Recaulking roof seams

[Frankg1]

I understand roof caulking should be re-done every year or two. Should the old caulking be completely removed or is new caulking applied over the old? What caulking is recommende?

[palehorse89]

Originally Posted by Frankg1

I understand roof caulking should be re-done every year or two. Should the old caulking be completely removed or is new caulking applied over the old? What caulking is recommende?

Hello and

Use the google search bar at the top of the page and type in "Eternabond Tape" and you will find a lot of reading with some photo's ............It is a space age tape, and will last for a long time. I did mine last year............Amazon is the cheapest place I found to buy it. Roof/seam prep is the most important step in applying it.
I do not worry about my roof seams no more...........
Here is a picture of my roof seam........

[RayChez1]

X2 on Eternabond. Caulking should be checked at least once a year. And NO you do not have to remove it. If you see a crack on the caulking, just buy a small can of lacquer thinner, wet the cloth to clean the grime off the old caulking. Then apply some Dicor self leveling over the cracked caulking. This is a lot of work, but that is the way to do it.

But as you get older, it is dangerous climbing on top of a coach. So it is best to Eternabond the seams from one end to the other and you never have to worry about leaks or cracking of caulking. You can get Eternabond through Amazon.

[marjoa]

Originally Posted by Frankg1

I understand roof caulking should be re-done every year or two. Should the old caulking be completely removed or is new caulking applied over the old? What caulking is recommende?

I could give you a simple answer here like, ("no you don't have to remove all the material") but I'm going to go into a lot of detail here not just for you but I know a lot of other folks ask this same question and what the process is, so for their sakes as well, Ill go into great detail here.

I don't know what type of MH, year or roof you have, but I'll address the proper way to do this for a Fiberglass roof like ours which is on a Winnie. I just did our complete roof about 4 months ago.

This is one of the most neglected maintenance items owners ignore and can cause serious damage so kudos to you for wanting to address it. It's not that you have to redo it every year or two, it's that you need to inspect it about every 6 months to a year. This recaulking process—is done regularly—not to just make sure it's sealed so it does leak but more importantly to STRENGTHEN AND BOND that area. There are several posts on this forum where this maintenance item was ignored and a lot of bad things happened. You must caulk not only the roof side to gutter area—but also the front and rear cap top and sides. Now this caulking is NOT just for the roof—look at your particular MH callout sheet—for many other areas of the coach that needs the same material applied. But since you're addressing the roof in your post, I'm only going to talk about this area. Now when I inspected our 4yr. old MH right after purchasing it, there were several areas where that caulking had either cracked, started to crack, dried out and contracted, creating some small gaps etc. These gaps ranged from maybe a 1/4" to maybe a foot or more all along that roof edge. It was obvious that this whole area needed to be be redone. I decided for—many reasons—to take this process several steps further to completely redo my entire fiberglass roof. (you can read & see the roof details here)
http://www.irv2.com/forums/f258/fina...ne-316925.html

FIRST, regardless what anyone tells you, DO NOT use silicone. The adhesive that Winnie calls for on their callout sheet (Sealant C) specifies is no longer available. The replacement product is NuFlex 640 (Clear) which is a Thermoplastic Sealant. These areas are not only to be sealed—but as I said before—they are to be strengthened and bonded. That's why you need to use the right stuff.

So to prepare the gutter seam area I used several tools:
• a tooth brush
• a standard 1" metal putty knife
• a small sharp digging tool
• air compressor with a blow out nozzle
• spray bottle with reg. rubbing alcohol
• a good caulking gun
• NuFlex 640 (Clear)

You don't have to remove all the old material, (because you'll find that some of the old material is still bonded. But as I said you will find some old caulking that has dried out and has become flaky and that does need to come out as you dig, scrap and so forth. You DO want to remove these areas as best as possible, blow out loose debris with an air hose, then spray liberally with the alcohol and wipe down with a rag so that area is as clean as possible so the new stuff will adhere properly.

