What type of plywood for trailer build?

[djcressman]

Update: after a lot of consideration, research, your input, and discussions with professionals, I chose 5x10, 9mm Okoume Marine Grade Plywood. I was strongly advised against ACX since it does have internal voids that can trap water and inevitably delaminate the plywood.

Original: This is my first post on Expedition Portal - I searched for answers with little luck. If you know of any threads, please advise!

For my trailer, I need more than your standard 4x8 sheets of plywood. I need of 5x10 sheets. I'm interested in 1/2 inch stock. I have few options, and even less affordable options. That's how it goes I guess!

I am going to seal all edges, fiberglass, and either coat with a bed liner or clad with aluminum. Please make suggestions. I'm not opposed to FRP either, I just struggle finding it, and I assume it's VERY expensive.

Plywood	ACX	Marine Grade	BB Birch, Exterior Rated	Other?
Pros	Affordable, 5x10 easily sourced, exterior rated glue	Exterior rated glue, meets specific standards (Lloyds) for few internal voids	Exterior rated glue, appealing, 7 or 9 ply (on 12mm)	??
Cons	Lower quality, more internal voids that can trap moisture and delaminate plys, 5 ply	Expensive, difficult (not impossible) to source 5x10, 5 ply	Can only find 4x8. Moderately expensive. Heavy.	??

Any help is appreciated!

 

[billiebob]

Baltic Birch comes 5x5 in many thicknesses and has zero voids.
One scarf joint gives you 5x10 sheets.
And it is light weight.

The zero voids plys can make beautiful projects.

 

[djcressman]

Baltic Birch comes 5x5 in many thicknesses and has zero voids.
One scarf joint gives you 5x10 sheets.
And it is light weight.

The zero voids plys can make beautiful projects.
View attachment 623700

Thanks! I did consider that, however, I do want exterior/waterproof glue between the plys. One lumberyard has 4x8 exterior rated BB... their 5x5 sheets are not exterior rated.

 

[old_CWO]

There is a good bit of discussion on this topic at the teardrop builder forum tnttt, you might want to check it out.

 

[ottsville]

If you are cladding with aluminum, look at @Teardropper 's builds (and his book). He's also active on TNTTT.com. If you're building a teardrop, you'll probably find better info over there.

 

[OverlandNA]

Thanks! I did consider that, however, I do want exterior/waterproof glue between the plys. One lumberyard has 4x8 exterior rated BB... their 5x5 sheets are not exterior rated.

ALL BALTIC birch ply is made with exterior glue.
There is birch ply that is only birch on the outer layers

 

[djcressman]

If you are cladding with aluminum, look at @Teardropper 's builds (and his book). He's also active on TNTTT.com. If you're building a teardrop, you'll probably find better info over there.

Got his book.. haven't gone through that in depth yet. Didn't scour TNTTT.com too much. Will be building a "square" drop offroad style trailer. Will check out TNTTT.com!

Thats odd. My local suppliers must be liars.

I specifically asked about the 5x5 sheets, and they said not exterior rated... they only have 4x8 in exterior rated BB birch.

I've established a relationship with a local offgrid trailer builder in the Denver area. He has been invaluable! His biggest concern for me is plywood delaminations - wanted to get everybody's opinion and real world experiences.

 

[1000arms]

This is my first post on Expedition Portal - I searched for answers with little luck. If you know of any threads, please advise!

For my trailer, I need more than your standard 4x8 sheets of plywood. I need of 5x10 sheets. I'm interested in 1/2 inch stock. I have few options, and even less affordable options. That's how it goes I guess!

I am going to seal all edges, fiberglass, and either coat with a bed liner or clad with aluminum. Please make suggestions. I'm not opposed to FRP either, I just struggle finding it, and I assume it's VERY expensive.

Plywood	ACX	Marine Grade	BB Birch, Exterior Rated	Other?
Pros	Affordable, 5x10 easily sourced, exterior rated glue	Exterior rated glue, meets specific standards (Lloyds) for few internal voids	Exterior rated glue, appealing, 7 or 9 ply (on 12mm)	??
Cons	Lower quality, more internal voids that can trap moisture and delaminate plys, 5 ply	Expensive, difficult (not impossible) to source 5x10, 5 ply	Can only find 4x8. Moderately expensive. Heavy.	??

Any help is appreciated!

This is my first post on Expedition Portal - I searched for answers with little luck. If you know of any threads, please advise!

