When is it ok to use plywood

The first time I thought about not using plywood was reading the requirements on a BB. The question, ‘Oh, so plywood’s not ok, I wonder why?’ Popped into my head. I mulled it over for a while and I concluded that the manufacturing process probably involves lots of petrochemical byproducts, so that makes sense. And then the dust probably has some nasty stuff in it. I could have searched online but anything to do with petrochemicals is going to be littered with misinformation from all sides. Searching for plywood here brings up lots of BB’s saying I can’t use it. I would like to know why. I’m ok with not using it, I don’t want to start an argument! I’d just like to be educated.

The main reason I’m asking is, I have a bunch of wooden draws that I removed from a cubby unit which are all made of ply. I’d normally deconstruct them and reuse the materials in other projects. I’d also like to know when is ok to use plywood? What about bamboo sheets? I had thought that they’re a neat idea as bamboo grows fast and is very strong. It’s a much more renewable crop than forests.

Personally, I feel like reusing a product is always a good idea.

The "harm" of plywood, such as there is, is pretty much in the manufacturing process. I don't see a problem with reusing salvaged materials. The problem, as I understand it, is that the plywood process requires a substantial amount of industrial glue. The flip side is that the process makes a strong and durable material from timber that might otherwise be little more than pulp grade. And making equivalent material for construction purposes - like drawers - can be very wasteful, as material needs to be trimmed and cut to thickness.

My view is that plywood has it's place. But in modern construction practices it's use is over emphasised.

The only place they'll let plywood or paint get by is in the Oddball section of PEP and the basic reason is that no matter if the paperwork claims its innocence, there is generally toxic gick used in the manufacture and far too often, the surrounding area pays an environmental price. I can remember a cute article when some sort of vent system had an oops  at a chocolate factory and the neighbors woke up to a fine layer of chocolate dust coating their cars. (The company offered to send out staff to clean the cars, but the neighbors felt the "spill" was sufficiently non-toxic in this case that they were willing to handle the clean-up themselves.)  

So the short answer is that Paul wants PEP to show that humans can make stuff and do stuff the old-fashioned way that doesn't involve gick that is either toxic to make or doesn't biodegrade. You'll see the same emphasis in the textile area where you'll need to find cotton or linen (or for one thing I did, antique silk) thread because, surprise, that 100% cotton t-shirt in your drawer will biodegrade - except for the stitching that holds it together which you'll be pulling out of the compost/garden.

That said, for non-PEP stuff, or for Oddball stuff, I agree with Stacy that re-use and upcycling is acceptable. At least then we're getting the best use out of the embodied energy that's in there. I tend to be sensitive to formaldehyde, so I'm *really* aware how much stuff like that is used in the manufacturing process and off-gasses slowly over time contributing to indoor air pollution etc. (Including new fabric, so I always wash it at least once before sewing with it.)

If you need more info, I'd suggest you do some research on exactly what is in the glues that plywood uses - particularly the ones where the glue is waterproof. We tend to think of glue as having been around for centuries, but 1. those glues aren't what's being made today and 2. many times in the past, they didn't know they were poisoning themselves or the environment, or if they did know, it was at least on a much smaller scale. If  you find good info, please post it here.

I think Michael sums it up well.  Plus if you're cutting the plywood you're sending glue into your local atmosphere to be breathed.

I suspect that within PEP Homesteading you could also get away with using it.  I use it around the property if I have to and haven't bought a new sheet in ages.

I am sure this will not qualify for a PEP that says "no plywood".

Though this, in a way explains why plywood is not used.

I am just giving this information in case someone is looking for a better plywood. I have never used this product.

PureBond plywood utilizes a soy-based, alternative to toxic, formaldehyde-based resins. In other words, PureBond replaces a toxic substance with a completely non-toxic substance. Our wood is sourced from sustainably harvested North American forests, a renewable resource.

https://www.columbiaforestproducts.com/product/purebond-hardwood-plywood/

Thank you all - excellent discussion and I really appreciate your feedback.

The amazing benefit of doing BB’s is the mind shift it comes with. 80% of what I’ve done so far, I was doing anyway, or aspiring to, especially in the Nest badge. In theory, I could just do something as a one off to get the badge and go back to your old ways. Once I changed, I don’t want to go back. Most of the time, the new way is easier, better and quicker.

Plywood is a tough one. Having a uniform sheet of material to work with produces very consistent results is hard to beat. But so is using a tumble drier. In this case easier isn’t better.

Thank you for the link to the Columbia ply. I do have one project to build a big box for my cargo bike and I’m struggling to find a material that has the same functionality as regular ply. That looks like a good compromise.

I’ll use the draw ply to make storage bins, jigs and other non BB projects.

[quote=Anne Miller

PureBond plywood utilizes a soy-based, alternative to toxic, formaldehyde-based resins. In other words, PureBond replaces a toxic substance with a completely non-toxic substance. Our wood is sourced from sustainably harvested North American forests, a renewable resource.

