Discovered a leak, where is it coming from?

[92DakotaHD]

My floor cracked a few winters back. Decided to fix it and pulling the old linoleum I found a leak in the back corner I wasn't aware of. It's wet even with the trailer sitting since labor day weekend and some recent rains. Oddity is that there is zero sign of the leak above the linoleum. The trim above it is dry, everything feels solid. Cant find any leaks on the water heater and the signs of moisture seem to end under it. Wet on one side, dry under the flooring on the other. The awning does have the lower clamp near it but I am stumped. Anyone have any ideas?

[LarryJM]

92DakotaHD wrote:
Thanks all. And Larry I keep an eye on that area as for the reason you mentioned it just looks less than ideal.when up there looking things over.

The problem with that area is that you can't tell visually if it's still sealed good since water can over time channel between the caulk and roof and then wick onto the wood soaking it and then running down the entire corner of the trailer. Pictures of the entire height of the corners in more than just a few trailers here have shown this issue and until the damage is visible it most often goes undetected.

As already mentioned lights and wicking screws are two other weak points and you can look thru the link in my signature for all various way that I have attempted to solve all these potential weak areas on a trailer. Because Eternabond is good for submerged use that is what I tried in most cases to use along with the Marine grade 3M adhesive/sealant 4000 and 5000 series.

Larry

[92DakotaHD]

Thanks all. And Larry I keep an eye on that area as for the reason you mentioned it just looks less than ideal.when up there looking things over.

[daystrom]

Here's a link to my pressure tester that I made:

Link

[LarryJM]

My bet would be you have a leak at the roof corner where the metal insert molding for the side/rear runs up onto the roof and meets the end cap seal where the roof meets the end side. This junction forms a right angle where water can "POOL" and over time will form a leak that will run down inside the walls to the floor and cause the damage you are seeing. Properly sealing that area is almost impossible because almost all the caulk normally used is not meant for "submerged" applications and once the leak has developed you might have wicking screws in that metal insert molding and trying to seal something with the main sealant as caulk is almost sure to fail at some point in the near future.

I solved this potential issue by entombing that entire corner in Eternabond ensuring it totally covered that junction down onto the roof/end cap/side areas. Not an elegant looking solution, but IMO 100% effective so here function trumps looks.

Larry

[keymastr]

Also if that area of floor is above the wheel well then it could be wet from tires throwing water at it.

[92DakotaHD]

Beaker wrote:
I had a leak around one of the bolts that hold the awning on. Look for signs of rust.

Just seal around them? I pulled the lower bolts and resealed around them. Not sure how wise it would be to pull the upper bolts.

Lynnmor wrote:
You can do your own pressure test. Open a roof vent, place a plastic tub upside down over it, then cut a hole in the tub for a leaf blower. Weight it down. Close up the trailer, turn on blower, and go around it spraying a soapy mixture at all joints and openings, taking a photo of the places bubble. Rinse before it drys.

I can do that!

[Lynnmor]

You can do your own pressure test. Open a roof vent, place a plastic tub upside down over it, then cut a hole in the tub for a leaf blower. Weight it down. Close up the trailer, turn on blower, and go around it spraying a soapy mixture at all joints and openings, taking a photo of the places bubble. Rinse before it drys.

[Beaker]

I had a leak around one of the bolts that hold the awning on. Look for signs of rust.

[92DakotaHD]

Seals look good around the lights nearby but have some marine sealant (3m 4000 UV) stuff on the way and lap sealant. Out at home and am at work when stores are open. The nails/staples right above the corner are dark but the trim just on the other side of the divider show no signs of moisture. One thing I saw up top is that the strip on either side of the roof that is screws covered by a curved strip of plastic that pops into place had popped out near the awning. I revealed around the lower awning mount bolts. Unsure if I should try the tops, just don't want to mess it up. Everything up top looks pretty sound. Going over the roof very hard when the lap sealant is here.

How much does pressure testing cost?

[daystrom]

I double what westend says. More than likely that leak is up near the roof and running down the inside of the wall. That wall board is the same stuff they use in showers so it is somewhat water impervious.

Hard to tell in the first photo but are those staples rusted near the bottom? Could just be the wallboard soaking the water up, could also indicate water coming down.

Is that the rear of the trailer and if so is there a marker light above? It looks like the darkest part of the floor is in the center. Water could be coming down the inside of the wall and the plywood is soaking it up under the floor covering. I would think if the water heater was leaking, you'd have the darker part near it.

[budwich]

92DakotaHD wrote:

donn0128 wrote:
Pay to have it seal tested.

The whole trailer? I can tell you now it's not air tight. Underbelly is "sealed" but not air or water tight, although water would have a hard time getting up there. And there are holes in the floor for utilities going up and down from trailer to the "basement" area.

the test is not looking for "air tight" and then you "point" at the one leak you are looking for..... if it was, you would likely blow out the windows during the test... 🙂
You are looking for air leaks some where near or in likely areas close to the problem. A significant amount of air is "pumped" in via an enclosed fan in an appropriate opening from the outside. Then you listen or spray soap water around areas to spot air leaks in various areas (ie. joints, fittings, etc). My guess from your pictures is that the water heater / piping / pump has a leak somewhere allowing a small amount of standing water to sit in the corner where you found the result.

[Lynnmor]

92DakotaHD wrote:

donn0128 wrote:
Pay to have it seal tested.

The whole trailer? I can tell you now it's not air tight. Underbelly is "sealed" but not air or water tight, although water would have a hard time getting up there. And there are holes in the floor for utilities going up and down from trailer to the "basement" area.

Folks on here know that most water leaks come from places far from where the damage is observed. Look at any and all joints and redo anything that is suspect. If in doubt, a pressure test is worthwhile. Of course there will be leaks out the bottom, but you would be looking elsewhere. If it were me, I would pull that water heater, check it, and redo the installation. Often the water heater area is not sealed at all.

[92DakotaHD]

donn0128 wrote:
Pay to have it seal tested.

The whole trailer? I can tell you now it's not air tight. Underbelly is "sealed" but not air or water tight, although water would have a hard time getting up there. And there are holes in the floor for utilities going up and down from trailer to the "basement" area.

[westend]

donn0128 wrote:
Pay to have it seal tested.

Yup, a pressurized interior test is the best for finding any leaks. I DIY it with a furnace blower. I should do a test this year just in case something has opened.