Can you apply sealer on concrete after it sets?

In this article, we will explore this topic in detail and provide you with the answers you need.

Understanding Concrete Sealers

Before addressing the question at hand, it is essential to understand what concrete sealers are and how they work. Concrete sealers are protective coatings applied to hardened concrete surfaces to prevent moisture infiltration, stains, and damage caused by the exposure to chemicals or the environment. They act as a barrier against these substances, helping to preserve the appearance and structural integrity of the concrete for an extended period.

The Best Time to Apply Concrete Sealer

While concrete can be sealed after it sets, it is crucial to understand that the ideal time to apply a sealer is when the concrete is still fresh and curing. Applying a sealer during the curing process allows for better penetration and bonding, resulting in a more effective and long-lasting protection. Generally, sealers should be applied a few weeks after the concrete has been poured, once it has cured and hardened.

Applying Sealer on Fresh Concrete

When applying a sealer on fresh concrete, it is important to consider the type of sealer you are using. There are two common types: topical sealers and penetrating sealers.

1. Topical Sealers: These sealers create a protective film on the surface of the concrete. They offer excellent resistance against staining, UV rays, and water. Topical sealers are generally applied using a sprayer or roller. It is crucial to ensure that the concrete is fully dry and free from any contaminants before applying a topical sealer.
2. Penetrating Sealers: These sealers penetrate the concrete and chemically react with it to create a protective barrier within the material. Penetrating sealers do not alter the appearance or texture of the concrete but provide excellent resistance against water and some types of chemical exposure. They are typically applied using a roller or brush and require the concrete to be cleaned thoroughly before application.

Applying Sealer on Cured Concrete

If you missed the ideal window of opportunity to apply a sealer during the concrete curing process, you can still seal your concrete after it sets. However, there are a few things to consider:

1. Surface Preparation: Before applying a sealer on cured concrete, it is vital to prepare the surface adequately. This includes cleaning the concrete by removing any dirt, stains, or residues. Pressure washing, scrubbing, or using a concrete cleaner are common methods for surface preparation.
2. Repairs: Any cracks, spalls, or damaged areas on the concrete should be repaired before applying a sealer. This ensures a uniform and consistent seal on the surface.
3. Compatibility: Ensure that the sealer you choose is compatible with cured concrete. Consult the manufacturer’s instructions or seek professional advice to select the appropriate sealer for your specific situation.
4. Application: Apply the sealer according to the manufacturer’s instructions, usually using a roller or sprayer. It is crucial to ensure that the sealer is evenly distributed and that excess sealer is removed from the surface.

While it is ideal to apply a sealer on fresh concrete, it is possible to seal cured concrete effectively. The key factors to consider when doing so include proper surface preparation, repairing any damaged areas, ensuring compatibility between the sealer and cured concrete, and following the manufacturer’s instructions for application. By utilizing the right sealer and following the recommended processes, you can provide long-lasting protection and enhance the durability of your concrete surfaces.