Affiliate disclosure: Some links on this page are affiliate links. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.
Thompson’s WaterSeal is the best-known name in clear waterproofers, and its current lineup includes the Waterproofer Plus Clear Multi-Surface Waterproofer (concrete, brick, masonry and wood) and the Clear Masonry Protector Waterproofer (masonry only). Both are easy, cheap-per-gallon products for homeowners who want water to bead on a patio, walkway or brick wall. The trade-off is that they are light-duty, need regular recoating and don’t publish much technical data.
| Type | Clear penetrating waterproofer (exterior only) |
| Chemistry | Not disclosed on product pages; applies milky white, dries clear, soap-and-water cleanup |
| Finish | Clear, natural look |
| Coverage | 50–375 sq. ft. per gallon, depending on porosity |
| Coats | Usually one light coat |
| Dry/recoat | Dry in 24–72 hours; recoat after 72 hours (Multi-Surface: 72 hours to 45 days) |
| Cure | Keep above 50°F for 48 hours after application |
| Application temp | Air and surface above 50°F; no rain for 24 hours |
| Best for | Patios, walkways, pavers, brick, stone and stucco |
| Not for | Below-grade walls with water pressure, painted or recently stained surfaces |
| New concrete | Wait at least 4 weeks |
| Sizes | Multi-Surface: quart to 6 gallon; Masonry Protector: 1, 1.2 and 5 gallon |
Watch: Thompson's WaterSeal in 60 seconds
What It Is / How It Works
Thompson's WaterSeal sells several clear waterproofers for wood and masonry. For concrete and masonry, the two relevant products today are:
- Clear Multi-Surface Waterproofer for concrete, brick, masonry and exterior wood.
- Clear Masonry Protector Waterproofer for pavers, brick, concrete, stone, stucco, and clay and quarry tile.
Both soak into the surface and leave a clear, water-beading finish. They go on milky white and dry clear, and wet tools clean up with soap and water. Thompson's doesn't list the active ingredients or solids content on its product pages, so it's hard to compare their strength directly with silane/siloxane sealers that publish those numbers. Thompson's says both products resist mildew and UV damage and help maintain the surface's natural color.
Where It Works Best (and where it doesn't)
These are good matches for a homeowner treating a patio, front walk, paver area or brick planter who wants an easy, one-coat job from a pump sprayer. The Multi-Surface version is handy if you're also doing a wood fence or deck rail in the same weekend.
Thompson's is clear about the limits: don't use them below grade where water pressure is an issue, and don't apply over painted or recently stained surfaces. They're exterior-only. Lifespan also "varies by environment," and Thompson's asks you to splash test once a year to see if you need to reapply. Surfaces that face the sun and heavy foot traffic usually need it sooner. For driveways that see deicing salt and hot tires, a dedicated product from our best driveway sealers list is a better long-term buy.
Pros
- Widely sold and easy to find in hardware and home stores
- Simple one-coat application with a garden pump sprayer, brush or roller
- Dries clear and keeps the natural look of concrete and masonry
- Soap-and-water cleanup for wet product
- Multi-Surface version handles wood and masonry with one can
- Built-in splash test makes it easy to know when to reapply
Cons
- No published chemistry, solids or service-life data
- Needs regular recoating; Thompson's recommends a yearly splash test
- Long dry time (24–72 hours) and a firm 50°F minimum for 48 hours after
- Can darken or turn tacky if nights drop below 50°F too soon
- Not for below-grade water pressure, painted or stained surfaces
- Smooth concrete must be etched first for the Multi-Surface product
How to Apply It
- Do the splash test. Sprinkle water on the surface. If it soaks in and darkens within about five seconds, it's ready for treatment. If it beads, it doesn't need protection yet.
- Make sure new concrete or stucco has cured at least 4 weeks and is dry. Thompson's calls for etching smooth concrete before using the Multi-Surface product.
- Clean the surface and let it dry. After cleaning or rain, wait at least 72 hours for concrete, brick and masonry (48 hours for wood).
- Pick your weather. Air and surface must be above 50°F during application and for 48 hours after, with no rain in the forecast for 24 hours.
- Stir well and don't thin it or mix it with other waterproofers. Cover plants and test a small patch first.
- Apply one light, even coat with a pump sprayer, brush or roller. Spread or wipe up any puddles within 15 minutes.
- Let it dry 24–72 hours. Recoat no sooner than 72 hours, and only if the splash test says a spot still absorbs water.
How It Compares
Seal-Krete Multi-Surface All-Purpose Water Repellent is a similar big-box, water-based product. Its data sheet is more detailed: 150–300 sq. ft. per gallon, recoat in a few hours and foot traffic in 24 hours. That faster turnaround is handy if your weather window is short.
Dedicated silane/siloxane penetrating sealers publish their active content, coverage and expected service life, and many are rated for driveways and deicing salts. They cost more per gallon, but the better ones state how long they're designed to last, which makes it easier to plan recoats. Our best silane siloxane concrete sealers guide covers the stronger options.
Film-forming acrylic sealers add sheen or a wet look and resist stains better on patios, but they can peel and get slippery. If you want a natural look, a penetrating product like Thompson's is the safer choice.
FAQ
Does Thompson's WaterSeal work on concrete?
Yes. Both the Clear Multi-Surface Waterproofer and the Clear Masonry Protector are labeled for concrete. The Masonry Protector is the more focused choice if you're only treating concrete, pavers, brick or stone.
How long does Thompson's WaterSeal last on concrete?
Thompson's doesn't give a fixed number of years. It says lifespan varies by environment and recommends a splash test once a year. When water stops beading and soaks in, it's time to reapply.
Can you paint over Thompson's WaterSeal?
For the Clear Multi-Surface Waterproofer, Thompson's says to wait 45 days before using latex paint and at least 3 days before oil-based paint.
Will it stop a leaking basement?
No. Thompson's says not to use it below grade where water pressure is a problem. See our best waterproofing concrete sealers guide for products made for that job.
Verdict
Thompson's WaterSeal clear waterproofers are fine for light-duty patios, walks and brick where you want a natural look and an easy weekend job. They're easy to find and simple to use. Their long dry times, strict temperature rules, lack of published chemistry and need for frequent recoating keep them behind dedicated concrete sealers for driveways and high-exposure surfaces. Our rating: 3.2/5
How we reviewed this product: this is a research-based review built from the manufacturer's technical data sheet and current retail listings. We have not run our own hands-on tests of this product. Details were checked in October 2026; always follow the current label.
