Sealer to use?

[Rondo]

Was up on the roof of the Monte yesterday and noticed a crack in the caulk up by the bedroom vent or where the second A/C goes! The crack was in the heavy caulk on top of the vent intallation. Besides cleaning it good before I reseal it is there anything else I need to do? Is there any specific caulk I should use? Looks like they used the regular white caulk like around the tubs and etc. Is this possible? If not the regular caulk what type should I use? Any help would be appreciated! Got to get the rig ready for Great Lakes Rallly!

[exav8tr]

Maybe the "self leveling kind" that is sold in the RV Stores. I got some to use on one of those venturi type exhaust vents that I need to install....

[Bill-N-Donna]

I would use a tube caulking called “dicor lap sealant.” 501 LSW Self-leveling Lap Sealant. I used this on my repairs for the roof. It is self leveling and when it sets up it makes a nice job. It is made to use with rubber roofs. I’m not sure if this repair was from the tube type or not but it looks about the same when it’s finished. I would definitely remove the old caulking first!

[Jolu]

I agree with Bill, Dicor 501 lap sealant is excellent. As Bill's photo shows it will self level and do a nice job. Works in the cracks also. I used it for my roof penetrations I made for the roof mounted dish and the screws. Another roof penetration I made for my WiFi antenna cable has been there for 1 1/2 years without any sign of need for attention.

[bruiser]

Good suggestions above. Always use caulking that is recommended for use on rubber roofs. Never use any caulking that is petroleum based as this will damage the roofing material.

[Art-n-Marge]

I used a self-leveling roof sealant (there are several brands) when I installed a new vent/fant in a prior rig. First I used a specific adhesive to install the vent/fan, then globbed on the sealant over the top of it. It came out great! It is especially made for rubber roofs and has the qualities of the similar caulk-looking stuff. But it is not caulk and do not use caulk because caulk does not have the proper qualities for rubber roofs according to the RV service guy who pointed me to the other stuff.

[KTManiac]

I have been having trouble finding the Dicor 501 self leveling in the Dove Gray color, which is what is on my roof. Everywhere that I have been to only has it in White and Ivory. Camping World has it on their Online Store, but the shipping is substantially more(IIRC double) than the tube of sealant, and the 2 CW stores near me don't stock it!

[jimcol]

If it is on the roof no one is going to see it. To avoid the shipping $'s I'd buy the available color.

[dsprik]

JC, I'm wondering if a major auto supply store might order it - minus shipping. Or there might be another RV supply dealer that would absorb the shipping charge.

I have some cracking going on on my 3 yr old Monty on the roof where the top of my ladder is anchored to the roof. I will eventually have to remove and re-caulk that area.

[Glenn and Lorraine]

Loads of good info above. I only have one comment to make and that is to re-inforce Bill's statement "I would definitely remove the old caulking first!" Removing the old sealant is very important. Otherwise all you are doing is sealing the old sealant which will continue to cause problems.

[TLightning]

Check the marine stores...lots of good products there that can take the harsh environment.