Help me solve my house mystery: urine smell after rain

[Anonymous]

We have lived in the same house in northern Virginia for more than a decade. It was built about 40 years ago and doesn't have any major problems. Except! Beginning about two years ago, our basement and first floor, toward the front of the house, would smell like urine after a heavy rain. We never saw any mouse/rodent problems, but we started using a pet service that put up bait traps just in case. Didn't help. We've had three plumbers visit to look for leaks or other issues, and they can't find any. One plumber made the good point that if there was a plumbing leak it would not just smell like urine. We've had two mold testing companies come out and they have not found anything. We are totally baffled and don't even know whether there is any kind of company that can help us at this point. But the smell gets so strong after rains that it's difficult to be in the rooms. Any suggestions/stories would be much appreciated!

[Anonymous]

Do you have any pets?

What is your basement drainage system and how old is it? Is the basement finished?

[Anonymous]

Anonymous wrote:Do you have any pets?

What is your basement drainage system and how old is it? Is the basement finished?

No pets. Finished basement. We have a standard municipal sewage system - and one of the plumbers checked the connection and said there were no problems.

[Anonymous]

Anonymous wrote:

Anonymous wrote:Do you have any pets?

What is your basement drainage system and how old is it? Is the basement finished?

No pets. Finished basement. We have a standard municipal sewage system - and one of the plumbers checked the connection and said there were no problems.

I meant storm water drainage, not sewer. I know it’s a urine smell but I would still want to rule out moisture in the basement.

Also when your plumbers came, they put water in any unused drains, right? Although this wouldn’t correspond with rain. That’s why I think you maybe have a storm water problem that smells like urine maybe because of an old cat or something that has been covered up.

[Anonymous]

Probably prior owner had cats.

Try painting with smell-absorbent paint.

[Anonymous]

This is an off the wall thought and probably not relevant since you smell it in certain rooms, but any chance there are boxwoods around? I've read they smell like cat pee.

[Anonymous]

Anonymous wrote:This is an off the wall thought and probably not relevant since you smell it in certain rooms, but any chance there are boxwoods around? I've read they smell like cat pee.

This.

Plus, if prior owners had pets and you have wood floors, that could be the issue: rain related humidity lures out the smell.

[Anonymous]

Our prior owners had a lot of dogs and cats over the years, and when it’s humid we can smell a pet smell. Not clearly urine but I’m sure that is a big part of it. We had all carpets professionally cleaned, fully painted, and had our tile floors acid cleaned and it has helped a lot but we still occasionally catch a whiff. We didn’t realize how dirty the home was during our brief tour before bidding!!

[Anonymous]

Check your house for a studor vent, and if you find one, replace it. They are $10.

[Anonymous]

Any chimneys in/near these rooms? We had a weird smell after rain in our last house and we needed to fox the flashing on the roof. Water was getting in and mildewing in the shaft on the way down.

[Anonymous]

Thanks for all the helpful replies. We don't have any boxwoods. There was only one owner of the house before us, and they said that they never had any pets. And the floors/walls don't typically smell like urine. We only get the urine smell during the heavy rains in the spring and summer. No studor vents and no chimneys in the rooms where we have the smell. While something sewage line-related is a likely culprit, it's very odd that it only smells like urine and not the, uh, other types of sewage smells. We're just totally stumped, and I don't even know what kind of repair service to call to help with this.

[Anonymous]

Black mold behind drywall or somewhere hidden. Crack in foundation.

Mold generates the ammonia-like smell.

[Anonymous]

Anonymous wrote:Our prior owners had a lot of dogs and cats over the years, and when it’s humid we can smell a pet smell. Not clearly urine but I’m sure that is a big part of it. We had all carpets professionally cleaned, fully painted, and had our tile floors acid cleaned and it has helped a lot but we still occasionally catch a whiff. We didn’t realize how dirty the home was during our brief tour before bidding!!

Omg you need to replace the carpet!!

[Anonymous]

I feel like the rain thing is the best clue and suggests it’s not sewer related. I bet there’s moisture in the basement behind the finishes.

[Anonymous]

Anonymous wrote:

Anonymous wrote:Our prior owners had a lot of dogs and cats over the years, and when it’s humid we can smell a pet smell. Not clearly urine but I’m sure that is a big part of it. We had all carpets professionally cleaned, fully painted, and had our tile floors acid cleaned and it has helped a lot but we still occasionally catch a whiff. We didn’t realize how dirty the home was during our brief tour before bidding!!

Omg you need to replace the carpet!!

OP again - we actually replaced the carpet a few months ago - and before the new carpet was installed we smelled the floor and did not smell any urine.

Also got extensive mold testing and everything was negative.