Help! Water damage - from where?

[AmandaRose]

2021 Hideout 29DFS
Puddle of water next to the bathroom sink. Coming from where I circled. I tore apart the bathroom - nothing is visibly leaking. I ran the sink, shower and ran the toilet. The puddle appeared after a rain storm. It’s not raining anymore and the water has stopped.

[wiredgeorge]

Not sure but since the water that leeched up into the sink's enclosure is adjacent to the vent, I would get up on the roof and make sure the vent is well sealed with self leveling sealant and is not damaged in some way.

[sourdough]

My thought as well. Where is the vent in relation to the water collecting?

[chuckster57]

vote #3 for a bad seal on the roof

[SargeW]

A simple way to test it is to take a water hose up to the roof and direct a stream of water at the base of the vent pipe while watching the pipe from the bottom. You will tell quickly if that is the intrusion point of the water. I did the same test to my roof when looking for the source of a water leak in the bedroom. It turned out to be a "standoff" that mounts the solar panel to the roof wasn't sealed well.

[NH_Bulldog]

That layout is similar to mine and I don’t think there is a vent line anywhere near there. It looks like the bathroom sink drain pipe with the tub/shower drain coming in from the side. On the other side of the wall is the pantry/linen closet and no vent there either.

That space under the pantry on the other side of the bathroom wall is where the outside shower and power cord opening are on mine. I would look at the exterior sidewall for proper sealing around any opening in that srea

[mikec557]

Another item to check is the black tank flush line. It's one of those white lines. Look up high while under the sink and you'll probably find a black plastic one way check valve. When you flush the black tank with a garden hose from outside it should maintain that water pressure within the white hose. If it's cracked or defective water will leak out of it.

Edit: white hose, not white house...

[firestation12]

Originally Posted by AmandaRose

2021 Hideout 29DFS
Puddle of water next to the bathroom sink. Coming from where I circled. I tore apart the bathroom - nothing is visibly leaking. I ran the sink, shower and ran the toilet. The puddle appeared after a rain storm. It’s not raining anymore and the water has stopped.

As Mikec557 suggested, if you haven’t found the leak yet, consider checking out those 2 white pex lines that terminate onto an anti-siphon valve. The valve if defective, can leak or even spray water whenever you are flushing your black tanks. The valve is tucked under the sink top. So did you recently flush the black tank?

[Balvar24]

Refrigerator?

[Farside]

It's hard to tell from the pictures. You are pretty far from the shower and toilet, so my next guess would be the sink valves themselves. Turn both hot and cold water on in the sink and feel if you are getting a spray under the sink. Do you ever plug the sink, try that also. You may have a bad PEX connection, or the sink might be leaking at the drain.

[LHaven]

I'm a little curious about that funky luan plate in back of everything else that seems to hint that at one time something untoward occurred inside that wall.

[popsshopga]

Originally Posted by LHaven

I'm a little curious about that funky luan plate in back of everything else that seems to hint that at one time something untoward occurred inside that wall.

Yep, caught my interest as well. He also said that it occurred after a rain. My vote would be the water is coming from the roof. A tear in the roofing material or from an unseen crack in the seal around a pipe.

Just my 2 cents worth

[notanlines]

I also am a little wary like CD mentioned of the partial sheet of luan plywood. It seems out of place.