Better is a relative term. It's so hard to judge when you might be getting greenwashed:
1. Most soya beans are grown with toxic gick and unsustainable farming practices. Since this is a non-food application, if they were grown in an effort to clean up a water system or to get the organic material out of sewage outflow before it reached a river, it could be a net benefit.
2. The car companies that went "green" by using a soya-based material to cover the electrical wires, have caused issues with owners who have found that rats particularly like soya cover wires!

That said, many traditional glues were made from waste stream products like hooves and chicken shit. Some of those glues may have been ecologically sound. However, we recently got rid of a brand-name set of plates from the 1980's because they had lead in the decorative paint that was wearing off and entering my environment. We've known lead is a dangerous, nasty chemical for a very long time - so why was it still being used on plates in the 1980'? Because it works and is cheap and who cares about the long term?

RE using it in PEP.

In quite a few of the BBs there are stated requirements, but little explanation of why each of those requirements exists. The "no plywood" rule makes sense, but if you haven't thought about it before the explanation is useful. And then when you come to your own projects you can make informed decisions, rather than follow someone else's rules which can seem arbitrary.

Michael Cox wrote: The "no plywood" rule makes sense, but if you haven't thought about it before the explanation is useful. And then when you come to your own projects you can make informed decisions, rather than follow someone else's rules which can seem arbitrary.

I would even say, "the most informed decision you can make". We don't always have the time or the access to research exactly where and how things are produced.

Sustainably produced wood from my own property is a no-brainer, but I'm totally aware how exceptional that is.
Wood from forests that would be less of a fire threat if they were thinned - same idea - there's a net benefit.
Wood from a tree downed in a storm - that wood has a benefit to the forest ecosystem, but it's still better than chopping down a healthy living tree, particularly if you leave all the brush behind.
Britain has demonstrated for hundreds of years how effective a coppicing system can be for producing some woods.

Industrially produced wood from a huge mono-culture plantation that clear cuts and burns the brush is not sustainable, but if it's all you can get to build your house, it might still win over concrete.

If we all do the best we can with the situation we're in, that's going the right direction.  There are a lot of people in my area building 4-6000 square feet homes if not larger. I don't know many permies who would do that, unless they intended the whole village to move in!

I find it easy to avoid buying ply,  because I'm a cheap skate, and plywood is expensive.
Last time bought any it was to protect the drywall I was transporting for a friend.
I returned it the store the same night.

Reuse, well that's another story.
I have a hard time giving up even a little 2'x2' square of the stuff.

For a lot of uses, there are alternatives.
Maybe the bike cargo box mentioned could be made with a wood skeleton and a sheet  metal skin.
Maybe poor man's fiber glass would work.
Depending on the usage, hardboard is an inexpensive option that doesn't use glues to hold it together.
For floors and the sheathing on buildings,  nail laminated timber or a diy version could work.

Can you help me;
What is a PEP and a BB please?
Acronyms drive me crazy!

Sorry John - I could explain PEP and BB but it’s all here:

https://permies.com/wiki/skip-pep-bb

BB / Badge Bits are the individual tasks

Mike Haasl wrote:I think Michael sums it up well.  Plus if you're cutting the plywood you're sending glue into your local atmosphere to be breathed.

I suspect that within PEP Homesteading you could also get away with using it.  I use it around the property if I have to and haven't bought a new sheet in ages.

Actually I'd be as worried about the wood dust as I would the glue. Fine wood dust that you might get off a tablesaw can give you cancer:
http://billpentz.com/woodworking/cyclone/index.php#index.php

And don't even get me started on MDF.

Just because something is natural doesn't mean it can't kill you - Ricin, arsenic and cyanide are all naturally occuring.

High quality plywood tends to be very strong and does not warp or crack under changes in atmospheric moisture, thus making it a reliable material for a wide variety of applications. It is used in many places like Exterior Wall Sheathing, Roofing & Flooring, Interior Walls and a lots of other furniture projects. Plywood can be a very practical and cost effective material for building furniture.
In situations where one particular side you want to be more furnished, a high grade plywood can be used.

Plywood is suitable for almost any furniture project imaginable within reason, so it’s not uncommon to find it used in custom built kitchen cabinets, almirahs, shelves, bookcases, console tables etc. Plywood is superb for making cabinet carcasses for kitchens, bedrooms and more.

My goal is to only use construction material that could one day end up being part of a garden I'd eat from. In this case, the question is exactly how nasty is the glue being used to form the plywood? Paying for new 'safe' plywood is expensive and begs the question. Answering the question adequately for found or reused plywood promises demands on time and mental energy that would for me make the prospect not worth it.

Not being a slave to perfection, I've used plywood as a stop gap material in a few places. It now becomes a matter of institutional memory to keep track of these instances and the reason for it in anything associated with my constructs. Sounds simple enough for these few pieces of plywood, until you consider how the bulk of corporate society consists of efforts to track such exceptions to the point where ignorance and apathetic acceptance of failure becomes the norm, such as with the lead plate example.