Driveway sealing fills small cracks and crevices, preventing water from seeping in and damaging the blacktop. Seal-coating also helps prevent ice and snow from sticking to the pavement and making it slippery.
Avoid bargain-brand concrete sealants, as they typically contain high amounts of water and have lower coverage rates. They also have a shorter guarantee and may not last as long as a premium product. Read on for some ideas.
Asphalt Emulsion Sealers
Asphalt emulsion sealers use a mix of asphalt and water to help protect the surface. It creates a flexible bond that reduces temperature fluctuations, expansion, contraction, and cracking. It also helps prevent water penetration and freeze-thaw damage.
This type of sealer is great for residential driveways, parking lots, and roads. It improves the appearance of the asphalt and is highly effective in protecting it from damage, oil, and UV rays.
There are several different types of asphalt emulsion sealers. Some are fast-drying and are usable for foot and vehicle traffic an hour after application. Some are more durable, however, and require an extra day or two for curing.
These sealers are made from a blend of asphalt and polymers and have low toxicity and health risks for those who apply them. They are more environmentally friendly and cost less than coal tar sealers. They can be used for a wide range of applications, including spray applications and chip seals.
Coal Tar Sealers
Coal tar sealants are products used to maintain and protect asphalt driveways, parking lots, and other paved surfaces. They contain coal tar pitch, an industrial byproduct composed of polycyclic aromatic hydrocarbons (PAHs). PAHs are toxic to humans and other living organisms. Rainwater runoff from sealed coal tar driveways and parking lots often contains PAHs, which then enter water streams, lakes, surrounding soil, and air. Many states and municipalities have banned the use of coal tar sealers statewide.
Coal tar-free asphalt sealant is an excellent alternative to traditional coal tar sealers. It’s low VOC, solvent, and odor-free, and provides a deep black color. It also helps protect against moisture and water penetration, chemical spills, surface deterioration, and freezing/thawing.
In addition, a new product called POLY-TAR offers the benefits of both asphalt emulsion and coal tar sealers without negative PAHs. It’s pre-mixed and sold to contractors in bulk to prevent excessive water dilution and can be mixed with sand onsite for fast application.
Penetrating Waterproofing Sealers
Penetrating concrete sealers work underneath the surface. They either chemically react with free lime to increase the concrete strength and density or clot the pores of the concrete to prevent water and other liquids from penetrating.
These products can last 5-7 years, and they can easily be reapplied to restore the look of the concrete. Buddy Rhodes offers both solvent and water-based Silane-Siloxane concrete sealers for different applications. Solvent-based products can be damaging to materials such as vinyl siding, wood, and paint while water-based products are safe for those types of surfaces.
Unlike film-forming sealers, the application process for penetrating sealers requires a wet-on-wet method so that the sealer can saturate the concrete and create an invisible barrier. This will also ensure that the sealer doesn’t peel off or wash away. It also helps to use heavy coats to really saturate the concrete and keep the coating looking natural.
Chemical sealers work by reacting with the concrete to create a crystalline structure that locks in moisture and resists wear. They offer excellent durability, reduce the need for resealing, and lower repair costs over time.
Silicones, silane-siloxanes, and silicates penetrate concrete to fill pores while also forming a hydrophobic surface that causes water droplets to bead. They are ideal for use on dense or porous concrete and other cementitious surfaces that require a waterproofing sealer.
Tech Tip: If a concrete sealer appears milky or cloudy, it may be an indication that the surface was cleaned with chemicals or solvents that have reduced its repellent qualities. This can be remedied by a quick xylene (or xylol) wash to re-solvate and redeposit the sealer on the substrate.
Polyurethane is one of the strongest abrasion-resistant topical sealers that can be used on concrete. It is generally a two-part system with a separate base and topcoat. It offers long-lasting protection and is able to withstand heavy foot and car traffic. Next article.