How do I fix cracks in the roof?

[Gus68]

Originally Posted by jesilvas

Lots of rot in the wood structure causing the screws to come loose causing the trim on the seams to pop up.

Here are some pics after 30 mins of scraping at 5:00 this AM.

Dirt has got into the cracks along with water. The old material on the outside still sticking on quite well (ie. hard to get off).

So now it's a trench! Fill trench with dicor then cover with Eternabond?

The whole roof (seams) have to be done. Going to try my air chisel after Denise wakes up...lol

If I'm not back this afternoon ... I forgot to wear a helmet!

[jesilvas]

You only need to Dicor OR Ebond, not both.

[Gus68]

Originally Posted by jesilvas

You only need to Dicor OR Ebond, not both.

I used an air chisel today and that worked great! 70' to fix!

I was thinking of running a bead on the joint with Dicor and then cover the area with 4" of Ebond. Ebond is coming the mail because it costs twice as much here. But do have some Dicor. Good or bad idea?

[Stan.Birch]

Originally Posted by Gus68

I started to scrape it and it's all coming off so I going to use Eternabond . A roll of it is $160 up here though. I will try to find another supplier.

Hi Gus!

Unfortunately, you are probably stuck with using Eternabond if you want a permanent fix.

A couple years ago, I paid an RV service facility (Hughes, Orangeville) to seal my roof. Two months later, on our rainy Fall trip, water was pouring in all over the place from the roof!! Upon inspecting the roof, within a couple months, ALL of the sealant they used had cracked wide open!! I asked them what they used: Dicor!!

Since I have a fibreglass (membrane) roof I got rid of the Dicor and replaced it with polyurethane sealant.

You are probably wise enduring one-time-pain, choosing Eternabond!

Originally Posted by Gus68

What could I find underneath that would require fixing?

Ignorance is Bliss!! Unless you can see the sky from the interior of your rig: Don't ask!

[Mr_D]

Originally Posted by Stan.Birch

Hi Gus!

Unfortunately, you are probably stuck with using Eternabond if you want a permanent fix.

A couple years ago, I paid an RV service facility (Hughes, Orangeville) to seal my roof. Two months later, on our rainy Fall trip, water was pouring in all over the place from the roof!! Upon inspecting the roof, within a couple months, ALL of the sealant they used had cracked wide open!! I asked them what they used: Dicor!!

OTH, ours was originally sealed with Dicor, it's still in good shape although I have patched a few spots over the 11 years we've owned it.
The shop may have told you they used Dicor but they might not have actually used it.

[Gus68]

I have ordered the Ebond off eBay and it will not be here till the end of the month.
I thought I would just put a small bead of Dicor on the exposed joint just to tie it over until
the Ebond shows up. Bad idea? What else can I do? It's going rain before I get the Ebond.

[ronspradley]

Gus, I agree that you need to fill in the valley of the seams before the EBond. So when you put on the EBond there will not be a dip remaining that will hold water. Seems like self-leveling Dicor would work for that. Or something that you could tool to make level. And maybe that will keep it from leaking while you are waiting for the EBond, Or maybe you can cover the roof until?

ronspradley

[Gus68]

Originally Posted by Stan.Birch

Hi Gus!
A couple years ago, I paid an RV service facility (Hughes, Orangeville) to seal my roof. Two months later, on our rainy Fall trip, water was pouring in all over the place from the roof!! Upon inspecting the roof, within a couple months, ALL of the sealant they used had cracked wide open!! I asked them what they used: Dicor!!

I used to do a lot of auto/house painting back in the day. Preparation is the key. Nothing sticks to grease, dirt. You gotta get clean before you paint.

[Stan.Birch]

Originally Posted by Gus68

I used to do a lot of auto/house painting back in the day. Preparation is the key. Nothing sticks to grease, dirt. You gotta get clean before you paint.

I agree with what you are saying. I used to do auto painting back in the early 60s!

But the problem had nothing to do with adhesion; it had to do with Dicor (501 LS?) sealant cracking at the joint, i.e. they sealed all around the large bathroom skylight; and the area over where the skylight joined the roof was cracked wide open all the way around the skylight.

I have used Dicor 501 sealant in the past, and have been rather unimpressed by it's performance; and I've heard other RVers carping about the stuff, which was supposed to be self-leveling but didn't. Maybe they got a bad batch.

With my rig, I ended up scraping all the junk off, cleaning with with lacquer thinner, and then applying polyurethane sealant, which from past experience should provide a permanent fix.

[jesilvas]

The issue with cracking Dicor is that it was probably applied to a spot that moved. I.E. a skylight that wasn't secured properly.

[steveclv]

When I did mine, I dug out all of the loose sealant and applied self leveling dicor so that it overlapped the area but about 1/4" - I let that cure off and then applied 4" Eternabond, having cleaned the area with acetone. I purchased 2 off 50' rolls to do both side and end seams and enough left over for skylights.

I used a wallpaper roller to really squeegee the Eternabond down, especially at the edges.

About a week later, I washed off the entire roof with TCP and let dry and then applied 3 coats of Henry's elastomeric - the most expensive one they do (about $160 for 5 gallons).

It shouldn't need attention for 2-3 years at which point I will just wash and reapply the elastomeric.

[Gus68]

Originally Posted by steveclv

When I did mine, I dug out all of the loose sealant and applied self leveling dicor so that it overlapped the area but about 1/4" - I let that cure off and then applied 4" Eternabond, having cleaned the area with acetone. I purchased 2 off 50' rolls to do both side and end seams and enough left over for skylights.

Just as a final note on this thread...

I did just as you did with yours.

1. Got all the old multi layers of cracked sealant off the roof
2. Cleaned up the the areas to reseal with Mineral Spirits or Laquer thinner
3. Put on self levelling Dicor in the crevus of the joint between panels
4. Put on 4" Ebond over the Dicor and the entire joint

We had to grind and chip to get the old crap off. Next time use a heat gun!!

I cost me $1600 to get someone to do the grunt work. This is NOT a FUN job by any stretch. BUT...if you do get someone to do it make sure you can witness the job during each stage. It's easy for the guy to skip the cleaning step. Most of the bad patches never stuck on because the roof was dirty. I am not aware of any product on the planet that sticks to dirt.

If your thinking of buying a older RV ... get up on the roof! If it's cracked then demand they fix or drop the price by $2k at least.

Hopefully we get her on the road next spring.

Cheers!
Brian