Putting Additional Insulation in an Attic
LESLIE: Angelo in Commack, New York is calling in with an insulation question. What can we do for you?
ANGELO: Hey, guys. Love the show.
TOM: Thank you.
ANGELO: I just had a question. I’m looking to reinsulate an attic so, obviously, I’m going to add new insulation perpendicular to what’s in the attic; to what’s already out there. But I’m not sure how to determine whether I should remove the existing insulation or not and – before I go ahead.
TOM: What kind of insulation do you have right now?
ANGELO: I think it’s kind of almost like – it looks like, I guess, a rockwool type. It’s not – it doesn’t look like fiberglass; it’s kind of beige and kind of thick.
TOM: How old is the house?
ANGELO: It’s probably built in the 60s.
TOM: It probably is not a rockwool; rockwool would be older than that.
TOM: Does it look like it’s compressed and sort of sunken and sagged?
ANGELO: It’s definitely an inch or two below the top of the joist.
TOM: OK. Well, if it’s only an inch or two, it probably has some life left in it. What you could do – an easy way to add more insulation then – would be to use unfaced fiberglass batts. I’d probably get 8-inch batts and I would put them perpendicular across the joists. And that will make a big difference.
TOM: So you don’t put it inside the joist, you don’t press them down into the joist; you put them across the joist. You’re going to give up a little bit of storage space by doing this but that’s the best way to get additional insulation up there, Angelo.
ANGELO: Now what about the space – putting the insulation perpendicular to that – that space that’s between the existing insulation and the new insulation.
LESLIE: That inch or two?
ANGELO: Is that OK?
TOM: Mm-hmm, yeah. I wouldn’t worry too much about that at this point, unless you wanted to go with blown-in insulation. And if that was the case, you’d obviously be filling it up on top of it.
ANGELO: OK, great.
TOM: Which is another option for you; blown-in. But again, if you do blown-in, you’re going to have very, very little storage space up there left. Is that an issue? Is storage an issue?
ANGELO: Not necessarily, no. We’re not really using that for storage right now.
TOM: Well, you might want to consider blown-in. Blown-in is a real good way to fill in all of those nooks and crannies that you can’t get batts into.
ANGELO: And is that more expensive than doing regular insulation?
TOM: No, you definitely can’t do it yourself unless you’re renting the machine, so it will be more expensive by virtue of the fact that you’re paying for labor. But otherwise, it’s pretty much even-steven.
ANGELO: Oh OK, great.
ANGELO: No, it’s good to know. I didn’t even think of that.
TOM: You know, if you want more tips on the options, you can go to the Owens Corning website and actually they have a micro-site called InsulateAndSave.com. It’s got a lot of calculators and tips on the different options that you can go through when you’re choosing insulation products.
ANGELO: OK, great. And if I do find – because I did look in only part of the attic – if the insulation is more than an inch or two below, if it’s really kind of compressed, then would I remove it?
TOM: Then you might want to think about pulling it out, yes.
ANGELO: OK. Alright, great. Well that’s – all that’s very helpful. I really appreciate that.
TOM: You’re welcome, Angelo. Good luck with the project. Let us know how it turns out.