Adding More Fiberglass Insulation to Attic
LESLIE: Alright. Now we’ve got Jed calling in with an insulation question. What can we do for you?
JED: I am looking to insulate my attic. We have fiberglass insulation and I have been told there’s a spray-on foam insulation that helps to insulate an attic and can cut down your power bill a whole lot.
TOM: Well, how old is your house?
JED: It was built in 1987.
TOM: OK. And right now you have fiberglass insulation. And you know how much insulation you have in that attic?
JED: It is supposed to be set for r19.
TOM: OK, so that’s not a lot today. That means you probably have about six inches of insulation and you really ought to have about three times that much.
Now yes, there are spray-on insulations and they do two things: not only do they insulate; they also air seal so that you don’t have as much air movement between the exterior and the interior of the house. Because the attic is essentially the same as being outside; it’s ambient temperature and you want to stop the air from moving in between the attic and the rest of the house.
However, it’s pretty expensive to do that on a retrofit basis. So what the simple thing is for you to do here is to add additional fiberglass insulation and you want to use unfaced fiberglass batts and put them in perpendicular to the batts that you do have. That’s going to be the easiest, the least expensive and probably give you the best return on investment over the next few years. And by the way, if you do it before the end of the year, you may even qualify for a federal tax credit on part of that money.
JED: OK. I appreciate it.
TOM: You’re very welcome. Thanks so much for calling us at 888-MONEY-PIT.