Why is all big box store plywood warped??????

[Randall J Cox]

Both Home Depot and Lowes here where I live have warped plywood. I've seen videos of them making plywood in huge hot presses with pressure and heat - and they are dead flat when they come out of the press. Where along the way do they intentionally warp them? It must be intentional as no matter what type or thickness or size, they are warped...……. Rant over...…. Randy

[Dick Mahany]

Both Home Depot and Lowes here where I live have warped plywood. I've seen videos of them making plywood in huge hot presses with pressure and heat - and they are dead flat when they come out of the press. Where along the way do they intentionally warp them? It must be intentional as no matter what type or thickness or size, they are warped...……. Rant over...…. Randy

And the ones that aren't warped are usually broken or damaged from the forklift or handling:rolleyes:

[Mike Hollingsworth]

Nature of the Beast. If you want flat Multi-Ply is the way to go. Baltic Birch or similar.

[Rod Sheridan]

Both Home Depot and Lowes here where I live have warped plywood. I've seen videos of them making plywood in huge hot presses with pressure and heat - and they are dead flat when they come out of the press. Where along the way do they intentionally warp them? It must be intentional as no matter what type or thickness or size, they are warped...……. Rant over...…. Randy

Randy, think price. A sheet of good plywood is about twice the price of what you're looking at, if you're thinking of cabinet making stuff.................Rod.

[Andrew Hughes]

The warping occurs during transport from the warp drive. Big Over priced Retail Giant. Also known as the Borg. Stay away unless you want to be assimilated :)

[Ben Rivel]

It is partially due to handling sure, but its also just junk quality. Useful for maybe shop projects that youre going to beat the heck out of, but certainly not anything nice.

[Mike Kreinhop]

Randy, think price. A sheet of good plywood is about twice the price of what you're looking at, if you're thinking of cabinet making stuff.................Rod.

...and it has to be stored correctly. I just discovered my last full sheet of 19mm cabinet grade plywood is now scrap because I leaned it on an angle against a wall in my garage a couple of weeks ago and forgot about it. It now has a significant warp. :(

[Simon MacGowen]

...and it has to be stored correctly. I just discovered my last full sheet of 19mm cabinet grade plywood is now scrap because I leaned it on an angle against a wall in my garage a couple of weeks ago and forgot about it. It now has a significant warp. :(

Many people make the same mistake in glue-ups. After assembly on a flat top but move the assembly in clamps to the floor or against, introducing possible twist to their work without realizing it ... until they try to hing a door to it (if a cabinet)!

Simon

[Steven Harrison]

I was picking up some ply from Lowes and the size I needed was all warped and water damaged. I let one of the employees know, and he said they already knew, but there was nothing they could do. Their AC unit was dripping condensation down on all the stacks.

[Todd Bender]

Most import (read Chinese) core plywood is not only warped, but sometimes will turn corners while being ripped.
I haven't used 1/2" Baltic birch in years because it was always warped.
You need a good local plywood/hardwood supplier carrying quality domestic plywood.

[Ron Citerone]

Many people make the same mistake in glue-ups. After assembly on a flat top but move the assembly in clamps to the floor or against, introducing possible twist to their work without realizing it ... until they try to hing a door to it (if a cabinet)!

Simon


That makes sense and I just learned something that I will try to correct! Thanks

[Steve Demuth]

It is partially due to handling sure, but its also just junk quality. Useful for maybe shop projects that youre going to beat the heck out of, but certainly not anything nice.

You can always buy framing at the same store that is equally crooked, and either go for an "organic" design sense in your construction, or maybe oppose the curves and pull everything back to straight. If neither of those works, probably need to pony up the much bigger bucks for quality material.

[Larry Frank]

The way they store plywood on rack with arms make them warp. I go to Menards where they store the plywood flat.

[Matt Day]

The way they store plywood on rack with arms make them warp. I go to Menards where they store the plywood flat.

This ^^^^^^

[johnny means]

The biggest problem is lack of QC in manufacturing. It takes extra steps and care to make plywood that doesn't easily warp. Extra steps and American thriftiness can't co-exist.

[Steve Demuth]

Plywood I have gotten at Menards in the past was as badly warped as any as soon as you removed it from the pressure of the pile. Poor storage doesn't help, but the quality of BORG plywood pretty much guarantees it won't be flat.

[Cary Falk]

I think some it is how it is stored. I very seldom see it laying flat. I also sink it is how it is made. That being said Borg plywood is better quality than some plywood I have paid almost 2x for at a real wood store.

[Dave Zellers]

For Heavens sake. We learned how to make quality plywood decades ago. If not a half century ago. If you want quality plywood, shop at a place that sells quality plywood.

It won’t be at any of the Borgs. Period. They sell on a price point. If you are looking for quality plywood, stop shopping price.

[Randall J Cox]

For Heavens sake. We learned how to make quality plywood decades ago. If not a half century ago. If you want quality plywood, shop at a place that sells quality plywood.

