I live in a home built in 2006. We are a clean family and have no pets. In ALL three of our bathrooms I am smelling an odor of "old urine". I do have a 3-year-old son so at first I thought he was simply missing the toilet in his bathroom, but days after both my husband and I noticed the same smell in the other two restrooms. I cleaned all with bleach thoroughly and still. . .the odor remains. Could this be something with our plumbing? Can we do a cleansing of the plumbing in the house?
Being a landlord I have tenants that just don't like to clean/scrub toilets weekly... try once or twice a year... however they do sometimes call up and say my toilet smells when I flush it. Every single time I have had this the solution has been the same with tenants... clean it with toilet bowl cleaner including under the RIM and clean it about 5 or 6 times as so much stuff is stuck everywhere... even change cleansers every other week.. but not in the same day (don't mix chemicals)...
Another possibility is the kid peed on the walls.. wash them.
Another possibility is ... are there warm air floor ducts near the toilet... maybe the kid pees in them for fun??? lift the covers and have a look... I did find one grill that was covered in pee spray... in a guest bathroom... once upon a time.
Another possibility there is a bad seal or no seal under the toilet... there is supposed to be a foam or wax ring under the toilet that keeps the air and water in the sewer system separate from the air and water in your house. I have had one instance in 20 years of a urine smell that happens every time you flush that cleansers did not solve... it turned out be a foam ring that was not wide enough to fill the gap between the floor and the bottom of the toilet and every time you flush - air from the sewer passes by after the water has passed by. Strangely there never were any water leaks that anyone ever noticed.
THe only way to check this is to remove the toilet by unscrewing the floor bolts, lifting and looking to see what is underneath... before you do this you might want to buy 3 regular wax rings and 3 extra thick wax rings... so you can choose which you want after you lift... if the rings are foam you might notice how one end might be squished and the other end appears full height... the full height is your clue that air might be getting through... Personally I don't care for the foam rings (hardware stores charge more for these than wax.. but it is harder to determine if you have a good fit.. with wax... it all just squishes out if it's too much and you get a good seal.
The last and least likely idea is that there is an issue with the vent stack for each toilet. Don't know the reputation or experience of your builder or the care with which city inspectors review builder work before signing off... but... you might want to check if there is a clear path from the stack inside the wall behind the toilet to the roof. Start with a quick look at each roof vent (the little chimney sticking out through the shingles) and see if you can see down it.. or is it plugged with a bird nest or some dead critter?
Once when visiting a friend her bathroom smelled like urine.
We finally tracked it down to POTTED PLANTS that she had in there.
Each potted plant was in a container and over time water had accumulated in the other pot and was stagnant/slimy. After we pitched those plants outside there was no more problem - but she had been battling this odor problem for months! You might keep that in mind and check.
We have lived in this well-built and well-maintained 25-year-old home for three years and for three years, one toilet smelled like old urine within hours of thorough cleaning. We called a plumber who said all was working well, and that there were no leaks.
I finally had the plumber come back and pull the toilet and check the wax ring. Which was FINE, but the plumber said there was quite a lot of old dried urine that had wicked under the toilet. (Perhaps in part due to not completely level new tile floor but who has a completely level floor?)
So he cleaned that up very well before resetting the toilet, and then put a bead of silicone grout around the front 3/4 of the toilet to avoid any normal "misses" from wicking in there again. Finally! No smell! WELL worth the $200 plumber bill. Of course, maybe you could do this yourself, but I am not a plumber.
I had a shower that smelled like cat urine for a year or more no matter what I did. I sniffed around and found it was a mold that was growing unnoticed on the tile grout. The tile is brown and the mold blended right in. It appeared to be brown and somewhat slimy. I believe it originated on the connection of the soap dish to the wall which had a layer of slimy mold on a tiny unnoticeable portion. I scrubbed with mild cleaner, and vinegar. Nevertheless, after a week of showering it can come back. So I constantly clean the shower walls with a mild mildew reducing shower cleaner and brush. That keeps the mold at bay. I will try baking soda, vinegar and hot water soon, to see if I can get rid of it forever.
That particular smell is quite surely related to some kind of mold, probably the same that grows when you miss the toilet and don't clean it for a couple of days. Reading your question I thought about some leaking from the shower or the back of the sink, but if you have the same problem in your 3 bathrooms there must be a connection.
If you live in a very humid area it is very easy to struggle with this kind of trouble. Bleach is a good solution for most kinds of mold and you don't have to use it in a very concentrated proportion. Every wet spot in the bathroom must be taken care of and if you live in a place with high levels of air humidity, every spot is a potential wet spot. Open your windows as much as you can, even if it is raining outside, humans make houses more humid than outside.
I know it can be disgusting, but you can save tons of cleaning time if you get to know where exactly does the smell come from. If it is the plumbing, smells shouldn't come back, but if you live by the sea or some very windy place, it happens.
Eureka! After weeks of a strong "urine" smell coming from the bathroom, we finally figured it out! Attempting to alleviate the problem, I had cleaned the toilet bowl until it was pristine. No boys (or men) using the bathroom and peeing on the floor. We checked the seal on the toilet and it was fine. Water was always in the tub and sink traps. I used a mixture of baking soda and vinegar down both drains, to no avail. The outside stack was clear. Nothing was amiss in the floor register. I cleaned, sanitized and scrubbed the entire bathroom. Then we inadvertently discovered that the problem originated from an open bottle of vitamin B6 that had been on a shelf in the medícine cabinet! Easy fix after two months of aggravation and frustration. Hope you resolve your problem as easily.
The urine smell could be caused by mold.
Our bathroom too had a strong smell of urine like cat pee and we have no pets. The smell came on suddenly and just got stronger every day! I searched our cabinet....low and behold in a small drawer that we hardly ever use was an ace bandage rolled up but it had fur and green mold spots all over it! The smell was so strong! That was the culprit. Since we've thrown that old ace bandage out and Lysoled, the smell disappeared almost immediately.
In very old houses, often the floorboards are wet (there is a hand-held instrument which measures the amount of moisture in a particular area); I suspect that such moisture can contain urine and I know from experience that there can be LOTS of mold growing under the flooring!
BTW, does no one know anymore that the word "smell" is a VERB, not a noun (odor, fragrance, scent.......)but not "smell".