We will be cleaning a 150 year-old mostly limestone church in a few weeks. It has a good amount of mold and mildew on it which is no problem to remove with low-pressure but I am concerned that underneath or along with those stains there might be tar stains which have bled down from the roof. Is it true that these stains are a petroleum product?
Anyway what can I do to get these stains off as well. I can't bear down on these surfaces with high-pressure.
Thanks for your help.
Anyway what can I do to get these stains off as well. I can't bear down on these surfaces with high-pressure.
Thanks for your help.