For my trailer, I need more than your standard 4x8 sheets of plywood. I need of 5x10 sheets. I'm interested in 1/2 inch stock. I have few options, and even less affordable options. That's how it goes I guess!

I am going to seal all edges, fiberglass, and either coat with a bed liner or clad with aluminum. Please make suggestions. I'm not opposed to FRP either, I just struggle finding it, and I assume it's VERY expensive.

Plywood	ACX	Marine Grade	BB Birch, Exterior Rated	Other?
Pros	Affordable, 5x10 easily sourced, exterior rated glue	Exterior rated glue, meets specific standards (Lloyds) for few internal voids	Exterior rated glue, appealing, 7 or 9 ply (on 12mm)	??
Cons	Lower quality, more internal voids that can trap moisture and delaminate plys, 5 ply	Expensive, difficult (not impossible) to source 5x10, 5 ply	Can only find 4x8. Moderately expensive. Heavy.	??

Any help is appreciated!

The link is for thicker plywood than you are asking about, but it is 5' x 10' ACX plywood:

https://www.menards.com/main/building-materials/panel-products/sanded-plywood/roseburg-3-4-x-5-x-10-acx-sanded-fir-plywood/1251070/p-1444452505105.htm

You might search for 5x10 marine plywood. You may not care for the prices, but, you might find some more options.

 

[quickfarms]

I would go with marine plywood

Most, if not all, plywood uses exterior glue. Just because it is not exterior rated does not mean that they use a different glue.

 

[Canlib]

I'm not sure if 5x10 is available, but I used marine poplar for my slide in camper and was amazed at how much lighter it is than fir.

 

[djcressman]

The link is for thicker plywood than you are asking about, but it is 5' x 10' ACX plywood:

https://www.menards.com/main/building-materials/panel-products/sanded-plywood/roseburg-3-4-x-5-x-10-acx-sanded-fir-plywood/1251070/p-1444452505105.htm

You might search for 5x10 marine plywood. You may not care for the prices, but, you might find some more options.

Found 5x10 marine online. Freight won't be cheap. Would obviously like cheaper, but will pay for the right product.

I would go with marine plywood

Most, if not all, plywood uses exterior glue. Just because it is not exterior rated does not mean that they use a different glue.

I'm thinking marine will be the way to go. Never heard of most/all plywood using exterior glue. Source?

 

[1000arms]

The link is for thicker plywood than you are asking about, but it is 5' x 10' ACX plywood:

https://www.menards.com/main/building-materials/panel-products/sanded-plywood/roseburg-3-4-x-5-x-10-acx-sanded-fir-plywood/1251070/p-1444452505105.htm

You might search for 5x10 marine plywood. You may not care for the prices, but, you might find some more options.

Found 5x10 marine online. Freight won't be cheap. Would obviously like cheaper, but will pay for the right product.

I'm thinking marine will be the way to go. ...

See my post in:

off-roading with hard side camper

So.... with a DIY camper like this... what do people think of things like this? Will this just rattle itself apart on a rough road? I'm not even talking about crazier off roading.

expeditionportal.com

I think it is harder to get good quality plywood today compared to when I designed and built the camper. Rustoleum paint may have changed. I designed my camper it to be simple to make, which cut down fabrication time.

Using the right product, especially in relation to the costs of time and money, makes a lot of sense (cent's too).

 

[OverlandNA]

Thats odd. My local suppliers must be liars.

Misinformed.
Birch veneer ply is a different product.

 

[djcressman]

Misinformed.
Birch veneer ply is a different product.

Do you have a source - even if it's a supplier or manufacturer?

I understand birch veneer plywood is different than baltic birch plywood. I've only heard the same as @Verkstad. I focus (maybe too much) on details. I want to make sure my money and time goes to the best solution for my application. I can't afford to spend $2000-$3000 on my exterior material... I also can't afford to waste my time by saving money only to have the plywood delaminate after a couple years... therefore possibly wasting my entire build time and build budget.

 

[OverlandNA]

I took some (poor) edge shots of 1/8" & 1/4" Baltic birch and 1/4" box store underlayment (last image). Notice the 1/4" BB has 5 layers where the 1/4" underlayment has 3.
Decent writeup here- https://kingsfinewoodworking.com/blogs/news/baltic-birch-plywood-what-is-it-why-is-it-better#:~:text=It also has more dimensional,likely to shrink or expand.