Puzzling Roof noise

[GRule]

I'm sure that some or all of you will think i'm crazy when you read this but i have a witness to this strange phenomenon.
We own a 2009 Flagstaff Microlite 21 BH.
Have owned it since 2012 and yet to figure this out.
Here goes....
I know Rv's will transmit the noise from rain but with our unit the sound of raindrops turns into something that i can only describe as water running through smalls passages in a trickling manner. This sound continues on for quite some time after the rain has stopped.
There has not been any internal leaking so far but its driving me crazy.
It seems that it travels over the entire roof surface.

I'm looking for any reasonable suggestions or solutions to this dilemma.
I use to own a slide in camper with aluminum siding and never experienced anything like this.

Thanks
GRule

[Iwannacamp]

Hmmmm. I love puzzles. You prolly know or have tried.

My first GUESS is water running off and flowing over roof etc. and takes a while..bla bla
2nd guess..something is storing the water to run out slowly.... reason for noise

Possible idea to narrow problem... raise/lower front of unit to allow to change direction of flow of water to see what sound is left.

[GRule]

Yes sir it is a puzzle.
I've been leaning towards your 2nd possibility but ya i think i will spray some water on roof and raise/lower unit to maybe isolate noise.
Good call.
I'll give it a go.
Let you know if i figure anything out.

Thanks

[Thurman]

Raising or lowering the camper end-to-end sounds like a good idea. IF you really suspect that you may have water running inside any wall buy a stethoscope at your local pharmacy and use it to listen to the inside of the walls the next time it rains. Even if the noise is coming from an outside source you may be able to localize it.

[GRule]

Well i tried raising/lowering trailer after a good soaking but i never heard anything.
I also figured i'd check AC and Frig vent by covering with plastic and soaking roof and listening then removing plastic one at a time but still nothing.
If nothing else it gave me a great opportunity to wash down the roof.
I'm not sure what else to try.
I'll wait till next rainfall to further investigate.

Thanks guys