How Does One Find a Water Leak?????????

[threeful]

I discovered a new leak that rotted (disintegrated) a small section of the interior wall panel, 8"x8", where the floor and panel join. This is in the right back corner where the back cap is attached and adjacent to the right rear window. Not sure the total extend of the damage but the wall seems dry above this section but I can feel a lot of moisture in the insulation immediately above this section.  I will fix this but 1st thing I need to do is find the leak.

This weekend I put eternaBond on the front and rear end caps, exhaust vent caps, antennae, and shower skylight.  The air vents are covered with Maxair Flo Vent Caps. The Maxair caps are not flush with the roof but I don't notice any water damage inside and I didn't put eternaBond on these, since the integrity of the enclosed vent caps seems ok.  I put silicon caulk where the end caps and outside fiberglass panels are joined and around the all the doors and windows last fall.  Yesterday it rained  and I could feel a lot of "new" moisture in the insulation above the damaged section. Dang!!! 

Today I am going to re-seal the ends of the guttering systems and where the roof is "folded" into the unit. (Suggestions on what caulk to use on the roof joints)

Now the question...How does one find the leak?     

 

[Johncmr]

Tracing leaks can indeed be tough.  Had to do a few over the years.  Best advise without pictures is to think a little outside the box - are the tail-lights and their wiring water tight?  How about Marker lights? Could the window be leaking, or holding water in a track until it overflows into the rig?  I had a window one time where they forgot to punch the track drain holes.  If the outside skin is aluminum, are all the panels locked together?  A small dent in the wrong place near a seam can cause a leak.  Pull off the vinyl screw covering strip in the corner and see in any screws have backed out, or were not put in at all. 

Good Luck

johncmr

 

[texnet]

This may/may not work but just a thought.  If you pressurize the inside of the RV then go over the areas where you feel the leak is with soapy water you might find the leak.  I had a leak one time and thought about finding the leak this way but I found it quickly and thus did not try the technique.  What I was going to do was to find a place that I could place one of those high volume blowers, like they dry carpet with, so it would blow in outside air.  This could be done at a window or the door by sealing off the rest of the area with 1/4" plywood and duct tape.  You would also need to seal off areas such as the hot water heater, heater and frig vent areas.  Don't forget to turn the gas OFF!

 

[Lou Schneider]

Commercial testers pressurize the inside of the RV by putting a blower inside, on the floor under a roof vent, then extending a duct upwards to the underside of the vent (with the lid open, of course).

The blower sucks air through the vent and duct, then discharges it into the inside of the RV, pressurizing it.

Might be simpler than blocking off part of a window.

 

[Ron from Big D]

The bad thing about you using Silicon last fall on the seams is the fact that you cannot put another sealant over Silicon.  The Eternabond may bridge it adequately.  (95%) of RV leaks are at penetrations or joints.  Water moves in mysterious ways, so don't assume the obvious.  The pressurizing approach is a good one.

 

[Ron from Big D]

Forgot one other thing.  Often Silicon looks like it is good and is still leaking, especially if the surface was not perfectly clean before application.  With a thin blade, carefully run it along both edges of the sealed joint and see if it has adhered to the surface.  If not, removed the sealant bead, abrade the surface and re-seal.

 

[Alfa38User]

And.... don't use silicone!!! Dicor makes a pretty good self-levelling sealer for the roof  horizontal surfaces. There are other brands too. Polyester sealants can also be used with success on vertical surfaces.

Silicone does not adhere to other sealers nor will others adhere to it. It is damaged by the sun and does not last. It does make a good glue on inside, out of the sunlight though.

 

[threeful]

Thanks for the help.

It is raining today and I will see if taking the "shotgun" approach on sealing eliminated the leak.  If not the when I get the damage fixed I will have them pressure test.  I'll give a report on the success or lack thereof, after it has rained awhile.
 
FYI clarification on sealants I used:

I used Dicor to seal any seam that had roof material in the seam.  I used silicone sealant on any seam that was metal/plastic to fiberglass ie, around door, windows, fiberglass panel seams, lights, storage doors, etc.

 

[threeful]

Well...still leaking!!!!!!!  Dang

 

[scottydl]

Dang indeed  :-\  It really seems like you've covered all the usual bases too.  On to the pressure test I assume?

 

[threeful]

Leak or not...heading for Maine and then the NY Finger Lakes for some wine tasting.  Hope it doesn't rain too much.