Olympic WaterGuard Clear Wood Sealer Review: Does It Really Keep Water Out?

I’ve been taking care of my outdoor deck and fences for years, and if you’re tired of water soaking into your wood, graying it prematurely, or letting mildew take over, you need to grab a can of Olympic WaterGuard Clear Wood Sealer right now.

This stuff delivers real protection without altering the natural look of your wood. It beads water like crazy, fights off UV damage, and keeps mildew at bay—all with one coat that penetrates deep.

Trust me, once you see how well it holds up, you’ll wonder why you waited so long to try it.

My Experience With Olympic WaterGuard Clear Wood Sealer

Last summer, my pressure-treated pine deck was starting to show its age.

Water would sit on the boards after rain, soaking in and leaving dark spots.

Mildew was creeping in on the shaded areas, and the whole thing looked dull and worn.

I didn’t want a tinted stain that would hide the grain—I wanted to keep that natural appearance while actually protecting it.

That’s when I decided to give Olympic WaterGuard Clear Wood Sealer a shot.

I started by cleaning the deck thoroughly with a wood cleaner to remove dirt, old mildew, and any loose fibers. The surface needed to be dry, with moisture content below 18%, so I waited for a stretch of good weather.

On a clear day with temperatures around 70°F, I stirred the sealer (it’s ready to use, no mixing required) and applied it with a brush and roller combo. It went on milky white at first, which made me a little nervous, but it leveled out nicely as I back-brushed it into the wood.

One coat was plenty—it penetrated quickly without puddling.

The next day, it dried clear, no sheen, just a natural matte finish that blended perfectly with the existing wood tone. I tested it by splashing water from the hose, and the droplets beaded up and rolled right off like they were on waxed paper.

A heavy rain hit two nights later, and the deck stayed dry underneath. No more black spots from standing water. Over the following months, I watched how it handled sun exposure—the UV protection kept fading minimal, and mildew didn’t stand a chance even in humid stretches.

By the end of the season, the wood still looked fresh, and the natural graying process was slow and even, just as promised.

Fast forward a year, and the beading was still strong on vertical surfaces like railings, though horizontal boards needed a touch-up after about 18 months of heavy foot traffic and direct rain.

The low odor during application was a huge plus—no headaches or strong fumes like some oil-based sealers. Cleanup was simple: soap and water for brushes and rollers.

Overall, it turned a maintenance headache into something manageable. If you’re dealing with similar issues on your deck, fence, or siding, this sealer genuinely delivers the protection you’re after without complicating things.

What Makes Olympic WaterGuard Clear Wood Sealer Stand Out?

This sealer is designed specifically for exterior wood that you want to keep looking natural. It’s a penetrating, water-based formula with low VOCs, so it doesn’t stink up the neighborhood.

The key is its four-way protection: it repels water, blocks UV rays with SunBlock technology, resists mildew growth, and lets the wood breathe so it weathers naturally to that soft gray patina. Unlike film-forming sealers that sit on top and peel, this one soaks in deep for lasting defense.

It works on new or weathered wood, pressure-treated lumber, and even surfaces with old clear or semi-transparent stains (after proper prep). One coat usually covers 250-350 square feet per gallon, depending on porosity.

I chose it because I wanted something straightforward—no fancy colors, no heavy buildup, just solid protection. You know how some products promise the world but underdeliver? This one backs up the claims with real performance.

Also Read: Comparison of Siloxa-Tek 8500 And 8510 Concrete Sealers.

Pros of Olympic WaterGuard Clear Wood Sealer

• Outstanding Water Repellency The moment you pour water on a treated surface, it beads and rolls away. I’ve seen it hold up through torrential downpours without letting moisture penetrate. That beading action is the first sign it’s working, and it keeps wood from warping, cracking, or rotting from the inside out. You don’t get that instant “wow” with every sealer, but this one delivers it consistently.
• Effective UV Protection Sun damage can turn wood silver-gray too fast or cause checking and splitting. The built-in UV blockers slow that process noticeably. My deck faces west, so it gets hammered by afternoon sun. After a full season, the boards retained more of their original tone than untreated areas nearby. It’s not like a tinted stain that masks fading—this preserves the natural look while fighting off those harmful rays.
• Strong Mildew Resistance Mildew loves damp, shaded wood, and it can turn your project black and ugly overnight. This sealer creates an environment where mold struggles to take hold. I have a north-facing fence section that always got mildewy before. Post-application, it stayed clean through humid months. The mildew-resistant coating is a game-changer for anyone in wet climates.
• Easy Application and Cleanup You can brush, roll, or spray it on. It spreads smoothly, penetrates fast, and doesn’t leave lap marks if you work board by board. The low-odor formula means you’re not choking on fumes, and cleanup is just soap and water—no mineral spirits required. For DIYers like me, that simplicity saves time and hassle.
• Natural Appearance Preservation No glossy film, no color change—just clear protection. The wood keeps its texture and grain visible, and it grays evenly over time if that’s the look you want. It’s ideal when you love the raw wood aesthetic but need to shield it from the elements.
• Value for the Performance At the coverage rate and with one-coat effectiveness, it stretches further than some competitors. You get deep protection without needing multiple layers or frequent touch-ups right away.