It won’t be at any of the Borgs. Period. They sell on a price point. If you are looking for quality plywood, stop shopping price.

My original question is why is it all warped.... I'm well aware that you can get anything you want if you want to pay enough.

[johnny means]

My original question is why is it all warped.... I'm well aware that you can get anything you want if you want to pay enough.

It warps because it is made with sub par materials that may or may not be properly dried. The adhesives may or may not be evenly applied amongst the plies. The gluing, heating, and cooling process may not be done properly, creating a product that is under stress from the very beginning.

[Sean Nagle]

I buy sheet goods from my local hardwoods supplier and millworks. My experience has been that veneer core plywood will eventually always bow to some degree. MDF core plywood is more stable. I have only once purchased plywood from Lowe's which I used right away with good results.

[Warren Lake]

I was at a bus one day, talked to the owner he said he was a past partner in a large supplier I knew of. We talked for a bit, very well to do guy. He said they brought in a lift of ply from offshore to try. Said it smelled so bad they had to leave it outside. One day months later they decided to cut into some of it and the found an underwear band inside a sheet. Have to give them credit at least they were recycling.

[scott vroom]

It warps because it is made with sub par materials that may or may not be properly dried. The adhesives may or may not be evenly applied amongst the plies. The gluing, heating, and cooling process may not be done properly, creating a product that is under stress from the very beginning.

I read somewhere that the veneers aren't dried to the same MC before they're sandwiched which causes warping/twisting.

[Rich Engelhardt]

Menards, Home Depot & Lowes in my area all sell red oak 3/4" (LOL! yeah right!) plywood for around $60 a sheet.
Hartville Hardware & Terry Lumber charge about double for the same thing.

The quality is about the same - regardless of price.

Yeah Menards does store their's flat instead of on racks w/arms, but, at the new Menards they just built down the road from me, they don't have anyone working there that knows how to stock shelves.
Instead of carefully putting the sheets in the rack, they jam them in with a forklift and tear the crud out of the edges.

What bothers me the absolute most though about the whole thing is - - they know it's junk, but, they refuse to open a new bundle of decent material until all the scrap on the rack is sold.



One day months later they decided to cut into some of it and the found an underwear band inside a sheet.Years ago, someone here posted about finding a utility knife inside a piece of imported plywood. I think about that every single time I cut a sheet.....

[Todd Bender]

Several years ago I cut through a piece of metal about 6" long in the middle of a sheet of import ply. It was a little thicker than a utility knife blade. Fun stuff.

[Ole Anderson]

The way they store plywood on rack with arms make them warp. I go to Menards where they store the plywood flat. That was going to be my observation also, but Larry and Matt beat me to it! My local cabinet shop supplier stores all sheet goods on flat shelves not on arms.

[lowell holmes]

Lumbercore plywood might be flatter. Also, buy from a lumber yard instead of big box stores.

[Mike Wilkins]

Find a local dealer that supplies the cabinet shops with their material. Their stock is usually of much better quality since they are selling to the consumer in the form of finished kitchen and bath cabinets and large built-in cabinets. The price will surely be a bit more but you pay for quality.

[Peter Christensen]

At one time plywood was made of old growth trees. Now second growth if lucky.

[Dave Lehnert]

My local hardwood dealer said overseas plywood core is stored outdoors then sandwiched with the good dry veneer.

[Nick Shattuck]

I believe most HDs buy plywood local suppliers. Mine sells birch (not Baltic birch) that's not too bad... thin veneer and thick plys but I've never seen them warped.

[Dave Zellers]

My original question is why is it all warped.... I'm well aware that you can get anything you want if you want to pay enough.
??? It’s warped because it’s poorly manufactured. That’s why it costs less.
On top of that, the stores selling crappy plywood don’t bother to handle/store it correctly.

But that’s a good thing since that would only deceive the consumer into thinking it was a better product than it is.

[Ole Anderson]

So my take on this thread (and my personal experience) is that big box ply isn't always as bad as some will make you believe. Hit or miss. And just because it is from a lumber yard doesn't guarantee a perfect product. Spend your money and take your chances. Best bet is to pay big bucks and get it from a cabinet supplier. If your pockets are deep.

[Mike Cutler]

What plywood are we referring to here?
The construction ply at the BORG near me is all Georgia Pacific. It does warp and potato chip, but it's not meant to be used for jigs and fixtures, or furniture. Some of the damage is caused by customers moving it around to find"the best piece" and then not put back on the piles. You should see some of the messes I've seen in the plywood aisle.
The "finer" ply comes from Canada. It's not furniture quality, but if you store it properly it will keep it's shape.
I know they have some oak and maple ply, but unless they're blowing it out of store, I leave it there. I have seen it priced less than construction grade because it gets damaged. It's good for making chicken coops and quail recall houses. It always warps and potato chips.
The places near me that actually sell furniture, or cabinet grade, ply do not let the customer go through the plywood panels. They'll pull it out for you and let you inspect it, but they put it back. You don't "handle it" until you've bought it.

