LESLIE: Mike in Missouri, what can we do for you here at The Money Pit today?
MIKE: Yes, ma’am. I’d like to know how would be the best way to insulate an attic in an old Victorian home that was built in 1890 because I’d like to finish it.
LESLIE: Do you have insulation up there now? What’s the situation going on up there now?
MIKE: Well, right now it’s all bare up there. The insulation would go right underneath where the roof is. So I didn’t know if it needed to be able to breathe or anything like that.
TOM: Yeah, you have – you have no floor – unfinished floor area, so to speak, that you could insulate, Mike? You have to put it under the roof sheathing?
MIKE: Well, I was wanting to turn it into like a room.
TOM: Oh, OK. OK. So you want to refinish an attic. That’s a little bit different than just putting insulation into an old house. If you want to refinish that attic space and you want to put insulation in in the roof rafters, which is what you’re talking about, there are some important considerations.
First of all, you can’t use insulation that’s the same thickness as the roof rafters are deep. So for example, if you have 2x8 roof rafters – and in an older house, it’s usually the original – the full 2x8. It’s a full two inches wide by eight inches deep – you can’t use eight inches of insulation there because there would be no room left for ventilation. So what you need to do is use insulation that’s less thick than the roof rafter is deep. So you might use six inches of insulation. It would be flush with the rafter on the inside of the house. You’d leave that two-inch gap between the back of the insulation and the roof sheathing for air to cool that roof surface area.
The next thing is you need to have ventilation to cool that space, which means you need a continuous soffit and continuous ridge vent. The ridge vent’s pretty easy. In an old house, the soffit vent can be a little tricky, depending on how the fascia and the soffits are constructed. If you have no overhang, you can use something called a drip edge vent, which lets just enough air into that space to keep the roof cool. Because if you don’t vent it, Mike, what’s going to happen is you’re going to get condensation in there that can potentially rot out the roof sheathing and you’re going to overheat that space and that’s going to make the roof wear out that much quicker.
Now Leslie, what about decorating that space? Any tips for a small space like that?
LESLIE: Well, with a small space, especially in a Victorian – is your ceiling very slanted? Is it sort of vaulted? You don’t really have a lot of space except for the middle of the room?
MIKE: No, it’s vaulted and it’s like almost 10 foot tall. You can walk around up there comfortably and it covers the whole side – you know, sides of the house. It’s huge.
LESLIE: Well, that’s great. So that gives you a lot of space to use up there. You can divide up that space by using fabric if you don’t want to put up walls to divide up separate areas. You can use interesting sliding fabric panels to create definition of what room is where. You can create a lot of interesting (inaudible) of uses of space, whether it’s a sleeping area or a sitting area; almost like a suite that occupies the whole upper floor. It’s going to be the favorite room in the house.
MIKE: Yes, my wife’s wanting to use it for her craft room to make quilts.
LESLIE: Oh good, and you should get good light up there. So that’ll be really nice.
MIKE: I thank you.