3 ms·

In Puerto Rico, roofs are flat and get dirty within a few months. You absolutely can easily determine when it was last powerwashed as well as when it was last s

In Puerto Rico, roofs are flat and get dirty within a few months. You absolutely can easily determine when it was last powerwashed as well as when it was last sealed. Sealing will leave you with a pure white roof for about a month or two. Powerwashing will leave you will light to medium gray. They'll turn dark gray to black within a few months in the parts where the water pools.

oakwhiz 4y ago
It's different for dyed sealant, but there is a time while the work is being done where old sections are stripped back and the new material is drying. Lots of false positives from HVAC work etc. though.
geysersam 4y ago
If this is such an issue, why not have sloped roofs? (Just curious)