Roof Sealant

[J.A.Casto]

I have a pop up with fiberglass (plastic) hardtop.  What is the best sealant to use to seal the edges where it meets the metal (aluminum) trim?  Noticed that the factory sealant has seperated leaving a noticable gap to where I am sure water will start to penetrate. 

[Jim Louiselle]

You will probably get more opinions on sealant than anything else.Every  sealant made keeps water out, for a while. If you are not talking about a roof treatment, but just caulking the seams at the edge, I would use basic lap sealant or even a vinyl based product like DAP or Phenoseal. You can use any product made to seal flashing or windows on your house. The key is prep the surface by scraping out the old sealant depending on what it looks like. I always wipe it down with de-natured alcohol  to make sure all soaps, wax or any other contaminates are gone. Regardless of what anyone or any web site tells you, there is no magic tube of anything that will forever seal your roof. You need to get up there and look at it a few times a year and maybe re-seal every year or two at the most or as it needs it. I personally would stay away from silicon. Even though it will last a little longer than water based products, it still will fail and it discolors, looks terrible and is a royal pain to remove.  Just my opinion, but I've scraped more of that silicon crap off of more roofs and windows than I care to think about.