My travail trailer front window is leaking around the frame, by the outside seal which is apparently compromised.Removing front windows is a pretty straight forward process... remove all screws from the inside frame, then push on the window while someone catch it from the outside. Okay.. fine then.. after you need to deep clean any trace of the old seal on RV exterior wall and window frame. I know the key is a proper surface prep for re-sealing. That's crystal clear for me.But any suggestion on the re-sealing process and right stuff to use? I saw some old videos on YouTube where people use some kind of putty tape that is applied directly on the RV exterior wall and then the window is pressed against it, but since my KZ trailer is made of rippled aluminium, I would expect something at his more "liquid" to follow curve and fill gap of rippled aluminium body, more like a caulk instead of a putty tape. So what should I use for re-sealing my front window? A specific brand of RV grade exterior wall caulk (not roof caulk as well) or any high quality residential window caulk such as GE window caulk?Thank you very much!!

Amazon link of what I used.This is what I used.

firemedic08 wrote:Amazon link of what I used.This is what I used.Thank you very much, but did your 5th wheel have fiberglass or rippled aluminium wall? Because I can't see how this thin butyl tape can fill the large gap between ripples when the actual seal (a black stuff) is at least two time thicker than this butyl tape? Do you put two layers of this tape?

I used it on a Rippled Aluminum sided Prowler camper, and a ripple sided Sunline TC, but Not my current 5th.

firemedic08 wrote:I used it on a Rippled Aluminum sided Prowler camper, and a ripple sided Sunline TC, but Not my current 5th. Wow, this is awesome! And just a single layer and that's it? You just screwed back the window (from the inside frame) in place and that's it?I assume the best place to make a single joint where the tape is beginning/finishing is on the middle-bottom of the window?Thanks again!

Yes, just one layer, and yes middle bottom is where I Started and Stopped. I can see the Argument Coming from some, for using Caulk on it after also, but I didn't do it. I had no more leaks from that window. It was leak free up to the day I got rid of it (both of them).

Fixing leaking front window (worn exterior seal)

13 Replies

Anonymous
May 06, 2017
I'd try a flex steel product
Fisherguy
Explorer
May 04, 2017
Chris Bryant wrote:
It all depends on the siding pattern- if the corrugations are too deep, I use 2 layers of butyl tape- I wind up wasting a lot, but it gives a good, water tight seal.
The main thing is to make sure you see some butyl squeeze out along the entire perimeter, then I trim with a plastic putty knife. The seal is the butyl, any caulk added is purely cosmetic, and not to actually seal the frame.
Be aware that the butyl will continue to squeeze out for a bit.

This is what I did when I rebuilt the front wall of our old Nomad.
vlopddap
Explorer
May 04, 2017
Mortimer Brewster wrote:
You might not have much access. My trailer had 1 inch of styrofoam sanchwiched between exterior and interior pieces of 1/8" luan board. If the separation is between the styrofoam and luan you could always drill a hole down into the styrofoam from above in order to get the sealant to the void. Then clamp. I'd be leery of using expandable foam as it might blow out the wall.

Well, if there really is a styrofoam somewhere in the front wall it's really not "sandwiched" because if I press anywhere on the wall with my hand (it's not a new behavior, it's the same since I purchase it brand new), the luan is moving very freely, that's why I was thinking the wall use fiberglass insulation or is just empty! I agree that the expandable foam need to be used carefully, but are you aware you can purchase a specific low-expansion foam which is intended for use in enclosed spaces? I agree that the traditional expansion foam would be very dangerous to use since it's strong enough to lift a concrete floor!

Thanks for your advices!
Mortimer_Brewst
Explorer II
May 04, 2017
You might not have much access. My trailer had 1 inch of styrofoam sanchwiched between exterior and interior pieces of 1/8" luan board. If the separation is between the styrofoam and luan you could always drill a hole down into the styrofoam from above in order to get the sealant to the void. Then clamp. I'd be leery of using expandable foam as it might blow out the wall.
vlopddap
Explorer
May 04, 2017
Mortimer Brewster wrote:
I had the same problem on my KZ. The window openings are oversized, the window being held in place with compression. This leaves a gap beneath the window. Over time the bouncing/vibrations of road travel take their toll, and the window shifts downward. This leads to small gaps on the top corners where water can intrude.
My solution was to shim the window up using some PVC trim that custom cut to fit. Be sure not to shim it so it's centered in the opening. This will prevent future sagging of the window. Nothing more than butyl tape is needed.
I would also inspect your other windows. If a window has sagged the butyl tape will leave a trace of it above the window. If you see this I'd go ahead and reset the window.

Thank you so much for this valuable information Mortimer! I would definitely check for any loose fit of the frame into the wall when I'll remove the window to fix the sealing and make the appropriate shimming.

I'll also check if I found some way to reinforce from the inside the very thin luan of the inside wall because when water spill around the window framing, it made a small "bubble" in the luan of about 3x3 inches and when it dried up completely the luan was cracked a little bit in the bubble and it's weird because it feels like if the wall is totally empty behind luan, like to isolation or nothing... so when I’ll remove the window I assume I'll have some kind of access to inside the wall and spray some expandable urethane behind the "bubble" to ensure if someone push on it it wont damage the wall...

For now the window is not leaking anymore because I made a quick "emergency" seal from outside the frame with RV caulk and it's 100% sealed for now. But now I need to make a more permanent fix to the seal. :-)

Thanks again for your advice!!
Chris_Bryant
Explorer II
May 04, 2017
It all depends on the siding pattern- if the corrugations are too deep, I use 2 layers of butyl tape- I wind up wasting a lot, but it gives a good, water tight seal.
The main thing is to make sure you see some butyl squeeze out along the entire perimeter, then I trim with a plastic putty knife. The seal is the butyl, any caulk added is purely cosmetic, and not to actually seal the frame.
Be aware that the butyl will continue to squeeze out for a bit.
Mortimer_Brewst
Explorer II
May 04, 2017
I had the same problem on my KZ. The window openings are oversized, the window being held in place with compression. This leaves a gap beneath the window. Over time the bouncing/vibrations of road travel take their toll, and the window shifts downward. This leads to small gaps on the top corners where water can intrude.
My solution was to shim the window up using some PVC trim that custom cut to fit. Be sure not to shim it so it's centered in the opening. This will prevent future sagging of the window. Nothing more than butyl tape is needed.
I would also inspect your other windows. If a window has sagged the butyl tape will leave a trace of it above the window. If you see this I'd go ahead and reset the window.
vlopddap
Explorer
May 03, 2017
firemedic08 wrote:
Yes, just one layer, and yes middle bottom is where I Started and Stopped. I can see the Argument Coming from some, for using Caulk on it after also, but I didn't do it. I had no more leaks from that window. It was leak free up to the day I got rid of it (both of them).

That's a good point! What I can still do is after installing the butyl tape, I can still apply a extra coat of a sealant around the exterior frame of the front window with RV grade wall caulk?
firemedic08
Explorer
May 03, 2017
Yes, just one layer, and yes middle bottom is where I Started and Stopped. I can see the Argument Coming from some, for using Caulk on it after also, but I didn't do it. I had no more leaks from that window. It was leak free up to the day I got rid of it (both of them).
vlopddap
Explorer
May 03, 2017
firemedic08 wrote:
I used it on a Rippled Aluminum sided Prowler camper,
and a ripple sided Sunline TC, but Not my current 5th.

Wow, this is awesome! And just a single layer and that's it? You just screwed back the window (from the inside frame) in place and that's it?

I assume the best place to make a single joint where the tape is beginning/finishing is on the middle-bottom of the window?

Thanks again!