I have 2 small flat roofs that had new rolled roofing material
installed approximately 4-5 years ago. One roof has more of a pitch
than the other.

The roofing contractor came back a month or so after the installation
and applied a silver coating over the top of both. He said the coating
would last about 5 years, (he was right).

Presently I have no leaks, however I have noticed that on the roof with
less of a pitch the aluminum coating is breaking up, "aligatoring?".
The roof with the greater pitch looks fine.

I have been thinking about recoating both roofing surfaces with
aluminum coating, (unsure about fibered or non-fibered varieites?), or
possibly switching to the white elastomeric coating to prevent the
aligatoring.

The house is in NJ by the coast and does experience it share of cold
winters and inclement weather.

Any suggestions are appreciated.