Is the chemical smell in your basement potentially linked to the concrete or walls rather than typical sources like mold or dampness?
Hey, does the concrete in the basement look normal to you? We’ve been dealing with a strong chemical smell in the mechanical room down there, especially when it’s hot in the summer or on humid, rainy days. When we leave the mechanical door open for a few hours, the smell goes away, but it always comes back after about 24 hours of closing the door. We’ve got all sorts of things like an ejector pump, air handlers, radon fan, and a gas water heater in there, but nobody can pinpoint where the smell is coming from. Just finished vacuuming the whole basement and exploring every possible cause of the odor. I’m wondering if it could be seeping through the concrete or the walls somehow. It doesn’t smell like the usual suspects of wet socks or mold.
Radon?
Unfortunately, lacks the ability to smell
Is unable to detect radon
Using concrete sealer and a dehumidifier will be beneficial.
I constructed it without realizing that haha. Thanks for the information.
It could actually be a variety of things, quite a mystery until the air is tested and the source is found.
Hey , we’ve got an in-line dehumidifier in the basement air handler now. The humidity reading in the mechanical room and basement is in the 30s-40s. The smell is still there but not as strong, and it doesn’t spread into the living space as much, though it’s still noticeable.
Hey , we’ve conducted air quality testing but didn’t find anything. I think we need to test for more specific things but I’m not sure what to request.
Hey there, it’s interesting that nothing would come up. Can I ask if there are any natural gas or oil veins or garbage dumps nearby?
I’m not sure, maybe the builder would know?
Do you notice the odor worsening when the water heater is in use? It may not be venting properly.
Chris mentioned that the smell is usually bad in the summer or on humid/rainy days, not just when hot water is used. They will keep an eye on it.
Wouldn’t the smell be more like gas if it was coming from the water heater?
Could be the case if it’s not venting properly. Natural gas is odorless, so they add a smell to it for safety reasons. If you’re detecting a smell when it’s burned, it might not be venting all the way outside.
Do they add a scent to natural gas to make it smell like gas? It doesn’t have that typical gas smell.
It sounds like you have pinpointed it to the mechanical room. Radon doesn’t have a smell, so it can’t be that. Have you considered replacing the water heater? How old is it? What else is in there?
If there’s a chemical smell that intensifies with water or moisture, could it be an electrical burning odor? Those can be really unpleasant sometimes. It could also be caused by too much equipment drawing too much power, or maybe your sump pump or something else is overheating. Try sniffing around all electrical components to see if you detect a foul smell.
Reports that everything is fresh and new. They have a radon fan, gas water tank, two air handlers, Dupont Thermax wall sheathing as the vapor barrier, an unsealed concrete floor, and some gas lines. A plumber inspected the ejector pump and confirmed its good condition
Consider getting a Carbon Monoxide detector to ensure your safety. CO mixes with gas, giving off a strange odor. If you’re unfamiliar with the smell, it can be alarming. Stay safe.
We have a CO monitor right outside of the mechanical room and it hasn’t gone off?
Co rises. Did you happen to sniff the ground? It could be the fumes from a sealant or if the previous owner sealed the floor, when the furnace is on, it might be burning off the gas from the sealant or possibly a moldicide product. You can try pouring hydrogen peroxide and baking soda on the floor, letting it sit, and then vacuuming it up
Did you notice that we smelled the concrete? It doesn’t seem to have a very strong odor. Since this is a new construction house with no previous owners, the floor is unsealed concrete. The smell is still present in the summer and gets even worse when the AC is on, so it’s probably not a furnace issue, right?
If it’s a new house, it’s normal for the materials to release gas. Try spraying some Odoban in the room. Have you checked for any dead mice? Also, make sure to inspect all of your return vents and supply vents to see if anything was accidentally left behind by the tradespeople. As a former contractor, I’ve come across some pretty disgusting things in vents and sump pits.
I don’t think it’s just a typical off-gassing smell. It’s strange how it improved over time but then worsened in the summer and improved again as the weather cooled down. One day, right before Thanksgiving, the odor was extremely strong after heavy rain.
