I own a 1983 Masterfab in California. I am looking to apply an elastomeric type roof coating over the exsting roofing. The previous owner actually used exterior paint over the original sheet good roof. The paint seems to have bonded OK to the original membrane, but my concern is that it does not expand/contract or flex with the roof and it is paint - not really intended for constant foot traffic, scrubbing with a stiff deck brush, furniture, etc. I am hoping just to lightly sand the existing painted roof, fill any cracks etc. and then apply no coating (and primer if required). Any suggestions on manuf. or brand names?