We installed sheets of red colored pvc sheeting under our upper deck to provide dry area below. It's spring I noticed a big area which has lots of splotches of dried gray stuff which looks like cement. Only thing I can think of is that we have a fire pit nearby outside the deck - but not sure how or what caused the splotches. I've tried a brush with soapy water, and tried Goof Off, then using a metal scraper which kind of works but leaves small scratches and WILL take FOREVER. Everything I've looked up says to use muriatic acid in water but I can't because it would drip down onto me. ANY BETTER IDEAS?
Do not use GOOF OFF! Do not use muriatic acid either. You need to find out what the splotches are first. You say it looks like cement but why? Did you have any concrete work or brick pointing work or any type of cement work done to your house? If so if it was done by a contractor he is responsible not you. Any type of cement would wipe off of pvc sheets easily with a wet rag unless you wait to long after. GOOF OFF would ruin the pvc sheets if its the solvent based strong smell type. Cement splotches only appear after a sloppy contractor or sloppy home owner did cement work around the sheets but you didn't specify??
