How big a drawer bottom until you should change to 3/8" ply instead of 1/4"

[Alan Lightstone]

I'm building an outfeed table with storage drawers for my jigs, miter sleds, and otherwise somewhat heavy stuff. The drawers will be large. The smallest is 25"L x 18"D, and the largest 45"L x 26"D.

At what point should I make the bottoms out of 3/8" baltic birch ply instead of 1/4"? Am I there?

The slides are rated for 100 lbs/pair. I don't imagine I'll exceed that, but could easily see reaching 50 lbs of contents in a drawer.

Am I over thinking this?

[Mike Cutler]

Alan
I think it's a matter of what is going in the drawers, but in my opinion, you're there. I also tend to "over build" though.;)
I'm doing our kitchen cabinets right now and the largest drawer is 31"x 21". 6 more will be about 18"x 21", 2 will be 30"x 27",and the final three are 22"x 21". I used 3/8" BB throughout, with Grass DynaPro slides rated for 132lbs. Dishes can get heavy.

You might someday worry about the 1/4" BB, but you'll never worry about the 3/8" BB.

[Dave Zellers]

Am I there?

You're definitely there. 3/8 would be the minimum for me on the big drawer.

[Judson Green]

I tend to over build too (almost always did ½" ply for drawer bottoms) but if you wanted (or don't want to go to the store to get another sheet) you could glue some reinforcement strips of ¼" to your ¼" ply bottoms. That should the trick.

[Kevin McCluney]

As my civil engineer brother always says "when in doubt, make it stout."

[Mike Heidrick]

1/2" BB is what I would use for shop drawer anything bottoms.

[Joe Samorodin]

Always 1/2" for drawer bottoms for me

[Steve Kohn]

Always 1/2" for drawer bottoms for me

Me three, I'm the same.

[Sal Kurban]

I have built pretty large drawers and used Baltic Birch 1/4 inch. For large drawers I always used a cross bar support at the bottom similar to the dovetail runners.
Sal.

[Bill Neely]

I tend to agree with Sal, 1/4" with a crossbar. That's assuming the bottom is glued in, I'd go thicker if it weren't.

[Richard McComas]

The sheeting on my house is 1/2'' on 24 inch centers. It's held tons of snow and Ice up to 3 feet deep and then get rained on making it very heavy. So far, so good.

http://i119.photobucket.com/albums/o159/rmccomas0043/Snow%20Jan%202012/Snow2012.jpg

I've been using 1/4 BB drawer bottom for years, large or small, shop drawers or pot and pan drawers. In the picture you see my 120 lb wife standing in the middle of a 22" x 46'' drawer box. I measured a deflection of less that 1/4''. If you're a civil engineer or a little deflection bothers you then go thicker. For me 1/4" has never failed me.


http://i119.photobucket.com/albums/o159/rmccomas0043/drawer.jpg

[Sal Kurban]

(...)

I've been using 1/4 BB drawer bottom for years, large or small, shop drawers or pot and pan drawers. In the picture you see my 120 lb wife standing in the middle of a 22" x 46'' drawer box. I measured a deflection of less that 1/4''. If you're a civil engineer or a little deflection bothers you then go thicker. For me 1/4" has never failed me.
(...)



I think credit must be given to the wife and not the drawer ;)
If my mother in law was to stand on a drawer like that, I would need a 1" thick drawer bottoms :)
Sal.

[eugene thomas]

For piece of mind go 3/8" or 1/2".

[phil harold]

"when in doubt, make it stout."
That's the ticket!

[phil harold]

I've been using 1/4 BB drawer bottom for years, large or small, shop drawers or pot and pan drawers. In the picture you see my 120 lb wife standing in the middle of a 22" x 46'' drawer box. I measured a deflection of less that 1/4''. If you're a civil engineer or a little deflection bothers you then go thicker. For me 1/4" has never failed me.
http://i119.photobucket.com/albums/o159/rmccomas0043/drawer.jpg
Testing it in the opposite of how it will be loaded?

[Richard McComas]

Testing it in the opposite of how it will be loaded?I've pretty much done that over a lot years under actual conditions.

[Larry Edgerton]

I think credit must be given to the wife and not the drawer ;)
If my mother in law was to stand on a drawer like that, I would need a 1" thick drawer bottoms :)
Sal.

I forwarded this to your mother in law............

Just kidding.

Larry

[Jeff Duncan]

I use 3/8" for everything…..it's just so much easier. I make dovetailed boxes and the max size of groove I can cut and hide behind the tail is……yup, 3/8"! So I keep 3/8" maple in stock and ready to go for drawer bottoms. Using 1/4" is too flimsy for my liking even in small drawers, and 1/2" would require me to make the boxes different or add steps to make rabbet the bottom. Either way it's added steps for little to no reward, so 3/8" is the magic number in my shop;)

good luck,
JeffD