I purchased a little cottage last fall, and got around to power washing the deck, and applying two coats of Behr semi-transparent weatherproofing stain/sealer. The deck probably was not treated in 10 years, but was in good shape. After powerwashing, I gave the deck a few days to dry then stained it when there was no chance of rain in the forecast. The first coat and second coat were applied on consecutive days. After day two, when I was done, I sat down to drink a cold drink and turned on the weather channel. A line of thunderstorms had formed, and looked like it was going to blow through 5 hours later. ARGH! All that hard work, was it going to ruin everything? When it started raining at the cottage, I decided to go back home, it was totally out of my hands. I spent time googling what would happen, and everyone's comments had me thinking I would have to completely redo the deck. Well, I am here to tell you, that was four days ago, and I just saw the deck today. Yes, it did rain, but the deck still looks as good as when I originally finished, and the rain didn't affect the stain finish at all. AND, the stain looks great!