Roof Cap Repair / Replace?

[n2evrythng]

Folks,

I've been checking out some of your individual projects for a few months now. There's some great work and very innovative people here. To boot, it's really fun to watch these projects take form.

At the time I found the site, I was thinking of building a teardrop. But after checking out some of your builds, I found a nice deal on a 2001 5x8' Pace trailer on craigslist. The trailer was in fairly good shape, but has been used as a storage shed for a few years, and I noticed it had a small crack in the roof cap. But, it was a good deal, so I took it.

I've since gotten it home and taken the plywood off the walls and inspected the sidewalls and roof cap a little better. It ended up that the cap just had a few small cracks where the screws dimpled the fiberglass material. Over time, that dimple apparently cracked the material slightly. Where there was a crack in a dimple, rain could come through. The damage - The thin plywood under the roof had a small water stain on the edge, the front face ribs had some surface rust, and the front floor piece had a water spot. Not too bad. See photos of the rig here.

So, I am contemplating replacing the cap. I spoke to the folks at Pace, and apparently they started using a different material in 2006 (TPO vs. older ABS). Also, my cap has a seam on each corner where the fiberglass was bent. This new cap is one piece (no seams) and better material for about $150.

If I take the time and money to finish the interior of this trailer, I want it to be as leak proof as possible. So after a lengthy introduction, please comment whether I could get by with some caulk or if you would lean toward my thought of a full cap replacement.

Thanks,
J.K.

[synaps3]

In my opinion, $150 is well worth the peace of mind you'll get from knowing it is replaced and done right.

Think about it -- let's say you caulk it, and it fails in a year. You don't notice immediately, and it ruins the interior. It'll do way more than $150 in damage!

In the scale of a trailer, $150 isn't that bad to make sure something gets done right. I was originally cutting every corner I could to try to keep my build under $1000, but it is better to do it right the first time than to have to go back again and redo it. Plus, it's cheaper in the long run that way.

By the way -- Welcome to the forum!

[Shadow Catcher]

I am also inclined to say spend the money for the piece of mind, BUT you can also treat it as fiberglass and do a repair with west system epoxy and fiberglass cloth. The question would be will this likely reoccur in another location at another time, and that Pace quite probably made the switch for a good reason, hopefully other than just $.

[Ageless]

Replace the cap. Caulk will not stop the cracks from growing thru use.

[Prem]

Re: Front roof caps

I'm vindicated.

n2,

Radical advice: The old one is UV damaged and brittle. Get the new one and fill it full of expanding foam when you get it home for extra strength and waterproofing. In this forum, read how Gil in southern Utah did his. And watch out for branches hitting or brushing it when moving the trailer.

Best wishes! Please post photos of your interior as you build it.

[n2evrythng]

Folks,

Thanks for all of your input - I really appreciate it. Although I would like to spend that money on windows or something more fun for the trailer, I think I will go forward with replacing the cap in the next few weeks.

Now that you mention it, now I remember a little about UV light making those little plasticizers leach out of the material making it brittle. To your points, it would likely crack again in a different place even if I fixed the existing cracks.

What's a good sealant for the new cap on the joints and the screw holes? The existing sealant looks similar to roof patch. Also, the front seam has an aluminum strip over the joint, but the top seam does not. I thought it may be a good idea to fashion a good aluminum strip for the top and seal under it to prevent the dimples in the top of the plastic. Thoughts?

[n2evrythng]

Prem,

Good thought about the expanding foam. That stuff is absolutely insane, but seems to work really well. I hadn't thought of it as a structural support, but it's tough enough to be!

As soon as I get my ducks in a row, I will post a thread on the build. Unfortunately, it will be a slow process to get to the finish - I'm working on a tight budget. However, that may be a good thing - It will give me plenty of time to think about what I want this beast to be like!

[Prem]

n2,

What's a good sealant for the new cap on the joints and the screw holes? The existing sealant looks similar to roof patch. Also, the front seam has an aluminum strip over the joint, but the top seam does not. I thought it may be a good idea to fashion a good aluminum strip for the top and seal under it to prevent the dimples in the top of the plastic. Thoughts?

Answers:

Butyl caulk in a tube.

Definitely (if you can make it work) put an aluminum strip on top where the cap meets the roof.

If you're good with fiberglass cloth and resin, I'd say use the old cap as a mold to make yourself a new one. Save $. If you're really good with sheet metal, I'd say fabricate a cap replacement. Save $ and no more UV worries. If you ever made surfboards or know the process, I'd say build a dam for the spray foam on the inside where the cap used to be, shape it rounded and fiberglass it (3/16" thick). when hard, caulk the edges with butyl and cover with aluminum strip riveted in place.

Best wishes,

Prem