How to Seal Concrete

The best way to protect your decorative concrete surface is to have it coated with a high-quality sealer.

You spent the time and money on a new decorative concrete surface. Now what? If you want it to look great for years to come, it's time to get it sealed.

Why do I need to seal my surface?

Sealing a decorative concrete surface is critical no matter where you live, but it’s especially important for outdoor surfaces that see lots of rain, hail, and snow—especially if snow sits on it for long periods of time. In addition to protecting your surface from the elements, a high-quality sealers can protect from everyday wear and tear, oil spills, chemical spills, and more.

How to seal a concrete surface

The exact steps you follow to apply a sealer to your surface depends on what surface you’re dealing with and what sealer you’re applying. Here are some things to keep in mind.

If you’re applying sealer to plain gray concrete, make sure to strip everything from the surface such as paint or any sealer that was previously applied. You’ll also want to sand or etch the surface to make it porous and ready to accept the sealer.
If you’re applying sealer to decorative concrete, make sure the surface is completely clean. See detailed information about cleaning concrete here.
Let the surface dry completely before applying sealer.
Apply sealer as even as possible to avoid puddling.
Follow manufacturer instructions to see how many coats of sealer you should apply.
Follow manufacturer instructions to see how long you need to wait until you can walk or drive on the surface. You typically need to wait anywhere from 24 to 48 hours.

For best results, follow manufacturer instructions and do thorough research before beginning the sealing process.

Can I apply sealer myself?

While it might be tempting to try to apply a sealer yourself, we highly recommend having a professional do it for you, as the conditions need to be practically perfect to do it. Here are some common issues encountered during the sealing process:

It’s difficult to distribute sealer evenly, and having too much in one spot can cause bubbling.
Sealer needs to be applied in just the right conditions. If outdoor temperatures are too hot or too cold, that can also cause bubbling.
The timing needs to be just right. If you do it too soon after the decorative coating was applied, your surface may end up looking discolored. Too late and you risk imperfections showing up in your surface.

A professional, experienced contractor such as SUNDEK of Washington will be familiar with these issues can will can make sure your sealer is applied properly.

Pros & Cons of Applying Sealer

Applying a sealer is highly recommended. But just like any improvement project, it’s important to know what to expect going in.

Pros of Applying Sealer

Protects concrete from damage such as flaking, wear and tear, color fading from UV rays, chemical and oil spills, saltwater, and more.
Prevents damage during freeze and thaw cycles (super important in this area of the country).
Makes the surface easier to clean than unsealed concrete.
Stops mold and mildew from forming.
You can include additives that make the surface non-slip.

Cons of Applying Sealer to Concrete

Creates a slippery floor if you’re applying it on top of a smooth surface without texture. Fortunately, this can be remedied by including non-slip additives in the sealer during the application process.
It adds an extra cost to your decorative concrete project. However, this additional cost will save you money in the long run by making your surface last longer.
Over time, it’s inevitable that the sealer will wear off and you’ll need to reapply it. You’ll need to check your sealers effectiveness every so often (your contractor can give you an estimate of how often you’ll need to reapply). On a positive note, reapplying your sealer—which protects your surface form wear and tear—is better and less expensive than having to resurface your concrete.

Overall, it’s clear that applying a sealer is better than not keeping your surface protected.

How often do I need to reseal my surface?

The frequency for reapplication depends on where your surface is located and how it’s used. For example, an infrequently used walkway that’s protected from the elements will need to be resealed less often than a driveway that has snow sitting on its surface for two months a year.

At SUNDEK of Washington, we’ve been working with decorative concrete for decades in the Washington D.C., Maryland, Delaware, and Virginia areas. Our experience means we’re well versed in the needs of decorative concrete in this region, so we can guide you through the process of determining a resealing schedule.

What sealers does SUNDEK of Washington offer?

SunClear EcoProtect is ideal for an indoor concrete floor sealer. This clear concrete sealer has low VOCs and is easy to use and clean up, so it’s environmentally friendly.
SunClear UltraProtect is an outdoor concrete sealer that is also ideal for high-traffic areas. It can protect surfaces that require impact resistance including service bays and aircraft hangars. This is also a great choice for sealing concrete driveways, garage floors, or basements. This sealer is hard yet flexible, so it provides protection against chemicals and abrasion. You can also add aggregates to it to make a surface less slippery.
AcryClear 25 is a UV stable acrylic sealer well suited for outdoor use on stamped concrete, exposed aggregate, or even pavers. It is available in gloss, satin and low VOC formulas.