We haven't needed this for the most time. I'm not spending on AC for a few days per year where it's really hot while it's really not most of of the year. Besid

We haven't needed this for the most time. I'm not spending on AC for a few days per year where it's really hot while it's really not most of of the year. Besides: I'd rather put sedum/green stuff on our flat roof, which also helps insulate a little bit in winter but really really helps in summer.