The water's coming from somewhere...

[geekette]

Not my circus, not my monkeys, but I need to vent/need ideas.

My sister's lived in her early 70's house in eastern TN for about 25 years.  It looks from the front like a ranch, but has a walk out basement because the land quickly slopes down to a flood plain about 600' or so behind their house.  I've seen videos of raging waters running by, but never close to the house or the ADU where their daughter lives (it's on the same meter).

In the summer of 2020, they started having humidity problems.  The insulation on the duct work under the kitchen was found to be wet (the dropped ceiling in the basement made it relatively easy to replace). Didn't help.

In the summer of 2021, my sister told me the humidity was so high the floors were sometimes damp.  They had a drainage system installed that would collect and remove any water coming into the basement from the street side of the basement wall. (They were somehow convinced that the water table had changed in the last few years?) Didn't help.

What they fail to consider is that they had some walls knocked down and new flooring put in on the main level in 2020.  I suggested (last year) that maybe someone nicked a supply line (probably near that damp duct under the kitchen), and they should, I dunno, check the meter, leave town for the weekend, and check to see if the meter had moved when they return.  Per them, that's not going to happen (especially now that their daughter has 2 week old foster child). 

Their water bill "hasn't changed" and while I don't think it would take a huge water leak to cause high humidity, would a couple hours away, like church and lunch, be enough to see a change in the meter?  FWIW, I googled, and their water system is supposed to have a meter that reads by the gallon.

[Sibley]

You can lead a horse to water, but you can't make them drink. And at that level of humidity, they're going to rot the house.

[sonofsven]

What you're proposing is possible (a small leak), but there are so many other possibilities.
You can buy a hygrometer to measure the humidity on Amazon for under ten bucks, I'd start there. You want it to be under 60% in the summer.
A dehumidifier might be needed, or a sump pump to remove water at the lowest point in the basement, or an exterior system of drain rock and perf pipe to "block" any water from breaching the foundation.
Or the footing drains on the exterior could be damaged (or non-existent). Where does the downspout water go?
Or there could be a small leak somewhere, but usually this would result in moisture in one specific location in the basement.
In answer to your last question, no, I don't think a few hours with the water shut off would be enough time to monitor any change in the humidity levels.

*Sorry, I think I misunderstood your question. You want to check the meter, not use any water for multiple hours, then re-check the meter for movement? Yes, that can tell you if there is a leak.
Also, it could be a leak on the drain side from the remodeling.

[JAYSLOL]

Most likely cause of moisture problems in a 50 year old home that has never had moisture problems before is definitely a very small leak somewhere, coupled with the renovation timing I’d say even more likely.  Not sure how to knock some sense into them though

[dblaace]

Curious if the humidity is the same in the whole house or just the lower level? If it just the lower level, a WAG the new flooring and walls are not allowing the floors to breath between them. Any return air ducts from the lower floor?

The city came out recently at my house because I have a leak in my yard. They had something like this https://www.amazon.com/Electronic-Stethoscope-Earphone-Detection-Equipment/dp/B07G27KPMV that they could hear a leak with. They heard a leak at the meter, shut off the water to my house and still heard it so that showed that the leak is on their side of the meter.

You could also use something like this https://www.amazon.com/Drywall-Moisture-Meter/s?k=Drywall+Moisture+Meter to check the moisture levels in different walls and locate where the moisture is the highest to find the leak.

[getsorted]

Downspout water is definitely a possibility, especially if coupled with a crack in the wall or foundation.

I live in humid country similar to eastern TN (humidity will go over 100% and yet the sky will refuse to rain out of spite) and sticky floors are just part of summer, though. If the flooring is new, it may just feel wetter during normal humid conditions. I also have cinderblock walls and they will get pretty damp when it's hot outside and I'm running AC-- I basically have to run a dehumidifier if the AC is on.

They should definitely check the meter, but parts of the mid-continent are already getting lots more rain as part of climate change, and it definitely is causing new problems like changes in the water table.

[clarkfan1979]

Not my circus, not my monkeys, but I need to vent/need ideas.

My sister's lived in her early 70's house in eastern TN for about 25 years.  It looks from the front like a ranch, but has a walk out basement because the land quickly slopes down to a flood plain about 600' or so behind their house.  I've seen videos of raging waters running by, but never close to the house or the ADU where their daughter lives (it's on the same meter).

In the summer of 2020, they started having humidity problems.  The insulation on the duct work under the kitchen was found to be wet (the dropped ceiling in the basement made it relatively easy to replace). Didn't help.

In the summer of 2021, my sister told me the humidity was so high the floors were sometimes damp.  They had a drainage system installed that would collect and remove any water coming into the basement from the street side of the basement wall. (They were somehow convinced that the water table had changed in the last few years?) Didn't help.

What they fail to consider is that they had some walls knocked down and new flooring put in on the main level in 2020.  I suggested (last year) that maybe someone nicked a supply line (probably near that damp duct under the kitchen), and they should, I dunno, check the meter, leave town for the weekend, and check to see if the meter had moved when they return.  Per them, that's not going to happen (especially now that their daughter has 2 week old foster child). 

Their water bill "hasn't changed" and while I don't think it would take a huge water leak to cause high humidity, would a couple hours away, like church and lunch, be enough to see a change in the meter?  FWIW, I googled, and their water system is supposed to have a meter that reads by the gallon.

Water meters that are at the street should be able to detect small leaks. There is usually a large dial that keeps track of gallons and a smaller dial that keeps track of small amounts (ounces?). If no one is using water in the house, the dial should not move. If the small dial moves, there is a leak.

[lutorm]

Water meters that are at the street should be able to detect small leaks. There is usually a large dial that keeps track of gallons and a smaller dial that keeps track of small amounts (ounces?). If no one is using water in the house, the dial should not move. If the small dial moves, there is a leak.

Yeah, we've always been able to see even a small seep by looking at the highest-resolution dial, a leak that's not noticeable by staring at that for a minute or two is very tiny.

[yachi]

Water meters that are at the street should be able to detect small leaks. There is usually a large dial that keeps track of gallons and a smaller dial that keeps track of small amounts (ounces?). If no one is using water in the house, the dial should not move. If the small dial moves, there is a leak.

Yeah, we've always been able to see even a small seep by looking at the highest-resolution dial, a leak that's not noticeable by staring at that for a minute or two is very tiny.

Mine has a small triangle that moves "whenever water is passing through".  It doesn't point to any particular measurements, it's just use to test is water is or is not moving through the meter.  This should work for troubleshooting.  They also make chlorine test strips that water utility guys use to determine if a puddle is natural groundwater or a watermain leak.  In the eastern US, we've always had a dehumidifier running in below-grade areas.  If not, we get musty smells and moist air, maybe some mold issues below storage bins, but not active wet spots.  I think any active wet spots are due to a leak somewhere.