Do some skylights have a frame underneath.

[153stars]

After 7 " of rain in 12hrs yesterday . My shower skylight shows some leaks. I had pumped some high quality gutter sealant in a gap/crack in sealant. that I had seen when I bought it 6 months ago.The lap sealant seemed to be good besides that cracked in sealant. The lexan seems to be a half inch plus higher than I would of expected it to be. That is where the crack gap was.Just want to know what to expect before repair. I've seen dicor for skylights is there better sealer I have fiberglass roof so rubber compatible sealant is not issue.

[grindstone01]

I would remove all the caulk around the skylight and replace it with new caulk.

[153stars]

I was thinking of using the black butyl sealer like windshields use under first. I've seen in with RV sealers online in round and flat.

[vito.a]

I've replaced skylights on two of our coaches. Monaco used gray butyl tape under the Lexan, but it was not applied properly on my coach.
Be careful with the sealant. You must use a non-petroleum based sealant or it will crack the Lexan. They recommend Surebond 140.
I also recommend stainless steel screws. When I replaced ours, I used two lenses, one over the other.
Here is a post I did on replacing the skylight.
http://www.irv2.com/forums/f115/inst...ht-392007.html

[153stars]

I think I may have read the thread. But the link won't work on my phone or if I copy and paste URL I get 404 error
Are you suggesting just 140 sealant under skylight and a lap bead at edge and no tape sealant under.