Metal Roof: OK to Insulate?

LESLIE: Jim in Ohio has a question about a metal roof. What can we do for you?

JIM: I have a small home and it’s covered in a new, metal roof with slats underneath it.

TOM: OK.

JIM: And I insulated the single-car garage, from sidewall all the way up to the trusses and everything, with r-13. In the house, which is hooked to the garage here, I have 13 inches of – I’m sorry – 24 inches of insulation blown underneath the trusses on the attic floor.

TOM: (overlapping voices) OK.

JIM: Should I insulate that metal roof there, also?

TOM: Well, the insulation, if I’m understanding you correctly is – can we say that it’s between the heated space of the house and the unheated space of the house? Is that correct?

JIM: Yes, sir.

TOM: Then you don’t have to go any further than that; you don’t have to do anything above the insulation. It’s OK. In fact, typically those attic spaces and those cavities are at ambient temperature, so they’re the same temperature as the outside. And I’ve got to say, the fact that you’ve got, you know, 22 or 24 inches is excellent because 19 to 22 is the standard and if you’ve got more than that, you are – you’ve done a great job.

Now, I noticed you insulated the garage. Was that because you work there or you spend some time there? Because that’s an unheated space.

JIM: Yes, sir, I do. I work out there quite a bit; on engines and my cars and stuff. Yeah.

TOM: (overlapping voices) Yeah. So that makes sense then. I think you’re doing all the right things there, Jim.

JIM: OK. Well, I appreciate your help then and I thank you very much then.

TOM: Thanks so much for calling us at 1-888-MONEY-PIT.