Learn how to eliminate mildew odor from under a wooden deck. Find out how adding a ventilation system can help get rid of humidity and moisture that causes smells from under wood decking.
LESLIE: Now we’ve got Richard calling to The Money Pit. What can we do for you here?
RICHARD: Well, I’ve got a problem. About two years ago I bought this house . It was built in 1970 and there’s a rear patio that had a roof over it. I’m sorry, it’s not a patio. It’s a wooden deck  with a roof over it. And I made a room out of that area. However, the decking was on the ground. It was ground level. You couldn’t really get under there and now I’ve got an odor coming up through the floors. It’s a damp …
TOM: Where the deck’s over top of it?
RICHARD: Well, it was a deck that was actually on the ground …
RICHARD: … and I enclosed it into a room.
RICHARD: And the odor coming up seems to be a dampness. It may be a mildew smell .
TOM: Well yeah, because decks are designed to be enclosed into rooms so it is going to be very, very damp in that space and you may very well get a mildew smell.
RICHARD: OK, is there anything I can do about that? Can it be vented or …
TOM: Well, what’s below it right now?
RICHARD: Just dirt.
TOM: And is it open? Wide open below there?
RICHARD: No, it’s not. No, that’s another thing I did because I poured around it.
TOM: Oh, man. You know, you’ve done this in such a backwards fashion that it’s hard for us to tell you how to get out from under this, Richard. Because what’s happening is you’ve essentially trapped this organic structure on top of soil and then you’ve blocked all of the access to the side so you can’t even vent it correctly.
RICHARD: Well, I was wondering if something like a radon – what they use to get radon out of the ground, if something like that would work. If I could tap in – because there’s a closet in this room …
RICHARD: … I could tap through the floor and then vent it out through the top.
TOM: Well, you mean by putting in a ventilation system ?
TOM: Well, I mean it might help. The other things that you can do is to try to take steps to reduce moisture around the foundation area wherever this is; making sure your gutters are clean and free-flowing and water’s discharging away from this area. Make sure the soil’s sloping away. Things of that nature may help to reduce the humidity  but it’s really going to be a shot in the dark as to whether it works.
Richard, thanks so much for calling us at 888-MONEY-PIT.
RICHARD: Thank you.