Prevent Attic Odor with Ventilation

LESLIE: Joining us from Ridgewood, New Jersey on WABC we’ve got Anna. What’s going on at your house?

ANNA: Well, we have a Tudor home and we have an unfinished attic. And we have noticed that when we’re in between seasons – like if the weather is very damp or really when we get those damp spells (ph) – we seem to get a smell in the attic. We have had some insulation blown into the attic and I don’t know if that’s what’s causing it.

LESLIE: What about ventilation?

ANNA: We have windows at either end of the attic but I, in the past, have kept them open. But I was afraid that maybe little mice were coming in through there so I closed …

TOM: Well, do you have screens on the windows?

ANNA: I have screens on the windows. I have that three track storm and screen window.

TOM: Because let me explain. In a perfectly ventilated attic, you’re going to have the air attic temperature should be the same as the outside. So the insulation stops the heat from the house from getting up into the attic. But the attic should be the same as the outside. So if you have any kind of an odor issue, it could be sourced with the moisture because you’re going to have a lot of humidity up there. And if you’re not letting …

LESLIE: Especially if those windows are closed.

TOM: Yeah, if you don’t let the humidity out, not only could you get odors but the other thing that’s happening is that insulation is getting damp. And what many folks don’t understand about fiberglass insulation is that if you add two percent moisture to the insulation it loses one-third of it’s r value or its ability to insulate. So it’s very, very important that you have plenty of ventilation as well as insulation in an attic space.

Now if you want something that doesn’t really require owner participation, like opening or closing a window, you simply could have additional roof vents installed – ridge vents are probably the best – that go down the peak of the roof. And I like ridge vents because as the wind blows over your roof, it constantly depressurizes the ridge.

ANNA: Thank you so much for your help.

TOM: Anna, thanks so much for calling us at 888-MONEY-PIT. 888-666-3974.