Re-coating trawler roof?

All, the trawler we just bought has an almost flat houseboat-like roof, which the paint is peeling off of. The fiberglass underneath has some spider cracks and what must be a couple minuscule leaks. I realize I could cut out the soft spots and redo the fiberglass, but that seems like a lot of unnecessary work. I would prefer to just apply a roll on roof coating to stop further leaks. Has anyone used a roll on roof coating before? Any recommendations for something that can take occasional foot traffic, paddle boards, and kayaks? I'm curious if I could just use an elastomeric coating, if I need an epoxy coating, if silicone really would be too soft and slippery, if a truck bed liner would be better.... What would you suggest?

Thanks

The truck bedliner type material might be the simplest fix. It's tough, flexible and tenacious. And it can be textured for a good non-slip surface. I've seen some low-end skiffs that had decks coated with the stuff.

Yeah, why would you want a solid roof to walk on anyway.

Go with the truck bed liner and just send young kids up to get the kayaks.

I was with you until you said soft spots. You need to cut out the rot and fix it.

HopCar said:

I was with you until you said soft spots. You need to cut out the rot and fix it.

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With all due respect Parks, unless one has bottomless pockets, that advice is possible overkill. Our upper deck has the odd soft spot, but I have sealed the leaks where that occurred as a result of the top layer of glass being penetrated by fittings, and the area is our flybridge, so we do walk on it - often - yet it does not leak inside, so I just call those places a bit springy, rather than soft, as no-one has come even close to going through in 14 years, and the soft spots have not enlarged in area in that time either.

Starting to cut out rotted/damp coring in these places can literally be like opening Pandora's box, and a can of worms all at the same time, and you can't tell where it will end. In the OP's case it is not even a deck that's normally walked on, so even less important to be absolutely rigid. Best solution in my view is to just waterproof, (e.g. the truck deck liner), and then get some good big solar panels up there and take advantage of the nice uncluttered, & not walked upon area to generate free battery charging.

Yes,
Old boats can have some imperfections.

Pete we can disagree. I think the soft spots should be fixed because there may be a hidden "can of worms" as you put it. If it was me, I'd want to open them up and see what is there. If they're small, it's an easy repair. If you find that can of worms, it really did need fixing.

It would be useful to know what the core material is.

Eric, old boats can have imperfections, mine certainly does. Rot is not an imperfection, it's boat cancer. It will eventually become uneconomical to repair and the boat is dead.

We're going to try a fairly new to the U.S. Product: KiwiGrip. We'll be sealing the decks and applying it to the flybridge/cabin top, too.

KiwiGrip | Non-Skid System

Did Kiwigrip originate in New Zealand?

Please let us know how it works out after you apply the Kiwigrip.

HopCar said:

Pete we can disagree. I think the soft spots should be fixed because there may be a hidden "can of worms" as you put it. Rot is not an imperfection, it's boat cancer. It will eventually become uneconomical to repair and the boat is dead.

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Parks, while I agree with you in principle re rot, especially if structural, or in a cosmetically visible place, or places when it adjoins other timber structures, in which case it can spread. However, here we are talking about damp core which is sandwiched between two layers of GRP and purely there to add substance and stiffness. It is in effect sealed away, out of sight, and unless the leak is coming through both layers of GRP, it is not connected to the actual ceiling support beams etc, so can't spread like the cancer you describe.

Once you get into replacing damp core, you can end up having to strip off the entire upper glass layer, re-coring, and then laying a completely new top GRP deck. That sort of repair can become hugely expensive, but with very little evident benefit except no springy parts, and that you know it was done. Sure, we all love things perfect, but boats are never perfect. Not even new ones. The day they are made they start developing imperfections - just like us. Just sayin'.

BruceK said:

Did Kiwigrip originate in New Zealand?

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One suspects it was Bruce, (a bit like International Products, (or Interlux in the US), which started life in NZ as Epiglass. However, at present the headquarters appears to be in Washington, USA.

KiwiGrip | Non-Skid System

The flexible sealing very white roof coatings for house trailers is just the item.

It is sold in the South and is found with lumber and roof mateerials at box stores , not in the paint dept.

At $15 to $25 a gallon it has a very high titanium content to keep the roof cooler in the sun.

It is very flexible and will seal all the hairline cracks , but not holes.

Multiple coats can be used , light blue when going on that changes to white as it dries.

Down side is it is ROOF not deck material, not meant to be in a traffic area.

Paint it up on things bolted to the roof and it will seal them too.

I would duct tape some 4mill poly - 2'x2' on an areas of the roof then inspect it for condensation the next day.

If there is considerable condensation that indicates significant vapor drive through the structure. You'll have a hard time getting anything to stick properly to it.

All, thanks for the input. To clarify, these are not soft or even spongy spots, they are just slightly something other than rock hard. Any damage is minimal and I simply want to prevent further damage. If money was not a concern, well, we would have bought a different boat . Also, because there is no ladder to the roof and we only have 6" of clearance under the fixed bridge by our house, there will be very little use of the roof.

Capt.Bill and HopCar, there are two or three 2'x2' soft spots in the deck, which I will cut out and properly fix.

Peter B, thanks and solar panels are exactly what I was thinking!! I'm glad to know I'm not the only one willing to live with a few imperfections .

ABfish, Moonfish, and FF, I appreciate the product recommendations. It looks like 5 gallons of elastomeric roof coating is ~$65 and I might need 20-25 gallons to get several coats. This seems cheaper than bed liner but I'll have to do a little more research. FF, thanks for the tips and I'll take a look for the stuff with titanium.

Wood, that's an excellent point and I hadn't considered vapor drive. Thanks for suggesting that!

BruceK said:

Did Kiwigrip originate in New Zealand?

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Yes

Miz Trom said:

Please let us know how it works out after you apply the Kiwigrip.

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Will do. And we're going to create an application video, too.