What’s That Smell?! (Basement Edition)
Our partially submerged basement has developed an unusual smell in the past few weeks, and I cannot figure out what it is. It’s making me crazy to not have resolution. Below is the best I can describe it. Any suggestions are welcome!
Location: Chicago, IL (Zone 5)
When it started: A few weeks ago. Peak of winter. Coincidentally or not, around the same time as severely frigid weather here. In our 4 years of being in this house, this smell has never occurred previously.
Basement description: Unfinished; solid concrete walls; concrete mud slab floor with lots of cracks; drain tile and sump at perimeter; about 3′-6″ below grade, 3′-6″ above grade; glass block windows above grade; boiler in basement, hydronic baseboard heating system throughout house; basement temperature stays around 60-ish to 70-ish, unless it’s super cold outside, in which case we’ve seen 50-ish or below down there.
What it smells like: To me, it honestly smells like melted butter for movie popcorn, but without the popcorn part. The alternate, less pleasant analogy has been sweaty socks. It’s prevalent and not a great smell, but I wouldn’t say it’s completely revolting either (not like sewage would be). To me, it DOESN’T smell like mold, mildew, dead animal, sewage, sulfur, natural gas, chemicals, spoiled food, or general basement. I can’t even trace a source, although I got the impression that it might be coming from a foundation crack under the front porch. The underside of the porch is solidly filled in between the walls and under the concrete porch slab. I don’t see any way for an animal or other organism to even get into that area behind the wall.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part