Sealing a concrete patio takes six steps: cure, clean, repair, test for porosity, pick a compatible sealer, and apply thin coats within the product’s temperature window.
For the full breakdown, see our best Patio Concrete Sealer guide.
The steps below follow manufacturer instructions from Quikrete and Behr, which control every temperature, coverage, and recoat number you’ll see.
Allow New Concrete to Cure First
New concrete must cure for a minimum of 30 days before sealing, per the instructions for Quikrete’s concrete and masonry sealers and Behr’s wet-look sealer. Concrete that hasn’t finished curing holds excess moisture, and trapping that moisture under a sealer causes cloudiness and adhesion failure. Give the slab its full month — a day or two extra doesn’t hurt.
Clean, Repair, and Test the Slab
Before any sealer touches the surface, remove wax, oil, grease, dirt, dust, and salts, then repair flaking or unsound areas. Pressure washing works well, but the slab must dry completely afterward. Do not apply these sealers over existing paint or stain.
Check porosity by placing water drops on the concrete. If the water absorbs, the surface is porous enough to accept sealer. If it beads and sits, the patio is too sealed or too dense — do not coat nonporous, painted, or solvent-based finishes unless the product label specifically allows it.
Pick a Sealer and the Right Weather
The sealer’s label sets the weather window, and each product differs. Quikrete’s general sealer guidance says not to apply below 40°F or when rain is likely; waterproofing sealer requires 50–90°F with no rain or heavy dew for 24 hours; Behr’s wet-look sealer wants 50–80°F and no direct sunlight or wet surface within that same 24-hour window.
Stir gently but thoroughly — vigorous stirring whips in bubbles that show up in the finish. Never thin the product. Test an inconspicuous patch first to confirm the finish looks right, and match the sealer to the slab’s condition:
| Sealer Type | Coverage Per Gallon | Second Coat |
|---|---|---|
| Concrete & masonry high-gloss | 200–400 sq. ft. | After 2 hours, perpendicular to first |
| Waterproofing sealer | 75–150 sq. ft. | While first coat is still wet, after 5–10 minutes |
| Premium wet-look sealer | Per label instructions | Per label instructions |
Comparing finishes before you commit is worth ten minutes — this roundup of the top patio concrete sealers covers how gloss, wet-look, and waterproofing options behave on real slabs.
Apply Thin, Even Coats
Apply with a brush, roller, mop, squeegee, garden sprayer, or pump sprayer. If you spray, back-roll immediately so the coating sits at uniform thickness.
For a high-gloss sealer, a second coat may follow after 2 hours, applied perpendicular to the first. Waterproofing sealer gets its second coat while the first is still wet, within 5 to 10 minutes. Wet-look sealer follows its own label.
Wait longer than you think on that last step. A sealer that looks dry can still be soft underfoot, and furniture legs leave permanent dents in a coating that hasn’t finished curing.
Common Questions
How Long After Pouring Can You Seal a Patio?
Wait a minimum of 30 days. Quikrete and Behr both specify a 30-day cure for new concrete before sealer goes down. Sealing sooner traps moisture still working its way out of the slab, which causes cloudiness and peeling. If the patio was poured in cool, damp weather, give it a little extra time.
Can You Seal Over an Already Sealed Patio?
Only if the surface is clean, porous, and able to accept more sealer. Do the water-drop test: absorption means it will take a new coat. If water beads, the existing coating is too dense, and additional sealer may not bond. Scuff-sanding glossy surfaces first can help. Never coat over paint or oil-based finishes unless the product label allows it.
What Temperature Is Too Cold for Sealing Concrete?
Below 40°F is too cold for general sealer application, per Quikrete’s guidance. Waterproofing sealer needs 50–90°F, and Behr’s wet-look sealer needs 50–80°F with no direct sunlight. Rain or heavy dew within 24 hours of application can also ruin the finish, so check the forecast before you start.
Sources
- Quikrete. “Sealing Concrete and Masonry” Source for cure time, prep steps, temperature limits, and coverage numbers.
- Behr. “Premium Wet-Look Sealer Product Detail” Source for wet-look sealer application temps and recoat instructions.
- American Concrete Institute. “Guide to the Use of Concrete Repair Materials” Source for warnings about pooling and uneven coating thickness.