Once area is prepped properly, apply the NuFlex 640 (Clear) with a good caulk gun, spray your fingers with some more alcohol and as you slide your fingers along the new caulking your also "pushing" the new caulking down into those fine old cracked areas and then leaving a nice smooth bead. I had to buy several tubes of NuFlex 640 (Clear) to do all the areas required on my MH, and it was tough to find but trust me the cheapest place to find it is at rvautoparts.com, Part# 96600 and no minimum. I ordered 6 tubes of clear. They shipped 3 white & 3 clear. The tubes on the outside looked exactly same and there was no mention of the color and the numbers on the tubes were exactly the same too. The only way you could tell the difference was to turn the tubes over and look at the end of the tube itself. One was white & one was clear. I called them and brought this to their attention. They sent me replacement tubes. So be sure to tell them to look at the ends and send you CLEAR.

So now that the job is complete, you've prepped the roof correctly, applied the right material, now about every 6 months or so, just get up there and check it the entire seam and roof caps. If you see a couple of areas that need tending to, clean properly again, apply new product to just those areas and DONE. Maintaining your roof this way will prevent bigger problems down the road.

Here's a picture of my roof I took last week, after redoing last year.

[RayChez1]

Martin, got a question for you. The picture of your motor home roof looks like it is rubber roof. I do not see any seams at all. Where are the seams you are talking about?

[f14av8r]

There is an INCREDIBLE amount of conflicting information out there on the subject of which type of sealant to use. Watch this video, especially if you own a Winnebago motorhome - https://youtu.be/BJz7doxPQXg

I avoided silicone for years until I saw this video. These guys are the experts. I've used it ever since for my the roof cove on my Journey. You have to get the right stuff though. Siding and Gutter silicone is the secret. It goes on easy, stays flexible, and is much easier to remove than the acrylic stuff. Again, watch the video.

[marjoa]

Comments to my post above:
Good video and was enlightening about the difference of what to use depending on whether you have full body paint (FBP) or not. I'm going to add this information in any future post I make concerning this topic.

Now my MH does not have FBP and the video recommended Manus-Bond Urethane Sealant which is pretty much the same thing as the NuFlex 640 or very close to it when you read the description of ingredients, it's properties, how it behaves and what it does. The NuFlex 640 is very flexible and bonds very well too. The way I got to know about Nuflex 640 was when I was researching this topic, I read I believe it was on Winnebagos website (I think it was either in the service or parts area) that the sealant that was to be used on the callout sheet was no longer available. There was a company in Canada that still sold it but was very difficult to get and very expensive, like $24/tube or something like that. Through more research the NuFlex 640 was recommended as equal substitute and way, way cheaper and readily available here in the US.

Now I will say, that in that video, they said to remove all the old factory sealant. I think they were saying this just to cover their rear end, and here's why. My MH which again does not have FBP, was only 4yrs. old and had the factory sealant used. There was NO WAY you were going to remove all that old sealant. According to their video then, that sealant must of been Manus-Bond. I built a scaffold all along the length on my MH to tackle all the roof work I was going to do, so I could have easy access and a birds-eye-view to my entire roof to do a thorough job and I can tell you from experience, the areas that were starting to crack or dry out and starting to pull away some...yes...I could dig down in there and remove most of that old stuff. But in the areas that were still bonded which was probably 60% - 70% maybe more, you couldn't chisel that stuff out of there it was so bonded and hard to the gutter and the roof cove. It obviously was still sealed and bonded in those areas. And like I said above, I dug and scrapped out what I could, cleaned thoroughly, pushed back the fiberglass when I could and then caulked and push it down inside that seam. I'm confident beyond any doubt that my seams are good. Now with Full Body Paint and the factory Silicone material they talked about, I have no experience with that product.

