LESLIE: Gary in Kentucky is calling in with an insulation question. How can we help you?
GARY: I have a home that was built in 1957, 1958. And back then, when they built them, they did not put any insulation in the exterior walls on them.
GARY: And it’s a masonry brick outside exterior and, of course, drywall inside.
GARY: And I’m just trying the find the most economical way to get insulation in the walls. I’ve talked to a few people about blown-in insulation but the problem with that is they have stubbed-in cross breaks in between the wall joists and there’s no way to make sure you get the whole cavity completely filled; so I’m kind of at a loss as to a good way to get it done.
TOM: Well, you’re right in that they do put what’s called a cat across the framing and that blocks the air flow.
TOM: So, when it comes to blown-in, sometimes on the inside what you have to do, Gary, is put in multiple holes and you have to put one up high, one down low. And then when you use the blown-in, it has to be put in under a certain amount of pressure so that it expands to fill that space.
Icynene has a formula that can do that that’s a very green formula. It’s actually made out of castor oil and it’s a foam insulation that will expand and fill all those nooks and crannies. You can also do it with cellulose but you have to make sure you have it under a certain level of pressure; otherwise, it won’t settle right.
And the best way to determine where those braces are is with an infrared camera and the prices on those cameras have come down and most insulators are going to have them today. With an infrared camera, you can actually look at the wall from the inside and you can physically see the framing. It’s pretty interesting. Because the temperature where the frame is is different than the temperature where the frame is not. Do you follow me? So, with an infrared camera, you can kind of see where those voids are and work around it.
But let me just take you in a completely separate direction and ask you what the insulation is like in your attic space. Because, typically, you want to make sure that you have the most insulation in your attic. That’s where you have the most heat loss – the walls maybe 15 percent and the floors maybe 10 percent of the heat loss but I want to make sure that we’re not ignoring the obvious here; that you’ve got a good, 19 to 22 inches in your attic.
GARY: And that’s one of the other problems. I’ve already addressed part of that. The home itself, I’ve put the rolled-in insulation in the joists in the attic and I’m in the process now of upgrading that to a higher r value to increase the insulation in the attic right now. But then, also, I was trying to get to the exterior walls. The only problem I have with the exterior walls is where it looks like sometimes when they do put the holes in them for the insulation, some companies use like a plastic type of cap or plug instead of refinishing the drywall back and it’s just not very pleasing to the eye to see.
TOM: (overlapping voices) Right. No, no. You don’t want to see the plug holes. If it’s done right, the plug is set just below the surface of the drywall and then it’s spackled over. With a 1950s house, do you have plaster walls or do you have drywall?
GARY: They’re drywall.
TOM: Because there was a time period in the early 50s that was sort of between what we call drywall today and a plaster finish; where you had a piece of drywall that was like 2’x4′ but then the whole thing was covered with plaster.
TOM: That’s a much harder surface than just the average drywall that we have today. But regardless of what kind you have, you definitely need to spackle over those and, sure, even a good spackle job is going to show a little bit but you certainly don’t want to be staring at plastic caps.