Sealing Concrete: When, Why and Whether to DIY

Summary:

Cesar describes a sealer as a surface layer that slows water penetration, which matters because water getting into concrete drives most long-term failures — freeze-thaw damage, staining, and surface breakdown. Sealing buys time against all three. How often a slab needs it depends on the finish and on sun and traffic exposure, with stamped and colored work needing more attention because the sealer also protects the color. Plain broom finish driveways are a different case. He offers homeowners a simple self-check: water thrown on the surface should bead and sit, and if it soaks straight in and darkens the concrete, resealing is due. Homeowners can do the work themselves, though applying too heavily or over a surface that isn't clean and dry causes bonding problems.

Answer:

A sealer is a layer on the surface that slows water down from getting into the concrete. That matters here because water getting in is behind most of what goes wrong long term, the freeze and thaw, the staining, the surface breaking down. So sealing buys you time on all of it. How often depends on the finish and on how much sun and traffic that area is getting. Stamped and colored work needs more attention, because the sealer is also protecting how that color looks. A plain broom finish driveway is a different situation. The easy way to check it yourself is to throw some water on it. If it beads up and sits there on top, your seal is doing its job. If it soaks straight in and the concrete goes dark, you're due. A homeowner can do this themselves and plenty do. The part people get wrong is putting it on too heavy, or putting it on a surface that isn't clean and dry, and then it doesn't bond and it looks bad.