Where is my Leak

[XR-duous]

I have a very small seeping leak at the front wall that I cant find the source of. Any suggestions would be helpful. I have pulled all the the screws, put silicone in the holes and re-screwed them, but that didnt help. I just dont see where it would be coming in. It only manifests on the bottom right under the bend of the diamond plate, as pictured. It's pretty much all across...heavier on the left and right. I dont feel or see any other moisture on the wall. Only at this location. You can see a couple of seems across the front of the siding, but they overlap. I think it would be tough to get in there unless the rain was blowing up from the ground. The black channel on the left and right are well caulked, but then again, the moisture is across the entire front, so I would think it would have to be something high or central. Thoughts?

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[Margali]

Maybe you already tried this... Block off all vents and tape door seams to eliminate light while you are in trailer. Turn off light and wait for your eyes to adjust then press on suspected areas. Might be able to spot something.

Another idea is poor man's dye penentrant test. Get a couple of different color spray chalks and put them on different zones. The color of water seapage showed us which selection of shed ridgeline was leaking Not sure if it would work here.

[Squigie]

Note the damage under the paint on the upper panel in the second photo.
Your leak is farther up the wall.

Active leaks inside roofs and walls will take the path of least resistance while following gravity.
The leak could be anywhere that is typically "up hill" from where it is manifesting.
It could even be a matter of extreme condensation running down the inside of the skin.

Extreme example:
I bought an ex-Cruise American C-class Winnebago in 2010. It was sold because they couldn't stop a recurring leak that was destroying the roof, window frame, and 'floor' in the cab-over section. They sealed the window, the roof, the marker lights, the TV antenna, the side windows, the side skin panels ... they sealed everything up there.

But that wasn't where the leak was. The leak was at the refrigerator vent, sixteen feet away on the roof. That motorhome (like most class-Cs) had a notable rake to it - lower in the front than the rear. Water was getting under the fridge vent base, running between the roof skin (aluminum) and the insulating laminate, leaking into the wall/roof attachment rail under the corner trim (that closed off the roof and capped the walls), running down that rail toward the front, pooling in the transition from flat roof to kerfed foam and fiberglass 'bullnose' panel that wrapped the front of the cab-over, and spreading everywhere as it went from the "top" of the panels to the interior skin.

The "cab-over bunk front window leak" was actually a refrigerator vent leak.
(Diagnosing the true source of that leak was a LOT of work. But, I got her dried out, put back together, sealed up, repaired, and it was perfectly fine until I sold the thing.)

[swoody126]

the seam where the rubber roof and fiberglass front cap came together caused similar issues in my RV

got "leaks" showing up on the inside wall covering along the front AND side walls below the window openings

just restating the above refrigerator like issue

water can travel a LONG WAY before it makes itself known to the naked eye

sw

[XR-duous]

Thanks for all of the input guys. I'll climb up on the roof again and see what I can see. The nature of that front design would necessitate a leak at the very top front where it rolls over. Any further back and the water would flow towards the back of the trailer and avoid my problem spot. I suppose it could possibly come in through the black bumpers on the front and then travel across that rail previously picture. Hmmm. These things are tough. The leak was there before I cut any vents, so I know I'm safe there. Plus, all my vents are further back, so it wouldn't create a problem in this area anyways.

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[McDave]

I would be highly suspect of those trim pieces on the end, the front wall to side wall extrusions. They look as if they have a vinyl insert? That would act as pipe or hose if water could enter it and would funnel the water to the first available point of entry. The amount of water contained in there could be quite a bit and as the water stacked up in the vertical the weight/pressure would be considerable and possibly enough to force its way in through a rivet or screw. The stain I see would require cups of water to make. So start at the roof and see if it is possible for water to enter that trim anywhere. You may have to pull the vinyl insert right out and seal the trim then replace the insert. Then again you may see a obvious point of damage etc.


You can see how this would act as a conduit for water... as an example

McDave

PS, I think I see some damage to that trim. Drivers side, just below the marker light above the diamond plate?

[hankaye]

XR-duous, Howdy;

From what I see, first thought was road spray from the tow vehicle getting sucked in at the bottom seam
right above the 'A' frame below those nice orange arrows. The plywood can and does act like a wick when wet.

Does it get wet when it's not traveling anywhere? I see a wrinkled bit of skin at the upper Right Corner (In photo),
just inboard of the trim piece. Can't see the joint where front skin joins with roof. What's the condition of the sealant
there?

All said an done My bet is on the front bottom seam and wicking by the plywood.

hank

[XR-duous]

Thanks guys. I'll check out those couple of spots and see what I come up with. I definitely think it's possible there is a small gap some place on those channels. I'll climb up to the top side and see how they look.

It leaks with a good rain while sitting in the drive.

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[XR-duous]

I would be highly suspect of those trim pieces on the end, the front wall to side wall extrusions. They look as if they have a vinyl insert? That would act as pipe or hose if water could enter it and would funnel the water to the first available point of entry. The amount of water contained in there could be quite a bit and as the water stacked up in the vertical the weight/pressure would be considerable and possibly enough to force its way in through a rivet or screw. The stain I see would require cups of water to make. So start at the roof and see if it is possible for water to enter that trim anywhere. You may have to pull the vinyl insert right out and seal the trim then replace the insert. Then again you may see a obvious point of damage etc.


You can see how this would act as a conduit for water... as an example

McDave

PS, I think I see some damage to that trim. Drivers side, just below the marker light above the diamond plate?

I think I may have found it. Someone must have replaced that driver's side trim at some point. When they did, they failed to use the rubber washer screws and just drove regular metal screws through. I pulled the molding and caulked all of those screws. I have had a couple of rains without noticable leaks. I'm looking for a gully washer to really test it though.....or maybe the water hose, as suggested. Thanks again for the help.

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[Tomterrific]

I don't know an accurate name for water hang or the drip but water gets on the bottom of plywood and migrates up due to capillary action. If your metal stops at just the bottom of the plywood this could be happening.

Tt

[hankaye]

XR-duous, Howdy;

It was these two sentences that you wrote in your first post regarding this water intrusion.

" It only manifests on the bottom right under the bend of the diamond plate, as pictured. It's pretty much all across...heavier on the left and right."

Those last 6 words, "heavier on the left and right." in other words, where the tires are
throwing the water into the frame and forward wall interface imo. Could also be the vertical
seams but give that cross seam a real good look-see. Some dark night shine a light to see if
it shines through somewhere along there. Just some ideas

hank