We also sent sets of stained boards to southern Florida, to find out how well the stains held up to fierce mildew and sunlight. The box at the end of the Ratings lists the products we've already dropped from the Ratings. Most of the stains we tested were easy to apply. It should prevent water from seeping into the wood, where it can promote rot or cracking as the weather cycles from wet to dry. It should retain its original color while preventing the sun's Color ultraviolet rays from turning the wood itself gray.
Solid stains have the advantage here because they contain greater levels of hiding pigment.
It should resist mildew growth on the surface and keep dirt from sticking. What we found We found significant differences in performance after nearly a year. As the Ratings show, many of the stains we tested are already judged fair or poor. And that's with two coats. One-coat results are often much worse.