5-ply Plywood
Jovanna Ponder
SIG Plywood USE DROP DOWN MENU TO SELECT SIZE The finest quality plywood available. Imported from Finland and laminated with waterproof glue.Note: Plywood thickness dimensions are nominal and slight variations...
Around here (NJ) I only have four-ply fir or three-ply southern pine at the big boxes. They're typically around the same price. Sometimes the pine is a little cheaper. I mostly use the four ply for the reasons you mentioned. Additionally, if the pine has defects or bad joints in the laminations, it's going to have a greater affect on the strength of the panel. Regardless of what I choose, I typically pick plywood myself. Even then, sometimes its hard to get nice pieces. Today's plywood is nothing like what it used to be. The fir plywood used to sheath my folks' house #built in the early to mid 60s# is so nice it would be used for cabinets today. Overall though, it really doesn't matter much - you could sheathe a house with the worst plywood out there and it would still be incredibly strong.
In northern California, three ply is really common and home depot seems to stock it in 5 times the quantity of five ply at my local store. This would tend to refute your analysis.It doesn't make any sense to me.Thanks for your input.Karl
Thanks for that opinion.
I don't have the experience to criticize 3 ply but I have always felt that the couple of dollars extra I might pay for 5 ply was well worth it.The fact that home depot is choosing to sell five ply cheaper is baffling but ultimately a stroke of good fortune.If 3 ply is garbage and unworthy of the burn pile where does osb fit into the line up?Karl
i too in Jersey and see a lot of three ply. I am seeing a lot on roofs and if the house has any type of venting problems the three ply delaminates very quickly. Around here its complete garbage even compared to the four ply.
Blue,
I have used 3 ply many times when we want to skin over existing roof deck and have a clean dry smooth surface. now adays-if 7/16 osb is $5-$6 a sheet we use that to skin over a deck-but there HAVE been times in recent history that 7/16 osb was more than 3 ply.
we aren't terribly concerned about strength since we are skinning over an existing deck also- some roofing materials glue down better to plywood than to OSB so-all in all- 3 ply does have it's uses.
stephen
We raised a couple of 'free-range' ducks out on the lake a number of years back. Named one 'Thanksgiving' and the other 'Christmas'. Went pretty well although catching them in the fall using a pedal boat did kinda resemble a Three Stooges or Keystone Kops routine.
I think some of mine got et, but 2 black australorp hens and a rooster went to the fair, they were sharp lookers. And my little white leghorn hen became a little girls pet. That hen was always very friendly to people.
I really didn't make my comment because of strength issues. I made my comments based on the overall product. 3 ply is like building with spaghetti and it delaminates if it rains in the sahara. There is nothing good about the stuff that I ever saw. The species is usually the worst. It's just a horrible product. Of course, I'm pining for the good old days when all the plywoods were good. Nowadays OSB is normally far superior to any of the plywoods I see. There might be some good mills left...I just don't know about them.
Luckily- I generally work on 1920's vintage houses- so I rarely encounter plywood or OSB. I am having some luck cracking a neighborhood a couple decades older than that- making my encounters with plywood even more rare. mondays project was on house that the homeowner tells me is 104 years old- which is pretty old here.
stephen
hey- I almost forgot. Ecatly WHEN was plywood ever great? my experiences with 1960's era plywood- horrible stuff ! 3/8" thick, glue totally gone, plies entirely delaminated-all the rigidity of a old magazine. stephen
Try some 1944 vintage 3/8 plywood sheathing on wartime ex military houses, like mine. If it got damp it fall completely apart. Luckily the house was so drafty it didn't get a chance to rot.I stripped it completely down and found a number of signatures written on the front of the house and their military rankings. Navy, army, marines all built it. Kind of gives me a good feeling having seen that. It's all covered in hardiplanks now.
In my experience 3, 4,or 5 ply can be garbage but it is more likely with less plys.and there's some 10 ply hardwood ply out there that will make good countour maps of the Rockies....
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"After the laws of Physics, everything else is opinion" -Neil deGrasse Tyson
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If Pasta and Antipasta meet is it the end of the Universe???
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according to statistical analysis, "for some time now, bears apparently have been going to the bathroom in the woods."
We do have 1/16" plies available for cabinetry, of course (" is 8 plies, etc.); in French we call it 'Russian' plywood. Comes in 4x8 or 5x5 sheets. I've gotta drive halfway to Montreal to get it, tho....
