Flat Roof with No Attic: How to Keep House Cool in Summer

LESLIE: Alright, now we’ve got Joe who’s calling in with a flat roofing question. What can we do for you today?

JOE: Is there a product that somebody produces or manufactures that can be put on a flat roof and below the roof there is no attic or crawlspace? And I’m wondering if this product can be used to keep the rooms below the roof cool in the summer and warm in the winter.

TOM: OK, so you have a flat roof with no attic and you’re looking for a roofing product that’s going to give you some thermal qualities.

JOE: Yes.

TOM: Well, in terms of the summer, that’s an easy one. Any type of membrane roof – especially a ballasted roof where you have a membrane and then it’s covered with either a fibrous aluminum type of paint which reflects the heat of the sun or a membrane roof that’s covered with a stone which is very, very common; usually uses a lightweight, white-colored stone – those both are designed to keep the roof cooler and, hence, the building cooler underneath.

In terms of retaining the heat, that’s another matter in its entirety.

JOE: Wait, you said stone – s-t-o-n-e?

TOM: Yes, correct.

JOE: Oh, OK. Alright. I wanted to be sure that I understood what you said.

TOM: Yes. Yeah, it’s called a ballasted roof because the stone actually is sort of a ballaster; a weight that keeps the roofing product in place. But there are roofing products that are designed specifically to reflect the heat of the sun. I don’t think you’re going to find one that holds the heat in but you will find one that reflects the heat.

JOE: I see, I see. I thank you very, very much.

TOM: You’re welcome, Joe. Thanks so much for calling us at 1-888-MONEY-PIT.