Soft spot on the back wall

2016 travel trailer, laminated fiberglass rear wall, ladder on the left (roadside) half of the rear wall. 30A shore, stored outside

Customer says: There's a wavy soft spot on the back wall next to the left tail light. A friend said the tail light is leaking.

The skin is wavy just inboard of the left tail light. The ladder's left rail runs up the wall right above the soft spot.

Tests you can run

• Press on the wall around the soft spot
• Moisture map inside the rear wall, top to bottom, same meter and setting
• Look at the left tail light and its sealant
• Look at the ladder brackets
• Water test from the bottom up, meter on the wet column: tail light, lower brackets, then the upper bracket
• From a shop ladder, look at the rear roof edge and corner moldings above the coach's ladder
• Measure and photograph the soft spot and the wet column
• Climb the coach's ladder to get on the roof
• Pull and reseal the left tail light

Repair options