TV
Why Do People Have Rocks on Their Roof?

My husband and I have started watching the new HBO show “Enlightened” with Laura Dern (no, this is not a sponsored post), and in the first episode when she goes to her mother’s cute mid-century California home there are rocks all over the roof. At first I couldn’t figure out what it was, but it dawned on me that I’d remembered seeing those as a kid on neighbors’ houses every now and then.
My husband and I tried to figure it out for a minute and even though he grew up in California he had no idea what it was for either. The house in the show had a regular-looking slanted roof, but one link I found refers to flat roofs where the rocks are part of a tar and gravel set-up with the rocks keeping the tar from flowing around the roof in the summer months. One Yahoo Answers said the rocks were part of a cheap fad, though they apparently helped with heat damage.
I also found some weird Arizona thing about large rocks being placed on the roof to supposedly control the heat but I don’t know if I buy that.
