STA-KOOL®+ 780 Elastomeric Pro White Roof Coating is another cool roof option that is also very highly rated with a two-coat application. Both are highly rated and offer protection and cooling properties in a one-coat application.
Take a look at Gardner Flat Roof Coat-N-Seal or Gardner Eterna-Kote S-100. If your goal is to end up with a white roof, you've got some very efficient, effective durable white coating options. The asphaltic roof coatings are much more compatible with aluminum coatings as the asphalt will 'bleed through' your white coating.
