That is Oriented Strand Board (OSB), typically used for sheathing. Looks like it has been used exposed to weather, which is not its intended use. There is no reasonable repair for that, other than r ... 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