How to Seal Concrete: Step-by-Step

You poured the slab. You finished it smoothly. Now don't let weather, oil stains, and tire marks tear it apart. Sealing concrete protects your work from water damage, cracking, and everyday wear.

The process isn't complicated, but the details matter. We'll walk through surface prep, sealer types, application, and dry times so you can seal confidently.

Why Seal Concrete?

Concrete is tough, but it's not invincible. It's porous, which means moisture can seep in and cause problems over time. Freeze-thaw cycles crack unsealed slabs. Oil and chemicals stain garage floors. UV rays fade decorative concrete.

Sealing concrete solves these problems. Here's what a good sealer does:

• Blocks moisture from penetrating the surface

• Prevents staining from oil, grease, and chemicals

• Reduces cracking and spalling caused by freeze-thaw cycles

• Protects against UV damage and fading

• Makes the concrete surface easier to clean

• Extends the lifespan of the concrete long term

Types of Concrete Sealers

Not all sealers work the same way. Choosing the right sealer depends on the surface, the environment, and how much traffic the concrete will see.

Penetrating Sealers

Penetrating sealers soak into the concrete and create a chemical barrier below the surface. They don't change the appearance of the concrete, which makes them a good choice if you want a natural look.

These work best for driveways, outdoor slabs, and any concrete exposed to moisture and freeze-thaw conditions. They're breathable, so trapped moisture can escape without damaging the slab. Penetrating sealers typically last longer than topical options and require less maintenance.

Acrylic Sealers

Acrylic sealers sit on top of the concrete surface and form a protective film. They're available as water-based sealer or solvent-based sealer options. Water-based versions are easier to apply and have lower odor. Solvent-based versions tend to be more durable and offer a higher gloss.

Acrylic sealers work well on decorative concrete, stamped patios, and pool decks. They enhance the color of the concrete and are available in matte finish or glossy options. Reapplication is needed every 1–3 years depending on traffic and exposure.

Epoxy Sealers

Epoxy sealers create a hard, thick coating that stands up to heavy use. They resist chemicals, abrasion, and impact better than other sealer types.

These are the go-to choice for garage floors and basement floors, especially in spaces that see vehicle traffic or heavy equipment. Epoxy can also be combined with paint chips or textures for a custom look. The tradeoff is that application is more involved, and the surface needs thorough preparation.

Tools and Materials You'll Need

Gather everything before you start. Having the right tools on hand keeps the job moving and helps you avoid mistakes.

• Concrete cleaner or degreaser

• Pressure washer or stiff-bristle brush

• Concrete sealer (matched to your project)

• Roller with extension pole, pump sprayer, or brush

• Paint tray or bucket

• Painter's tape for edges and control joints

• Protective gloves and safety glasses

• Respirator (for solvent-based sealers)

If your project involves any concrete repair, patching, or pouring before sealing, the mixing phase matters just as much as the application. And you know this step can eat up hours. Hauling bags, loading the wheelbarrow, mixing batch after batch...it adds up fast.

The MudMixer fixes this problem. One person can run through 45+ bags of dry mix per hour with continuous output. No stopping between batches. No waiting around.

Surface Preparation

Surface preparation makes or breaks a sealing job. Sealer won't bond to dirty, oily, or damp concrete. Rushing this step leads to peeling, bubbling, and wasted product.

#1 Clean the Concrete Surface

Start by removing all dirt, dust, debris, and stains. Sweep the area thoroughly, then use a pressure washer to deep clean the surface. For oil stains or heavy grime, apply a concrete cleaner or degreaser and scrub with a stiff brush before rinsing.

Let the concrete dry completely before moving forward. Depending on conditions, this may take 24–48 hours.

#2 Repair Cracks and Damage

Inspect the slab for cracks, chips, or spalling. Fill any damage with a concrete patching compound and smooth it level with the surrounding surface. Allow repairs to cure fully according to the product instructions before sealing.

#3 Remove Existing Sealer

If the concrete was previously sealed, you need to determine whether the old sealer is compatible with the new sealer you plan to apply. Perform a water test. Sprinkle water on the surface. If it beads up, there's an existing sealer present.

Applying a new sealer over an incompatible existing sealer causes adhesion failure. Strip the old sealer using a chemical stripper or mechanical grinding if needed. Clean the surface again after stripping.

