We’ve had non-stop issues as it is impossible to travel around in upstate NY without rain (especially this year). But after 2.5 years of trying things, I think I have it under control, finally.
As Cary indicates above, the lovely teardrop shape of our trailers maybe acts as an airplane wing, under certain circumstances. A Honda CRV at 65 mph seems to be ideal. Non-turbulent, fast moving air creates low pressure over the trailer, lifts up the fan cover, creates low pressure in the cabin and then water gets sucked in through even the smallest of openings. Unusual but it seems logical. Look at that shape of our trailers! But some openings are not so small as I’ll describe below.
I have replaced the standard fan with a Maxair fan which has closing arms on each side, but that didn’t solve it. It must still lift up somehow. Maybe more so because its cap is bigger than the original fan.
So I searched for leaks and the biggest source of the leaks: under the fenders. There shouldn’t any leaks there. Greg thought it to be impossible but it is undeniable for our trailer. The mattress was often wet underneath, and the wettest right at the wheel wells, on both sides.
I took the wheels off, put the garden hose on the side and bottom of the trailer under all kinds of angles. Behind the wheel under the fender where the wall meets the floor, there was a hole somewhere. I have video of water shooting into the cabin from underneath the triangular reinformcement piece on the wall/floor joint. Happened on both sides! But impossible to see it visually. But that place is one of the wettest on the outside of the trailer so with a vacuum assist, water will get in. I tried several times to seal it with silicone caulk in a few places but never quite got it sealed. Eventually put heavy duty car sealant all along bottom corner starting a foot in front of the fender to a foot behind it. worked it into every corner and crevice I could find. Then I sprayed black truckbed coating on top of that. That finally did the trick. At least for water in those spots under the mattress.
2nd biggest source: where the ends of the door seals meet. The sides of the mattress gets soaked in the middle of the doors with any rain. Even after the fender area sealing I described above. On ours those door seal ends were cut in a little V-shape. Maybe that was done for draining potential condensate on cold doors. But if you put the water hose at the bottom of the door, it shoots right in. Again with a vacuum assist, water surely gets sucked in that way. I inverted the door seals to have the ends meet at the top of the door instead. Less water there. And then I filled the V-shaped gap with silicone. Mattress was dry! If there is a condensate problem, I’ll manage that another way. We always have the windows open and have very little condensate anyway.
The last source was a little water coming in along the door. On the right side, the door is warped a little bit under the door handle, enough to not seal completely. Sitting in the trailer, with the curtains closed and peering along the door seal, I could see light come in. I had some 5/16” soft tubing laying around that I put under the door seal. Enough to push it out a little bit, still soft to flex as the door closes. A new door seal probably works also.
There is a vent hole above the windows, but I’ve never seen water come in that way. Might be too high up. But if it leaks there, I’ll resort to removable rubber plugs.
This memorial day weekend we drove 4 hours in the pouring rain to the ADK mountains on Friday. The mattress was folded up and lifted up because we’ve had to deal with wet sides a few too many times. However, everything was dry! Great relief. I’m still a bit hesitant to declare complete success but it was the most significant improvement I’ve made so far. To be extra sure, I think I’ll replace two screws on the fan rim with screw-eyes and then I can add a strap over the fan cover to prevent any movement. That would solve the root cause but I think it is difficult make that fan seal completely.
BTW, the trailer is completely dry when not driven. And we’ve had some tremendous downpours while camping.
Hope this helps someone else. Curious if our experience is unique.
I have pictures that I might post later.
Rutger
thanks
