How to Seal Concrete and Pavers: A Complete DIY Guide

Before buying any sealer, find out whether your concrete or masonry will even accept it. Sprinkle a small amount of water on the surface and watch what happens. If the water beads up and sits on top, the surface is already sealed or too dense, and a penetrating sealer will not soak in. If the water soaks in and darkens the surface within a minute or two, it is porous and ready to accept a penetrating sealer.

This one test drives your whole plan. A surface that beads water needs either a film-forming sealer or full stripping of the old sealer before you can use a penetrating product. A surface that drinks water is a good candidate for a silane/siloxane or siliconate repellent that reacts below the surface.

Match the sealer to the surface and the finish you want. For pavers and patios where you want a rich wet look and stabilized joint sand, a film-forming acrylic like DOMINATOR SG+ or Behr Premium Wet-Look is the right call. For a natural, invisible finish on bare light-colored concrete, a penetrating siliconate like Armor SC25 protects without any gloss or slip risk.

For vertical brick, block, and stucco walls above grade, use a breathable silane/siloxane repellent like Rainguard Micro-Seal that sheds wind-driven rain while letting the wall breathe. For below-grade basement and foundation walls that see liquid water and pressure, step up to a waterproofer: DRYLOK Extreme forms a barrier rated in psi, while RadonSeal Plus penetrates and densifies to cut moisture vapor and radon.

The key rule: repellents and penetrating sealers reduce absorption but will not hold back standing water, while film waterproofers form a barrier but require bare, clean masonry and will not breathe the same way.

Sealer bonds only to a clean surface. Remove dirt, oil, and old coatings, and pressure wash if needed. On smooth or previously sealed concrete, etch with a masonry etcher or degreaser so a penetrating sealer can soak in. On stamped or decorative concrete, use a dedicated cleaner to strip any leftover release agent, or the sealer can cloud or fail to bond.

Efflorescence - the white chalky salt deposit on brick, block, and concrete - must be removed before sealing, because sealing over it traps the salts and ruins adhesion. Brush off the deposits dry, then use an efflorescence remover or a mild acidic masonry cleaner, rinse thoroughly, and let the surface dry fully. Trapped moisture behind a film is the most common cause of a sealer turning white or peeling.

Sealers are sensitive to temperature and moisture. Most products want a surface and air temperature between roughly 50 and 80 degrees F and a dry surface, with no rain in the forecast for at least 24 hours (longer for film-formers). Applying over damp concrete or just before rain is the number-one cause of whitening, blushing, and adhesion failure.

Avoid sealing in direct hot sun, which flashes the surface and can trap solvent or leave lap marks, and avoid late-day application when dew will settle before the coating cures. Give new concrete its full cure - typically 28 days - before applying most sealers, unless the product is specifically rated for fresh concrete.

Penetrating sealers like silane/siloxane repellents are best applied with a low-pressure pump sprayer in a saturating, wet-on-wet flood coat - keep the surface visibly wet for the recommended dwell time so it soaks in, then remove any residue that fails to penetrate. Do not let a penetrating sealer dry on the surface as a film, or you can get a blotchy white haze.

Film-forming acrylics can be applied by pump sprayer, roller, or brush in thin, even coats. Thin is critical: two thin coats always outperform one thick coat, which can trap air, whiten, or stay tacky. On basement walls, DRYLOK-type waterproofers are worked into the pores with a stiff brush on the first coat, then rolled for the second, and two full coats are required for the warranty to apply.

Maintain a wet edge, work in manageable sections, and add a fine anti-slip aggregate to any glossy sealer used on walkways or pool decks to keep the surface from getting slippery when wet.

Let the sealer cure before use. Most sealers need several hours before light foot traffic and 24 to 48 hours before heavy traffic or vehicles, and longer before exposure to standing water. Rushing traffic onto an uncured film is a common way to mar the finish.

Plan for maintenance based on the sealer type. Film-forming wet-look sealers on pavers and decorative concrete typically need a reseal every 2 to 4 years as the gloss wears. Penetrating repellents last longer - often 5 to 10 years - and reapply invisibly when a fresh water bead test shows the surface starting to absorb water again. Re-run the bead test yearly and reseal when water stops beading.