Ghostshield Siloxa-Tek 8500 Ready to Use - 1 Gallon Penetrating Concrete Sealer, Water and Salt Repellent. Clear, Water-Based DOT Approved Silane/Siloxane for Concrete, Brick, Masonry & Pavers

What it is and who it’s for

Siloxa-Tek 8500 is a penetrating, water-based silane/siloxane sealer designed to keep water and deicing salts out of porous mineral surfaces—concrete, brick, block, stone, and pavers—without changing how they look or feel. It’s breathable, non-film-forming, and dries invisible. If you want a “wet look” or gloss, this isn’t it. If you want to stop wind-driven rain, reduce freeze–thaw damage, and avoid the slick, plasticky sheen common to topical sealers, this product hits the bullseye.

I’ve used it on three areas: a broom-finished concrete driveway, a stamped concrete patio, and a brick chimney that historically took on water during storms. Across all three, it performed consistently: strong water beading, zero change to the appearance or traction, and noticeably easier cleanup of dirt and grime.

Application experience

I applied 8500 with both a pump sprayer and a 3/8-inch roller to compare methods. My preference is a pump sprayer with a fan tip, then a quick back-roll to even out any heavy spots. The product is almost odorless, has a thin, watery viscosity, and saturates the surface quickly. It won’t build a film, so the goal is to achieve uniform absorption rather than a “coating.”

A few practical notes from my installs:
- Prep matters. I pressure-washed, removed any stains I could, and let the surfaces dry thoroughly (48 hours in my case). On dense concrete, I also etched lightly to open the pores; on the chimney, I just cleaned and dried.
- Two coats, wet-on-wet. I applied the second pass within about 10 minutes while the first was still damp. This helped the active ingredients penetrate deeper.
- Coverage varied with porosity. On broom-finished concrete, I averaged around 200–225 sq ft per gallon per coat. On the denser stamped patio, I was closer to the high end (around 250 sq ft).
- Gentle learning curve. Because it dries clear with no film, there’s little risk of lap marks. Still, I worked in manageable sections to avoid missing spots.

The surface looks unchanged when dry—no color deepening, no sheen, and no “plastic” feel. On the patio, traction remained excellent, even when wet.

Performance and protection

Water repellency is the headline here. I saw tight, uniform beading after the first 24 hours and more consistent sheeting after a week. On the chimney, this translated into tangible results: no damp patches during wind-driven storms since treatment. On the driveway, snowmelt and rain stopped penetrating, and the slab dried faster after weather events.

In cold climates, the core benefit is reduced freeze–thaw damage. Penetrating sealers like this limit the water that can occupy the pore structure, which in turn reduces the risk of scaling, spalling, and microcracking. That’s especially relevant if your surfaces see deicing salts—Siloxa-Tek 8500 is engineered to resist chloride intrusion and is DOT-approved, which aligns with the performance I’ve observed during a winter season of salt exposure.

A couple of caveats:
- It won’t heal existing damage. If your concrete is already scaling or flaking, address that first; 8500 is a preventative measure.
- It’s for water and salt—not oil. For garage slabs that see frequent oil drips, you’ll still need to be vigilant with cleanup or consider an additional product specifically rated for oil repellency.

UV stability has been excellent. I haven’t noticed any breakdown or chalking, and because there’s no film, there’s nothing to peel or delaminate later. That absence of a film is also why surfaces stay non-slip.

Where it shines—and where it doesn’t

Best uses I’ve found:
- Driveways and sidewalks in freeze–thaw regions
- Brick and masonry walls exposed to wind-driven rain
- Stamped concrete patios where you want to preserve the natural look and traction
- Pavers, especially around pool decks, where water repellency without slipperiness is key

Where it’s not the right fit:
- Decorative concrete or countertops where you want color enhancement, a wet look, or any level of gloss. Because 8500 dries invisible and non-film-forming, it won’t enrich color or add sheen. If you’re chasing a richer tone or a “sealed” appearance, a topical acrylic or urethane is more appropriate.
- Surfaces requiring oil and grease repellency. Look for a sealer with an oleophobic component if oil is your primary concern.

Longevity and maintenance

Penetrating sealers trade visual drama for longevity. There’s no film to wear away, and the active ingredients bond within the pore structure. On vertical, less-trafficked surfaces like brick, service life can be many years. Horizontal, high-traffic slabs (driveways, sidewalks) typically need reapplication more often due to abrasion and UV exposure. Practically speaking, I plan to reassess every 3–5 years on horizontals and much farther out on verticals.

A simple way to check when it’s time: sprinkle water on the surface. If it beads tightly and stays on top, you’re still protected. If it darkens quickly and soaks in, it’s time for another application.

Maintenance is straightforward. Dirt and grime don’t bond as readily, so a hose or light power wash brings things back fast. Efflorescence has been less pronounced on my pavers since treatment, which I attribute to the reduced moisture movement through the surface.

Safety and cleanup

Being water-based and low VOC, 8500 is easy to work with. I had no heavy chemical odor, even in a garage bay with moderate ventilation. Tools clean up with water if you get to them promptly. As always, mask adjacent glass, metals, and plants; while it won’t etch, it can leave a hydrophobic smudge on glass that’s tedious to remove.

Apply between roughly 40–95°F, avoid direct rain during application and cure, and give it a day before heavy water exposure. On hot days, work in the shade or cooler hours to maintain that wet-on-wet window.

Value and alternatives

Against big-box sealers, this product costs more per gallon, but the performance per coat and the higher active content show up in the results: deeper penetration, stronger beading, and longer intervals between applications. If your goal is invisible, high-performance water and salt protection, the cost delta is justified.

If you want:
- A wet look or gloss: consider a topical acrylic or urethane.
- Oil and water repellency: look for a penetrating sealer that adds oleophobic chemistry.
- Breathability with subtle darkening: some hybrid products offer minimal sheen, but they’ll still change appearance.

Siloxa-Tek 8500 sits squarely in the “functional and invisible” category and excels there.

Tips from use

• Do a splash test before and after. It sets expectations and helps you spot any missed areas.
• Plan the second coat. Have your sprayer/roller ready and work in sections so you can apply wet-on-wet within about 5–10 minutes.
• Don’t skimp on cleaning and drying. Trapped moisture and contaminants reduce penetration.
• For highly porous substrates (old block, soft brick), buy a little extra. You’ll use more product to reach refusal.

The bottom line

Siloxa-Tek 8500 is a strong choice if you want high-level water and salt protection without changing how your concrete, brick, or pavers look or feel. It’s easy to apply, low odor, and leaves no film to peel or make surfaces slippery. In my use, it delivered exactly what a penetrating sealer should: tight beading, faster dry-outs after weather, and peace of mind through freeze–thaw cycles. It’s not a cosmetic product, and it won’t enhance color or add shine—by design. For anyone expecting “wow” visuals, that’s a dealbreaker; for everyone else, it’s the point.

Recommendation: I recommend this sealer for homeowners and pros who prioritize durable, invisible protection against water and deicing salts on concrete, brick, and masonry. It’s especially compelling in cold or coastal climates, on driveways and walkways that must stay non-slip, and on vertical masonry where wind-driven rain is a concern. If you’re after a glossy or color-enhanced finish or need oil repellency, choose a different class of product; otherwise, this has become my go-to for breathable, no-drama protection.