Rico De Paz with Consumer Reports tested 29 stains. He says it’s important to use one, because untreated wood can crack and turn grey.
To find which stains last the longest, De Paz applied them to wood panels left on the roof at Consumer Reports for 3 years. Other panels are left in a shady spot to test for mildew resistance.
A clear finish shows off the wood’s natural grain and texture but tends to only last a year, and it won’t keep the wood from turning gray. The only one to earn a Consumer Reports’ recommendation is Thompson’s Water Seal Advanced Waterproofer for 23 dollars.
A solid stain lasts longer, but it covers up the natural grain of the wood. De Paz says “It’s more durable. So three years later, it’s almost exactly the same.” Consumer Reports named a best buy -Behr’s solid color waterproofing wood stain. It’s sold at Home Depot for 29 dollars a can.
A compromise would be a semi-transparent, which will still look good after two years. Testers compared the semi-transparent Cabot Express Deck Wood Stain to a semi-transparent stain from Behr. De Paz says “after two years the Behr still looked really good, while the Cabot had started to break down.” In fact, the Premium Semi-Transparent Weather Proofing Wood Stain from Behr earned top ratings. It costs 37 dollars at Home Depot.
This report is based on an article in the current June 2014 issue of Consumer Reports magazine, pages 24-27. The issue will be on newsstands from May 1st to June 2nd.