Interior Plywood Thickness

[Capebuild]

I'm planning out the interior of the cabin and have a question about plywood thicknesses used.

I'll be using baltic birch ply. For areas like shelving, the headboard and "cabinetry" areas like that, is it best to use 3/4 inch ply (18mm-13 ply) or is 1/2 inch (12mm-9 ply) an okay choice.
The supplier also has a 5/8 inch ply (15 mm-11 ply).

I'm thinking about weight savings but also wondering if 3/4 is a bit hefty.

I'd be interested in people's thoughts on this.

thanks very much!!

John

[OP827]

I used 3mm Baltic birch plywood with 1x.75 clear pine sticks everywhere for furniture. Drawer faces and counter top are 6mm with more plywood reinforcement for appearance and rigidity where needed. Strong panels such as table are XPS foam sandwich with same 3mm plywood skins. I would do it again.

[halfdome, Danny]

My cabinets are an integral part of the structure and as a Cabinetmaker I wouldn’t use anything less than 3/4” thickness.
Design your build so your not using cleats but screw shelves etc with pocket screws or from the exterior if you’ll be covering with aluminum.
As you can see in this photo the cabinet members are part of the TD not something built and installed later.
They strengthen the structure.
I use dados wherever possible.
I always lay out full size complicated projects on a sheet of 4x8 cardboard or a sheet good that will get covered up later, use pencil for corrections.
Danny

[tony.latham]

I'm planning out the interior of the cabin and have a question about plywood thicknesses used.

I assume this means you will be using single-wall construction and not building sandwich walls?

Tony

[Capebuild]

Thank you for the replies.

Danny, I'll be building the interior members integrated with the framing members, using dado recesses where it makes sense to do so. I'm just wondering if some of the face fronts and hatch doors could be 1/2 inch. They don't seem
to be so "structural" in nature.

Tony, yes, I am planning on using the "sandwich" tecnique (3/4 ply on inside, 1/8 ply on outside and inside face). I know in your book you had used 1/4 inch on the outside. I'm planning on aluminum sheeting on outside, so I figure 1/8 inch should work okay. Please let me know if you have any comments about that.

Thanks very much for the insights.

John

[halfdome, Danny]

Thank you for the replies.

Danny, I'll be building the interior members integrated with the framing members, using dado recesses where it makes sense to do so. I'm just wondering if some of the face fronts and hatch doors could be 1/2 inch. They don't seem
to be so "structural" in nature. John

John, The face frames should be 3/4" thick but I guess you could go frameless but the face frames in my builds are a integral part of the build.
You could make your doors with 3/4" lumber frames and 1/4" backs (panel back doors).
With what I'd consider an uncontrolled environment where your out in the wide open, 1/2" doors could warp, and it poses hardware issues.


At one shop I worked at in Oceanside CA we did all the cabinets in a multi storied hospital in the same city.
We made 3/4" slab doors where the back was vinyl and the faces were plam (Formica).
We had to replace all the doors as they warped because the doors were not sealed equally, being the vinyl was the weaker of the two.
Something to think about when building.
Danny

[bdosborn]

My last build was stick frame, sandwich style. I used 1/4" Baltic birch ply on the exterior walls and 1/8" on the interior. I used 1x2 framing (3/4"x1-1/2" actual) for everything, including my cabinet doors. I used 1/8" ply for the cabinet door inserts. Shelves were the same as the cabinet faces. 12 years later its still in great condition. Most people overbuild and add weight, IMHO. Especially the first one.


Bruce

[tony.latham]

...so I figure 1/8 inch should work okay. Please let me know if you have any comments about that.

That will work fine.

Tony

[noseoil]

I built with 1/2" Baltic birch & 3/4" Alder face frames for the cabinets, but it was still too heavy, IMO. The cabinets were made with a "traditional" build style using glue, nails, 1/2" panels throughout & full face frames, what you would see in a house. They were through-fastened from the outside walls with drywall screws & it's a very solid build structurally, but overkill in terms of the strength of materials (an over engineered, 1st build, what Bruce said).

Here's the headboard, lofted to fit the headliner for final assembly.


Here it is in place & mocked-up


The upper galley cabinet with door & drawer openings, as well as provisions for wiring switches, etc.




Rolling weight with my "weight savings" techniques was 1660#, prior to adding a 3500# axle with 10" drum brakes. It's a bit over the top, but strong like buffalo. Sticks & 1/8" panels would have been strong enough & would have saved a lot of weight...