Need Help With Composite Walls

[starleen2]

a house is built using 2x4 or 2x6 studs spaced at 16 or 24 inches, held in place between the plates with two 3-1/4 inch nails top and bottom and sheeted with 1/2 OSB nailed every 4 inches around the perimeter and 6 inches in the field. no epoxy, no glue no screws. this will hold the weight of the second floor, another wall and the entire roof plus a snow load and all your stuff..

'cmon people, it's a 4x8 trailer for christ's sake. step away from the glue, the fumes are getting to you..

The same principle applies here too - except on a smaller scale with less dimensional lumber. To support thinner ply (which was the original question) you need a support structure that will hold the shape and not buckle under the forces it was meant to sustain. Airplane wings have an immense lightweight structure underneath the skin because the SKIN is thin aluminum. - boats are almost the same way: bulkheads to support fiberglass or it will collapse due to the water pressure pushing in on all sides. What I'm trying to say is the skin - if it 1/8 needs some support contrast this to 3/4 inch ply which will support itself. The method described by aggie79 is a tried and acceptable approach in answering the question. Sure you can do it another way - you could build the entire thing out of brick - but just because you can - doesn't always make it practical!

[afreegreek]

a house is built using 2x4 or 2x6 studs spaced at 16 or 24 inches, held in place between the plates with two 3-1/4 inch nails top and bottom and sheeted with 1/2 OSB nailed every 4 inches around the perimeter and 6 inches in the field. no epoxy, no glue no screws. this will hold the weight of the second floor, another wall and the entire roof plus a snow load and all your stuff..

'cmon people, it's a 4x8 trailer for christ's sake. step away from the glue, the fumes are getting to you..

The same principle applies here too - except on a smaller scale with less dimensional lumber. To support thinner ply (which was the original question) you need a support structure that will hold the shape and not buckle under the forces it was meant to sustain. Airplane wings have an immense lightweight structure underneath the skin because the SKIN is thin aluminum. - boats are almost the same way: bulkheads to support fiberglass or it will collapse due to the water pressure pushing in on all sides. What I'm trying to say is the skin - if it 1/8 needs some support contrast this to 3/4 inch ply which will support itself. The method described by aggie79 is a tried and acceptable approach in answering the question. Sure you can do it another way - you could build the entire thing out of brick - but just because you can - doesn't always make it practical!

the question was whether to add a second 1/8 or 1/4 skin to a 3/4 ply frame with one side skinned already..


I'm going with composite walls, a 3/4" plywood core, cut out to a skeleton, 1/4" outside skin, and want to use wood panneling on the inside. Can I get away with 1/8" panneling on the walls? I found some stuff I like, and I can get it in either 1/4" or 1/8", at first I was thinking about 1/4" on the walls, and 1/8" on the celing, but it would shave a few lbs going 1/8" all around.


. adding another 1/4" skin on the inside to an already strong enough panel is over kill was my point.. no need for 1/4 on the outside either. 1/8" is tons.

[bobhenry]

DOUBLE OUCH

[dwgriff1]

I'm going with composite walls, a 3/4" plywood core, cut out to a skeleton, 1/4" outside skin, and want to use wood panneling on the inside. Can I get away with 1/8" panneling on the walls? I found some stuff I like, and I can get it in either 1/4" or 1/8", at first I was thinking about 1/4" on the walls, and 1/8" on the celing, but it would shave a few lbs going 1/8" all around.

Yes you can frame it any way you wish and add 1/8 skin and it will work well. Part of the "toughness" comes from the foam insulation panels inside the frame work.

Mine is all 1/8 plywood and has worked very well.

dave

[Ageless]

Having torn down several 40 - 50 year old trailers; framing was 3/4", inside was 3/36 panel, skin was .032 aluminum. Lasted quite rigid for all those years until the skin was pierced allowing water in . . .dryrot of the framing.

