Tech help Roof caulk application

fifelife · 06-16-2021, 06:16 PM

Greetings, I'm posting my first question. I require an application confirmation on my 2018 minnie Winnie C 31k. I'm posting a pic to show a caulk job lh/rh corners front cap to top interface. I discovered moisture weeping into the overhead bunk in the corners. I' think it's creating a dam. This was performed by a certified service center.Please review and reply. Thank you!!

Morich · 06-16-2021, 07:22 PM

No big fan of caulking and find it is tricky to find leaks but just my thoughts here.

I would have done thins different in a couple ways if what I see is correct. One is the obvious spot that is not sealed and the other is the combo of what appears to be just plain clear silicone caulk.
Silicone is famous for being hard to rework as new will not stick to old, so it requires a really good removal and scrubbing to get even traces of silicone off before trying to go with any other caulk, even new silicone.

First guess would be that there is a leak where there is no caulk or a leak between the old that looks like some form of a "Dicor" type self leveling caulk and the new which I'm guessing is silicone.

Since this is on the roof where appearance is not the prime idea, my move might be to remove all the clear and scrub the area really good with denatured alcohol and then go back with Dicor over all of it as new Dicor will stick to old.

Expensive stuff but lots cheaper than rotten interior! One ad that caught my eye, but available lots of places.
https://thervpartshouse.com/products...xoCj-MQAvD_BwE

Wyatt · 06-16-2021, 08:16 PM

I agree with Morich, it’s hard to get two dissimilar sealants to meld together seamlessly. And the circle in red, is also particularly troubling…

imnprsd · 06-16-2021, 09:22 PM

I would leave the black Dicor if it is still sealing.

* Use mineral spirits to lift the old silicon.

* Use a high quality silicon where you see a seam.

Note: Silicon will offer the best UV resistance.

If you have a Winnebago roof radius you need to re-glue, the cleaning process is the same, but you will want to use Geocell "Proflex" Clear instead of Silicon because you need need some bonding strength and flexibility.

Then I discovered this tip last month:

* Let the Proflex cure for at least 1 month.

* Then tape the roof lines and use a brush to apply Flex Seal Clear (out of the can) over the Proflex. This will add a rubber UV protection layer that should help your Proflex last 2x-4x as long. TBD. Ask me in 3 years and I will let you know if it works.

Preliminary results look real good!

Note: The problem with putting silicon on top of the Proflex has to do with an unfavorable chemical reaction between the silicon and the Proflex clear, which is a hybrid polyurethane sealant.

Twpinaz · 06-16-2021, 10:23 PM

After the first year inspected roof end caps and had missing dicor. I cleaned roof and applied self leveling dicor. After cured applied 4” Eternabond tape both end caps and 2” Eternabond tape down each roof side and any penetrations. After application rolled with roller to activate adhesion (butyl tape). This was 2 Yrs ago and recently inspected roof and looks good. Didn’t want the annual maintenance or risk any roof leaks. Prep was a pain, but using tall platform ladder was able to complete over a weekend. Due to dry times.

fifelife · 06-17-2021, 05:13 AM

Thank you for the reply, I agree, dissimilar materials, not good. And the gap with no sealant is trouble.

**creativepart** · 06-17-2021, 07:22 AM

Quote:

Originally Posted by imnprsd

* Then tape the roof lines and use a brush to apply Flex Seal Clear (out of the can) over the Proflex. This will add a rubber UV protection layer that should help your Proflex last 2x-4x as long. TBD. Ask me in 3 years and I will let you know if it works.

It should be noted that the above step in this quote is not a usual, proven or normal step in roof sealing but something this member came up with and is just now testing. As he says, check back in three years before he’ll know if this helps or not.

Morich · 06-17-2021, 07:44 AM

The problems with silicone is one that gets real attention when dealing with fish aquariums where it is pretty common to want to seal what seems like "just a small leak" but requires almost total teardown to actually stop the leak. The silicone is not a bad caulk but it does require lots more work if you need to touch it up at some point as you can't just go in and add a dab over the old.

In this case, it seems a real shame that they went to all the effort to seal so much but then stopped an inch or so short of finishing! Now getting the silicone cleaned and adding other is so much more trouble.

DryCreek · 06-23-2021, 05:40 PM

Quote:

Originally Posted by creativepart

It should be noted that the above step in this quote is not a usual, proven or normal step in roof sealing but something this member came up with and is just now testing. As he says, check back in three years before he’ll know if this helps or not.

And it should also be mentioned that some of the roof radius seams need Manus Bond per the factory sealant callout sheets.

jabass · 06-23-2021, 06:29 PM

I agree that eternabond tape placed over the caulking (after proper prep of surface) will give you peace of mind for many years to come.

BobC · 06-23-2021, 07:19 PM

As a former sailboat owner, it always amazes me that RVs have so much sealant glopped on their roofs. I was shocked when I first saw this on my first TT. And, glopping more on an old glop is a waste of time and money. You'd never see this on a boat deck or cabin top and boats are exposed to much harsher conditions and fittings like cleats are subjected to stresses that an RV fitting will never experience.

I suppose it's cheaper this way and RV roofs are pretty much out of sight. On boats, the sealant is under the fitting and in the screw holes, with a little along the edge, with nothing on top. What's the point of 1/2" of sealant extending 2" over the top of a vent flange, solid plastic doesn't leak?

