Strange smell coming from inside wall cavity of renovated bathroom
Hello.
Hoping someone can help. We moved into a renovated 1950s split level in June. Initially, the house smelled of “new house” smell that dissipated soon after we moved in. But now there is a very strong chemical type odor coming from a wall in between a renovated bathroom and utility room. We traced high levels of VOCs and formaldehyde coming from something in the wall cavity. On that wall, there is shower tile, then some sort of cement board, then 2 by 4s, then a small gap of space, and then the exterior brick wall. Does anyone have any idea as to what product, coating, waterproofing material or sealant might have been used within that wall cavity that would smell so bad? The smell has permeated the entire house (it’s a small house). Im ready to rip out entire shower and wall behind it to figure it out. Thanks in advance!
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You say exterior brick wall? Do you see any insulation anywhere?
Haven't previous posts stated that they have experienced bad odors from spray foam insulation?
Can you see any or had the chance to experience what that smells like?
If the house was flipped it would be a surprise to think spray foam was used but it might be a starting point to eliminate possible causes or help lead to something.
I assume the bathroom has an exhaust fan? If you run the fan, does the smell lessen?
I'm not in the trade, but what's in the utility room? Any open space on the common wall, such that you could have the wall cut open for inspection?
Drywall repairs are a *lot* more affordable than tile.
Also, do you have any info on the contractors who performed the renovation work? Perhaps they have insight into what could cause the smell.
We cut open the drywall and only found an abandoned vent pipe that we have since sealed. We thought that might be the culprit but smell prevails.
No spray foam insulation used. Utility room is for laundry and all mechanicals. The bathroom itself has no odor. It seems like the tile and grouting sealed the odor so it doesn’t come through bathroom. But utility room side is awful. And that’s where HVAC is and I think the odor is maki g it’s way into HVAC and spreading the chemical smell around the house.
I’ve been reading that sometimes various waterproofing products can have an awful chemical smell to them. I’m going to buy one or two today and smell test. I’m tempted to just redo entire bathroom shower so I can have access to what’s behind the wall.
It could be a roll-on waterproofing. Do a smell test on "RedGard" or similar products. Our house was smelly for a couple days after it was installed on the cement board substrate on our shower walls before thinset and tile. We ran the bath fan and the smell cleared but maybe it would linger longer if tile was installed before it fully set?
Is this on the second floor? What is above or below it? The wall cavity might be acting as a kind of chimney for something below it. I've used a ton of RedGard over the years and it does have a distinct smell but I've never found that it lingered once dry.