Mysterious Leak

preacher50 · 06-22-2019, 08:03 PM

I have a Jayco 174 SLX BH and the last couple of days there has been a wet spot on top of the mattress that has soaked through and gone all the way down to the wood below. The wood is wet too. I opened the bed frame up and looked below it and it is dry everywhere. There is no sign of leaking in the roof above at all either. I cannot seem to find out where the wet spot is coming from. Has anyone else ever experienced this?

First time RV owner and trying to learn the ropes! Thanks for any help you can give!

oldmanAZ · 06-22-2019, 08:27 PM

Welcome to the forum.

I can't help, but I have a few questions:
- What year is your TT?
- Which mattress is wet?
- Have you camped in this unit before?
- Were you camping in the rain?
- Were you running the air cond? Is the wet mattress directly under the air cond or an air cond vent?

preacher50 · 06-22-2019, 08:32 PM

-2018
-The queen size mattress up front in the RV
-Have not camped yet. Parked in my driveway trying to learn everything.
-Not camped but it has rained sitting in my driveway. But also has been sitting before in the rain and not had this wet spot.
-Have run the air cond both times. But the air conditioner sits way back from the bed.
-Thanks!

tott9713 · 06-23-2019, 04:47 AM

Which side of the bed is leaking? The AC + window side or the other side?

I pulled some photos of this trailer. In my leak battle experience with my aluminum starcraft I have learned a lot. Here are the failure points i’ve discovered.

The foam seals used for the windows suck and don’t conform well to the ribbed siding. Check both windows and reseal with proflex.

The corner molding works loose and allows water in. Pull the center plastic trim insert and make sure all screws are tight and reseal edges of corner trim with proflex or white OSI quad.

Not too familiar with how those AC units seal in the wall but double check that.

The front roof edge where it meets the front cap especially on the ends. Even an ever so small crack in the sealant can let lots of water in.

I’m here for more questions if needed. Been there and know the awful feeling of having an unsolved leak.

preacher50 · 06-23-2019, 06:09 AM

It is the side of the bed that is under the big front window. I checked all around the window and I cannot see any evidence of leaking but that is the closest place for the water to come in. The AC is a roof mount and is farther back from the bed towards the middle of the camper.

preacher50 · 06-23-2019, 06:23 AM

Quote:

Originally Posted by tott9713

Which side of the bed is leaking? The AC + window side or the other side?

I pulled some photos of this trailer. In my leak battle experience with my aluminum starcraft I have learned a lot. Here are the failure points i’ve discovered.

The foam seals used for the windows suck and don’t conform well to the ribbed siding. Check both windows and reseal with proflex.

The corner molding works loose and allows water in. Pull the center plastic trim insert and make sure all screws are tight and reseal edges of corner trim with proflex or white OSI quad.

Not too familiar with how those AC units seal in the wall but double check that.

The front roof edge where it meets the front cap especially on the ends. Even an ever so small crack in the sealant can let lots of water in.

I’m here for more questions if needed. Been there and know the awful feeling of having an unsolved leak.

There is no evidence of all from a water trail as to where the water is even coming from.

Learner · 06-23-2019, 06:47 AM

Hello Preacher:

We previously had a 154bh. It hd multiple leaks when brand new. A major one was that front window.

I am curious: what exactly is directly above the wet spot? And is the spot just an area in the middle of the mattress, or does it run all the way to the side of the mattress?

preacher50 · 06-23-2019, 06:53 AM

They spot is a ways away from that front window more toward the middle of the mattress. From the way the spot looks, there doesn’t seem to be any way that the water could just drop down from the window into this spot because it’s not right below the window. And there is no evidence of a water trail right above the spot either where the upper storage cabinets are. Puzzling!

Learner · 06-23-2019, 07:18 AM

Quote:

Originally Posted by preacher50

They spot is a ways away from that front window more toward the middle of the mattress. From the way the spot looks, there doesn’t seem to be any way that the water could just drop down from the window into this spot because it’s not right below the window. And there is no evidence of a water trail right above the spot either where the upper storage cabinets are. Puzzling!

So is there a puck light, speaker, or fire alarm directly above the wet spot? Those are the items that I see, in the 360° view on Jayco's website, which could be spots for water to drop straight down.

**norty1** · 06-23-2019, 07:21 AM

I have had good luck finding leaks by laying an old shower curtain over the bed and covering it with clean paper towels. Let it sit thru a rain event and look for a drop of water which will be very evident on that dry paper.

We have done it successfully several times in our camper and even under a sink.

tott9713 · 06-23-2019, 07:22 AM

My bad on the AC the photo that came up googling that floor plan had a wall mount AC.

Any who, with my window leak there was zero evidence on the interior wall that it leak. I finally found out after the dampness within the wall corroded the aluminum. Once I pulled the window out it was very evident it leaked into the wall as the lower right corner 2x2s were stained and wet. The water then traveled down and soaked into the board that the taillight mounts to. Luckily I was able to rebuild everything from access in the outdoor kitchen.

When it comes to leaks, don’t ever think you have it figured out or rule out what may seem obvious because it just may not be. The siding corrosion in my case that started all this was referred to as galvanic corrosion and just a phenomenon that happens to aluminum by Jayco/Starcraft. It wasn’t until a second corrosion point appeared that I began exploring.

Do you have any pictures?

Learner · 06-23-2019, 07:32 AM

Quote:

Originally Posted by norty1

I have had good luck finding leaks by laying an old shower curtain over the bed and covering it with clean paper towels. Let it sit thru a rain event and look for a drop of water which will be very evident on that dry paper.

