Need opinions about recaulking roof

[shelbyj]

I noticed that the caulking on the roof is starting to crack and has a few spots on the ends that has started to pull up. Wondering if I should just caulk over the old stuff (after properly prepping) or remove the old stuff amd start fresh.

[LarryJM]

shelbyj wrote:
I noticed that the caulking on the roof is starting to crack and has a few spots on the ends that has started to pull up. Wondering if I should just caulk over the old stuff (after properly prepping) or remove the old stuff amd start fresh.

I know a lot of folks say clean good and just add more, but IMO you will never get a clean surface down inside those cracks and thus will not have good adhesion there. Not positive what the actual caulk manufacturer's recommend re: existing caulking, but in general I believe then sealing a new fixture they want the caulk to go well onto the actual roof material so one could extend that to mean you would need to TOTALLY ENTOMB the existing caulk and then go somewhat onto virgin roof material to get a good new sealing job. All this is one reason I'm in the camp of REMOVE IT ALL and go the ETERNABOND route ONE TIME and FORGET ABOUT IT.

Larry

[FrankShore]

I'd prep the areas really well and wait for a sunny day (you're in WA) and re-caulk using Dicor Self Leveling Lap Sealant. The prep job is really important. I'd use mineral spirits and a good roughish bath rag (smaller than a hand towel) - prep the area, let it dry out really well, then caulk.

[darsben]

I tried going over the old stuff when I developed a leak. I just spent today removing the old and the new as the leak persisted. I think the water trapped under the old caulk was evaporating in the hot sun causing areas to not adhere correctly.
Today I removed all caulking and dried area thoroughly. Then I recaulked the area all fresh caulk. To early to tell if this will stop the leak.
While I own a MH and not a TT the principle is the same