Why the Stain Is Never Where the Leak Actually Is
OCRV Center Service Desk
Water enters high, at a penetration or a seam, then runs down the inside face of the wall until something interrupts it. The stain marks the interruption, not the entry. Sealing what you can see is how the same repair ends up paid for twice.
Four constructions, four destinations
Laminated coach: surfaces as a bulge or a hollow area in the sidewall, well below the entry.
Stick and tin trailer: wicks down the stud bay and surfaces at the floor to wall joint.
Fifth wheel: runs behind the front cap radius and surfaces in the bedroom floor or the front bay ceiling.
Van or fleet body: reaches the harness raceway and surfaces as an electrical fault, frequently months before anything visible appears.
That last one catches people out
An intermittent fault on a van with a roof fan or a solar mount added after the fact is a water symptom until proven otherwise.
Owners take it to an auto electrician, who finds corrosion in a connector, cleans it, and returns the vehicle. The water is still arriving.
How the path gets mapped
Moisture mapping works from the visible damage upward, testing at intervals to find where the readings stop. The entry point is above the highest reading, not at it.
It is part of the priced evaluation, and like every evaluation here it is credited against an authorized repair.
Common questions
Can I trace an RV leak with a garden hose?
A hose confirms an entry point you already suspect. It is poor at finding one you do not, because it floods the whole area and tells you nothing about the internal run.
How long does water travel before it shows?
Months, commonly, and sometimes years. By the time an interior stain appears the luan or the subfloor along the path has usually been taking damage for a while.
Is a moisture meter reading enough on its own?
It locates wet material. It does not tell you where the water entered, which is the only thing that stops it happening again. The reading is a starting point for the map rather than the answer.
More field notes
- What Months on a Whittier Grade Do to a Coach
How the slopes of Friendly Hills, College Hills and the Whittier Hills change what fails on a stored RV, and what it costs.
- On a Van, the Body Is the Structure, and That Changes Everything
Why corrosion that would be cosmetic on a coach is structural on a Sprinter, Transit or ProMaster, and why filler over a perforated rocker is not a repair.
Bring it in
Insurance walk ins are welcome. The teardown hour is priced at $210 and credited against an authorized repair, so the evaluation is not a cost you lose if the work proceeds.
23281 La Palma Ave, Yorba Linda, CA 92887. Monday to Friday 8:00 AM to 5:00 PM, Saturday 9:30 AM to 3:00 PM.