Also, later on in the video...if you don't want the accumulation of dirt and debris around screws and seams around vents like in their example a shower skylight, apply the self leveling sealant evenly around the whole entire fixture, screws and all. Here's a picture but not a real good one.

[f14av8r]

I use 3M Caulk Remover to soften sealants for removal and to clean up any remaining debris. Works great. Here's a link - http://a.co/4vDF9YW

[-Gramps-]

Originally Posted by palehorse89

Hello and

Use the google search bar at the top of the page and type in "Eternabond Tape" and you will find a lot of reading with some photo's ............It is a space age tape, and will last for a long time. I did mine last year............Amazon is the cheapest place I found to buy it. Roof/seam prep is the most important step in applying it.
I do not worry about my roof seams no more...........
Here is a picture of my roof seam........

This looks great. I want to do the same thing on my roof seams and around all the skylights. Did you apply the tape over the existing chaulk?

[gtsum2]

^^. I agree. That looks easier and likely last longer, vs using Dixie sealant right? If so, I'm tempted to get some and do every seen on the roof and call it good

[-Gramps-]

Originally Posted by gtsum2

^^. I agree. That looks easier and likely last longer, vs using Dixie sealant right? If so, I'm tempted to get some and do every seen on the roof and call it good

I learned that you have to use a heavy roller (and they sell one) to apply it or it may curl along the edges. Then you have to apply a bead of caulk to hold it down. The HR guys applied it to my roof a bit fast I guess, I had to repair some spots around the big skylight over our bedroom right after I got the coach in 08. Now I want to apply Erternabond correctly over all my seams.

[palehorse89]

Originally Posted by -Gramps-

This looks great. I want to do the same thing on my roof seams and around all the skylights. Did you apply the tape over the existing chaulk?

Yes, I followed Eternabonds instructions to a tee.........and went right over the old caulk........removing any big lumps for a better finish when the Eternabond was applied. There is no need to re-caulk before applying Eternabond, unless you have a low point that you would like to fill in before hand.............
Water is not getting under this product........and if it does...........the surface was not prep'ed correctly.............
The surface cleaning and preparation is the most important factor before applying the Eternabond!

[marjoa]

Originally Posted by -Gramps-

I learned that you have to use a heavy roller (and they sell one) to apply it or it may curl along the edges. Then you have to apply a bead of caulk to hold it down. The HR guys applied it to my roof a bit fast I guess, I had to repair some spots around the big skylight over our bedroom right after I got the coach in 08. Now I want to apply Erternabond correctly over all my seams.

Yeah, I believe what gramps is saying here by "use a heavy roller" is when you lay down the Eternabond tape you have to use a small heavy metal hand roller and vigorously roll it back & forth over the tape. That rolling motion creates friction & heat creating a chemical reaction in the adhesive on the tape to actually make it adhere to the surface. Something like this:
https://www.walmart.com/ip/ETERNABOND-EBR125-Steel-Roller-Applicator/44048662?wmlspartner=wlpa&selectedSellerId=1148&ad id=22222222227031893187&wl0=&wl1=g&wl2=c&wl3=61129 989536&wl4=aud-273067695102la-51333671527&wl5=9027658&wl6=&wl7=&wl8=&wl9=pla&wl1 0=112562587&wl11=online&wl12=44048662&wl13=&veh=se m

[palehorse89]

Originally Posted by marjoa

Yeah what gramps is saying here by "use a heavy roller" is when you lay down the Eternabond tape you have to use a small heavy metal hand roller and vigorously roll it back & forth over the tape. That rolling motion creates friction & heat creating a chemical reaction in the adhesive on the tape to actually make it adhere to the surface. Something like this:
https://www.walmart.com/ip/ETERNABON...&wl13=&veh=sem

I tried the roller thing.........due to the un even surface at times, I just put a pair of cotton work gloves on and rubbed the hell out of it. The gloves slid right across the smooth/slippery surface of the Eternabond tape..............and heated it up. Worked for me........