literally anything but dicor buytl caulk sag or non-sag or silicone. neither should be put on a rv ever.
If you watch even a few of these videos of brand new like not even a year old rv's you will quickly change your mind about dicor. Its no secret that rv's are made like total garbage
RV roof installHis famous line is dicor wants you to put more on the only one that puts more on is a MORON.
if you dig deep into dicors more industrial side of rv products even they are recommmending polyurethane extrusion for rv makers mostly on the framless window side. for a more positive longer lasting seal. similar to the windshield industry which very few of those leak or ever need to be replaced until you crack it. haha:)
silicon sticks to nothing. dicor shrinks and cracks and requires reapplication up to 2 times a year. Polyurethane is rated for 20-25 years is often cheaper more pliable and is also an adhesive. two good brands are chemlink m-1 and sikaflex 1a as well as many many others. these are applied to commercial roofing that doesn't need reapplication constantly and are subjected to the same forces of nature as an rv numero uno being sun damage.
caulks are not intended to "waterproof" anything just to keep the majority of the water from getting to the actual seal. rvs are made so terrible this is often the only line of defense in most places as there is nothing below the caulk except raw wood to rot.
So buy the best you possibly can and look into eternabond under corner seals or even dicor's seam seal tape for a first line and follow with polyurethane only as a 2nd line of defense.
If i had the chance to drive all the way to Georgia i'd be putting on a roof with these guys and having curbs built and everything heatwelded. Very high quality work. for now its sika, and chemlink.