We have done it successfully several times in our camper and even under a sink.

Superb idea!

preacher50 · 06-23-2019, 07:32 AM

Quote:

Originally Posted by Learner

So is there a puck light, speaker, or fire alarm directly above the wet spot? Those are the items that I see, in the 360° view on Jayco's website, which could be spots for water to drop straight down.

Storage cabinet right above the spot. I will check on the light That is farther away from the spot. Thanks!

preacher50 · 06-23-2019, 07:39 AM

Quote:

Originally Posted by Learner

Superb idea!

That’s what we are doing now. We have removed the mattress and put a plastic shower curtain over the wood frame we will keep a check on it to see if we see a water leak. Thanks!

preacher50 · 06-23-2019, 07:42 AM

Quote:

Originally Posted by tott9713

My bad on the AC the photo that came up googling that floor plan had a wall mount AC.

Any who, with my window leak there was zero evidence on the interior wall that it leak. I finally found out after the dampness within the wall corroded the aluminum. Once I pulled the window out it was very evident it leaked into the wall as the lower right corner 2x2s were stained and wet. The water then traveled down and soaked into the board that the taillight mounts to. Luckily I was able to rebuild everything from access in the outdoor kitchen.

When it comes to leaks, don’t ever think you have it figured out or rule out what may seem obvious because it just may not be. The siding corrosion in my case that started all this was referred to as galvanic corrosion and just a phenomenon that happens to aluminum by Jayco/Starcraft. It wasn’t until a second corrosion point appeared that I began exploring.

Do you have any pictures?

I will re-check the window but the position of the spot on top of the mattress does not show any kind of water trail to wear it to get there from the window. It is just too far away. But I will re-check the window to make sure. I will send pictures later when I get time.

Learner · 06-23-2019, 11:12 AM

Something to check on is the bottom of that cabinet above the bed. Those cabinet bottoms are not solid. Rather, they are built from two pieces of thin plywood, the width of the bottom cabinet stiles apart.

In other words, the bottom of the cabinet is hollow. That's how they can mount a light on the bottom of it without the wires showing inside.

So if you have a leak on the front wall or ceiling of the trailer, that's running down the inside wall board behind the cabinet, it could run into a nail that is securing the cabinet, or the wiring for the light, and find its way in between the bottom layers, subsequently leaking out onto the mattress.

preacher50 · 06-23-2019, 02:47 PM

Quote:

Originally Posted by tott9713

My bad on the AC the photo that came up googling that floor plan had a wall mount AC.

Any who, with my window leak there was zero evidence on the interior wall that it leak. I finally found out after the dampness within the wall corroded the aluminum. Once I pulled the window out it was very evident it leaked into the wall as the lower right corner 2x2s were stained and wet. The water then traveled down and soaked into the board that the taillight mounts to. Luckily I was able to rebuild everything from access in the outdoor kitchen.

When it comes to leaks, don’t ever think you have it figured out or rule out what may seem obvious because it just may not be. The siding corrosion in my case that started all this was referred to as galvanic corrosion and just a phenomenon that happens to aluminum by Jayco/Starcraft. It wasn’t until a second corrosion point appeared that I began exploring.

Do you have any pictures?

Here is a pic with the mattress out. I have circled the place where it looks like the water just drops down. The closest place to this is the top left corner of the front window. I have stood outside for 30 minutes or more running a water hose over the front window to see if anything leaks and I see nothing.

tott9713 · 06-23-2019, 02:59 PM

With that photo...I’d bet hard money that either one of the two is happening:

the window is leaking in the lower left corner (picture view, lower right corner from the outside view)

or

the corner trim that bends down along the front cap is leaking. tighten the screws and proflex along the metal trim piece. (this leak point is very hard to pinpoint. the trim looks good however where the aluminum j channels link is the weak point)

preacher50 · 06-23-2019, 03:02 PM

Quote:

Originally Posted by tott9713

With that photo...I’d bet hard money that either one of the two is happening:

the window is leaking in the lower left corner (picture view, lower right corner from the outside view)

or

the corner trim that bends down along the front cap is leaking. tighten the screws and proflex along the metal trim piece. (this leak point is very hard to pinpoint. the trim looks good however where the aluminum j channels link is the weak point)

I will look at those areas and see if anything looks bad. Thanks!

ttavasc · 06-23-2019, 03:47 PM

Quote:

Originally Posted by tott9713

With that photo...I’d bet hard money that either one of the two is happening:

the window is leaking in the lower left corner (picture view, lower right corner from the outside view)

or

the corner trim that bends down along the front cap is leaking. tighten the screws and proflex along the metal trim piece. (this leak point is very hard to pinpoint. the trim looks good however where the aluminum j channels link is the weak point)

Something else to check for along the corner trims are gaps in the butyl tape - see image below. I had a similar issue with the front of my 195RB and this is ultimately where my problem was. Water would run along the bottom edge of the aluminum at the joint and even with just the slightest lean torwards the side the water would run into these gaps. It ultimately came out about the same place inside.

While I didn't pull my window completely I did caulk all the way around, replaced the foam weather strip on the rock guard because in several places it didn't even line up correctly, replaced the exterior glazing around the window, caulked both corner trim strips making sure to fill any holes as noted in the image below (there were 2 of them). I also forced a thin bead of caulk up each of the overlap joints between aluminum panels as a couple of the joints were a little loose and I would get a little bit of water inside after towing in heavy rain. To finish it off I also re-caulked around both front running lights. That was about 2 years ago and I've had no further trouble.

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