Penetrating Sealers for Concrete

Water beading on concrete sealed with Stealth-Seal from Brickform

Penetrating sealers, such as silanes, siloxanes, silicates and siliconates, penetrate into the concrete to form a chemical barrier that shields against moisture penetration and deicing chemicals. Usually they provide invisible protection without changing the surface appearance, and most products are breathable, allowing moisture vapor to escape. They are most commonly used outdoors, since they provide excellent protection against harsh exposure conditions.

Where to Use Penetrating Sealers

A penetrating sealer is your best choice if your goal is to:

• Protect exterior concrete surfaces subject to corrosion and freeze-thaw damage.
• Obtain a natural, matte finish.
• Provide invisible protection without changing the surface appearance or leaving a sheen.

They are commonly used when:

• Sealing driveways
• Sealing sidewalks
• Sealing concrete patios
• Sealing pool decks

For driveways and walkways where good traction is important, a penetrating sealer is a better choice than a film-forming product, such as an acrylic or polyurethane. Because a penetrating sealer does not leave a glossy film, it will not contribute to the slipperiness of the concrete surface.

How to Apply Penetrating Sealers

You can apply penetrating sealers with basic equipment:

• Low-pressure, high-volume sprayer
• Pump-up garden-type sprayer
• Roller

Most modern penetrating sealers are designed to work in one saturation coat. Apply until the concrete stops absorbing, then you're done. Some products specify "two coats," but this typically means wet-on-wet application: apply the second pass while the first is still wet to redistribute sealer into any spots still absorbing. Once absorption stops, additional coats won't help and may cause residue.

Pro Tip: Keep an eye out for areas where the sealer pools or stops absorbing. Backroll or wipe off any excess to prevent white residue or streaking.

FAQs About Penetrating Concrete Sealers

Are penetrating sealers water-based or solvent-based?

Both types exist. Water-based versions use water as the carrier and have lower odor and VOCs, which is why homeowners tend to prefer them. Solvent-based versions use chemical solvents and often penetrate deeper in dense concrete, but they smell stronger.

Both use similar active ingredients (silane, siloxane, or siliconate) and protect the same way. The main differences are how they feel to work with and how they smell.

Can I add color to a penetrating sealer?

No. Penetrating sealers soak into the concrete and react below the surface. Since they don't form any kind of film, there's nothing at the surface to hold pigment. If a product claims to be a colored penetrating sealer, it's actually a topical sealer (which sits on top), or you're thinking of concrete stains or dyes, which are completely separate products applied before sealing.

How long do penetrating sealers last?

Usually 5 to 10 years, though it depends on the formula and what the concrete goes through. Silane-based sealers often make it 7 to 10+ years, while siloxane versions typically last 5 to 7 years. Driveways and surfaces that see deicing salts wear out faster than a covered patio. Unlike topical sealers that peel or flake when they fail, penetrating sealers just slowly lose effectiveness inside the concrete. So the decline is gradual, not sudden.

D-One Penetrating Sealer Non-yellowing, low sheen, good adhesion

Deep Penetrating Sealer RadonSeal - Waterproofs & strengthens.

Clear-Seal by Increte Systems Seals and protects decorative surfaces.

Heavy Duty Oil & Stain Protector TS210 - 4 gal. kit ($439.95)

Gem-Guard SB Penetrating sealer that protects against salt damage

Decorative Sealers Reactive and penetrating formulas in various levels of gloss.

Water Repellent Penetrating Sealer for driveways, parking structures, plazas, walkways & more.

Clear Acrylic Concrete Sealer $219.30 (5 gal.)

Colored Concrete Sealer X-4 High gloss finish available in 20 colors

How can I tell when a penetrating sealer needs reapplication?

Try a simple water drop test. Put a few drops of water on clean, dry concrete and watch for 30 to 60 seconds. If the water beads up or takes a while to soak in, you're still protected. If it immediately spreads and darkens the concrete, the sealer's mostly gone. This works because even though there's no film on the surface, the sealer makes the pore walls repel water, so absorption should be noticeably slower than bare concrete.

Can I remove a penetrating sealer if I change my mind?

Not easily. Since the sealer soaks in and bonds chemically inside the concrete, there's no surface film to strip off. The most reliable way to remove it is grinding or shot blasting, which physically removes the top layer of concrete along with the sealer. Chemical strippers and heavy-duty cleaners rarely work. This usually only becomes an issue when you're prepping for a coating, overlay, or stain. At that point, you'd need mechanical surface prep anyway.

Do I need to remove the old sealer before resealing?

Nope. That's actually one of the best things about penetrating sealers, you just reseal right over the old stuff. The concrete will only absorb new sealer where protection has worn down. Areas that are still sealed will reject it. Just clean the surface well, do a water test to confirm it needs resealing, then apply following the directions. If excess sealer sits on the surface and won't absorb, wipe it off to avoid residue.

Learn more: How to Reseal Concrete

What's the difference between penetrating sealers and topical sealers?

Penetrating sealers soak into the concrete and change how it absorbs water, but they don't create any visible coating. The surface looks completely natural, no sheen, no color change. They last longer and need less upkeep. Topical sealers sit on the surface as a film and typically add gloss or a slight tint. They wear off faster and need reapplication more often. So if you want invisible, long-term protection, go with penetrating. If you want to change how the concrete looks, you'll need a topical sealer.

Topical sealers are often referred to as film-forming and include:

• Acrylic sealers
• Polyurethanes
• Epoxies

What don't penetrating sealers protect against?

They're great at repelling water and limiting salt damage, but they're not a miracle product. They won't fully stop oil stains, won't prevent acid etching, and won't hide cracks or surface wear. They also don't strengthen weak concrete or work as a bonding layer for coatings. Think of them as a protection system, not a finish or a fix for existing problems.

What's the most common mistake people make with penetrating sealers?

Using too much. Penetrating sealers don't build up in layers. Once the concrete stops absorbing, any extra sealer just sits there and causes streaking or a white haze. More product doesn't equal more protection. The concrete will only take what it needs, so if it stops soaking in, you need to wipe off the excess. One careful application beats dumping on extra and hoping for the best.

Related resources:

Choosing the Best Applicator for Concrete Sealer

Advice on Choosing and Applying Sealers