Water Leak: Out of The Box Ideas

[Doc007]

Not intermittent problem. Happened every time in recent rains but never before this way in my three years of owning this coach.

We have recently been in the path of cold fronts and Helene and experienced days of hard rain. It happened last week then went a week before another spell of hard rain from Helene.

First time: Two days of hard rain....no leaks. About 6-8 hours after rain stops we get a steady drip of water falling from a center line ceiling light fixture. 1" in a 5 gallon bucket.

Second time during cold front passage before Helene: 24 hours of hard rain...no leak. 8 hours later it is not raining and the leak starts from the same light fixture and drips 1" in a 5 gallon bucket.

Third..today..48 hours of hard rain from Helene and no leak. 4 hours after the rain stops the leak starts dripping into the bucket.

I have experienced many water leaks on motorhomes and boats. Why does the ceiling not leak during the rain but starts once the rain stops?

[appsol]

Are you turning on roof A/C or heat pump after the rain, when it warms up later in the day? Perhaps a drain hose came loose from the A/C unit and what you are getting is defrost water when A/C is cycling.

[Doc007]

Originally Posted by appsol

Are you turning on roof A/C or heat pump after the rain, when it warms up later in the day? Perhaps a drain hose came loose from the A/C unit and what you are getting is defrost water when A/C is cycling.

Not running anything on the roof in all cases.

[TonyMac]

The ceiling is not supposed to be water tight, but the roof is. It takes a while for water to find its way out of the area between the roof and ceiling. Thankfully, it IS finding a way, otherwise it would collect until it brought the whole ceiling down. I'd fix the leak in the roof, don't worry about the ceiling, be glad it's leaking.

[terrylane]

Sounds like you need to check out the condition of your roof and the sealant.

The time delay may mean water is getting in from the roof and accumulating someplace until it overflows. It may be getting in from strong horizontal winds that you have not encountered before.

[Argosy]

Have you looked at the roof to see if it's puddling anywhere? If you pull the light out you should be able to see which direction it's coming from. The time delay is to get through the insulation, between the ceiling and supports, etc. That tells you the leak isn't real close to where you're seeing it come through the ceiling.

[Doc007]

Originally Posted by TonyMac

The ceiling is not supposed to be water tight, but the roof is. It takes a while for water to find its way out of the area between the roof and ceiling. Thankfully, it IS finding a way, otherwise it would collect until it brought the whole ceiling down. I'd fix the leak in the roof, don't worry about the ceiling, be glad it's leaking.

I can't quite get glad but thanks for the thought. I have a tech coming tomorrow to look for it.

[Doc007]

Originally Posted by Argosy

Have you looked at the roof to see if it's puddling anywhere? If you pull the light out you should be able to see which direction it's coming from. The time delay is to get through the insulation, between the ceiling and supports, etc. That tells you the leak isn't real close to where you're seeing it come through the ceiling.

Leak not real close is my fear.

[shepardmike]

I would inspect your front marker lights. Water has been known to follow the wires back into the coach.

[johnhicks]

A leak through the a/c gasket can travel a long way, and might only leak when a puddle is deep enough.

[jacwjames]

I was having trouble with leaks on my AC's so decided to change the gaskets. I was stunned when i turned both over, the gaskets were not aligned at all.

I have the drain cups which require 2 stacked gaskets,

Must have been a Monday at the factory.


Changed these ~3 years ago and haven't had another problem since.

[Dutch Star Don]

Your leak really sounds like an AC gasket issue. The water pools on the roof around the AC units and then seeps through the gasket. It takes a while for the seeping to occur after the rain, then work its way along the roof interior until it can find a place to exit.

Roof AC bolts are supposed to be snugged every few years to keep the gaskets sealed.

[egwilly]

You'll have to do a very close inspection of every item on the roof that penetrates the surface. The AC unit is a good possibility.

I have found little leaks at various places that I thought would never cause a leak. I wait until dry weather and use small amounts of water in each area to find the leaking area. One area at a time. It gets the job done. If you just run water on the whole roof, you won't find it.

Best for good luck resolving this issue. This is my out of the box procedure It's always worked good for me.

[Ray,IN]

By far, the best leak detection system is the SealTech System. Locate an RV service shop that has and knows how to use the system.
We bought a new 5er in 2008, while overnighting in the dealers CG, it rained. Their service dept. hooked up the SealTech system and the technician found the leak source over 8' from where water was dripping inside the 5er.
He continued and found 3 more as-yet undetected water leaks. After he repairs all of them we never had a water leak for the rest of our ownership of the 5er.


BTW, apparently you and your MH survived Helene OK.