is 1/4" plywood too thin for walls and ceilings?

[belfert]

Is 1/4" plywood too thin for walls and ceilings?  I was going to do 3/8", but my friend is pushing hard for 1/4" due to weight.

I will eventually be putting 5/16" tongue and groove pine over most of the plywood.

Brian Elfert

[Brian Diehl]

I put 1/4" on my walls.  On my MCI 96A3 there are some very large spans that I did not add supplemental bracing to.  I have two spots where I wished I added bracing or had used 3/8".  Otherwise, 1/4" worked and continues to work very well for me.

I used 1/2" on my ceiling, but think I could have gotten away with 3/8".  I would not use 1/4" on my ceiling due to the large spans.  I did not want to worry about any sagging after the fact during humid or moist interior weather/conditions.  If you have braces such that you have very short spans then 1/4" is more than sufficient.

[TomC]

I used 1/4" on the side walls and 1/8" on the ceiling since it curves easily to the roof.  Course you can use wiggle board too (didn't know about it until after I did the ceiling). But wiggle board needs more support although it conforms better to the curvature of the roof.  I also have 1x2 strips on about 12" centers so my ceiling has plenty of support.  I did the unthinkable and painted my ceiling white semi gloss with oak strips holding the 1/8" plywood over the 1x2 strips.  Easy, and didn't have to glue anything.  Good Luck, TomC

[belfert]

I used 1/4" on the side walls and 1/8" on the ceiling since it curves easily to the roof.  Course you can use wiggle board too (didn't know about it until after I did the ceiling). But wiggle board needs more support although it conforms better to the curvature of the roof.  I also have 1x2 strips on about 12" centers so my ceiling has plenty of support.  I did the unthinkable and painted my ceiling white semi gloss with oak strips holding the 1/8" plywood over the 1x2 strips.  Easy, and didn't have to glue anything.  Good Luck, TomC

Where would one find wiggle board?  I don't think I have seen this at a HD or Lowes. 

I better get back out to my bus I guess.

Brian Elfert

[Ross]

Where would one find wiggle board? 

I think Outwater sells it.  You don't even want to ask what it costs.  Stupid, STUPID money.....and totally unnessessary for a ceiling.  It's nice for doing curved cabinets and things like that.

[FloridaCliff]

!/4 is fine for ceiling if you have 12" spacings on attachment points.

But remember you will make your life alot easier if you can attach cabinets,  etc...anywhere you want by having a thicker backer.

I used 1/4 on ceiling, but I have 1X4's on 12" centers on overhead and on 16" centers with 1/2 on the walls.

I used the 1X4 to allow for an extra 3/4 inch insulation all around....

Cliff

[Clarke Echols]

You're converting a 30,000 or 40,000-pound bus and you're concerned about weight?!!!

Winebago uses 1/8" hardboard glued to 1-inch white styrofoam bead board with fiberglass on the
outside and calls it a "wall".  You should see what's left of it after a minor collision.

Assuming you have about 24 feet from floor up the wall, across the ceiling, and back to the floor
on the other side in a 40-foot bus, that's about 24 X 40 square feet, or the equivalent of about
7 sheets of 1/2" plywood if you're talking the difference between 1/4" and 3/8" material.  Difference
in weight is about 300 pounds.  Not enough to notice.

I normally use 1/2" plywood or 7/16" OSB.

Clarke

[JerryH]

Brian:

Curious ... does your friend own a bus?  I would not use (only) 1/4" material.  I wouldn't consider the savings in weight between 1/4" and 1/2" (or 3/4") a major factor.  I'd be apprehensive about using wiggle wood on the inside radius of the bus, as it really needs support.  Try two layers of 1/4" on the radius.  As far as finding wiggle wood.  You'll likely not find it at Lowes or Home Depot as it's not really a home owner item.  A plywoods/ laminate supplier will likely have it.  Not sure where you are, but Fessenden Hall (Pennsauken, NJ) does have it.

Just my $0.02,
Jerry H.

[David Anderson]

I used 1/4" luan screwed up at 12"oc.  I covered it with white marine vinyl glued up with contact cement.  I covered the screws with those white upholstery screw covers.  So, far 4 years up and no problems.  It is washable and reflects cove lighting very well. 

The 1' centers is important for this thin of product.

Sorry, the picture isn't better.

David

[belfert]

Brian:

Curious ... does your friend own a bus?  I would not use (only) 1/4" material.  I wouldn't consider the savings in weight between 1/4" and 1/2" (or 3/4") a major factor.  I'd be apprehensive

No, my friend doesn't own a bus.  This is my project that I alone have invested over $60k into.  He has helped me a lot, but no money into it.  In fact, I've paid him enough to cover his fuel when he does come over.  He will probably travel with me on just about every trip the bus makes out of town.

I think he is really into saving weight because he doesn't want fuel mileage to suffer from unnecessary weight.  We split the fuel bill on trips and he doesn't have all that much money.  I think the aero profile of the bus has as much to do with fuel mileage as the weight.

Brian Elfert

[Clarke Echols]

I think he is really into saving weight because he doesn't want fuel mileage to suffer from unnecessary weight.  We split the fuel bill on trips and he doesn't have all that much money.  I think the aero profile of the bus has as much to do with fuel mileage as the weight.

Brian Elfert

I once had a 3/4-ton Ford pickup (1960 model) with a 6-cylinder engine.  Whether I was hauling
2 tons of cargo or running empty, it got the same mileage on the road: 16 mpg.

The fuel savings by cutting weight in a bus is negligible unless you're talking several tons.  You
might save a smidgen on uphills, but not enough that you could ever measure it accurately.
And what percentage of total miles travelled are uphill at 3-7% grade?

Weight just doesn't matter in most big busses.

Clarke