Silicone sealing roof trim on 2016 Flagstaff HW27SC

[EBW83]

I'm chasing some roof leaks on our HW27SC. I had success earlier this year sealing around the power vent using GE Supreme Silicone. The most recent leak is at the front part of the roof. The clear sealant between white roof and black edge and corner trim seems to be the culprit. I've cleaned and re-caulked those areas.

While sealing, I noticed that the factory sealant between roof and black side rail/trim did not extend from front to back. From front, it goes about 3 feet then stops. Same in back. So there is a center section about 8 feet long on each side where there was no sealant. Is there a good engineering reason for this or can I seal up that area too? The attached picture shows one side of my roof. The area between blue tape and blue tape roll was not sealed while the back and front ends were.

[dannyabear]

NEVER use silicone sealer on a camper; now, the correct sealant will not work

[rapidly]

what is the correct sealant?

[GalsofEscape]

Dicor or Geocel Pro Flex RV sealant, but i have used Eternabond tape instead. Once down, it does not come up.

[flyerdp]

Originally Posted by rapidly

what is the correct sealant?

Ok so here is a long story for you to get to the point.

Firstly, the sealant on each end only runs so far because of what I will explain next with the trim. The visible sealant is only there to cover the end caps on the 4 corners.

Under that metal trim piece is supposed to be that putty like "dicor" stuff like this:

https://tinyurl.com/474prrts

Sadly, the manufacturer uses JUNK there. It dries up and hardens and doesn't do its job then.

My camper had a gap in the black "dicor" like sealant that let water in. I hate to be the bearer of bad news but the geniuses who design these things used chipboard for the roof side panels. Guess what happens to chipboard when water infiltrates? What's worse is the side panel perimeter edges are raw, exposed with no seal of any kind so its like a sponge just waiting for water to soak up. I just replaced that side panel at the cost of about $70 per panel and almost $300 to ship. Rest assured when I replaced that panel I put sealant all around the perimeter to prevent water infiltration again!

How can you tell if your side panel is bad? Walk front to back knocking and pressing and looking carefully. If the knock suddenly sounds different or if the panel pushes in at some point or if it looks "wavy" in an area yours is likely in bad shape. When I got the panel off about a 4 foot section of chipboard just dropped out of it from between the outer metal and inner plastic skins and then it turned in to a noodle there and just buckled. That side panel is what holds your roof up/on.

Save yourself from a big headache and ALWAYS make sure its sealed front to back. I second the Pro Flex:

https://tinyurl.com/5fc7m59s

Pro Tip: Use painters tape to define the area you are sealing both on the roof and trim piece (and to protect where you don't want sealant). Once a bead is applied use a cup of soapy water (not too many suds) and dip a finger in it and you can press/shape the bead without it sticking to your finger. Peel the tape off before it has time to harden and beware there will be sealant on that tape and anything else the tape comes in to contact as you remove it

Oh and yes, seal front to back all along that trim pieces edge don't just stop where the factory did to make up for their inferior sealant under the trim piece.

[Lincman983]

Here is what is used on the roof and cap joints 1021 self leveling sealant

[5picker]

Do not use Silicone.
Alpha 1021. Comes in many colors.