Hi everyone,
We have a musty smell in our house that is driving us crazy, and we cannot find out what/where it is coming from. The smell is mainly around the outside of our bathroom. We have already remodelled both due to water damage, but I have inspected as much as I can around and under the house (in a crawlspace without insulation in there) and see no evidence of any water damage, mildew, or mold. Everything looks dry and intact. Our bathroom is centered in the house, so there are no heater ducts there. It does not seem to correlate with flushing the toilet or anything. My wife started noticing it shortly after we finished this second bathroom, but there is just nothing obvious. This particular bathroom is only used for bathing our son, not showering. The caulking around the bathtub is fine, and even if it wasn’t the backing is well waterproofed with Redguard. Another part of the problem is that the smell is not constant. So many times we don’t smell it at all, and then it just happens to be there. The other day we could smell it in our bedroom, which is adjacent to the bathroom, but does not share a doorway or anything. We’ve turned on the water faucets and flushed the toilets to see if those could be it, but nothing. But the smell is never in the bathroom, just on one of the outside corners.
As a side note, the other bathroom also has no smell, but there is an occasional moldy smell that occurs when I turn on the faucet in the mornings sometimes. But again, there is nothing that is obvious anywhere, and we just don’t know what to do. I have no problem hiring someone to help figure this out, but who, and if it is intermittent, how could this be identified?
Thanks for any help you can provide.
Ryan
Replies
Best I can suggest is to consider where the drain and vent pipes run and consider whether there's a nail through one of them or a joint that's not quite good or some such. But if the drains aren't running through the area then that's probably not it.
Also consider whether it could be a leak at the roof jack for the plumbing vent, with rainwater following the vent pipe down into the wall. Similarly, rain can get in a vent fan duct and drip out through the joints.
And consider the possibility that what you're smelling is musty air being drawn up from the crawl space through some air leak.
As to the moldy smell in the other bath, do you know if it's associated with the hot water or the cold, or both/either? Could be a smell originating in the water heater (eg, iron bacteria). Another possibility is gunk growing in the overflow drain of the sink, or a leak in said overflow connection.
Those first two paragrahs are right on.....those a lot of times are the cause of smells in first case and leaks in the second case...when all the other obvious has been eliminated.
I have seen folks use a stud detector to locate what they think is a stud , but it was really a PVC verticak vent stack...and power nail a horizontal 2x4 for say a tub decking and bamm they bplow a chunk out of the PCV vent stack..
When this happens you will get slight wiffs of what smells like sewer gas..and it will come and go...if there is an electrical outlet in that 2x4 bay...the smell can come out through there.
Also i have seen some plumbers when dryfitting PVC for the vent stack...they forget to glue one of the joints in the attic. The smell can leak out in the attic and then into the house. I have even seen that happen, even after an inspector supposedly did the plug/fill the whole thing with water- leak test. hmmm kind of defies physics.
So could musty smell be a sewery smell?
Thanks to you too. I still have to check some of the walls more thoroughly, but I'm pretty sure the smell is not coming from there. I had all this exposed at one point, and I did not modify it, and there were no holes or cracks. I cannot smell it in the attick. I'll just have to keep looking. Is doesn't smell a lot like sewage, though. It's a smell I have never had the pleasure of smelling before.
Thanks. I've looked, and see no evidence of any of those. I still need to check a few more things out, but so far I'm not convinced that a water leak or sewer leak is the culprit. I do think it is coming from under the house, and the transient nature of it would make sense as the air pressure can vary. We are suspecting the rats, but I've pulled out the insulation and there is nothing obvious. The iron bacteria is an interesting thing I hadn't thought of. But I only smell that problem in one bathroom. We have a vessel sink with no overflow, so I'm wondering if there is something in the drain that could be causing this. The vanity is clean and free of smell.
What you might want to do is get someone whose nose is "better trained" than yours to help you out. Sewer, rot, rodent, damp earth all have different relatively distinct smells, and knowing which you have would help quite a bit.
I live right beside the Pacific ocean and our house has the same problem. In fact another house we bought and flipped also had a musty smell. Never did find out the cause. Thought we did on several occassions but the smell came back. Sometimes you come into the house and the smell would knock your hat off. It must have something to do with dampness because in the summer ( the air is dry as a bone) the smell goes away.
A friend with a great sniffer said it was a musty smell which was great because all I could tell was that it just stank.
Another thing: Sometimes when I cut into a fresh piece of wood, say a 2x4 or 1x8 there is a smell that is enough to make me gag. Not all the time but just sometimes and that smell is very similar to what is inside my house though a lot less concentrated.
I don't know what causes that smell in the wood but I wonder if it is a species of wood that gives off the smell in damp conditions.
In all my years I have never smelled wood so bad until I moved to the west coast and have smelled it since cutting fresh bought lumber many times.
Having checked out all the plumbing and venting and done lots of reno on my house I don't think it is any of the that and I might be grasping at straws about the lumber.
roger
In our house we have a peculiar situation where any smell anywhere in the house will collect in the front entryway. Somehow the airflow tends to concentrate odors there. And, of course, since this confronts you when you first enter the house the effect is doubly strong.
I've learned to not look near the entryway for the source of the odors but instead to check other possible origins.