How to Seal a Concrete Floor

Contact

Prepare the concrete for sealing

First things first, you’ve got to clean that floor thoroughly. Sweep away any loose debris and dirt. For tougher grime, use a degreaser or a concrete cleaner. A power washer can be a great tool if you’ve got one handy. The goal is to get the surface as clean as possible because any dirt left behind can prevent the sealer from sticking properly.

Next up, check for any cracks or damage. You don’t want to seal over imperfections because they’ll just get worse over time. Use a concrete patching compound to fill in any cracks or holes. Smooth it out and let it dry completely. A well-prepped surface makes all the difference in the final result.

Finally, make sure the floor is completely dry before you apply the sealer. Moisture trapped under the sealer can cause it to peel or bubble. If you’ve used water to clean the floor, give it plenty of time to dry out. You might even use a moisture meter to be sure.

A man preparing a concrete floor to be sealed by jet washing it
A man preparing a concrete floor to be sealed by jetwashing it
  • Penetrating sealers
    These soak into the concrete, providing protection from within. They’re great for exterior surfaces as they resist water and contaminants.
  • Acrylic sealers
    These form a thin, protective layer on the surface, enhancing color and providing a low to high-gloss finish. Good for both indoor and outdoor use.
  • Epoxy sealers
    These are thicker and provide a durable, glossy finish. They’re ideal for indoor floors, like garages and basements.
  • Polyurethane sealers
    These offer excellent abrasion resistance and a glossy finish, making them perfect for high-traffic areas.

Now there are certain considerations you'll need to take in order to decide which sealer suits the job at hand, including but not limited to:

  • Indoor or outdoor?
    Different environments need different types of protection. For outdoor surfaces, penetrating sealers work wonders because they resist water and contaminants, protecting the concrete from the elements. Indoors, you might prefer acrylic or epoxy sealers for their durability and finish, especially in spaces like garages or basements.
  • Natural look or glossy finish?
    The type of sealer you choose will impact the look of your floor. If you want to enhance the natural appearance of the concrete without adding too much shine, penetrating sealers are ideal. For a bit more sheen, acrylic sealers offer a range of gloss levels from matte to high-gloss. Polyurethane sealers provide a glossy finish that's not only attractive but also highly protective.
  • The amount of foot traffic
    For places with heavy foot traffic, like commercial spaces or busy home areas, epoxy and polyurethane sealers are top choices. They offer superior abrasion resistance and can handle the wear and tear of daily use.
  • Will the floor be prone to moisture?
    For areas that are exposed to high levels of moisture, like basements or outdoor patios, penetrating sealers are a smart choice. They seep into the concrete and create a barrier against water, preventing infiltration and protecting the floor from damage like cracking and spalling.
Tools and materials for sealing concrete flooring.
Tools and materials for sealing concrete flooring.

Tools and materials needed to seal your concrete

  • A high-quality sealer (penetrating, acrylic, epoxy, or polyurethane)
  • A paint roller or sprayer (for even application)
  • A paint tray (if using a roller)
  • Clean rags or a mop (for wiping and cleaning)
  • Protective gear (gloves and mask)

Applying sealer to the concrete

Always read the sealer manufacturer’s instructions for specific guidelines, as this will ensure you get the best results. If you’re using a roller, pour the sealer into a paint tray and load your roller or sprayer with the sealer.

Start applying the sealer in a corner and work your way out, ensuring you apply it in thin, even coats without leaving any puddles or uneven spots. Let the first coat dry completely, which usually takes a few hours, depending on the sealer's instructions.

For maximum protection, you've got to apply multiple coats. Once the first coat is dry, apply a second coat in the same manner, which helps create a more durable and even finish. Allow each coat to dry thoroughly before applying the next, typically a few hours to overnight. After the final coat, let the floor cure for the recommended time to ensure the sealer is fully set and provides the best protection.

A man applying concrete sealer to a floor outside, using a roller.
A man applying concrete sealer to a floor outside, using a roller.

One of the biggest mistakes is over applying the sealer. More isn’t always better. Applying too much can cause puddles and uneven spots, leading to a sticky, unattractive finish that doesn’t cure properly. Thin, even coats are the key to a smooth, durable surface.

Skipping or skimping on surface preparation is a sure way to ruin your sealing job. If the concrete isn’t clean and dry, the sealer won’t adhere properly. Dirt, grease, and moisture can all interfere with the bonding process, leading to peeling and bubbling down the line. Make sure you thoroughly clean and repair the surface before you start.

Ignoring the manufacturer’s instructions can lead to all sorts of problems. Each sealer has specific guidelines for application, drying times, and the number of coats. Following these instructions ensures that you get the best results and that your floor is properly protected. Don’t try to wing it – read and follow the directions to the letter.

If the sealer isn’t adhering, it’s often due to inadequate cleaning or moisture. Remove the faulty sealer, clean the surface thoroughly, ensure it’s dry, and reapply following the manufacturer’s instructions.

Typically, two to three thin coats are recommended, allowing each coat to dry completely before applying the next. Follow the manufacturer’s guidelines for the best results.

Apply the sealer in thin, even coats using a roller or sprayer. Work systematically from one corner to the other and avoid going over the same spot multiple times while it’s wet.

Our team of experts is ready to transform your floors with precision and craftsmanship. Don't settle for ordinary when you can have exceptional. Contact us regarding concrete flooring by emailing us at info@britishconcretepolishing.co.uk or by filling in the form below and our team will get back to you shortly.