While concrete may seem like an extremely strong building material, it is naturally porous and prone to water absorption. Beginning on the surface, concrete is filled with tiny pores and hairline cracks that extend throughout the material. While concrete may seem strong enough without any treatment, it is not as strong and protected as it can be. The tiny pores of a concrete slab and foundation can absorb water if not treated with a waterproofing concrete sealer. Basements are one of the most vulnerable areas of a home and if left untreated they are at high risk of flooding, excessive mold and mildew build-up and the passage of radon gases.

While trace amounts of moisture are not a problem, water that can physically pass through the concrete and drip through the walls will lead to mold and mildew build-up and dampness. A lot of times basements will not completely flood, but they will have seepage. Seepage occurs when water creeps in through the pores and capillary tracts of the concrete thus soaking into the finished walls and carpets. Seepage usually occurs through small cracks in a basement foundation or through extremely porous concrete blocks.

The best way to remediate and prevent water absorption is to use a basement waterproofing sealer. In order to figure out the best basement waterproofing sealer, we first must assess the situation: Are you currently experiencing active water seepage or water damage? If so, there are a few steps you need to take before you can begin to think about sealing your concrete.

  1. Where is the water coming from? If you notice the water is leaking from a crack, you must first seal the crack. Is it a horizontal or vertical crack? Is the leak coming from a seam or an expansion joint? Contact a concrete crack repair kit specialist or seal the crack yourself with a crack repair product.
  2. Determine how much moisture is present in the concrete itself by performing a Calcium Chloride Test. Once the cracks are sealed and you have determined how much moisture is present in your basement, a sealer can be chosen and applied to protect the concrete from future water damage.
  3. If the moisture in the concrete is greater than 3 pounds yet less than 20 pounds per 1,000 square feet per 24 hours per ASTM F1869, a moisture vapor barrier coating is going to the best option.
  4. If the moisture in the concrete is less than 4% by a concrete moisture meter you can use a penetrating concrete sealer. Penetrating concrete sealers are also great for preventatively sealing concrete basements.

In order to determine how much moisture is present it is best to perform a calcium chloride test to determine the moisture vapor emission rate (MVER) of a concrete slab. To perform the test, a small amount of calcium chloride (salt) is placed under plastic on a clean piece of concrete. The calcium chloride (salt) absorbs the moisture coming from the concrete slab over a period of about 72 hours. The weight gain of the calcium chloride is then measured and the moisture vapor emission rate MVER is calculated. If a high amount of moisture is present in the concrete (over 3 lb according to a calcium chloride test) it is best to use a moisture vapor barrier coating. A calcium chloride test can be purchased directly through Amazon for about 18 USD.

When it comes to sealing a basement there are a few different routes you can take. You can hire a professional basement waterproofing company to come to your home, assess the damage and charge you an astronomical amount of money. Or you can use an easy to apply, industrial grade waterproofing sealer and do it yourself.

There are a few reasons why you want to seize the moment and seal your basement before winter. Spring brings melting, flooding and an all-around wet season. When snow melts, and the ground is wet, basements are prone to flooding, and water damage.

Choosing a Treatment

The easiest way to deal with basement water problems is, of course, to prevent them. By using a concrete sealer proactively, you can stop basement floors and walls from ever seeping water. While it is better to apply a concrete sealer as soon as possible, you can also apply it later, though you have to be sure that you properly clean the slab and remove all paint before beginning the application process.

When sealing basement floors and foundation walls the best concrete sealers to use are the Lithi-Tek 4500 primer followed by the Siloxa-Tek 8510 waterproofing sealer.

If you are going to be installing flooring in the basement, it is best to use a moisture vapor barrier coating like the Vapor-Tek 440.

Alternatively, if your concrete has never had a moisture or dampness problem and you are looking for a preventative, cost-effective solution, use the Lithi-Tek 9500.

Why Ghostshield?

Vapor-Tek 440 - Moisture Vapor Barrier Coating: Buy Now

  • Controls moisture vapor emission rates up to 20lb/24 hr/1000ft prior to the application of hardwood flooring, carpet and tile
  • Resists water vapor transmission and hydrostatic pressure
  • Stops mold & mildew, reducing cleaning frequency
  • Leaves an amber clear, high gloss finish
  • Lifespan: +10 Years

Lithi-Tek 9500 - Penetrating Concrete Waterproofer & Densifier: Buy Now

  • Cost effective - 1 gallon mixes with water to cover up to 500SF
  • Resists mold & mildew reducing cleaning frequency and dampness
  • Leaves a clear, natural finish that will never yellow, peel, flake or delaminate
  • Lifespan: +5 years
8510 Concrete Sealer Bottle Image

Siloxa-Tek 8510

Water, Salt & Oil Repel +

9500 Concrete Sealer Bottle Image

Lithi-Tek 9500

Waterproofer/Densifier

440 Concrete Sealer Bottle Image

Vapor-Tek 440

Vapor Barrier Coating

4500 Concrete Sealer Bottle Image

Lithi-Tek 4500

Lithium-Based Densifier

Published Monday 20th of December 2021 // Updated Tuesday 26th of October 2021

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