Community Forums

OnTheMove2 · 10-21-2020, 02:56 PM

Hi all,

Once again posting my plea for help in figuring out the best way to do a repair on a long crack running along the top of my roof.

I just got back from a trip and bad weather is a comin! This coupled with my fear of height (which I shall overcome As Hey, I need to) is making me feel a bit desperate.

I have read lots of posts, here and on the net, and some say to just use a marine expoxy, while other posts indicate a much more complex process to do with sanding, applying a resin and a fiberglass mat.

Is there a definitive approach to this fix? And, should I consider a temporary patch given the cooling weather with a permanent one in the future and would I regret this? Or should I go with the right repair the first time and hope the weather will hold off?

If anyone out there has nothing better to do than take pity on a poor unfortunate newbie!! I would really appreciate your response.

Thanks, Terry

FIRE UP · 10-21-2020, 05:51 PM

Well Terry,
I'm the kind-a guy that likes to fix things ONE TIME, and one time only. If it were mine, the answer is simple. I'd trace that crack as far as possible, including the use of a magnifying glass if needed. Then, after each end was found and marked, I'd begin by a thorough cleaning. And that means with some soap and water. Then, I'd hit it with either Lacquer thinner or alcohol. And I'd wipe it down several times.

Then, I'd break out some maybe 100 grit sand paper and, I'd maybe go at least an inch to an inch and a half on each side of the crack and sand away. I'd do that for both sides, end to end. Then, once more, a thorough wipe down and maybe blow things clean with compressed air, if you have access to it. That way, you'd blow out the crack too and that would remove any particles from that crack.

Then, I'd already have some fiberglass matting ready, cut to length and width. I'd mix up some fiberglass resin and hardner, enough to coat that sanded area, then lay down your matt, then another coat. And, a second layer of matt would be the ultimate, and a final coat of resin. DONE.

If you'd like, a nice, high quality, exterior paint, AUTOMOTIVE TYPE, not house paint, would dress up the repair, especially if you could find a close match to the actual color of the orginal fiberglass roof. That's what I'd do. In my opinion, anything else is a band aid.
Scott

Bobby F · 10-21-2020, 06:19 PM

If the oncoming bad weather is making you do things faster than you would normally like, then you might simply cover the crack with Eternabond tape so that you can make further repair decisions at your leisure, without pressure.

If I was torn between repair methods, that's what I would do.

https://www.amazon.com/s?k=eternabon...b_sb_ss_i_1_10

Ray,IN · 10-21-2020, 08:11 PM

Quote:

Originally Posted by Bobby F

If the oncoming bad weather is making you do things faster than you would normally like, then you might simply cover the crack with Eternabond tape so that you can make further repair decisions at your leisure, without pressure.

If I was torn between repair methods, that's what I would do.

https://www.amazon.com/s?k=eternabon...b_sb_ss_i_1_10

Who knows the Eternabond tape may last longer than the rest of the roof material.

SuperGewl · 10-22-2020, 12:46 AM

Flexseal Paste it does it all, just clean the roof area real good and apply it overlapping the area. Or Flexseal tape. Quick and easy peasy.

be-happy · 10-22-2020, 07:38 AM

I am on the same page as "fireup" working with the fiberglass is a way lot easier than it sounds. Preparing the area is most important if you follow fireup's plan you can not go wrong.

I have used the fiberglass method on two cracks and would not go another way with a fiberglass roof.

Mark_K5LXP · 10-22-2020, 08:54 AM

Is this crack following a seam or other structural feature? It's one thing to have damage from an impact but a long crack implies something bigger is going on. Fiberglass is anything but brittle so for it to crack means some flexing or support failure.

From what I've read, Flex Seal is silicone based and I wouldn't be using that on an RV roof.

Mark B.
Albuquerque, NM

Ljwt330 · 10-22-2020, 10:29 AM

All the above posts are the proper way to proceed, IMO, but a lot depends on your particular circumstance.

