I have the top of our boat carpeted with cheapo Home Depot .30 cents a sq ft indoor-outdoor carpet. I have found that the areas that are shaded get moldy but the rest exposed to rain and sun all day stay mold-free. I have the same stuff on our swim platform and no problems. I did spray down our trex deck with that stuff they sell to remove mold and algae from shingle roofs. I also sprayed it on the carpet. It takes a couple of weeks to work it's magic but it is magic. It ate the black algae off the deck I had difficulty removing with a wire brush. I'm told the active ingredient is the same stuff in Lysol and Bactine???