A sealer is a clear product applied to concrete to protect it from water, stains, and wear. Some sealers form a film on the surface, while others soak in and work from inside the concrete. Sealers are used on bare, stained, and decorative concrete. Film-forming sealers wear over time and need to be reapplied periodically.
Types of Concrete Sealer
Concrete sealers fall into two main groups:
- Film-forming (topical) sealers, like an acrylic sealer, sit on top like a clear coat on a car. They can add sheen and deepen color, and they’re the usual choice over stained floors.
- Penetrating sealers soak in and work like waterproofing spray on a jacket. They bond with the concrete and don’t alter the surface appearance, and they’re common on driveways and patios.
Film-forming sealers wear in traffic and need recoating every few years. Most decorative acrylic sealers last about 2 to 3 years, while tougher epoxy and urethane topcoats generally hold up longer. Penetrating sealers have no film to wear off, so they tend to need less frequent attention.
Does Concrete Really Need a Sealer?
Not every slab needs one, but colored and decorative floors do. On a stained floor, the sealer is what protects the color. Outdoors in a snowy climate, a sealer helps keep water and salt out. Plain interior concrete that’s been polished usually gets a guard instead.
Concrete Sealer FAQ
What is the downside of sealing concrete?
Film-forming sealers wear and need resealing every few years. Some can make a floor slick when wet, and sealing damp concrete can leave a cloudy haze. Penetrating sealers won’t add shine or deepen color.
What time of year is best to seal concrete?
Seal in dry, mild weather after the concrete has dried out from rain. In cold climates, late summer or early fall works well, since it protects the slab before winter salt goes down.