Caulking Rant

[BCam]

I came to RVs from boating and I'm amazed, or should I say appalled, by the way caulking is generally applied to RVs. On boats, it is used sparingly under the fitting. All excess is removed and, if done correctly, no (or very little) caulking or sealant is visible, just the nice clean fitting with a thin line of sealant between it and the deck and nice bright stainless steel screws.

In 25+ years of sailboat ownership, I seldom experienced leaky fittings when they were properly sealed. The roof of an RV is much less vulnerable than the deck of a sailboat and I can't think of anything on the roof of an RV that is subjected to the same degree of stress as are sailboat fittings.

On RVs it seems that the theory is that the more caulking or sealant the better and, if you're re-caulking something, just goop on 1/2" more rather than dealing with the cause of the leak. I've just spent 2 1/2 hours removing a broken and leaky skylight, including at least three layers of caulking, some of which were clearly incompatible.

This motorhome was a recent purchase and I was aware there were some issues to attend to on the roof but was assured by the seller that the skylight leak had been fixed. Our recent rains proved him to be less than truthful.

If something is going to leak, it will be between the mounting flange of the fixture and the roof or around the mounting screws. Gooping caulk 3/4" up the vertical side of a fixture isn't going to achieve anything. In some cases the multiple layers of caulking create places for water to accumulate and cracks for it to seep through.

Thanks for the opportunity to get this off my chest.

[CampDaven]

You got it right!
I removed and replaced it on my rig.

[BCam]

I just took a look at the underside of the mounting flange on the skylight I removed. There were several long 6" - 10" gaps where the caulking didn't adhere to the flange. Overall, I'd say that at least 1/3+ of the circumference of the skylight lacked a secure seal between it and my Itasca's fiberglass roof. No wonder it leaked. I don't know if this was a replacement skylight or the original. If original, Winnebago sure did a lousy job of mounting it.

My replacement skylight should be here sometime today. I will be interested to see what the mounting instructions say.

[grumpy0374]

I think you will find the biggest difference in how and how much caulk is used will lie with the construction method and the workers who are building these rigs.
Know what your talking about. Owned several smaller cuddy cabin sailboats years ago.
RV's are slapped togather on an assembly line by hourly workers. Many are seasonal or at best loyal workers who have to assemble as fast as possible.
Sailboats, and boats in general, must be watertight from day one, and I would venture to say they are assembled with alot more care, by workers who know what their doing. With the 3 that I owned over the years, never had a deck fitting, window, hatch leak from improperly applied caulk.
Just a matter of production policies. Fast assembly and sloppy workmenship is the norm for RV's. Also, quality of parts used in boats are way above what is used in the RV industry.
Grumpy

[keymastr]

Most new work on RVs looks better than what you describe. The problems come when someone who has not educated themselves on materials and methods gets up there to seal a leak that happened because they had ignored the caulking for way too long. Then they slather some silicone on it and when it leaks again they slather some more on ignoring the fact that nothing will stick to that previous layer of silicone.

So rather than spend the time to remove their mistake and seal it properly they sell it and complain to anyone who will listen about the shoddy roof on the RV they used to own.

[CampDaven]

BCam, give it up, fix it, move on.
Don't fight what is 100% futile.
Happy Trails

[FatChance]

The correct way to fix it is to remove the caulk, remove the skylight, reinstall it with new urethane. Then seal the edges and screws with a thin coat of Dicor self leveling, then cover with 4" Eternabond extending over the screws out to about 2"on the roof. Proper preparation, proper materials, proper installation. That will last for 10+ years.

[biggdave92]

I recently purchased a 2005 Gulfstream class c. First time RV owner. PO said no leaks. Spent a good 8 hours this weekend removing old caulk/silicone and resealing with geocel. Small leak over the cab still. Haven't found it yet. All I can think about while working on this RV is calling PO up and giving him an earful. People are so dishonest. Kitchen faucet leaks too. Lp leaks. Oh well. I'll chip away at it. If we enjoy it, I'll get rid of it and get one in better shape. Live and learn.

[Arizona]

I’ve replaced kitchen faucets in all my RV’s. Really cheap original equipment. Second new skylight in six years going on next week. Sealant was fine but plastic skylight is cracked again.

[ftodaro]

Just a few weeks ago, I totally striped and re sealed my MH roof. It too is fiberglass. It took me awhile to figure out what to do and what material to use. Winnebago uses silicone caulk on the original build. They recommend silicone on the reseal.

Subsequent owners over the years before I bought it, tried to reseal the silicone by covering it beyond the original silicone so that they would get a tight bond with the fiberglass.

If you get the picture, I assume they knew that you cannot caulk anything over silicone, as it will not stick so they needed to get to fresh fiberglass. So if they were covering a screw the size of a dime they would lay caulk the size of a quarter to do so.

As you can imagine i had a lot of caulk on my roof. I decided to do it the right way and stripped the entire roof of the silicone. If you have not removed silicone caulk it is the most difficult to work with, its vary hard to get that last bit of residue off the fiberglass.

This is my opinion only but i did not reapply silicone, i used DiCore which is much easier to work with and remove if you need to reseal it. I think that silicone is a good durable product on new builds but its more difficult to work with on reapplications and much more work with reapplications. So time will tell if i made the right decision.

[trx430ex]

Feel your rant pain and respect it. True believer in Geocel, a sealant that does not harden. Moves with the flow.

Still remember getting chewed out as a young lad. Thinking I was finishing up sealing around fresh capping around a garage door.
Still remember Howy, turning around screaming, it is sealed from underneath, you just made this look like crap.

Never did it again.

[deandec]

After reading this and 16 years of ownership of a 22 year old rig, I feel really great.

[All_talk]

I completely agree with the OP and will join the rant. Sealer should be used as a gasket between mechanically mated parts. Not 1/2" of marshmallow goo slathered over the top of everything, that's just lazy, sloppy work. I'm just boggled that this seems to be an accepted practice for RVs, I don't see people doing this kind of thing on their car or home. I think this may be part of the reason RVs have the reputation of always being leaky, people just don't take the time to do it right.

Don't get me wrong, I'm not above patch work when time or money are tight and I've been guilty of letting temporary work stand longer than it should, but I try do thinks right, especially when effort is the only difference between the two paths. To the point, I recently had to chase down a small leak in the front cap of my MH, I committed to resealing all the penetrations. All the hardware was removed, everything was cleaned, and reinstalled. More work, but no leaks and I'm confident the repair will last.

Supplementary rant over.
Gary

[Sweetbriar]

Bigger the glob, better the job.


AND


Doing the same thing over and over again and expecting different results or in this case using the same product.