You mentioned,"Maybe it's easier to kerf the back and bend it for curved applications?"In my experience it is really brittle and if you try to bend it you hear all sorts of cracking.I would go for the five ply if I wanted to bend it.Your other question, "Why wouldn't one, given the option, go for the ply with more layers than another?"I think it is marketed to builders who want to save a buck or two and only meet the minimum requirements. This goes back to my initial bafflement at the price of five ply being lower. It has always been more costly prior to this year.Karl
True, it's been a long time since I actually bought any plywood, but I have never seen or heard of 4 ply. All the plywood I have ever heard of had an odd number of plys with each ply running in a different direction.
An even number of plys means one of the outer skins is perpendicular to the other outer skin. This seems to defeat the very theory of how plywood works. It is designed to act as a stressed panel. I really have a hard time even envisioning such a critter.
I am gong to check this out with APA. I suppose that I should have check it out before I replied but I was so surprised at seeing 4 ply even mentioned.
Plywood with an even number of plies is made with a specific rotation of grain angle on the inner plies so that the outer plies can have parallel grain. I forget the actual angles, but IIRC I don't think it's something as simple or obvious as 0, +45, +135, 180. ;o)
's get placed here -->XReplies [email protected] Sep 05, 2007 10:30pm #1As a general rule the more plys the stiffer, and less voids. It also should machine better and hold screws better with more plys. But the glue type comes into play, so that isn't a hard and fast rule. There is quite a bit of plywood coming in from over seas, that is of suspect quality. There is also some great stuff coming in.
My local lumberyard had some "shop grade", which means ungraded, 17-ply 3/4 hardwood stuff for a while that had started life to be AA cabinet grade, but had sand throughs in one or both faces. Stuff was dirt cheap, and I should have bought a bunch more of it.
The quality of the veneer core plies is more important than the quantity . 5 ply domestic hardwood is the bottom of the line in most cases hardwood plywood 3/4" comes 7 and often 9 ply . The 11 ply or 17 ply is surely an overseas ( China probably ) product .
Plywood is graded several ways , the face may be a B face and a 3 back , there are core grades as well , C core D core and so on A-1 being the best grade usually.Face materials have different allowances within each classification such as Monarch Birch may have large but tight knots Plain Sliced is bookmatched and Rotary cut Oak may be whole piece face (wpf) split face is chopped pieces of rotary cut. Plain Sliced is not created on a lathe like rotary cut veneers.Vine marks are allowed with some grades of Maple .
While we are on the subject of plywood, I have just started considering a couple of products where sheet goods are the only reasonable way to go. My question, I haven't had much luck finding a good source of reasonably priced plywood. Any suggestions on where to look besides the big box guys? There are plenty of distributors but none seem to be interested in someone looking for 3-4 sheets at a time.
You can look in the yellow pages under cabinet makers and may find suppliers , try one , if not then try a small to medium size cabinet maker .Tell them what your up to and if they feel you are no threat to them they may be more willing to help. Some guy's might even look at it as beer money if you catch him just right .
Kenny , sit down , if you want good plywood and haven't found a reasonably priced source yet , the reality is close to this ,the quality plywood products are made for all types of applications . But ,,,
The better grades of hardwood veneers and such are not going to be bargain basement priced . Downfall and shop grade of these nicer panels are less then the on-grade certified and graded panels price point .
Then we now have the China Syndrome ,,, maybe some of the product is the best of it's kind ever made ? But I'm not so sure I've heard many rave about the product , maybe we will now? When it is all that's offered , that's what you get .
First off the face (Jatoba) was really nice. The back of the wooden ply looked just a bit better than C grade.. I should have stopped there but (Me being me, I got that sheet of wooden ply 3/4 inch). I couldn't't wait for MDF backed at the time..
I want to go back to the place I got it from and raise hell but overall I usually get nice stuff from them.. I want to raise hell, but I'm just not that way.. I should have known better when I saw the back.
The 11-ply that I think you are asking about is Acathus. I am fairly certain that it is from China. Proceed with caution as this stuff can be highly unstable. Yeah the price is cheap, until they put the competition out of business. There is a reason why some are now calling Homer's the Borg. Please support your local hardwood lumber dealer and buy your goods there, while you still have a choice.
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