How to Treat a Patio Deck

Sweep decking often and clean it at least twice a year. Scrub down the wood with oxygen bleach in the spring, after pollen has settled, and again in the fall, after the bulk of entertaining is over. Use a long-handled brush to scrub the wood and remove debris, then hose off the surface. If your decking has mold or mildew issues, use a cleaner formulated to kill molds. You could also use a bleach solution of 1 part bleach to 10 parts water to kill mold.

Test the decking annually by sprinkling water on it. If the water soaks in, it is time to reseal. If it beads up, you can wait another year and test again. If it beads, then starts to soak in after a few minutes, try testing it later in the year or the following year because it will need sealing soon.

Paint the deck patio with a wood sealer that also protects against mold and mildew. You might also select a sealer that has UV (ultraviolet) protection as well, especially if you are trying to maintain the natural wood color.

Use paintbrushes to apply the sealer along railings and between slats. Work backward toward a door or steps so you don't block yourself in. Let the sealer dry overnight.