Do HVAC companies have a way to inspect the duct work? I already asked the HVAC company that installed it to check, but they don’t believe it’s needed.
Someone who didn’t share their name mentioned that a duct cleaning company with a camera should inspect the system
Hey Robert, do you think most HVAC companies are able to handle this?
Someone who didn’t share their name
The fire department told me that just because my CO monitors didn’t go off, it doesn’t mean the smelly, chlorine-like vapors from the afterburn of my ‘nonvented’ gas woodstove aren’t harmful.
You might want to consider having a plumber inspect your hot water anodes. It’s usually an affordable and straightforward fix. They can get rusty and emit an unpleasant smell. Alternatively, if it smells like plastic, you should have an electrician examine your wiring. There may be overheating wires.
https://www.corroprotec.com/troubleshoot/rotten-egg-smell/?zcgas=zcgas&gad_source=1&gclid=Cj0KCQiAsvWrBhC0ARIsAO4E6f-otHsOqWHAYUUuDoHiEQIBXTlEL8zKshjtueDa-3__Zm2tYG1X-DwaAminEALw_wcB#
Hey , the smell doesn’t resemble rotten eggs. A plumber checked the ejector pump and said it’s fine. Do you know where the hot water anodes are located? Could it be a chemical smell? It doesn’t smell like hot plastic.
Hey there, the anode rod can be found in the hot water heater. If you notice a smell, try running your hot water on full blast to see if it has an odor. Build-up of hard water minerals can cause bacteria to create an odor. Also, do you have any moisture coming into your basement? I had an odor for 6 months before discovering a burst septic line in front of my house. I thought it was just rainwater seeping in, but I was mistaken.
Hey , I didn’t see any water in the basement but I just finished cleaning everything out, so I’ll keep an eye on it. My ejector pump has a lot of gravel on it that seems to have gotten wet and hardened. I can’t vacuum it up. Is that normal? I’ll turn on all the hot water in the house to see if the odor gets worse.
Have you ever had an old oil burner before? My basement used to have one and even after cleaning up, the cement still smells like oil on certain days.
Hey, it’s actually a new construction. Do you think they might use oils or something during the building of basements? I’ve been in other basements like ours in the neighborhood and they don’t have that smell.
Could you please provide more details about the odor?
It doesn’t smell like the typical mildew or wet clothes scent. It’s more like a chemical or industrial odor, but not quite like waste water or gas. I’ve had about 20 people from different backgrounds come by, and no one can quite pinpoint the smell, but they all agree it’s strong.
Maybe try using formaldehyde? There are air quality testing services in the cities that can come and basically use a mass spectrometer to identify pollutants.
How do I even search for someone who does that? We had an air quality test done and they performed a general VOC test which didn’t give us much insight
Do you use a dehumidifier when it gets humid?
No, we didn’t have one before but now we do. With the winter humidity being in the 30s-40s, there’s still a chemical smell, though it’s not as strong in the mechanical room as it is in the summer.
Is there a natural gas leak? Maybe one of your floor drains is dry and needs some water added to it?
If there was a natural gas leak like , it would have that typical gas smell that they add as a scent. But this one had more of a chemical or industrial smell. We had a plumber inspect our ejector pump, and he checked the small hole cap on the big dome and confirmed everything was fine. I even smelled near the open hole and did not detect any odor.
Does the scent resemble burning fiberglass or plastic? It might indicate insulation heating up due to an overheating source. There are several possibilities, so it may require some trial and error. Turn off any heating appliances for a while to see if the smell goes away.
If something was overheating, the room wouldn’t feel hot because that hot spot would be small but very intense. If you’re familiar with the smell of an electric drill when it’s being overworked, that’s the scent associated with electrical issues and overheating fiberglass insulation
Do you think not having proper ventilation during the construction of that mechanical room could be the cause? Also, adding an exhaust fan down there and keeping it running continuously for a while might help, right? In the worst-case scenario, if it’s something that continues to release gas because it’s from an external source, then having that fan run 24/7 will at least air out the area
It’s not giving off the scent of electrical burning … just keeping my fingers crossed that someone will come along who can figure it out