Thompson's Thompson’s WaterSeal Multi-Surface Waterproofer Stain, Clear, 1 Gallon

A clear sealer is only as good as the prep—and as forgiving as the weather window. With that in mind, I put Thompson’s WaterSeal (clear) through a few real-world chores: a weathered pine deck section, a new redwood planter/bench, a broom-finished concrete walkway, and a run of old brick steps. I wanted to see if a single product could handle a mixed-material exterior without fuss, change the look minimally, and actually keep water out. Short answer: it can, with a few caveats worth knowing before you crack the lid.

What it is (and isn’t)

This is a clear, water-based, penetrating waterproofer designed for exterior wood, concrete, and masonry. It’s billed as a one-coat solution that adds UV and fade resistance while preserving the surface texture. “Clear” is the operative word—if you’re after color or a dramatic cosmetic refresh, this isn’t the right product. If you want your surfaces to look essentially the same after sealing (maybe a touch richer while wet, then back to normal once dry), it fits the brief.

Because it’s water-based, the liquid looks slightly milky in the can and during application, then dries clear. Cleanup is straightforward with soap and water. Odor is low compared to solvent-based sealers, a real plus for weekend projects in close quarters.

Surface prep and tools

With any sealer, performance hinges on prep. I washed each surface, let it dry thoroughly (24–48 hours for wood, 48+ after power-washing concrete/brick), and knocked down any loose fibers on the deck. For application, I tried:

• Low-pressure pump sprayer (fan tip)
• 3/8-inch nap roller on a pole
• Synthetic brush for edges and back-brushing

All three methods worked. If you spray, plan to back-brush or back-roll immediately to even out absorption and avoid lap marks—especially on porous wood and textured concrete.

Before starting, I shook the container vigorously and gave it a good stir. This product does separate; skipping agitation can lead to uneven sheen or the occasional streak.

Application and working time

The sweet spot is a shaded, dry day in the 60–80°F range with light wind. I’ve applied it in hotter conditions; it still worked, but the open time dropped and I had to move faster to maintain a wet edge. The product goes on thin, so it’s easy to over-apply if you treat it like a paint. One uniform coat is the goal. Any puddles should be brushed out within a few minutes—let them sit and you risk tackiness or a patchy finish on wood.

Dry-to-touch was about 1–2 hours for me depending on temperature and airflow. I keep foot traffic off wood for 24 hours and avoid heavy water exposure for a day or two if possible.

Results by surface

• Wood (new redwood planter/bench): Application was painless. The milky look disappeared quickly, and within an hour the surface read as natural redwood—with a very subtle, even low-sheen. After curing, water beaded cleanly and didn’t darken the wood. Texture remained intact with no film-like feel.

• Wood (weathered pine deck panel): The deck drank it in, which is to be expected. Water beaded strongly after cure. Because the boards were thirsty, coverage was on the low side, and this is where restraint matters: I tested a second “insurance” coat on one board and it stayed slightly tacky longer than I liked. On soft, weathered wood, more is not better—stick to one coat and wipe any excess.

• Concrete (broom-finished walkway): The look didn’t change after drying; no gloss, no color shift. Water beaded rather than soaking in. The surface didn’t feel slick underfoot, which is a common worry with sealers. Cleanup after application was simple—no hazing or residue.

• Brick (old exterior steps): Penetrated well and dried clear. The brick deepened very slightly while wet, then returned to its original tone. The sealer helped repel splashback and made subsequent cleaning easier.

Durability and UV resistance

On water repellency, performance was solid across the board: rain beaded up and blew off instead of soaking in. On wood, that’s the main job—slowing down swelling, checking, and rot. On masonry, it helps reduce freeze-thaw absorption and the grime that comes with wetting.

The UV story is more nuanced. Clear sealers offer limited protection against UV graying compared to tinted or semi-transparent products. After a season, wood treated with this clear coat still looked better than an untreated control board, but it didn’t lock the color the way a pigmented stain would. If your priority is preventing gray on high-sun, horizontal surfaces, consider a lightly tinted version. If you want a “just-sealed, not-stained” look and accept that some UV change will occur over time, this clear formula is appropriate.

In terms of maintenance, plan on annual inspection and touch-ups in high-wear or high-sun zones. Vertical wood (fences, planters) and masonry may go longer between coats; horizontal decks and thresholds typically need attention sooner. The nice part: reapplication is easy as long as you clean and let it dry.

Coverage and value

Coverage varies dramatically with porosity:

• Dense, newer wood and smooth masonry: I saw roughly a “normal” spread rate—no surprises.
• Weathered softwood and very porous surfaces: Coverage dropped significantly; a gallon didn’t go as far as I’d like.

As a rule of thumb, budget conservatively if your substrate is old, rough, or previously unsealed. It’s better to have an extra gallon on hand than to under-apply and end up with dry spots. If you’re sealing mixed materials in one go—say, a deck perimeter, adjacent brick, and a concrete pad—the convenience of using a single product across all surfaces is a real time saver.

Common pitfalls to avoid

• Over-application: This is the number-one way to end up with a tacky or uneven finish. One coat, spread uniformly, is enough. Brush out puddles quickly.
• Hot sun and hot surfaces: Working in direct sun can flash-dry the surface and trap uneven absorption. Pick a cooler part of the day or work in shade.
• Poorly mixed product: Always shake and stir. If the product looks curdled or clumpy after thorough mixing, don’t use it—most likely a storage or freeze issue.
• Inadequate dry time after cleaning: Trapped moisture undermines penetration. Err on the side of longer dry times, especially after power washing.

Where it shines

• Mixed-material projects: One product for wood, concrete, and brick is legitimately convenient.
• Low-odor, easy cleanup: The water-based formula is DIY friendly.
• Minimal change in appearance: Preserves texture and keeps the original look with only a slight deepening while wet.
• One-coat workflow: Fast coverage when you have the weather window.

Where it falls short

• Long-term UV color retention: Clear isn’t a magic shield against graying on sun-baked decks; tint performs better here.
• Coverage on thirsty substrates: Expect to use more on aged, rough wood or porous masonry.
• Not for heavy film build: If you want a glossy, film-forming finish, this isn’t that product.

Practical tips for best results

• Clean thoroughly and allow full dry time before sealing.
• Shake and stir before and during use to keep the formula uniform.
• Work in manageable sections, keep a wet edge, and back-brush/spray to even out the application.
• Avoid application on hot surfaces or in direct sun; aim for a mild, dry day.
• Wipe or brush out any puddles within minutes.
• Test a small inconspicuous area if you’re unsure about absorption or appearance.

The bottom line

I like Thompson’s WaterSeal (clear) for what it is: a straightforward, multi-surface waterproofer that dries truly clear, beads water convincingly, and doesn’t complicate a project with heavy prep or finicky application. It’s especially useful when you’ve got wood, masonry, and concrete in the same workday and you want a uniform, unobtrusive finish.

I recommend it for homeowners and pros who want reliable water repellency with minimal visual change and the convenience of one product across different exterior surfaces. If your priority is long-term color preservation on sun-exposed wood, step up to a tinted/sem-transparent formula. If you’re dealing with very porous, weathered substrates, plan your coverage accordingly and resist the temptation to over-apply. Used as directed, it’s a dependable, low-drama sealer that earns its keep.