roof reseal before the season, Dicor lap sealant or Eternabond tape?

in this sun, 18 months on a self leveling bead is normal. i tell my customers to get up there every six months, april and october, and touch up what is cracked rather than redo the whole roof every year. the whole roof is a march job when the sun is lower.

products. Dicor 501LSW is the self leveling one, horizontal surfaces only, vents, skylight, antenna base. it runs like honey so it fills its own cracks. on the front and rear cap seams that are sloped use the 551 non sag, the self leveling will just run off. before either one, scrape the loose stuff, wipe with denatured alcohol, let it dry, then a fresh bead over the old bead is fine, you do not need to get down to bare membrane.

Eternabond RoofSeal on the long cap seams, yes, on a rig that sits in the sun. 4 inch is the usual. clean the same way, roll it hard with a seam roller or you get bubbles, and never put it over silicone because it will not stick and neither will anything else after that. once it is down it stays for years. the one downside is that if somebody ever needs to get under it for a repair it comes off in pieces. for what you are describing i would tape the two cap seams and keep touching up the vents with the 501.

check what membrane you have before you buy anything, the Cedar Creeks of that era could be either. wipe a spot with a wet white rag. if the rag comes up with chalky white residue it is EPDM rubber. if it comes up clean and the surface is slick it is TPO. the sealants are fine on both but the cleaner is not, on EPDM you do not want a petroleum solvent anywhere near it. the alcohol is safe on either.

we do ours every fall before the trip, on the driveway in Winnipeg while it is still above freezing. Dicor and the Eternabond are on the shelf at the rv dealers here, about 26 dollars canadian a tube for the 501 and 90 something for a 25 foot roll of the 4 inch tape. the dealer fellow said the same as the tech, tape the seams, tube the fittings. we did the front cap seam with tape three years ago and it is still down flat.

the owner's manual for our Tiffin says inspect the roof sealants every three months and i will be honest, nobody does that. the Forest River manuals say something close to it, there is a copy on forestriverinc.com under owners. the point is the same one the tech made, look at it twice a year and you catch it before it is a ceiling stain. we learned that the expensive way in 2019.