Marine grade alternative?

[Indiana Rambler]

I’m in the process of putting the underfloor payment (first barrier from the frame to floor) and I’m having a difficult time finding marine grade plywood. I’m planing on sealing it up with the asphalt fence post paint for a weather barrier. Just trying to find some alternative since I’m not able to find any in a 50 mile radius. Thanks in advance!


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[Sparksalot]

My floor consists of studs ripped to 2X, then a piece of BC plywood. I did coat the whole thing in black goo. If I were doing it again, I'd skip the goo, and just use several coats of exterior paint. No marine ply anywhere in Rose.

[TimC]

+1 on Sparks reply. No marine only in my woodie or the other two builds. Floor is BC ply coated with roofing tar. Six years and no evidence of water penetration.

On my son's foamie the floor is a sheet of 3/4 pressure treated ply. Roofing tar coated.

I think the most critical areas on a teardrop are areas water can pool. Flat, horizontal surfaces.
After that the next most critical are bottom edges of the structure where water should have some drip edge to keep water from working it's way back under the floor.

[tony.latham]

I don't think you need marine plywood. As you know, it's the same wood (fir) and the same glue as used in the manufacture of ACX and CDX plywoods. The better grades of the marine stuff have thinner plys. It's affected by moisture the same as construction-grade plywoods.

The reason folks used tar products for teardrop floors in the '30s and 40's was that it was what was available. Eighty years later we have better products. I use epoxy. It soaks in and plasticizes the wood. If I were short on the stuff, I would give it three coats of thinned oil-based polyurethane. But enamel paint would be fine too.

Now... having said that, the black goo will work. But sooner or later you'll have to crawl under there...

I build my floors using a 3/4" framework.



The gussets are temporary until one side is sheathed. I sheath both sides with 1/4" floor underlayment and fill the voids with foam board. It's stiff, strong, and not too heavy. You can walk on it when it's not supported by the chassis.



Just a couple of thoughts.

Tony

[Indiana Rambler]

Thanks guys. I was planning on sealing the top layer with this resin. Maybe I should just do the bottom as well.


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[TimC]

Wood needs to breath. If there is any moisture in the wood prior to sealing it, or water somehow gets in, it is less likely to dry out properly and quickly. I'm not saying don't seal both top and bottom as many folks have no problem with it. Just make sure your wood is dry and there is no chance of water penetration. I don't seal the interior surface so the wood can breath.

As far as roofing tar. Yes it works. I used it because I had a gallon of it in my shed that was probably ten + years old. It was still like tar. It takes a few days to firm up and after six years if I take my finger and press and drag it across the surface my finger will get a little black on it. If I just bump it with my head It doesn't transfer (ask me how I know!).

[tony.latham]

I was planning on sealing the top layer with this resin. Maybe I should just do the bottom as well.

I'd use that for the bottom and seal the interior with a couple of coats of oil-based poly. But I do seal the galley floor with epoxy. That place will get wet, sooner or later.





Tony

[Indiana Rambler]

I don't think you need marine plywood. As you know, it's the same wood (fir) and the same glue as used in the manufacture of ACX and CDX plywoods. The better grades of the marine stuff have thinner plys. It's affected by moisture the same as construction-grade plywoods.

The reason folks used tar products for teardrop floors in the '30s and 40's was that it was what was available. Eighty years later we have better products. I use epoxy. It soaks in and plasticizes the wood. If I were short on the stuff, I would give it three coats of thinned oil-based polyurethane. But enamel paint would be fine too.

Now... having said that, the black goo will work. But sooner or later you'll have to crawl under there...

I build my floors using a 3/4" framework.



The gussets are temporary until one side is sheathed. I sheath both sides with 1/4" floor underlayment and fill the voids with foam board. It's stiff, strong, and not too heavy. You can walk on it when it's not supported by the chassis.



Just a couple of thoughts.

Tony

I ripped the 6x8s that were on the original trailer and mortised the ends. So would 1/4 plywood on both sides be sturdy enough with a buildup of foam board insulation in the voids?
I still have to put in the spars at this point, but I’m getting close.


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[halfdome, Danny]

I just contact cement one continuous piece of plam (plastic laminate) on each side of 3/4" plywood.
I do the road side first then after I elevator bolt the floor to the chassis I plam the topside.
Plam is impervious to moisture and looks great.
Danny

[tony.latham]

I don't think you need marine plywood. As you know, it's the same wood (fir) and the same glue as used in the manufacture of ACX and CDX plywoods. The better grades of the marine stuff have thinner plys. It's affected by moisture the same as construction-grade plywoods.

The reason folks used tar products for teardrop floors in the '30s and 40's was that it was what was available. Eighty years later we have better products. I use epoxy. It soaks in and plasticizes the wood. If I were short on the stuff, I would give it three coats of thinned oil-based polyurethane. But enamel paint would be fine too.

Now... having said that, the black goo will work. But sooner or later you'll have to crawl under there...

I build my floors using a 3/4" framework.



The gussets are temporary until one side is sheathed. I sheath both sides with 1/4" floor underlayment and fill the voids with foam board. It's stiff, strong, and not too heavy. You can walk on it when it's not supported by the chassis.



Just a couple of thoughts.

Tony

I ripped the 6x8s that were on the original trailer and mortised the ends. So would 1/4 plywood on both sides be sturdy enough with a buildup of foam board insulation in the voids?
I still have to put in the spars at this point, but I’m getting close.


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Plenty.

Tony

[Indiana Rambler]

I don't think you need marine plywood. As you know, it's the same wood (fir) and the same glue as used in the manufacture of ACX and CDX plywoods. The better grades of the marine stuff have thinner plys. It's affected by moisture the same as construction-grade plywoods.

The reason folks used tar products for teardrop floors in the '30s and 40's was that it was what was available. Eighty years later we have better products. I use epoxy. It soaks in and plasticizes the wood. If I were short on the stuff, I would give it three coats of thinned oil-based polyurethane. But enamel paint would be fine too.

Now... having said that, the black goo will work. But sooner or later you'll have to crawl under there...

I build my floors using a 3/4" framework.



The gussets are temporary until one side is sheathed. I sheath both sides with 1/4" floor underlayment and fill the voids with foam board. It's stiff, strong, and not too heavy. You can walk on it when it's not supported by the chassis.



Just a couple of thoughts.

Tony

I ripped the 6x8s that were on the original trailer and mortised the ends. So would 1/4 plywood on both sides be sturdy enough with a buildup of foam board insulation in the voids?
I still have to put in the spars at this point, but I’m getting close.


Sent from my iPhone using Tapatalk

Plenty.

Tony

Thank you very much!


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[Indiana Rambler]

I just contact cement one continuous piece of plam (plastic laminate) on each side of 3/4" plywood.
I do the road side first then after I elevator bolt the floor to the chassis I plam the topside.
Plam is impervious to moisture and looks great.
Danny

Thank you!


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