can use a primer. For compatibility purposes, use a primer that can work with AquaDefense. Examples include Planitop Fast 330 or Eco Prim T Plus. A leveler can also come in handy.

MAPEI AquaDefense

How to Apply AquaDefense Over Concrete Floors?

AquaDefense is very easy to use because it comes as a premixed formula. To apply it over concrete, follow this step-by-step guide.

Step 1 – Inspect the Concrete Floor for Cracks or Damage

If you spot either damage or cracks, that will take you several steps back because you will have to fix any problems with the floor. But if there are none, you can proceed to the next step.

Step 2 – Clean the Concrete Floor

Liquid dish soap is usually strong enough to get rid of any contaminants that may be on the concrete floor. Pour a mixture of dish soap and water, then scrub it with a brush.

Rinse it with water and give the floor a couple of days to dry thoroughly. Remember, AquaDefense doesn’t do very well under moisture.

Step 3 – Apply the AquaDefense with a Roller

You can use many tools to apply AquaDefense on a concrete floor, but the best option is a roller brush. This type of brush allows you to apply a layer that is thin enough without taking up a lot of time.

Brush the product all over the concrete floor. Pay keen attention to the corners.

Step 4 – Let It Dry Before Flood Testing

AquaDefense dries within thirty to fifty minutes. However, for it to fully cure, you need to give it around 12 hours. This will depend on your area of residence and the climate. Once it dries, you can flood-test the AquaDefense and see if it works. If everything goes well, you can then lay the tiles.

What Benefits Do You Get from Using AquaDefense Over a Concrete Floor?

We have already established that AquaDefense can be used on a concrete floor. However, why should you use AquaDefense in the first place? What benefits does it offer on a concrete floor?

• It Waterproofs the Concrete – Concrete is a highly porous material. That is, it easily lets water through. If you have a concrete floor and let’s assume you want to build a shower on top of it.

If you tile directly over it, there is a high chance that water will pass through to the rooms below, which will be a disaster. With a layer of AquaDefense, you can shield the rooms below from water damage.

• It Facilitates Tile Installation – Yes, concrete is a suitable tiling substrate. But so is AquaDefense. If you plan to tile a concrete floor, you can waterproof it with a tile-friendly membrane.

• It Isolates Cracks – Another benefit that makes AquaDefense a popular option is that it isolates cracks. AquaDefense creates a thin membrane that absorbs any movements within the concrete floor.

Without such a membrane, these movements would reach the tiles and crack them. Having a barrier in between goes a long way in ensuring your tiles last for the longest time over a concrete floor.

• It is Easier to Use than Most Waterproofing Products – You can use a lot of waterproofing and crack isolation products instead of AquaDefense. But one of the areas it shines the most is how easy it is to apply.

To apply AquaDefense, you only need to grab a roller, dip in the premixed formula and apply it on the concrete floor. There is no cutting or drilling involved.

Will a Floor Waterproofed with AquaDefense Leak?

The answer is both yes and no. AquaDefense is a remarkable waterproofing membrane. However, it will leak if you apply it incorrectly or leave voids on the concrete floor.

It would be best to be very careful when using AquaDefense over your floor. Even though the manufacturer only recommends a thin layer, ensure it’s not too thin to the point that there are voids in between.

You can’t compare a concrete floor to a drywall. Concrete isn’t smooth, and the particles are located slightly apart.

You need to get a considerable amount of AquaDefense between these particles to create a solid and uniform membrane.

How Does AquaDefense Compare to Concrete Sealers?

AquaDefense though effective is no match for concrete sealers. The latter are products that are made explicitly for waterproof concrete floors.

The likes of Foundation Armor and Masonry Defender concrete sealers will prevent water from passing through your concrete floor and can take up a lot of abuse. However, some of these sealers lack AquaDefense crack isolation capabilities.

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