At 74, I realize my DIY roof repair days are limited (or, according to my wife, are over) so I want to minimize my need to re-seal my roof. Since I don't want to remove and re-bed all my fittings on my MH, I've taken a middle ground approach. I've removed all the globs, cleaned everything carefully and applied a relatively small bead overlapping the edge of the fitting using the sealant specified in Winnebago's sealant call-out sheet. After it's cured, I've used Eternabond tape for a final barrier. I'm four years into this and, so far, so good, including a roof vent and skylight replacement.

imnprsd · 06-23-2021, 11:41 PM

creativepart: Why do you do stuff like that?

It's clear you have a problem with me trying to help other people; and I wish you would back off.

"Proven." What is "proven" when it comes to roof sealants. Over 20 years Winnebago has changed suppliers and does not like to give definitive answers when it comes to recommending roof sealants.

And I feel qualified to say this because I paid Winnebago over $35,000 to replace my roof in 2018. And believe me I grilled those techs when it came to roof sealants.

I have also use Eternabond and very much like this option, but I don't like the looks of that 2" black tape -- running down my roof radius.

As for Mantus Bond being on Winnebago's "Call Out Sheet" that depends on which year they printed those sheets, which has since changed many of times.

Here's my testimonial: If you are looking for a clear sealant, so your pretty painted roof radius can look natural, then I recommend the the newest hybrid sealant called GeoCell "ProFlex" Clear... and I'm adding that if you paint over this stuff with Flex Glue Clear, liquid rubber sealant, out of the can, that you might not need to redo your roof sealant for years to come.

Note: Winnebago put their recommended sealant on my roof in 2018. I store my RV in a Pole Barn so it does not get sun 8 months out of the year.

That mean ~16 month my RV roof gets no sun and 8 months it gets full sun.

...So, in just 2 years, my roof radius sealant was cracked and compromized, and needed to be replaced. So, IMO, we need (us owners) to find a better mouse trap on our own.

What's your solution to achieve that goal? ...Is it to warn people off trying what I have proven to work for me up until this point?

You have no basis for doing that, especially since you are not an authority on this subject.

Now if you are a materials expert and can tell me/us how Flex Seal Clear chemically interacts (negatively) with GeoCell ProFlex Clear, then I'm listening!

FACT: For 20 years Winnebago has not stood behind their roof design and sealant recommendations; and at one time they were just inches from being sued in a class action, and us owners are left pretending Winnebago wouldn't do that to us... But oh yes, they did. So why would you poo-poo my efforts to find a better solution?

Or maybe you don't like the picture I posted?

Wyatt · 06-24-2021, 01:54 AM

As President Ronald Regan once said, “There you go again”

imnprsd · 06-24-2021, 04:51 PM

If nothing else it's entertaining. The point is to stop to the "cancel" and let people help one another. This website feels like another FB.

BobC · 06-24-2021, 05:12 PM

With respect to Winnebago's sealant call out sheets, they do change as time marches on. I check out the newer sheets to see what my options might be.

NeilV · 06-25-2021, 05:25 AM

Quote:

Originally Posted by DryCreek

And it should also be mentioned that some of the roof radius seams need Manus Bond per the factory sealant callout sheets.

Yes indeed! The application due to flexing, stress and long term maintenance requires a high quality Urethane Adhesive Sealant such as Manus Bond and not a silicone caulking. The silicone residue will be hard to completely remove afterwards and may for some time cause repeated failures of the correct adhesive sealant being applied afterwards. Silicone caulking can also cause EternaBond and other similar Butyl Rubber tapes to fail to adhere so silicone should never be used on a seam that you intend to cover with an EternaBond type product.

On the original issue while the dams created with the caulking caused pooling its the gaps not sealed nearby that caused the leaks. The tech who applied the sealants did a poor job apparently using incorrect products.

iezzif · 06-26-2021, 12:43 PM

Amen! Why can't we just compare notes and make decisions without negativity? Just state your opinion.

Twpinaz · 07-04-2021, 12:24 AM

Just a quick update but Eternabond tape does come in white and blends nicely if you have a white roof.

imnprsd · 07-05-2021, 07:22 PM

If my roof radius was white, I would not hesitate to use "white" Eternabond 2" tape -- just so I would never have to worry about my roof blowing off in the wind again.

I have used the "black" Eternabond tape on my dark green roof radius in the past, and it looks okay, but it's still looks like a band aid of sorts on dark green paint.

I know a lot of people don't look at the roof, but I'm picky and I do look at my roof radius when I look at my RV.

When Winnebago put a new roof on my 2004 Itasca Horizon 40AD in OCT-2018, I sure expected the glue they used to last more than 2 years, especially since I keep it stored out of the sun for 75% of the time, but to no avail. The glue they used cracked.

So now the glue du jour is called Geocell "Clear" Proflex and that's what I had put on in OCT-2020... and then the RV went into storage for 7 months.

Then I came up with the idea, what if I coated the Proflex with a clear, rubber coating to protect the Proflex from UV; and the best material for job I came up with was the Flex Glue "Clear" brush-on type. And I added that in MAY-2021.

So far it's showing no signs of wear, but only time will tell. And I'm amazed at how clear this brush-on Flex Glue Clear is! In fact, it's crystal clear!

What do you have to lose by trying this method of using both ProFlex & Flex Glue "Clear" out of the can?

...Nothing, but you may be able to get 4+ years between regluing your roof seams using this approach -- and that is what I am hoping for.

Note: If this does not work, then I will use "black" Eternabond tape, again, over my evergreen color roof radius.

fifelife · 10-31-2023, 08:30 AM

Update from my original post. The unthinkable happened and delamination occurred this past spring. The leakage had penetrated. The Michigan 4 seasons doesn't help. I shared pics with a local repair. w/o seeing it $5000 or more? ouchhhh!! I'm looking for some advise. I was thinking what about cutting out the cancer and add the window which is standard on the driver side?