Having worked with large commercial aircraft, thin aluminum can become quite rigid with the addition of foming such as beads and flanges. However, all that light material still needs hefty support; the keel beam. The wings are fabbed the same, however the bottom skin is much thicker, up to 1"+ on a 747 ( ever see a 125 hp electric motor? 2 of them on a skin mill)

[mwallace61]

ouch huh?

Geek, I'd like to see more pics of the boat if you gots 'em. A build journal would be cool too!

[afreegreek]

ouch huh?

Geek, I'd like to see more pics of the boat if you gots 'em. A build journal would be cool too!

if you like to see more I'll post more on my gallery. the boat is now painted and in fitting so all the cool bits are yet to happen.. just doing some of the wiring now before it gets sprayed with foam. I'll post a few a day for the next 7-8 weeks. got another coming after this too but it's the same boat. just different colours.

[vwbeamer]

ouch huh?

I don't see how using glue is over building. Maybe i missed something.

I agree many here over build, and while I think light is right, something about having a sturdy design gives people a warm feeling. And in the end, it's just a trailer and a few extra pounds doesn't really hurt much.

[dh]

a house is built using 2x4 or 2x6 studs spaced at 16 or 24 inches, held in place between the plates with two 3-1/4 inch nails top and bottom and sheeted with 1/2 OSB nailed every 4 inches around the perimeter and 6 inches in the field. no epoxy, no glue no screws. this will hold the weight of the second floor, another wall and the entire roof plus a snow load and all your stuff..

'cmon people, it's a 4x8 trailer for christ's sake. step away from the glue, the fumes are getting to you..

You ever seen them move a house? there is a reason they go REALLY slow.

[afreegreek]

ouch huh?

I don't see how using glue is over building. Maybe i missed something.

I agree many here over build, and while I think light is right, something about having a sturdy design gives people a warm feeling. And in the end, it's just a trailer and a few extra pounds doesn't really hurt much.

not talking about glue, I was comparing the loads a framed wall can carry without using glue and only being skinned on one side to the loads a TD will endure.

for example, a tall free standing book case with no back will rack under a load of books so, you have a choice.. install a back or screw it to the wall. doing both is over kill. now if you don't want to see the wall colour behind the books you could choose a back, if you don't want to see a wood back you could choose to screw it to the wall. you could do either or do both but you don't need to do both. now change the book case to a case of drawers. totally different loads so a different decision to make because it's going to tip over if you pull a bunch of drawers out whether it has a back or not.

if you want to build strong, you need to look at the loads it will endure and build accordingly. adding more to something that is already enough isn't going to gain you a thing.

A TD is an arch and is an immensely strong shape. consider it half a wheel. you don't need a solid disk to make a strong wheel, all you need is a rim, a hub and a few spokes. the reason they make disk wheels for bicycles is not to add strength, (in fact they are weaker pound for pound) it's to give the air something smooth to pass over and nothing else. a TD is the same thing, all you need is a rim, a few spokes and a hub to attach them to. the skin keeps the cold and rain out and prevents a person form watching you shag the wife.

[afreegreek]

a house is built using 2x4 or 2x6 studs spaced at 16 or 24 inches, held in place between the plates with two 3-1/4 inch nails top and bottom and sheeted with 1/2 OSB nailed every 4 inches around the perimeter and 6 inches in the field. no epoxy, no glue no screws. this will hold the weight of the second floor, another wall and the entire roof plus a snow load and all your stuff..

'cmon people, it's a 4x8 trailer for christ's sake. step away from the glue, the fumes are getting to you..

You ever seen them move a house? there is a reason they go REALLY slow.

ever watch them move a mobile home at 55 mph on the highway?

[afreegreek]

yeah but............

[Miriam C.]

[StPatron]

not talking about glue, I was comparing the loads a framed wall can carry without using glue and only being skinned on one side to the loads a TD will endure.

Some great info. here, I'll keep it in mind when I build my two-story teardrop!

[afreegreek]

not talking about glue, I was comparing the loads a framed wall can carry without using glue and only being skinned on one side to the loads a TD will endure.

Some great info. here, I'll keep it in mind when I build my two-story teardrop!

you could also keep this in mind...