Thompsons WaterSeal Review

by Gail on June 3, 2012

One of our decks is made of good 4 sides cedar 2×4. It has faded over the few months since we built it.

Somehow, after reading the literature in the hardware store, I convinced myself that Thompsons WaterSeal, cedar-tinted, advanced (“UV-protection, low VOC, water clean-up, 2 year warranty”) would be the best choice for finishing the deck.

It turns out that it applies in a kind of splotchy way. It doesn’t look anything like natural cedar.

It does seal out the water, as evidenced by the pooled water on the surface. But, for how long? I read some reviews AFTER applying it to our deck, and they were not positive – some suggested the water-proofing was not long-lasting.

What I did learn myself is that there is no way it’s water clean-up. It appears to be a wax (petroleum) product, and just clumps up on the brushes. I would give this product two thumbs down, mostly because of false claims about water clean-up/low VOC and the difficulty of applying it smoothly.

UPDATE: April 1, 2013

So, 10 months after I applied it, it’s worn off in places:

thompsons water seal


I really hate this stuff.

At the very least, I will get my money back. But what a waste of time. It’s an inferior product.


{ 8 comments… read them below or add one }

Chris August 27, 2012 at 11:40 am

The label states clean up with water.
Absolutely does not work, it is strange stuff, sort of a queer emulsion? You need a solvent based products like varsol or a paint thinner.


deckowner1 October 23, 2013 at 8:51 pm

I sealed my deck with Thompson’s water sealer and regretted it within three months. It allowed the deck to begin turning grey and it was impossible to remove. The reason I could not remove it was that it consists of parafin oils and heavy hydrocarbons. After getting my money back from Thompsons, I finally found an outstanding product to remove the stuff completely. It is EC 1800 degreaser sold by EcoChem. It totally removed the Thompsons product and left me with clean fresh deck boards. here is their website:


Gail October 23, 2013 at 8:58 pm

Thanks for the tip. It’s interesting that my Thompson’s Water Seal review is my most-read post of all, over the year plus since I posted it. It seems many others have issues with the product.


deckowner1 October 24, 2013 at 8:35 am

Yes, from my research on the web, I have determined that there must be hundreds of people who have endured the nightmare of trying to remove the Thompsons product. I failed to mention that EC 1800 is completely natual, biodegradable, with no chemicals. Therefore, it is not harmful to plants or animals and does not require any special treatment after application to reset the ph balance of the wood. I stripped the deck of the Thompsons product using EC 1800 and, once the boards dried, applied a new sealer, which worked beautifully. EC 1800 is easy to use – just brush it on, wait 20 minutes, lightly scrub and wash it off with heavy water spray from a hose or light pressure washer. It was an answer to my prayers. We nearly destroyed our new deck trying to strip the Thompsons before I found EC 1800. I sound like I am advertising for them because maybe I work for them or have some vested interest – not so – I am just a very happy comsumer who wants others to find out how to get Thompsons off their decks.


Marlene Pittoors August 22, 2016 at 4:37 pm

what was the sealer that you applied that you are happy with?
thanks Marlene


Gail August 22, 2016 at 5:09 pm

Hi, Marlene
See this post:

I used Behr’s semi-transparent stain for decks and siding.


John Kelmer June 13, 2015 at 8:08 am

Just read article by Gale, 2012. This looks like what happened to us. Summer of 2014 we used Thompson WaterSeal Semi-Transparent Dessert Brown waterproofing. Did the power washing, oxy clean, deck clean and final rinse. Totally dry before applying stain. Had to apply 2 coats plus some areas needed the Thompson Gel Stain to blend color. It looked beautiful. Left for the winter and returned in June, 2015 to our horror 90% of the stain in gone, flaking and peeling. We have 2 levels which we did ourselves and got all the help from Thompson WaterSeal people. They asked us questions, we answered this was not new wood. What a horrible mess. Trying to deal with company now. This project took us 3 months because we followed directions by them to a tee. We are seniors and probably cannot do this by ourselves again, no family in the same state, on a limited income. Now what? Waiting for their reply after I send in photos of deck done and damage now and receipts. Talked to many people at Thompson. First reply on line was telling me all our fault. No way…they gave us info on products to use and how to do it all.


mike July 22, 2017 at 6:17 am

used thompsons water seal with brown tint on deck .went on good .no one walks on deck.rental property.renter drives truck comes home once in 3 weeks and basically stays inside.6 months later it has all come off. other friends have had problems with it never drying,stayed sticky.hod to power wash deck again and retreat with cwf cedar treatment.have never had a proplem with it.dont waste your time and money on thompsons


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