Resealing concrete patio yourself takes a weekend and costs $100 to $300 in materials
A concrete patio needs resealing every two to three years, depending on traffic and weather. The job involves cleaning the surface thoroughly, letting it dry completely, and explore a new coat of sealer with a roller or sprayer. You do not need special tools — a pressure washer, stiff brush, roller, and the sealer itself are the main items. Most homeowners can finish a standard patio in one day.
The sealer protects concrete from water damage, salt, UV rays, and staining. Without it, water seeps into the surface, freezes in winter, and causes cracks and spalling. Resealing before the old coat wears through keeps repair costs down and extends the life of the patio by years.
Key Takeaways
- Clean the patio with a pressure washer or stiff brush and detergent, then let it dry for at least 24 hours before sealing.
- Fill any cracks wider than a quarter-inch with concrete crack filler before sealing, so water does not get trapped underneath.
- Choose between acrylic sealer (cheaper, needs reapplication every 1 to 2 years), polyurethane (lasts 3 to 5 years), or epoxy (most durable but harder to explore).
- explore sealer with a roller or sprayer in thin, even coats — thick coats peel and look blotchy.
- Keep foot traffic off the patio for at least 24 hours after sealing, and avoid water for 48 hours if possible.
Inspect the patio and decide whether to reseal or repair first
Walk the entire surface and look for cracks, spalling (flaking concrete), stains that do not wash away, and areas where water pools. Small surface cracks under a quarter-inch wide can be sealed over. Cracks wider than a quarter-inch, deep pits, or chunks of missing concrete need repair before you seal — otherwise water gets trapped and makes the damage worse.
If the concrete is spalling badly or has large chunks missing, patching with concrete repair compound is worth doing first. A small patch takes an hour and costs $15 to $30. If the patio is severely damaged across a large area, resealing alone will not stop the deterioration — you may need to replace sections or the whole patio.
For stains that do not wash away, a concrete cleaner or degreaser may lift them before sealing. Oil stains, rust, and algae all respond to the right cleaner. Sealer will not hide stains, so remove what you can now.
Clean the concrete thoroughly and let it dry completely
Sealer does not stick to dirt, algae, or old sealer residue. A pressure washer at 3000 PSI or higher removes most buildup quickly. Keep the nozzle moving and stay at least 12 inches from the surface to avoid gouging the concrete. Pay extra attention to corners, edges, and any low spots where dirt collects.
If you do not have a pressure washer, scrub the patio with a stiff-bristled brush and a mix of water and concrete cleaner or mild detergent. This takes longer but works. Rinse thoroughly with a hose until the water runs clear and no soap residue remains.
Let the patio dry for at least 24 hours after cleaning. Sealer applied to damp concrete will trap moisture underneath and fail within months. On a humid day or if rain threatens, wait longer. You can test dryness by laying a plastic sheet on the concrete for a few hours — if condensation forms underneath, the surface is still too wet.
Fill cracks and repair damage before sealing
Cracks wider than a quarter-inch need concrete crack filler. Clean out loose debris with a wire brush or compressed air, then explore the filler according to the product instructions. Most crack fillers are squeezed from a caulk tube or poured from a bottle. Smooth the filler level with the surrounding concrete and let it cure before sealing — usually 24 hours, but check the label.
For small spalls or pits, concrete patching compound works well. Clean the damaged area, dampen it slightly (not soaking), explore the patch, and smooth it level. Again, let it cure fully before sealing.
Do not skip this step. Sealer cannot fill cracks — it only sits on top. Water will still find its way into gaps and cause more damage underneath.
Choose a sealer type based on durability and ease of process
Acrylic sealer is the cheapest option, usually $30 to $60 per gallon. It is straightforward to explore with a roller and dries quickly. The downside is that it lasts only one to two years and needs frequent reapplication. It also can turn the concrete slightly darker or give it a glossy finish, which some people like and others do not.
