A concrete sealer is a protective barrier designed to enhance the longevity of concrete surfaces and simplify the cleaning process. If you are working with new concrete, it is essential to allow it to cure properly, which typically requires waiting at least one month before applying any sealer.
Before commencing the application of a sealer, it is crucial to check the weather forecast. Sealers must be applied under dry conditions, as they will not adhere effectively to damp concrete. Additionally, the temperature should remain above 50 degrees Fahrenheit during both the application and the drying period, which can extend up to three days.
Types of Concrete Sealers
There are several types of concrete sealers available, each suited for different applications and preferences. These include acrylic, water-based, solvent-based, and penetrating sealers. Choosing the right type of sealer is vital for the success of your project.
Acrylic Sealers
Acrylic-based sealers offer a cost-effective method for adding a protective layer to concrete surfaces. They are known for their ease of application, making them a popular choice for DIY enthusiasts. Their relatively quick drying time is also advantageous for projects with tight deadlines. However, acrylic sealers may show signs of wear and tear more rapidly than other types, necessitating more frequent reapplication. These sealers are available in both water- and solvent-based formulations, with solvent-based options generally being more suitable for outdoor use.
Water-Based Sealers
Featuring low volatile organic compounds (VOCs), water-based sealers present a safer option, particularly for interior applications. They often provide a matte or low-sheen finish, preserving the natural appearance of the concrete, although glossier finishes are also available. Like acrylic sealers, water-based sealants are easy to apply, making them another accessible choice for DIY projects. It is important to note that water-based sealants cannot be applied over concrete that has been previously sealed with a solvent-based sealer. A test can be performed to determine the existing sealer type if unsure.
Solvent-Based Sealers
Solvent-based sealers are generally more durable than their water-based counterparts. Many solvent-based sealers create a high-gloss or wet look, which can enhance or darken the concrete's color, a characteristic preferred by some homeowners. Due to their high VOC content, it is imperative to use appropriate protective gear during application.
Penetrating Sealers
Penetrating sealers are an excellent choice for areas such as driveways, patios, and walkways. As their name suggests, they penetrate deeply into the concrete, establishing a protective barrier against damaging elements like moisture and de-icing salts. Penetrating sealers can be formulated as either water- or solvent-based.
Transparency and Finish Options
Beyond the base composition, concrete sealers also vary in transparency. Most sealers are transparent or clear, enhancing the concrete's appearance based on their sheen. However, semi-transparent and solid sealer options are also available for those seeking a more pronounced coating.
Addressing Moisture Issues with Concrete Sealers
A common concern is whether sealing a concrete floor can help reduce humidity and moisture spots, especially when water appears to emanate from the floor itself, potentially due to groundwater seepage or condensation. While sealers can help mitigate moisture issues, it's crucial to understand the source of the moisture.
Condensation vs. Groundwater Seepage
Moisture on concrete surfaces can be caused by condensation or actual groundwater seepage. Condensation occurs when warm, moist air comes into contact with a colder concrete surface, causing the moisture in the air to form droplets. This is a common issue, especially in basements or garages where the concrete is in contact with the cooler earth.
If water is seeping through the concrete from below, especially if the area is below grade, it indicates a more significant issue. This could be due to poor drainage, high water tables, or cracks in the foundation allowing groundwater to enter. In such cases, a simple surface sealer might not be sufficient, and a more robust vapor barrier or drainage system may be required.
Testing for Moisture
Before applying any sealer, particularly if moisture is a concern, it is advisable to test the concrete's dryness. A common method, often used before applying epoxy coatings, involves taping a piece of plastic to the concrete surface for 24-48 hours and checking for moisture accumulation underneath. Failing this test suggests that significant moisture is present within or below the concrete.
Specialized Sealers for Moisture Control
For persistent moisture problems, specialized products are available:
Ion-Bond Armor
Ion-Bond Armor is a highly specialized polysiloxane sealer known for its deep penetration capabilities. It forms a sub-surface, elastomeric waterproofing barrier that can withstand negative-side water pressure, making it effective against both surface water and underground water infiltration. It is breathable, allowing concrete to release water vapor, and does not alter the surface's slip resistance. Ion-Bond Armor is suitable for both indoor and outdoor use and can improve maintenance and longevity.
RadonSeal Deep-Penetrating Concrete Sealer
RadonSeal is a penetrating sealer designed for dampproofing basement walls and slabs. It reacts with the Portland cement in concrete to form an insoluble CSH gel, densifying and strengthening the concrete. RadonSeal is permanent and helps reduce dusting, spalling, and crazing. It is particularly effective for sealing concrete before installing moisture-sensitive flooring.
G Guard Concrete Moisture Barrier / Vapor Barrier
G Guard Concrete Moisture Barrier / Vapor Barrier is a two-component, 100% solids epoxy system designed to manage moisture and vapor emission rates. It requires proper surface preparation, including grinding and patching, to ensure a strong bond. The application involves careful mixing and spreading, with attention to temperature and humidity limits. A second application may be necessary to address any pinholes or gaps. This barrier is designed to be coated or covered after it has adequately hardened.
Concrete floor Vapor barrier. Controlling moisture migration
Combining Sealers
For the most robust protection against moisture, water vapor, and even radon gas, combining RadonSeal Concrete Sealers with Ion-Bond Armor is recommended. This combination provides an exceptionally tight seal, particularly beneficial before installing moisture-sensitive flooring or when dealing with significant moisture concerns.
Bone Dry Original Concrete Floor Sealer
Bone Dry Original Concrete Floor Sealer is a penetrating, permanent waterproof sealer initially developed for hazardous waste containment. It fills concrete pores, creating a vapor barrier that eliminates concrete sweating and mitigates moisture. It is non-toxic, easy to apply, and prepares the surface for various floor coverings. When combined with Quick Dry, its cure time can be reduced to as little as 6 hours.
Important Safety Note: Bone Dry Sealers can be slightly corrosive. Proper safety precautions, including wearing protective gear like chemical goggles, rubber gloves, and a respirator, are essential during application.
Considerations for Sealing Concrete Floors
Sealing concrete floors is generally a wise decision if the floor is exposed to regular moisture or if new flooring is being installed. It helps protect the investment, prevent health risks associated with mold, and improve comfort.
- Benefits: Sealing prevents water seepage, reduces mold growth, protects against wear and tear from traffic, oil, and chemicals, and enhances the floor's appearance.
- Drawbacks: Professional sealing can be costly, some topical sealers require reapplication, and sealing may not resolve underlying issues like hydrostatic pressure. Some glossy sealers can also become slippery when wet.
If existing moisture problems are present, such as visible mold, warped flooring, or musty odors, simply sealing the floor might not be sufficient. Identifying the moisture source is critical. While DIY sealing is possible, professional application ensures proper surface preparation, correct sealer selection, and accurate moisture testing, which can prevent trapping moisture and causing more significant problems.
Professional testing using specialized meters can accurately assess moisture levels in concrete. For moisture resistance, penetrating sealers are generally preferred due to their durability and effectiveness against water vapor. The lifespan of a sealer varies; penetrating sealers can last 5â10 years or more, while topical sealers may need reapplication every 2â5 years.