#4 Check Moisture Levels

Moisture trapped under sealer causes whitening, bubbling, and peeling. Test the slab by taping a plastic sheet to the concrete and leaving it for 24 hours. If moisture collects underneath, the concrete is too wet. Wait for it to dry further.

New concrete needs at least 28 days to cure before sealing. Sealing too early traps moisture inside the slab and weakens the bond.

How to Seal Concrete: Step-by-Step

With the surface prepped and materials ready, it's time to apply the sealer. Follow these steps for a professional result.

Step 1: Choose the Right Conditions

Weather matters. Apply sealer when the temperature is between 50°F and 80°F. Avoid sealing in direct sunlight. It causes the sealer to dry too fast and can create bubbles or uneven coverage.

Check the forecast. You need at least 24–48 hours of dry weather after application. Rain on wet sealer ruins the finish.

Step 2: Apply the First Coat

Stir the sealer thoroughly before use. Don't shake it. Shaking creates air bubbles that transfer to the surface.

Pour the sealer into a paint tray or pump sprayer. Using a roller or sprayer, apply a thin coat in even, overlapping strokes. Work in manageable sections and maintain a wet edge to avoid lap marks.

Apply the sealer in one direction across the entire surface. Keep the coat thin. Thick applications cause problems, like pooling, bubbling, and extended dry time. A thin layer bonds better and cures more evenly.

Step 3: Allow Proper Dry Time

Let the first coat dry according to the manufacturer's instructions. Most sealers require 2–4 hours of drying time between coats, but this varies based on product type, humidity, and temperature.

The surface should feel dry to the touch before applying the second coat. Don't rush this step.

Step 4: Apply the Second Coat

Apply the second coat in the opposite direction of the first coat. This cross-hatch pattern fills in any thin spots and creates more uniform coverage.

Keep this coat thin as well. Two thin coats outperform one thick coat every time. Inspect the surface as you work and address any missed areas or drips immediately.

Step 5: Let It Cure

After the final coat, the sealer needs time to fully cure before use.

• Light foot traffic: 24 hours

• Vehicle traffic: 48–72 hours

• Full cure: up to 7 days

Check the product label for specific guidance. Avoid dragging furniture, parking vehicles, or placing heavy objects on the surface until the sealer has fully hardened.

Tips for Best Results

Small details make a big difference in how your sealed concrete looks and performs.

• Test the sealer on a small, hidden area first to check appearance and adhesion.

• Calculate the square footage of your project before buying sealer to ensure you have enough product.

• Apply multiple thin layers rather than one thick coat.

• Don't seal in temperatures below 50°F or above 80°F.

• Work in sections and keep a wet edge to avoid lap marks.

• Store leftover sealer in a sealed container away from extreme temperatures.

• Plan to reapply sealer every 2–5 years depending on wear and exposure.

Common Mistakes to Avoid

Even experienced contractors make these errors. Avoid them and save yourself time and money.

• Skipping surface preparation. Dirt, oil, or moisture under the sealer leads to failure.

• Sealing damp or uncured concrete. This traps moisture and causes white hazing or peeling.

• Choosing the wrong type of sealer. Match the sealer to the surface and conditions.

• Applying coats too thick. Thick coats bubble, peel, and take forever to dry.

• Not allowing enough dry time between coats. Patience pays off. Let each coat cure.

• Sealing over incompatible products. Test or strip existing sealer before applying something new.

• Ignoring manufacturer's instructions. Every product has specific requirements. Read the label.

Speed Up Your Concrete Projects with MudMixer

Sealing is often the final step in a larger project. But before you ever crack open a bucket of sealer, there's prep work, and that usually means mixing.

Maybe you're patching cracks and spalled areas before sealing a driveway. Maybe you're pouring a new concrete slab for a garage floor or patio. Either way, you've probably spent more time than you'd like loading a wheelbarrow, mixing by hand, and waiting on batch after batch to get enough material down.

That's where the MudMixer comes in.

One person can mix a full yard of concrete in an hour. That's over 45 bags of dry mix with no stopping between batches. The continuous mixing system keeps material flowing as long as you keep feeding the hopper. Walk it right up to your forms and pour directly where you need it. No more back-and-forth trips with a wheelbarrow. The fully adjustable water dial gives you complete control over your mix consistency. Dial it in once and get the same reliable output bag after bag. 

Whether you're a contractor running jobs solo or a homeowner tackling a weekend project, MudMixer cuts your mixing time in half and keeps the project moving. It's available at over 2,000 dealers nationwide or directly at mudmixer.com.