First, it is important to determine the cause of the crack, as mentioned. Without a picture we are just guessing as to how extreme the crack is as well as its cause. The fiberglass skin of the roof is very thin, but cracking is unusual without some causation.

Second, don't rush and if bad weather is coming a temporary patch is smart. Eternabond or Dicor will do fine. I cannot comment on FlexSeal.

Finally, if you eventually use fiberglass mat to do a permanent repair, be aware that it will always be visible as the area above the crack will be thicker than the rest of the roof, especially if you use more than one layer of fiberglass. This can be mitigated by lots of sanding and blending, but it will never go away.

Ray,IN · 10-22-2020, 03:57 PM

Quote:

Originally Posted by SuperGewl

Flexseal Paste it does it all, just clean the roof area real good and apply it overlapping the area. Or Flexseal tape. Quick and easy peasy.

Many FlexSeal products contain petroleum distillates, or so says the container.

bruceh · 10-24-2020, 04:16 PM

Eternabond goes on easy but it's a bear to remove.

Quote:

Originally Posted by Bobby F

If the oncoming bad weather is making you do things faster than you would normally like, then you might simply cover the crack with Eternabond tape so that you can make further repair decisions at your leisure, without pressure.

If I was torn between repair methods, that's what I would do.

https://www.amazon.com/s?k=eternabon...b_sb_ss_i_1_10

49Deluxe · 10-24-2020, 05:28 PM

Whichever method you use, I think I would find the end if the crack and drill a small hole at each end of it to help prevent further cracking.

johninsd · 10-24-2020, 05:47 PM

I'd do it the way that FIRE-UP recommends but I would use fiberglass cloth instead of mat and use epoxy resin instead of polyester. The epoxy needs to be painted for uv protection - don't know about the polyester. The epoxy takes longer to cure but it also gives you a longer working time. Use disposable chip brushes to apply it and the biggest "secret" to using epoxy is to mix it thoroughly, then mix it some more - almost all epoxy failures are due to inadequate mixing. Whatever you do don't use silicone - nothing will ever stick to it so if it fails you have to remove every trace of it before you can do anything else.

Mikesmowing · 10-24-2020, 06:53 PM

You can go to a automotive paint supplier and let them scan the roof and they put it in a aerosol can , paint and clear in one shot in my area it’s around $30 bucks a can sounds pricey but it’s good stuff

OnTheMove2 · 10-28-2020, 03:05 PM

Quote:

Originally Posted by FIRE UP

Well Terry,
I'm the kind-a guy that likes to fix things ONE TIME, and one time only. If it were mine, the answer is simple. I'd trace that crack as far as possible, including the use of a magnifying glass if needed. Then, after each end was found and marked, I'd begin by a thorough cleaning. And that means with some soap and water. Then, I'd hit it with either Lacquer thinner or alcohol. And I'd wipe it down several times.

Then, I'd break out some maybe 100 grit sand paper and, I'd maybe go at least an inch to an inch and a half on each side of the crack and sand away. I'd do that for both sides, end to end. Then, once more, a thorough wipe down and maybe blow things clean with compressed air, if you have access to it. That way, you'd blow out the crack too and that would remove any particles from that crack.

Then, I'd already have some fiberglass matting ready, cut to length and width. I'd mix up some fiberglass resin and hardner, enough to coat that sanded area, then lay down your matt, then another coat. And, a second layer of matt would be the ultimate, and a final coat of resin. DONE.

If you'd like, a nice, high quality, exterior paint, AUTOMOTIVE TYPE, not house paint, would dress up the repair, especially if you could find a close match to the actual color of the orginal fiberglass roof. That's what I'd do. In my opinion, anything else is a band aid.
Scott

Hi Scott, sorry for the tardy response. I agree with you that doing it right the first time is always the very best approach, but I am running out of time. I have a number of family issues going on right now which keeps pulling me away from addressing this, so that plus the weather is giving me a headache. I’m not sure how quickly it will take for the resin to harden while I’m doing this, especially as the temperature is dropping and having to apply a second coat. Could I cover it with something to protect it from rain while it cures?

Thanks a bunch, Terry