Leak… just after solar installation

[Dennis C]

Our Airstream has never shown any noticeable signs of leaking until the last big rain storm that we experienced. Interestingly, we had two new solar panels installed by our local dealer just prior to that experience. I washed the Airstream today, and I noticed that the caulking around the new installation is piss poor at best. I need to caulk/re-caulk this installation.

What caulk should I use? I assume that I should remove all old caulk, but is this true? Can I caulk over the existing bad caulk job?

Thanks for any comments or recommendations.

[Dennis C]

Sikaflex? Adseal? Is one better than the other?

[OrangeCrush]

Yikes Dennis, sorry to hear that.

I just went through the sealant plethora installing some new Maxxfans. I am going to assume since you have a leak then they are screwed down. In that case I would suggest Sikaflex 715 self leveling as it has some nice attributes that came in handy for me yesterday (can take rain in only 1 hour). I got it same day delivery from Amazon. Below is a selection guide that had some technical information I found useful. They carefully point out you must completely remove old sealant before apply Sikaflex 715. I found this to be the most difficult part and used an oscillating tool with flexible blade and citrus dissolve with a plastic scraper to complete followed by alcohol prep. If they used Dicor 501 and you don't want to completely remove then you might stick with that which I saw on the shelf at Camping World. Good luck!

https://askthervengineer.com/my-favo...y-amazon-list/

[Dennis C]

Unfortunately I don’t know what they used. It looks like white caulk, and that’s all I know. The solar panel feet are screwed into the roof, and they have a rubber gasket between the foot and the roof. A few of the feet look to be sealed properly. One has no caulk at all, and a few have a dollop of caulk on top of the foot, not contacting the roof at all. Thanks for the suggestions.

[OrangeCrush]

Definitely sounds like shoddy work. When you say local dealer without naming names I can guess who that is. I have heard they have gone downhill since Will left. If you want someone to fix it for you I can highly recommend Master Tech RV repair in Henderson. He deals almost exclusively with Airstreams. Otherwise you might post a pic and maybe some of us can speculate on what sealant they used but it would just be a guess. I would think that even if there is a rubber gasket between the foot and roof standard practice would be to seal everything including the screw heads and 1/2 inch or so onto the roof with something like Dicor. I know this sounds hokey but you could just put some duct tape around them to provide a temporary seal until you find out what was used.

[Dennis C]

I may just remove whatever they used and start over. That’s probably the best course of action. The other two panels were installed by Airstream of Chicago when we bought the trailer new. They did a proper installation and caulking job and we haven’t experienced any leaks there. I’ll use that as my guide.

[DaveP]

Are you sure it is leaking from the feet? They may have popped a seam moving around on the roof. Just a thought.

[Tim A.]

I would remove all of the existing caulk. It will only get in the way of a proper seal. Sikaflex caulk of almost any variety will work and 3M makes a good urethane marine-grade caulk, too. After removing the old caulk and before recaulking, I would treat each screw penetration of the roof with Captain Tolley's Creeping Crack Cure (Amazon has it).

If the dealer made a rivet leak, Captain Tolley's works well for those leaks, too.

Tim

[Dennis C]

Originally Posted by DaveP

Are you sure it is leaking from the feet? They may have popped a seam moving around on the roof. Just a thought.

I’m not sure. I looked around and the poor caulking was the only thing that I noticed.

[Hermes]

Although the dealer seems to have perforated the roof with screws, the technique used for non perforated roof installations could be of use here.

If your Sikaflex exceeds the foot surface by a 1/2" all around (I made a little wall 1/4" high with 1/4" x 1/4" foam weather stripping around each foot to keep the 1/4" thick of Sikaflex 221 cleanly in place), it will act as a very good additional adhesive to the screws (or to the 3M VHB tape for non perforated installations).

After reading about professional installers like Lou Webster who have installed many hundreds of panels with 3M VHB tape + Sikaflex 221 over the years without a single one flying off, that convinced me, in addition to my abhorrence to drilling holes in my AS roof. My install is 4 years old and still rock solid.