# weight per square foot



## len

Does anyone know of the relative weights per square foot of some building materials? I need to re-build some case dividers and want the lightest building material. But something that still retains some stiffness. Found some 1/4" mdf, but it's only available in 2 x 4' sheets, and it's kind of $$ compared to other products. But it might be worth it. 

Figured I'd post this in scenery since it's the closet to the project I'm working on.


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## Footer

I assume you are looking for the physical weight of the piece and not how much weight it can hold? 

Lightest your going to get for the thinnest possible and still retain strength is probably going to be masonite.


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## ajb

All values psf. Obviously since weight in psf is a function of density, you can derive values for other thickness very easily: 1/4" masonite is twice as thick as 1/8" masonite so it will weigh twice as much. The exception is plywood, where density may vary from one ply to another, so it's not necessarily linear the way a homogeneous material like MDF is, for instance.

Masonite:
1/8": .59
1/4": 1.19

Plywood:
1/8": .42
1/4": .80
1/2": 1.52

Particle Board:
1/4": .75
1/2": 1.94

MDF:
1/4": .79
1/2": 1.58

MDF weight in psf is calculated from the density listed on Wikipedia, all other values are from Structural Design for the Stage.


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## jwl868

"psf" is an abbreviation for what units? 


Joe


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## ajb

psf = pounds per square foot


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## len

Footer said:


> I assume you are looking for the physical weight of the piece and not how much weight it can hold?
> 
> Lightest your going to get for the thinnest possible and still retain strength is probably going to be masonite.



Yeah, I'm not building new cases, but I have some cases with dividers for lights. The dividers are crap, and they're falling apart. I have to build new ones. 

Masonite is fine, but it's too flexible, which is why I'm leaning to mdf. Less flexible. The 1/4" plywood I can find is junky as well. I would prefer to do this once, not once every couple years.

And looking at the numbers provided by AJB, even tho mdf is heaviest per square foot at 1/4", the dividers will be a total of less than 10 S.F. per case, adding a whopping 8 pounds at most.

I also considered hardiboard, which is a newer exterior building material that looks like siding, but is more durable than concrete (so they say). But I don't know that I could get any foam padding to adhere to it, which is a problem.


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## kicknargel

A couple plastic options: Coroplast (corrugated plastic--like what political yard signs are made of) is pretty stiff, light and cheap. Might not take the abuse, though. It might, though. They also make postal bins and all kinds of stuff out of it. I use it a lot.

Expanded PVC sheets are pretty light, very stiff and strong. Not so cheap.

Either can be had at a good plastics supplier (in Denver I use Regal).


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## seanandkate

If you can get a good price on baltic birch plywood, that's a great option. It usually comes in 5 x 5 sheets, and it's _really _sturdy. Meso might be pretty flexible, but what if you laminated two 1/8 squares together (bumping it to your 1/4" target) ? That might sturdy it up, and it would certainly be a cheap option.


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## len

kicknargel said:


> A couple plastic options: Coroplast (corrugated plastic--like what political yard signs are made of) is pretty stiff, light and cheap. Might not take the abuse, though. It might, though. They also make postal bins and all kinds of stuff out of it. I use it a lot.
> 
> Expanded PVC sheets are pretty light, very stiff and strong. Not so cheap.
> 
> Either can be had at a good plastics supplier (in Denver I use Regal).



Coroplast is similar to what was in there to begin with, which was foamboard. I spent too many hours reinforcing that. 

Went with mdf and the only problem I'm having now is that I can't find a source for foam padding that isn't outrageous. Oddly enough, the craft stores are actually cheaper than the industrial places online, and for the same quality foam.


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