Cons of Olympic WaterGuard Clear Wood Sealer

• Reapplication Needed on High-Traffic Areas Horizontal surfaces like decks take a beating from foot traffic, furniture, and pooling water. The protection lasts well initially, but you’ll likely need to reapply every 1-2 years on decks to keep that strong beading. Vertical surfaces like fences hold up longer, often 3-4 years, but it’s not a “set it and forget it” product forever.
• Milky Appearance During Application It goes on white and opaque, which can look alarming at first. If you don’t spread it evenly or back-brush properly, you might get temporary streaks. It always dries clear for me, but that initial look can make you second-guess yourself mid-project.
• Surface Preparation Is Key You can’t slap it over dirty, painted, or heavily coated wood. Proper cleaning and drying are non-negotiable. Skip that step, and adhesion suffers, leading to uneven results or reduced performance. It’s not hard work, but it requires effort upfront.
• Not Ideal for Every Surface This is for wood only—no brick, concrete, or painted projects. It’s penetrating, so it won’t work over solid films or stains that block absorption. If your wood has old paint or varnish, you’ll need to strip first.

Also Read: Comparison of Siloxa-Tek 8505 And 8510 Concrete Sealers.

Application Tips For Olympic WaterGuard Clear Wood Sealer

• Proper Surface Preparation Always start clean. Sweep off debris, then use a deck cleaner to remove dirt, mildew, and graying. Rinse thoroughly and let the wood dry completely—wait at least 48 hours after rain or cleaning. Check moisture content if possible; under 18% is ideal for pressure-treated wood. Tape off nearby plants or siding to avoid overspray. Good prep means better penetration and longer protection.
• Application Techniques Apply on a dry day with temps between 50°F and 90°F. Avoid direct sun to prevent fast drying and lap marks. Work one board at a time, brushing or rolling on generously, then back-brush to push it into the grain. One coat is usually enough, but if the wood is super dry and absorbent, a light second coat can help. Don’t overapply—excess can stay sticky or run.
• Drying and Curing Expect dry-to-touch in a few hours, but full cure takes 12-24 hours. Keep foot traffic off for at least a day, longer if humid. Test water beading after 24-48 hours to confirm it’s set. If rain threatens, cover the project until dry.
• Regular Inspections Every few months, splash water on different areas. If it soaks in instead of beading, it’s time to plan a refresh. On decks, check high-traffic spots first—they wear faster. Vertical fences usually need less frequent attention.
• Reapplication Strategy When beading weakens, clean the surface again (no stripping needed if the old sealer is still intact), then reapply one coat. It bonds well to previous layers of itself. For decks, aim for every 1-2 years; fences and siding, every 3-4 years depending on exposure. Consistent maintenance keeps protection strong without letting damage creep in.
• Cleaning Treated Wood Use mild soap and water for routine cleaning. Avoid harsh pressure washing that can strip the sealer. For mildew spots, spot-treat with a wood cleaner before they spread. Gentle care extends the life between applications.
• Storage Tips Store leftover sealer in a cool, dry place with the lid tight. It lasts well for future touch-ups. Stir thoroughly before reusing.

Comparing Olympic WaterGuard Clear Wood Sealer To Other Brands

• How It Performs Against Thompson’s WaterSeal Thompson’s WaterSeal is everywhere, and it’s cheap, but many users—including me—find it falls short on longevity. It beads water at first, but that effect fades fast, often within months on decks. Reapplication every year or two is common, and some complain it doesn’t penetrate as deeply, leading to surface cracking or peeling. Olympic WaterGuard soaks in better, giving more consistent protection over time. The UV and mildew resistance feels stronger too. If you want something that lasts longer between coats without sacrificing ease, Olympic edges it out for real-world durability.
• Olympic WaterGuard vs. Cabot Products Cabot makes solid options, like their Australian Timber Oil or clear sealers, and they often get praise for rich penetration and color enhancement. However, many Cabot products add tint or a slight sheen, which changes the look more than a truly clear option. Olympic WaterGuard keeps things completely natural—no added color, no gloss—just protection while letting the wood age gracefully. Cabot can last longer on vertical surfaces in some cases, but on decks, I’ve found Olympic holds up comparably or better in wet conditions without the extra cost or complexity. If you prefer zero visual change, Olympic wins.
• Standing Up to Behr Premium Sealers Behr offers good value with strong water repellency and UV protection in their clear formulas. They apply smoothly and clean up easily too. But some users report Behr can feel thinner during application, requiring extra coats for full coverage on porous wood. Olympic WaterGuard often needs just one solid coat, and the beading action seems more pronounced in my tests. Behr is reliable, but Olympic feels more robust against mildew in shaded areas. For straightforward, no-fuss protection that prioritizes natural wood appearance, Olympic pulls ahead slightly.
• Overall Brand Comparison Insights When I weigh these options, Olympic WaterGuard strikes a sweet spot: easy to use, low odor, deep penetration, and reliable defense without gimmicks. Other brands might shine in one area, but this one balances everything for everyday homeowners who want results without constant upkeep.

Also Read: Is Granite Gold Sealer Worth It?

Frequently Asked Questions (FAQ)

Final Thoughts

If you’ve been putting off protecting your outdoor wood, stop waiting. Olympic WaterGuard Clear Wood Sealer gives you reliable, easy-to-apply defense that keeps water out, mildew away, and your wood looking good longer. I’ve used it, seen it work, and I keep coming back to it.

Pick up a can—you’ll be glad you did.