If you are building a basement or have a concrete garage floor, you may want to consider using a concrete sealant to protect it from water damage, mold and ensure your garage lasts a long time.
Concrete sealant forms an impenetrable layer over your concrete floor. Good sealant will also work into the tiny pores in the concrete, sealing out moisture and covering cracks to reduce damage and mold. Sealing a concrete floor works to maintain an even color and blocks stains as well.
There are two main types of sealants: film formers and penetrating. Film formers do what the names says--they form a film that protects the concrete from water damage and leave a shine on the surface. Penetrating sealers penetrate into the concrete and are used to resist stains and water. Most will not change the color of the concrete. Each sealer has varieties in terms of colors and the final look. Some leave a wet look, others a dry shine.
Concrete sealers have two main features. They repel water, and they bond. They will bond to the concrete itself and in doing so, they help to resist and repel stains and water. How far the sealer penetrates into the concrete is determined by the liquidity of the solution and size of the liquid molecules. Other features include color, which varies by sealant, and gloss.
Applying a concrete sealer has two effects. It will stop moisture from getting into your concrete and maintain the integrity of the surface. The sealant does this by reducing the amount of absorption of moisture into the pores. Each time water is absorbed into the concrete, it must breathe to release it. When water freezes, it causes damage in the concrete because the water expands. Over time, this weakens the concrete. Acids and other liquids can also work their way into concrete pores to cause damage, so sealant prevents this as well.
If you are choosing your sealant, you need to consider where your concrete floor is, what types of damage you are trying to prevent, and which type of surface you want to create. If you want a shiny surface and are not as concerned about damage from water, choose a film sealant. For the most protection against water, a penetrator is your best option. Each comes in several colors and thicknesses. For concrete that is submerged under water or exposed to the weather, choose a stronger sealant made for those conditions.