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Topic: Roof cracks (Read 3877 times) previous topic - next topic

Re: Roof cracks

Reply #50 –
I am using West System 105 with the 206 slow hardener. For most of the cracks I am adding fumed silica to the epoxy to thicken it. I used fiberglass chopped mat with epoxy to patch in the plywood for closing the larger holes. I used some spray foam to fill up the void under the antenna holes.

Between the skylight and the bath ceiling vent there was a small area of delamination. I was able to drill a few holes and inject epoxy and also inject into the layers at the vent opening. As the vent has solid metal framing on all 4 sides it made a nice clamping action and I could see that I completely filled the area as excess epoxy squeezed out the drilled holes. It seems to be rock solid in that area now.

I only want to do this repair once so I am leaning toward getting some biaxial fiberglass fabric and epoxy and doing one or 2 layers over most if not the entire surface of the roof. The fiberglass comes in 50" wide rolls so that would do one side with an overlap in the center. I measure the white unpainted roof width at 89". In some areas I do have some very fine cracks running lengthwise along the edge of the roof about 2 inches in from the edge of the paint. This is what is leading me toward covering the entire roof. I have to learn more about how to break up the work. I don't think you could epoxy 4ft by 37ft in one continuous operation even with a helper mixing. Primer and paint sounds easy compared to the fiberglass.

I did buy a top end Bosch electric random orbit sander that makes pretty quick work of the sanding so if I do proceed with the entire roof it wouldn't be too bad a job.
Bruce & Linda
2004 U295, Build # 6268, ISL400 CAPS
2016 Ford Explorer Sport or 1985 Jeep CJ7

Re: Roof cracks

Reply #51 –
Bruce sounds like a really good plan. If you look on YouTube there's a channel called sail Life. The guy's name is mads and he is been refinishing a 40-ft sailboat for the last couple years. He's done extensive fiberglass work and both on the deck which he had to completely replace, some of the hull, and he fiberglassed in a lot of the interior hall supports. Essentially he's almost rebuilt this boat. In the deck sections he had a three-person team, with one person mixing in the epoxy and the other two laying the glass and smoothing it out.  I believe he put down two or three layers of both by biaxial and triaxial, although don't quote me on that. He then put a epoxy fairing compound over it. he did do a lot of sanding with some pretty specialized sanding equipment including 4 ft long sanding bars. But a boat deck is a little bit different than the RV roof I'm not sure that it would need that much. Finally as he painted the deck he put in a non-skid additive. It turned out perfect. The guy started out with little knowledge refinished state small sailboat which he lived in with his dog for many years, and then bought this 40 ft warrior sailboat which he's refinishing with the intention of him and his fiance to sail the world soon. He's even building a zone boiler heating system since he lives in Denmark and his plans are mostly cold weather sailing. It's also working on a really cool generator using a really small Perkins diesel engine. He's pretty cool guy. He's taught himself to do a lot of things that I wish I could do or had the time to learn. Not sure if this will interest you or not but I thought I'd put it out there might help.

http://youtu.be/SfLZEiBiDU4
'99 U320 40 WTFE
Build #5462,
1500 Watts Solar 600 amp Victron lithium
2012 Jeep Grand Cherokee Overland Hemi
Instagram bobfnbw
Retired

Re: Roof cracks

Reply #52 –
No reason not to be able to do it all in a day. Plan it out and it will work fine. I have done a 16ft x40ft deck in one go, and 2 layers and a year ago a 8x 14ft deck.
Yes they are at just above ground level but planning the job right will make it fine
JohnH
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Roof cracks

Reply #53 –
Bruce consider triaxial vs bi on this. More money per yard  but only should need one layer of glass and that means less resin and less work.

For paint check out the interlux bright side and add some interlux non-skid to your walk areas. It's a one-part polyurethane paint. With UV additives. Can easily be rolled and tipped. Or sprayed.
'99 U320 40 WTFE
Build #5462,
1500 Watts Solar 600 amp Victron lithium
2012 Jeep Grand Cherokee Overland Hemi
Instagram bobfnbw
Retired

Re: Roof cracks

Reply #54 –
I painted our U300 roof with Pettit EZ-Poxy: Pettit | Single Part Polyurethane They also sell spraying, brushing thinners and a catylist for making the paint easier to flow and harder and more durable once it dries. The EZ-Poxy Performance Enhancer Topside Finish Performance Enhancing Additive - 3021 is not sold by most paint companies as it can be hazardous if sprayed and a full body suit and outside air supply should be used. I rolled and tipped and got a good result. This takes two people to do it right. One with the roller and the other with a brush.

