Q&A / 

Deck Stain Test Results After Two Years

In May of 2012, I started an extensive outdoor test in real conditions of quite a few name brand deck sealers.  The test was conducted here in central New Hampshire.

The sealers were tested on treated lumber and cedar decking. Both are very popular wood species used for outdoor wood decks and structures.

Here's the list of manufacturers who's products were in the test:

  • TWP
  • Armstrong's
  • Defy
  • Behr
  • Benjamin Moore
  • Wolman's
  • Sherwin Williams
  • Olympic
  • Thompson's

Some products failed within 60 days or so. You can SEE THE RESULTS FOR FREE of dramatic Before and After photos of each sample by going to the this page.

The following photos were shot on June 3, 2014, in the shade. Twenty-five months before, in May of 2012, these panels had just been stained and put out to weather here in New Hampshire.

The first photo shows just five pieces of the cedar decking. The reason for that is after just ONE YEAR, a majority of the stain products had COMPLETELY FAILED and it was useless to continue to expose them to the weather. You can see after an additional year of weather, the others are dead on arrival.

But look at the stain samples on the smaller treated lumber. Isn't it amazing the stain is in much better shape on just about every one! What's more, there's very little mildew or mold on any of them. For the most part, they look quite good.

The reason, I believe, is the treated yellow pine absorbs the stain more as opposed to the harder summer wood found in the cedar. Cedar also has natural oils in it that act as a natural preservative. I suspect these oils interfere with the adhesion of the stains on the wood.

The copper in the treated lumber, I believe, leaches out through the sealers. Copper is a natural biocide and its presence stops the growth of mildew and mold.

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.

These are cedar wood samples. All of the stain products have now failed. Photo credit: Tim Carter

These are cedar wood samples. All of the stain products have now failed. Photo credit: Tim Carter


Stain Test Panel 2

This is the beginning of the treated lumber samples. Note that each of the photos overlaps the one before/after it. You can easily see this. Photo credit; Tim Carter


Stain Test Panel 3


Stain Test Panel 4


25 Responses to Deck Stain Test Results After Two Years

  1. Hi Tim
    I received my 9 Pound container of Stain Solver yesterday. When I purchased it I also bought you test results for the Stains, that was only thru May of 2013, I would like to see the results thru June of 2014 without having to buy for them again. If I had known I would have waited a week to purchase.
    Ed Gorman

  2. Penofin is the only stain I have found that will not wear off with exposure to the weather. Is this product different from the products you tested above? I have tried the Behr stain and found the same results as you.

  3. Good information to have Tim. I always wondered if desk stains were just a futile effort.

    On a related note, for those of us with an unstained deck is there any rule of thumb for how many years:
    1. treated SPF or
    2. untreated cedar will last?

    I am up in Ottawa, Canada.

    Many thanks

  4. Have a large deck at our campsite. It needs to be refinished now. The boards are cedar. What stain should I use? Will have to clean the decking before I restain. Might even need to do some sanding unless I can find a color the same as I previously used. Had bought the video you had for sale showing the different stains but when converted to windows 7 lost a lot of my files so am not able to see the video. Someone told me Fleet Farm has a product that can be used on decks that is supposed to be real good and will last quite long. Haven't checked it out yet. Don't know if Fleet Farm has different colors/stains with this product.

  5. I purchased the test results, and I'm trying to match up with the 2 year results. Are the treated lumber samples in order of the test results file, A-P or are they in a different order, as the stain colors don't seem to match the order in the results file.

      • It is difficult to match them up as there are several stains that look similar, and the 2 year results is critical. Is there a pdf with the 2 year results, as the dst pdf only has the 1 year results, and I can't match them without guessing.

        Also, is there any additional detail besides the pictures, as it would be nice to know which stains experienced flaking/peeling vs which simply lost or changed color, as peeling certainly seems like the worst case scenario.

  6. I purchased the 2013 test results and would like to know the results of the 2014 results. I think it is unreasonable to ask others who have paid for this to have to try and match by eye the above photos with the original test results. IS there a separate PDF file for the 2-year results? Please post or provide access for those who paid to know this info.

    • Will, because of a health issue, no 2014 test was conducted. What you see in the above photos tell the tale. ALL OF THE PRODUCTS FAILED after two years.

      That's all a report would have said. You can clearly see the flaking finishes and black mold in the above photos.

      Your takeaway should be: Be prepared to refinish your deck every two years no matter what you use.

  7. HI Tim,

    I've been using DEFY stain on my deck and on customer's decks since reading your column about deck stains a number of years ago. So I was stunted when I saw your 2016 comment "I no longer would apply Defy deck sealer to any exterior wood that I own at my own home."

    Can you expand on that? Why the change, what product would you recommend now (is it different than the 2013 deck stain test)?

    Thank you. I really appreciate the columns and advice

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