just a simple question for you guys

[Tdoggy187]

Is Aluminum siding a good insulator? Enough that I don't have to worry about insulating the walls beneath it?

[suemarkp]

Absolutely not. Metal is a poor insulator, so is glass, so is concrete. Wood is fair (about R1 per inch). Fiberglass is good (about R3 to R4 per inch). Foam is great (about R5 to R6 per inch).

If the walls are thin, or you're not ready to insulate them yet, a half inch of foam sheet insulation on the exterior wall under the siding will help a lot compared to an uninsulated wall. An inch would be even better, but this may be too thick around your windows depending on how thick your siding is. I'd consider Hardi board type siding (looks like wood, but is fiber-cement) with foam underneath. I don't like aluminum siding -- its easy to ding and you'll never get it to look right again.

[Tdoggy187]

Thank You very much. Someone told me it was a good insulator and I thought they were wrong. Thanks again. :adore:

[CraigFL]

Thank You very much. Someone told me it was a good insulator and I thought they were wrong. Thanks again. :adore:


They may have been 1/2 right.... Aluminum is not a good insulator because of what was said above but when it's sold as siding, it usually has an insulating material attached to the back to give it some rigidity too. So if you were to compare it to vinyl siding which has no insulation as backing, you could say it was "good" or at least better than the vinyl. But the reality is that usually no siding has a significant amount of insulating properties -- at least enough to warrant not using some kind of regular insulation.