I applied an elastomeric roof coating to my Montana a year ago. I would strongly recommend not to apply that junk to your roof because after a few months mine started to peel off I also found it was trapping water under it which caused serious water damage to wood under rubber roof and mould .I followed application instruction s to the letter and still that product failed.The roof had to be replaced at a cost of $4800.The guy that fixed the roof said he has had several similar repairs because of that product. If the roof is not leaking don't do anything but regular cleaning it will save you a lot of time and money.