[julian abram]

My original question is why is it all warped.... I'm well aware that you can get anything you want if you want to pay enough.

I'm no plywood expert for sure but I've always guessed varying densities and moisture content of the inner cores is the main factor. Of course shipping, handling and storage affects flatness as well but I consider those secondary to the manufacturing process of materials used.
I would guess if you had a sheet with all plies of uniform density with no voids and uniform mc, 90% of warp problems would be eliminated.

[Rick Peek]

In my area there is only one real supplier of quality ply. They are open
Mon - Thurs and really have no interest selling to hobbiest. They are located
In an idustrial area no where close to anybody,which makes it all but
Impossible for me to get there. There is also a lumber yard that sells to
All the builders with a plywood and hardwood department. I found their
Plywood is of no better quality than the the borg,and it is twice the price!
I let the manager of the wood department know my feelings and she
Agreed 100%. She said she has talked to the owners of the company
And they basically told her, tough crap.So I make due with borg ply,
But only buy when I see they
have some decent stuff, ( which occasionally
They do) . I find the products they carry are not always the same each time.

[Mike Cutler]

My original question is why is it all warped.... I'm well aware that you can get anything you want if you want to pay enough..



It's not a quality product to begin with.
It's made with inferior graded woods.
It's processed and pressed green.
The adhesive/glue component is probably just as inferior as the wood.
It's bundled and banded "wet".
It's poorly stored and handled at the store.
There is very little humidity control at all in any of the big box stores.

I'm only referring to the "cabinet quality" ply sheets they sell. The construction ply is made to a spec for building codes. It's not meant for wood working.

The same is true of the softwoods and hardwoods they sell by the linear foot. You would have to try hard, to find a way to pay more per bd/ft. than the stuff at a home center.It's generally just bottom of the barrel and barely meets the spec they're claiming.

It's all generally crap, but every now and then they seem to get some usable quality materials.
The Canadian ply they're selling near me is actually not bad stuff for general use and home projects. Not furniture, or cabinets.

[Jim Andrew]

About 40 years ago, before the US was trading with China, I built a house, and also built the cabinets in that house. In those days builders used sheet goods for the doors, and routered a decorative groove in the face. Birch ply. After I had finished the house and sold it, the purchaser called up and said he had some warped doors. So I had to replace several of the cabinet doors that just had warped huge, probably 1" across corners. So I made replacement doors, finished them, and changed them out, then took the warped doors and put them in the shop, where they just laid. Later the doors flatened out, after they had finally dryed out, so was just a moisture in the plywood issue.

[Jim Dwight]

I have been buying nominal 3/4 plywood at the local Home Depot for shop use and for one painted bathroom cabinet. It has a sticker that says it is made in Chile. It is softwood. There are few voids and I have not had an issue with warping. In addition to a floor to ceiling cabinet in my bathroom, I've made my workbench/outfeed table and some cabinets for the shop out of it. I've probably used 4 sheets so far - not a lot.

Over the years I've used oak veneer from big box stores and cherry veneered mdf from a big wholesale/retail outlet in Charlotte. The mdf was the flatest but I've never had plywood too warped to use. I've even used B/C plywood from a local lumber yard. It was poorly sanded on the C side but was decent.

I've seen it warped in the store but I just didn't buy that sheet.

I suspect plywood warps for the same reason solid lumber warps - the moisture content changed.

[Joe Chritz]

The local Menards in my area has some very good sheet goods with a lot available on special order. It is expensive and even with that there are still some bad sheets here and there.

It pays to look around and even see what is available on order.

Joe

[Ronald Blue]

The local Menards in my area has some very good sheet goods with a lot available on special order. It is expensive and even with that there are still some bad sheets here and there.

It pays to look around and even see what is available on order.

Joe

I had similar results at Menards. I picked up 3/4" birch for a project and it was flat. I think it was 7 ply. I have looked at their oak and walnut and it appeared to be flat as well. No matter where you shop you can find warped sheets. It's wood and it moves. You can pay more but there's no guarantee it will be better.

[Randy Rush]

I tried to purchase 2 sheets of Baltic Birch on Saturday from one of the BB stores and every sheet we looked at was bowed so bad I would not be able to use them. The store employee just shook his head and told us we would be better off to go elsewhere--so I'll try the OTHER BB store and see what they have

[bill tindall]

The plies were wet when they were assembled into plywood. I checked moisture level on some that was warping as it dried and it was an astonishing 18%!. that is framing lumber moisture content.

[Tim M Tuttle]

The only plywood I use from the big box stores is Purebond from HD. It's pretty good and usually flat if they've stacked it decently. The plywood at my area Lowes stores is absolute junk. Menards is better than Lowes but not nearly as good as Purebond. If I need something better than Purebond I'll just go to Woodcraft and buy BB for $60 a sheet.