Finding source of water leak?

[vavroom]

First - Happy New Year to everyone!


About 2 months ago, we found water dripping from our ceiling in the lounge. Wiped it off, then a couple days later, when it was not raining, I went on our roof and cleaned, dried and sealed everything that even remotely looked like it needed resealed. Used Dycor sealant. I redid all the existing seals. That seemed to have taken care of the problem - not leak since.


A few days ago, the overhead light in our bathroom went out. It was Christmas Eve, and I opted to fix the light after the New Year. We'd had a massive storm. Extreme winds, lots of rain. Yesterday, my wife was dripped on while in the bathroom. I had a look last night, and a bit of water was dripping through the light fixture (which probably explains why it is no longer working!).


Today, I went on the roof and examined the whole surface very carefully. I cannot see any hole or cracks through wich water could be coming in. Obviously, it's coming in from somewhere! But, where? That's the question.


I just took the light fixture out to see just how much water was in there and where it might have been travelling from. To my surprise, everything around the light fixture is dry, dry, dry. The only bit of wet is a pea sized bit on insulating wool. But the rest of the wool is dry. There doesn't appear to be any moisture, much less water wicking throughout the insulating wool.


I'm very puzzled, and obviously concerned. Need to find and stop water leak.


What would you suggest I can do to trace the water?



Thanks in advance for any and all info.

[TJ]

I don't know your specific coach, so my comments are general.

First, water can wick horizontally over substantial distances, so don't just look in the area where you've found water below. I'd be looking at the obvious sources first; AC units, vents, and any other areas where there are roof penetrations. If you have roof drains, be sure they are clean.

Water leaks are sometimes quite hard to find. Good luck.

TJ

[Podivin]

Could it just be condensation from a hot shower, possibly combined with not using the exhaust fan?

[BCam]

I'd start with anything that's close to the light fixture, roof vent, skylight, etc. If I had this problem, I'd re-seal everything within a few feet and, time and weather permitting, I'd do everything on the roof to be safe. And, personally, I'd do it with Eternabond tape. If you want to narrow it down, areas of black sealant around the edges of a fixture, between it and the roof, can be signs of leakage.

Alternatively, you can remove the internal trim from each of the above and see if you can see any signs of moisture penetration.

[vavroom]

Thanks for the answers.


Update: I removed the wool insulation and soon as I touched it, it dripped water. The thing was waterlogged like a sponge. It's now removed from that area. The roof was damp - it's been dried. The wool is in the rubbish bin. Not putting anything back there until we have more rain and I can see if there's a way to have a clearer idea of where the water is coming in.



I don't think it would be condensation, although it COULD be. We never shower without running the fans. OTOH, we have a fair bit of condensation around the bathroom window, sooo, perhaps.


I'm aware water could wick over long distance. It's something that I was wondering. But there doesn't seem to be moisture away from that area.


All the areas that have items penetrating through the roof have been resealed a couple months ago - no trace of dark/dirty/aged sealant left. The two items nearest the water leak (grey water exhaust, and fantastic fan) were actually resealed by Newmar when we were in Nappannee in October.


Anyway, right now, the light fixture is in the electrical cupboard. The ceiling is open into the ceiling/roof cavity, and we're playing a waiting game.

[Dav L]

A good water test with a hose in in order.
Apply water for a long time in one area only. See if any water accumulates in the roof.
Move the water, reexamine, etc.
Know that the water travels in the roof.
Ideally the RV is "pointed uphill" and start from the back. To better isolate the section that is leaking. Concentrate on HVAC, antennas, wires that protrude through the roof.

The biggest problem is drying out the insulation in the roof before mold sets in.

[MD-Keith]

You might also check the mounting bolts for the AC units. Sometimes they need to be tightened down to put pressure on the sealing gasket. I believe on most units they can be accessed from below (inside the rig) and just add another turn or two if they are not fully tight. Mine were loose on my last Ventana and the water ran several feet across the ceiling and came out at a light fixture in the rear bath.

[vavroom]

Originally Posted by Dav L

A good water test with a hose in in order.
Apply water for a long time in one area only. See if any water accumulates in the roof.

Interesting idea. Thank you. Will have to see if I can do it - our setup may not be ideal for it. And the rain in the pacific northwest is... hard to avoid, so I may not be able to run a localized test.

Originally Posted by MD-Keith

You might also check the mounting bolts for the AC units. Sometimes they need to be tightened down to put pressure on the sealing gasket. I believe on most units they can be accessed from below

I can't access the AC bolts from inside, not without taking out the ceiling in our coach. But I'll have a check of them from above. I *think* they are fine, but I'll double check.


Thank you

[C.Martin]

I have seen a YouTube video by Independence RV. They hang a gizmo from one of your roof vents that draws air into the rig and slightly pressurizes the cabin. Then they head for the roof with a soapy water solution and look for bubbles.

Pretty thorough system... they locate trouble spots...then clean and reseal those areas.

https://youtu.be/tDKaBEcMLQA

[dc3carl]

We are also chasing the source of a water leak in the area of the shower (midship) in our 2012 DS 4342. Had a Flex-Armor roof installed (applied?) one year ago and all has been dry and awesome all year across many miles and many states. Last month, while camped in cold, rainy and windy Myrtle Beach we had water dripping from a light in the hall ceiling. I contacted Elite RV in Palmetto Florida (they did our roof) and they had us in the shop this morning.
We believe the issue was condensation in the shower skylight as there are no penetrations to be found. We had the Flex-Armor applied over the exterior of the skylight and indirect LED light strip installed inside the skylight. Looks great.
The shop called the Flex Armor office and they also believe the leak (which only appeared one day and condensation was visible in the skylight) was caused by the condensation running down the inside surface of the outer layer of the skylight and migrating to the light fixture. The effort to prevent recurrence involves putting insulation between the inner and outer skylight layers. We’ll see.
Note that this leak was a one-time observation and no condensation has been seen in the skylight since. I guess the long-term solution for condensation will be to stay in warmer climes. Oh, and use the fantastic fans too.
Happy New Year and Happy Travels!

[BCam]

Our weather here in the Sacramento area is pretty moderate but I always leave my vents cracked open a little (I have hoods over them) to ensure adequate ventilation, even when the MH is at the storage lot.