Rear leak 2003 Marathon XLII

[gbland7424]

After about 10 hours of rain I have a rear leak that has my floor wet. It seems it’s not coming from the roof but perhaps the window seal or perhaps the trim piece under the window. The LVP flooring is very soft and wet. Any recommendations on where I should look after the Rian has stopped? The walls are dry as is the ceiling so i am confused. The leak seems to be on the non slide side of the bedroom. Thanks

[Fratto]

I assume that the most evident water is on the floor at the base of the window?

Is there any evidence of water at the wall to floor intersection?

I am not that familiar with the XLII window construction / installation.

[shahzadlateef]

I had to deal with some water leaks in my previous motor home (not Prevost). The bottom line is that water travels in grooves, down a slope, and can end up in places fairly far from the origin of the leak. I will not only be looking near where you found water/moisture in the floor (i.e. not necessarily the window seal or the ceiling above the water). Not knowing XLII construction, I would first suspect some place along the roof, especially where the rear cap is attached. Other potential culprits can be roof mounted air conditioners (older seals), roof vent(s), or other roof installation. If you see any roof material deterioration, just redo that section. Unless you were in torrential downpour with sideways wind, or your bus was leaning significantly to allow water penetrate sideways, it is hard to imagine that much water getting in.

Do you get water in the bus when you wash it? It is easy to spray water around the window to see if any shows up inside. If you are unable to duplicate the results from washing the sides of the bus, inspect the roof. Even if you don't see stains on the ceiling materials inside, water is notorious about traveling through small groves etc.

I know this sounds tedious work trying to find a source of water leak. It will pay dividends in the long run as you may discover other areas that are not leaking yet but may appear weak.

All the best, and safe travels.

Regards, Shahzad