Do things painting the roof white help to reduce the heat in a significant way? Have seen it being mentioned in videos on black vs white coloured cars.
Are there any drawbacks noted by people who tried it for roofs?
Or are there other options that are easier to start with?
Yes, very effective. I worked in commercial construction for a few years.
We didn’t use paint, but the gist is the same. A black EPDM roof may reflect about 5% of incident irradiance and a white TPO roof reflects about 80% which means that a white TPO roof reflects 16x more light than a black EPDM roof and the black roof absorbs 4.75x more than the white.
This means white is easier to cool in the summer and black is may be easier to heat in the winter, but the amount of sun in the winter is less so its not like 1:1.
All true, great post. I can only add that proper attic insulation matters much more for indoor warmth in winter than the color of the roof itself.