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Better Basement Finishing

Better Basement Finishing

Posted by Mike and Connie Hernandez on Feb 12th 2021

About basements and Inside concrete floors

Proper basement finishing differs from above-ground construction in many ways including taking into account different moisture and temperature conditions. These differences need to start from the earliest stages of planning. 

Any concrete floor below surface level (grade level) is always exposed to some level of humidity. Concrete is very porous and therefore it transfers moisture very easily from a humid environment to a dry environment. Many concrete foundations on the outside are treated with a black tar to prevent direct moisture transfer through the concrete. Usually this method works well for a few years. Overtime the tar becomes brittle and fails to prevent moisture transfer through the foundation.

SealGreen - ReUse Concrete Sealing has developed a line of SealGreen products to address this problem even when the outside foundation wall is already covered with dirt.

Our SealGreen Concrete Sealer (About SealGreen Concrete Sealer) can be sprayed on the inside of the concrete foundation wall that is not painted or treated with any other chemicals. Sealing these walls will mitigate the humidity (moisture vapor transfer) from the outside getting into the basement.  Less humidity in your basement keeps the temperatures warmer, enhances the ability of your air conditioner to work using less energy and enables your to achieve a good-looking painted surface on the concrete foundation walls. 

Humidity transfers from the cold humid environment (outside concrete foundation wall or floor) to a dry warm environment (inside your basement) through the concrete foundation walls. It is common to have a basement that is not finished show no humidity problems, but as a soon as the inside of the basement is warmed by the air-conditioning unit it will start drawing humidity through the floor and the walls if untreated. Air conditioning systems warm the air by drawing all the cold moisture out of the air. This dries the room and starts pulling moisture from concrete floors and walls.  A common solution to this problem is to put dehumidifiers into basements.  These simply draw more moisture through the floor and the walls exacerbating the humidity problems.

There are many sealers in the industry penetrating, acrylics, epoxies, polyurethanes, etc. (Concrete Sealer Types) They are all designed for special purposes so before sealing concrete it is important to define the purpose of why you are sealing.

  1. When you are addressing humidity problems in concrete you have to select a sealer that will stop the humid molecules from transferring through the floor as well as allowing the concrete to breathe to prevent sealer failure.
  2. All sealers with moisture vapor barrier capabilities have a maximum limit to stop humidity transfer. This is why a humidity test is important before a sealer is applied. A humidity test will provide a number that can be easily related to the vapor barrier capabilities of the sealer.

The typical signs of a basement or inside floor with humidity problems are:

1. Humidity smell

2. White powder on the floor (efflorescence – humidity is leaching salts from the concrete to the surface)

3. Paint peeling off the floor

4. Random dark areas on the concrete surface 

5. When a plastic container is set on top of concrete after a few days it leaves a humid spot under the item.

6. Vinyl floor peeling off the floor

7. Loose ceramic tiles or white powder showing on the grout.

8. Carpet padding melting or sticking to the concrete surface creating a strange smell

You get these benefits from sealing your inside or basement concrete floors:

1. Can provide a beautiful stained floor (Basement Pictures in Photo Album)

2. Eliminates the problem of having carpet in the basement

3. Easy and simple to clean and maintain

4. Eliminate humidity and reduce Radon Gas in the basement (Radon gas is transferred into the basement on the moisture vapor transfer).

5. Total green flooring solution (no solvents)

6. Easy to clean up pet accidents – no smell entrapped in concrete

7. Healthier environment because floor does not dust

8. Healthier environment which mitigates mold growth when the floor is covered with a rug or carpet

9. More light reflectivity from the floor

10. Not damageable from flood waters

11. By mitigating humidity you will create a warmer environment

12. Sealed walls can be painted any color to enhance the room

 Easy Six Step System to solve your humidity problems and have a great usable space:

1. Test floor for humidity levels

2. Define final look – Clear , variegated or solid color

3. Prepare the floor

4. Stain floor

5. Seal floor with vapor barrier sealer

6. Seal floor with gloss sealer

Other Notes:

Proper basement finishing differs from above-ground construction in many ways including taking into account different moisture and temperature conditions. These differences need to start from the earliest stages of planning. 

Q: What is the trickiest part of finishing a basement?
The trickiest part of finishing a basement is recognizing how the situation differs from above-ground construction. So many common basement finishing design details are simply borrowed from ordinary construction. This is a mistake because above-ground construction methods don’t take into account the unique moisture and temperature conditions many basements have. Even professional builders don’t always understand the current best practices when it comes to finishing a basement optimally.

Q: What 3 things should you keep in mind when finishing a basement?

1. Choose building methods that offer some resistance to liquid water and water vapor. Even a dry basement can sometimes have unexpected moisture (a flooded basement). You don’t want this to be a catastrophe.
2. Insulation alone will never make for a toasty basement floor temperature.
3. With the right information you can do a better job finishing a basement than a professional because as a homeowner you can take more time to get key details right. The slower pace of DIY construction also means you have more time to make optimal decisions about everything from room layout to plumbing fixtures.