Hard to tell for sure without a close look, but the roofing / waterproofing material looks like TPO, a single-ply roofing membrance. It is not made for direct traffic, so appears someone has installe ... read more
a stainless steel film will be easy to keep clean and won't do much damge to the wall when removed. http://www.amazon.com/Instant-Appliance-Stick-Stainless-Steel/dp/B00BAUPS9M