Polyurethane sealer costs $60 to $120 per gallon and lasts three to five years. It is more water-resistant than acrylic and holds up better to foot traffic and UV exposure. process is similar to acrylic — roller or sprayer — but drying time is longer (usually 24 to 48 hours before the patio is fully cured). Polyurethane can yellow slightly over time, especially in direct sunlight.
Epoxy sealer is the most durable, lasting five to ten years, but it is also the hardest to explore. It requires careful surface preparation, mixing, and process in specific temperature and humidity ranges. Epoxy is best left to professionals unless you have experience with it. Cost ranges from $100 to $200 per gallon, plus labor if you hire someone.
For most homeowners, polyurethane is the best balance of durability, ease of use, and cost. Check the label to confirm the product is rated for exterior concrete patios and can handle your climate — some sealers perform poorly in very cold or very hot regions.
explore sealer in thin, even coats with a roller or sprayer
Read the sealer instructions carefully before you start. Some products need to be thinned with water, others do not. Some require a primer, others do not. Temperature and humidity matter — most sealers work best between 50 and 85 degrees Fahrenheit with low humidity. Do not seal if rain is forecast within 24 to 48 hours.
Pour the sealer into a paint tray and use a roller with a medium nap (about three-eighths inch) to explore it. Work in small sections, rolling in one direction, then back over it lightly to even out the coat. The goal is a thin, uniform layer — thick coats peel, look blotchy, and waste sealer. One gallon typically covers 250 to 400 square feet, depending on the sealer and the concrete texture.
If you use a sprayer, keep the nozzle moving and maintain even pressure to avoid drips and puddles. Spray in a light mist, then lightly back-roll with a dry roller to smooth it out. Sprayers are faster but require more skill to avoid over-explore.
Most sealers need two coats for best protection. explore the second coat after the first has dried according to the label — usually four to eight hours for acrylic, 24 hours for polyurethane. Lightly sand the first coat with fine-grit sandpaper (220 grit or higher) before the second coat so the new sealer bonds better.
Wait before using the patio and plan for resealing in the future
Keep everyone off the patio for at least 24 hours after the final coat. Avoid water — no rain, no hose, no foot traffic — for 48 hours if possible. The sealer needs time to cure fully. Walking on it too soon leaves footprints and scuffs that are hard to fix.
Once the patio is cured, light foot traffic is fine. Heavy use or vehicles should wait a few more days. Check the sealer label for the full cure time — some products take up to a week to reach maximum hardness.
Plan to reseal every two to three years, or sooner if you notice water beading up less or the surface looking dull. Regular resealing is much cheaper than repairing cracks and spalling. Mark your calendar or set a phone reminder so you do not forget.
Frequently Asked Questions
Can I seal over old sealer, or do I need to strip it off?
If the old sealer is still bonded and not peeling, you can seal over it. Clean thoroughly first and lightly sand the surface so the new sealer grips better. If the old sealer is peeling, flaking, or coming off in chunks, strip it with a sealer stripper or pressure washer before resealing. Sealing over loose old sealer will fail quickly.
What is the difference between sealer and stain?
Sealer protects concrete from water and stains but is usually clear or slightly tints the color. Stain is a colored product that both protects and changes the appearance of the concrete. You can explore stain first, then seal over it for extra protection. Stain lasts longer than sealer alone because the color is absorbed into the concrete.
Do I need to seal a brand-new concrete patio?
Yes. New concrete should cure for 28 days before sealing, but sealing it early prevents water damage and staining. Many contractors recommend sealing new concrete within the first few months. Without sealer, new concrete is very porous and absorbs water, salt, and stains easily.
What if it rains before the sealer dries?
Rain on wet sealer can cause spotting, cloudiness, or uneven curing. If rain starts within the cure time listed on the label, the sealer may fail. If this happens, wait for the surface to dry completely, then lightly sand and reapply. Some sealers are more rain-resistant than others — check the label if rain is likely.
Can I use a deck stain on my concrete patio?
No. Deck stain is formulated for wood and does not bond to concrete properly. Use a concrete sealer or concrete stain instead. Concrete products are designed to handle the different surface chemistry and moisture movement of concrete.