ST Water Leak Sensor mounted to wall?

Hi all, I’m looking at the SmartThings Water Leak Sensor for a particular purpose.

We have a dodgy gutter outside, and if it has a short sharp downpour it starts overflowing. When this happens we start getting a small trickle of water down an inside wall… similar to water droplets you would see on tiles of a shower. The gutter has since been fixed to handle larger downpours, but my wife has gone and hung a nice piece of artwork on that wall.

It would be awesome to stick the sensor on the wall somehow to detect the trickles of water coming down, and in turn, rescue the artwork (contentious topic in my household :wink:

All topics point to people putting these on the floor, for obvious reasons, but this is not viable in our situation.


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The placement of the trickle would have to be really consistent and your placement of the sensor really precise to be successful with this. Is it possible to put the sensor on a small shelf, maybe near the ceiling, that would catch the drip and form a puddle that the sensor can pick up? That’s the only way I can think of doing this reliably, but it’s not exactly pretty.

Maybe you could add some accent lighting for the artwork, like this, and put the sensor on top, with some tape on the top edge to direct the water to the sensor.

Thanks @MarkTr much appreciated for your suggestions. When the water starts coming down the wall, it does come in a steady thin stream.

I’m assuming the 2 smaller metal nodes on the bottom of the sensor are the ones that make the initial detection? In theory, how deep does the puddle need to be? Just enough for those nodes to touch water?

And is there a standard water threshold on the sensor? Eg. it won’t raise an alert unless it’s detected Xmm of water for XX seconds. Therefore a small stream that runs past it might not get detected?

Thanks again for your help. I thought I’d raise this question as I’m sure a lot of people have gutter/roof problems and the first signs of an issue is water coming down an inside wall?

The sensor is tripped when those two contacts are shorted together. Nominally that’s from sitting in a puddle; that’s why I’d worry about it not triggering if the placement isn’t perfect. There’s no concept of "depth"and the standard handling through STHM doesn’t consider a minimum amount of time, though you could probably find a smart app or create an automation that builds in a delay if that’s what you’re looking for.

If there’s space behind the art, maybe you could create a funnel shape to direct the water to a central location and put the sensor there, either laid flat or in the standard orientation.

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Water inside due to a gutter issue is new to me. If water is coming into the house I’d be concerned about bigger problems like water within the walls causing mold or structural issues. If your outer walls are sealed properly (paint, siding, caulk, flashing, roof shingles, etc) you should never have water inside.

If it were me I’d have the issue permanently fixed outside. Worth the investment for health reasons too. My father in law had a mold issue from a leaky water heater and he wasn’t feeling well until it was fixed.

I hear you @ritchierich. It’s been completely fixed. This is a preventative measure due to the artwork being hung there now. And in case we have a once a year storm and something gets through again.

FYI, the walls are double brick / concrete. No plaster / mold type issues.

Ok cool. As @MarkTr mentions the sensors work by the fact the two probes are connected so catching that with a small stream will be difficult. If there is a specific small area it does come down you could cut a piece of sponge or use a piece of paper towel and put the sensor on it. This way those would absorb the water and the sensor would trip.


Thanks @MarkTr and @ritchierich for your help. I’ll let you know how I go.


Hi all, I’ve conducted a few experiments based on the above suggestions. And I’ve had great results.

I placed a wafer thin piece of sponge cloth that touches the 2 bottom nodes. The cloth has to be super thin so it keeps the bottom sensors touching the wall/surface.

I placed this on a dry angled bathroom sink. This allowed me to run 2-3 small droplets of water down towards the device. I purposely aimed for the edges of the device, hoping the sponge cloth would pick up the water, become damp and connect the 2 nodes.

Success. I found that even the slightest drop of water (I mean a tiny drop) triggered the sensor.

I have now mounted the device on the wall architrave, with the the nodes as close the wall as possible.

Let’s hope I never get an alert :wink: