My basement smells of decaying fruit. Help!

May 7, 2009 7:56 AM

My basement smells like rotting fruit. What is causing it and, since I'm thinking it needs dehumidifying, any dehumidifier tips or recommendations?

I moved into my 1966 house in October. The basement is finished; i.e., it's not really a basement, it functions more as the first floor of the house - 2 bedrooms, a bathroom, a laundry room. The house is built into a hill, so the basement level is completely underground on one side and half underground on the other two sides. The people who owned my house before me were enthusiastic if not completely skillful remodelers and they turned the basement into living space - it has concrete floors painted blue, a couple of windows, one room composed completely of glass doors and, well, it's hard to describe. There is not a lot of ventilation - a couple of sliding glass doors, one window.

All would be well except that there is this terrible sort of rotting fruit smell down there. If I leave all the windows and doors open the smell goes away for a while or at least recedes, but I can't leave them open while I'm sleeping or at work. It went away after I mopped the entire floor with pine sol, too, but then it came back.

We've had a lot of rain recently and it's very bad at the moment. I mean it smells like someone has been making pruno or something down there; like a still, like a giant heap of rotting fruit. Has anyone ever encountered this before? What could be causing it? Is it something scary, like black mold? It doesn't smell like mold and there's no visible mold or mildew anywhere.

I'm going to go buy a dehumidifier and see if that works. I know nothing about dehumidifiers, which brings me to the second part of this question: do I need one or two? It's about 800 square feet total. What should I be looking for? How often will I have to empty it (them)? And, should I be looking for any specific brands?

posted by mygothlaundry to home & garden (9 comments total)

Regarding the dehumidifier... I purchased a small one (50pint - about $130 at Sears) for our 800-900sqft basement, and it certainly kept things dry down there, which did help with our musty, basement smell. It has a port to attach a hose, which we placed in a floor drain; so, we didn't have to worry about emptying it. Without the hose, it would have stopped after reaching a certain level of water and then beeped until we emptied the bucket.

All was well and good, until we got the electric bill. Even with the 'energy star' label, and being set to a three hours on, three hours off cycle, we noticed a sizable difference in our bill. It was enough for us to decide that we could live with the damp musty smell.

Our basement is just a basement though. If we ever turn it into a living space, we might very well pony up the extra for the utilities. ymmv
posted by wg at 8:10 AM on May 7

Any chance there could be a rat? The urine can have a sweet rotty smell. But you'd see feces somewhere.
posted by fish tick at 9:00 AM on May 7

Sounds like you have mold - the house is built into the side of a hill. Why not get a mold specialist to come and check the place out? Your local government may also provide inspections.
posted by KokuRyu at 9:15 AM on May 7

Has it always smelled bad, or just recently.

I had the same thought about the rat. When one died inside our wall, it started as sort of a sickly sweet smell before gradually turning into a horrible baby diaper smell.

Also, check that mold isn't growing in the water pan of your furnace humidifier.

I'd get a heavy duty box cutter (and safety glasses) to cut a square hole in a section of wall that seems most suspicious to examine the back side for mold. Score it repeatedly until it pops free. If it's a waterleak problem, I'd expect it to smell worse in the space behind the wall.
posted by bonobothegreat at 9:36 AM on May 7

Yeah, we had a dead mouse in a past house and it smelled sickyly-sweet rottingish. I'd get investigating for a dead beast somewheres.
posted by amanda at 9:50 AM on May 7

The only problem with the dead animal idea is that it's been like this since last summer when I first looked at the house (I chalked it up then to a) enclosed basement with no air flow and b) truly horrible cleaning products/air fresheners.) A dead thing would have mummified by now.
posted by mygothlaundry at 11:00 AM on May 7

Could be more than one dead thing (ugh, sorry to put that idea into your head). Dehumidifiers help but are not a perfect solution -- is there a laundry sink down there? Some models can automatically drain into that so you don't have to constantly monitor / empty the container.

Are the ceilings high enough to install a ceiling fan? I find that putting a stand fan in our basement and turning it on full blast definitely helps in the summer when things get funky-scented.

Last resort: those plug in air freshener things with built in fans of their own can take the edge off, too...doesn't solve the underlying problem, whatever it is, but can make things more bearable.
posted by bitter-girl.com at 12:19 PM on May 7

This might be out of left field but I have resolved somewhat similar problems in basements with concrete floors with drains. Pouring 4L of HOT water (optional, 1/4 cup bleach) down the drains. This resolved the "dank castle smell" which could be fruity (maybe?).

As for something dying there - the smell of death seems close to your "terrible sort of rotting fruit smell " - if there was a dead mouse there last year, there'll be more by now. Pests usually keep coming to a place until access is restricted. Leave the windows open, leave the house for a couple of hours then come back with a fresh "palate" and do your best nose detective work to locate a focal area.
posted by saradarlin at 2:42 PM on May 7

saradarlin writes "This might be out of left field but I have resolved somewhat similar problems in basements with concrete floors with drains. Pouring 4L of HOT water (optional, 1/4 cup bleach) down the drains. This resolved the 'dank castle smell' which could be fruity (maybe?). "

Follow up with a couple litres of plumbing antifreeze so the p-traps in the floor drains don't dry out again.
posted by Mitheral at 3:10 PM on May 7