EcoRenovator - View Single Post

rvCharlie · 02-05-16, 03:42 PM

I think the subject of roof coatings deserves a more detailed answer. The ceramic insulation product may or may not have merit, but in a sunny, hot environment, a WHITE roof coating can have a tremendous effect on heat gain in the structure. One of my neighbors covered the galvanized metal roof of his hangar with this stuff:
Black Jack- 5530-1-30

It has virtually no insulation ability; it's basically a roof sealant with a bonus of providing a radiant barrier for sunlight. After coating his roof (no insulation under the roofing metal), he measured the metal temp from inside the hangar on a hot sunny day with a laser thermometer, then went next door & did the same measurement in an uncoated hangar. I don't remember the exact number, but the temp spread was well above 10 degrees F. If you go from a dark roofing material to pure white, the spread would be even greater.

edit: Should have said that I'm in Mississippi, southern USA. A lot more humidity, & probably a little less solar gain than Riyadh.

02-05-16, 03:42 PM	#1843
rvCharlie Lurking Renovator Join Date: Jul 2013 Location: central MS Posts: 23 Thanks: 2 Thanked 3 Times in 3 Posts	I think the subject of roof coatings deserves a more detailed answer. The ceramic insulation product may or may not have merit, but in a sunny, hot environment, a WHITE roof coating can have a tremendous effect on heat gain in the structure. One of my neighbors covered the galvanized metal roof of his hangar with this stuff: Black Jack- 5530-1-30 It has virtually no insulation ability; it's basically a roof sealant with a bonus of providing a radiant barrier for sunlight. After coating his roof (no insulation under the roofing metal), he measured the metal temp from inside the hangar on a hot sunny day with a laser thermometer, then went next door & did the same measurement in an uncoated hangar. I don't remember the exact number, but the temp spread was well above 10 degrees F. If you go from a dark roofing material to pure white, the spread would be even greater. edit: Should have said that I'm in Mississippi, southern USA. A lot more humidity, & probably a little less solar gain than Riyadh.