LESLIE: Milt in Delaware needs some help with ventilation. What’s going on at your money pit?
MILT: Well, I bought this house. It’s an older house. And I got these two bathrooms and they have no ventilation. So, I’m trying to put some ventilation in or figure out how to put some ventilation in. And I was wondering, can I just put a hole and a vent and blow it outside the side wall? Can I blow it up into the attic? I guess what can I do to get some ventilation? Because you guys say water makes mold and I don’t want to have any mold in my bathroom.
TOM: Yep. Yeah, yeah. OK. So you certainly could either install the bath-exhaust fan on the wall so it blows directly outside. That’s possible. You need, of course, to make sure you have the right termination on the outside so that you don’t get all that draft rolling in, especially on an exterior wall.
If you want to blow it up towards the attic, you cannot dump the moisture into the attic. So you certainly can go up in that direction but once it gets to the attic, you have to hook up a duct that will take it to the exterior, which could be through the roof or it could be through the side wall up there. But either way is fine.
And then make sure that, since you’re going through all this work, that you wire it with – if the fan doesn’t have this built in which many do, especially the better ones – but wire it so that is humidistatically controlled so that when you step out of the shower and dry off and leave the bathroom, the fan stays on until the air is dry in that space. And that’s what’s going to cut back on the mold and the cleaning that would be required.
MILT: OK. So I can ventilate it out through the end cable – end gable, whatever it’s called? I mean there is ventilation at the roof vent. That’s not good enough. I have to run it up through the …?
TOM: No. Yeah, you don’t want to dump it at that roof vent. What’ll happen is you’ll get a lot of condensation because you’re taking warm, moist air. So you don’t want to drop it underneath the roof vent. I’ve seen those ducts sort of being tacked to the side of a rafter, like right under a roof vent. And then what happens is the roof sheathing rots out in that area or even the rafter starts to grow mold.
So, no, you want to take it right out through that gable and you’re going to put it through a dryer vent. There’s a piece of flashing that has a (inaudible) on the outside and has a flap – a damper – that closes so no birds get in there. And then you’re basically going to drive it out that way, OK?
MILT: OK. So I can’t drop it off – so I was thinking about maybe going out through the fascia on the side of the roof area there. Can you run it out that way or does it matter?
TOM: Oh, you mean to the soffit. Yeah, I know what you’re saying. No, the soffit.
MILT: The soffit.
TOM: No, no. Same reason. First of all, the soffit vents are – those pores are not big enough to let the dryer exhaust get out there. It’s just going to clog up. So you’re better off just running it right through that gable wall in the end. If you can do that, that’s what I’d recommend.
MILT: OK, great. Thanks for your help today.