Roll and Tip method:

https://www.youtube.com/watch?v=TK8A82dVJDE

Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Roof cracks- Before/After Marine-Clean Work on My Coach

Reply #55 –
Very pleased with the work. They repaired several stress cracks, rock chips, buffed & waxed, caulked from the roof on down. Also, repaired small wear of gel coat under batwing ant. Also offers complete roof replacement with stronger fiberglass than new with lifetime guarantee against hail, etc. Also, offers same lifetime for boat hulls. He says his replacement roofs & hulls are that strong. I have no financial interest or receive compensation from Marine-Clean.
Before:


After:


Walt, Dawn, Matt & the Poodles
99 36' U320 #5515 MC #17977 "Axle"
Not All Who Wander Are Lost (not original but I like it)

Re: Roof cracks

Reply #56 –
After reading this I am getting very worried about what I will likely be told!!  As you can see, I have many of those same type of cracks and worse yet I have some soft spots on my roof. Not terribly soft but not as hard as the rest of the roof.  And let me mention that the interior ceiling fabric has stains from past leaks.  I currently have a very slight leak near the shower so I know I need to do something.
Really I was thinking I would simply clean, lightly sand and coat the roof.  I am not sure what would be better as there are many opinions out there. Gel coat, paint or coating.

Lets hear your thoughts.
2000 U320 36'
Build #5705

Re: Roof cracks

Reply #57 –
Farrfark
The way these coaches are built, fiberglass over plywood, any place the fiberglass has a screw through it the opportunity for water to get in exists. When water finds its way in eventually the wood decays and the glue joint between the wood and fiberglass is gone. Soft spot. Delamination.
This probably will require opening it to repair.
I had one that started at the sky light and bad wood went all the way across the roof to the hand rail on the other side.
They kept cutting out pieces of fiberglass until they got to good wood. Replaced the bad wood the put the glass pieces back and fixed the joints. When done it was again solid and you couldn't tell it had been open.
There are other ways to repair small delaminations with out opening it up.
Depends on how extensive it is. 

John Duld
1995 U320C SE 40'

Re: Roof cracks

Reply #58 –
Quote from: John Duld –
Farrfark
The way these coaches are built, fiberglass over plywood, any place the fiberglass has a screw through it the opportunity for water to get in exists. When water finds its way in eventually the wood decays and the glue joint between the wood and fiberglass is gone. Soft spot. Delamination.
This probably will require opening it to repair.
I had one that started at the sky light and bad wood went all the way across the roof to the hand rail on the other side.
They kept cutting out pieces of fiberglass until they got to good wood. Replaced the bad wood the put the glass pieces back and fixed the joints. When done it was again solid and you couldn't tell it had been open.
There are other ways to repair small delaminations with out opening it up.
Depends on how extensive it is. 


I am a roofer and have put single ply systems on RVs before but do not want to do that here! I really do not feel like the delamination is bad enough to even bother with (as of now). So I am leaning towards using a Bus Kote to seal the roof and reseal the penetrations. I believe the water damage has come from penetrations more then it has these cracks but both need maintenance!!

I appreciate your and anyones insight on this.
2000 U320 36'
Build #5705

Re: Roof cracks

Reply #59 –
I bought my Foretravel after it had had a refrigerator fire that burned a 5'x6' hole in the roof. A metal panel was placed over the hole and caulked to seal the hole as a temporary fix.

I'm NOT a fiberglass expert so I approached the repair with that knowledge in mind at all times.
My solution was to remove the temporary metal panel, cut out the hole, replace the insulation, replace the plywood with marine grade plywood and then cover the plywood with FRP (fiberglass reinforced panels comes in 4'x8' sheets at Menards or HD) bonding the fiberglass to the plywood with 5200 adhesive. All I had to do then was fiberglass the seams from the old roof area to the new roof (4 sides), sand the seams to blend to the old roof and then paint on a layer of gelcoat.

6 years later its still every bit as strong as the rest of the roof, maybe stronger. I can see the seems but I don't care. Its the roof, not the side of the coach. The seems now are covered with solar panels and can't be seen.
With a 1995 coach I have far worse problems as far as appearance than a few seems on the roof that nobody but me see's and probably would not even be seen unless pointed out.
As long as the roof is structurally sound and does not leak, its good to go in my book.
1995 U320C SE 40'
Jeep 4x4 Commander - Limited - Hemi
"The Pack"  Yogi and Diesel our Airedales -  Charlie our Boxer/Akita mix. Gone but NEVER forgotten Jake our yellow Lab.
NRA Law Enforcement Firearms instructor - Handgun/shotgun
Regional Firearms instructor for national Armored Transp. Co.