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Deck Sealer Tests

Deck Sealer Performance Test Results

NOTE FROM TIM CARTER - Founder of AsktheBuilder.com - posted October, 2016: I no longer would apply Defy deck sealer to any exterior wood that I own at my own home.

In July of 1996, the Earlham Analytical Laboratory released independent test results derived from testing 25 wood sealants and water repellents. The test was conducted to judge color change in wood specimens. The outdoor test was conducted from December of 1995 to July of 1996. Products that block water absorption and ultraviolet (UV) radiation retain the highest degree of color.

Synthetic resins happen to do this best it turns out. The products were rated in two ways: Relative Performance to those tested in the group (1 being the best and 25 being the worst) and Performance Ranking (A being excellent down through D being total failure).

In the spring of 1997, a very popular consumers magazine that doesn't accept ads came out with a special announcement regarding early results from a five-year study they were conducting on deck care products. At the end of one year, nine products failed so miserably they felt they had to warn the consumer.

In the years since then, not much has changed. They continue to test and there continues to be deck sealer failures. The interesting thing is that this publication is not aware of the synthetic resin products! I can't believe I scooped them, as I made my discovery of these great products about three months before they went to press in May, 1997.

Be careful! Some of the products below are film forming sealants - NOT penetrating water repellents. Film forming products lay on top of your wood decks and will peel off over time. Avoid film forming products - these are the ones that need to be stripped off when they eventually fail. For example, the top rated product that was tested - Sikkens - is a synthetic resin film former. The actual product that was tested is a two part system. It is also very, very expensive.

Author Update: In 2012 I began a one-year test of popular deck sealers. CLICK HERE or the following graphic ad to get the results.

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The second place product - Defy - is not a film former. It is a water based penetrating water repellent made with synthetic resins. I have used it for years with unbelievable results. What's more, I have received hundreds of written reviews from readers who have also achieved the same results using Defy. The only other synthetic resin sealer I could locate was the TWP product. I have not used it so I can't tell you about its performance.

NOTE FROM TIM CARTER - Founder of AsktheBuilder.com - posted October, 2016: I no longer would apply Defy deck sealer to any exterior wood that I own at my own home.

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14 Responses to Deck Sealer Tests

  1. Dear Tim
    In regards to your past recommendation I cleaned my deck with Stain Solver and then sealed it with One Time wood preservative. It has held up pretty well but now it is time to do the whole process again. However I see no mention of One Time on the site anymore. Has it fallen out of favor? You mention a product called Defy and seem to have high regards for it. If I chose to use it would I have to use the One Time stripper before I applied Defy.Seems that One Time has epoxy resins if I remember correctly. Thanks for your help with my deck.

  2. Tim, what is the status of your most recent side-by-side deck sealer comparison test? Do you have a time table for releasing the results?

  3. Do you have any experience with the Defy Hardwood formula? We are considering an eastern red cedar deck. Seems to be the same idea as the product you have had good experiences with, but specially formulated for cedar, etc. Also, how long should we wait after installation to stain? Thanks.

  4. I am really interested in the product name for the most recently tested clear sealer with excellent results! Thanks.

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