Plywood Thickness Guide: Sizes, Grades & Uses

Plywood thickness sizes determine appropriate applications in construction, furniture, and various projects. The thickness of plywood directly impacts its structural integrity, influencing its ability to withstand loads and resist bending or deformation. Selecting the correct plywood thickness also correlates to project cost, as thicker sheets are generally more expensive. Standard plywood grades are available in a range of thicknesses from 1/8 inch to 1 inch or more, while sheet dimensions typically are 4 x 8 feet, allowing flexibility for different project needs.

Contents

The Essential Guide to Plywood Thickness: Get it Right the First Time!

Why Plywood Thickness Matters: A Nail-Biting Intro

Ever feel like you’re swimming in a sea of wood options? Plywood, my friends, is that trusty life raft – versatile, reliable, and used in just about everything. From crafting Pinterest-worthy furniture to building the very roof over your head, plywood is a superstar in the construction and DIY world.

But here’s the kicker: like Goldilocks searching for the perfect porridge, you’ve got to find the right thickness. Pick too thin, and your project might resemble a wobbly house of cards. Too thick, and you’re lugging around unnecessary weight (and spending extra dough!).

Think of it like this: choosing the right plywood thickness is like picking the right tires for your car. You wouldn’t put bicycle tires on a truck, would you? (Unless you’re going for some seriously avant-garde art, of course).

From whisper-thin sheets for delicate crafts to beefy slabs for heavy-duty construction, the range of plywood thicknesses can feel overwhelming. But fear not! This blog is your friendly neighborhood guide, here to help you navigate the world of plywood like a pro.

Our mission is simple: equip you with the knowledge to confidently select the perfect plywood thickness for every project. Consider this your cheat sheet to avoid costly mistakes, ensure rock-solid results, and maybe even impress your friends with your newfound plywood wisdom.

Decoding Plywood: A Thickness Tour!

Alright, let’s get down to brass tacks – or, you know, wood screws – and talk about plywood thickness. It’s not the most glamorous topic, but trust me, getting this right is crucial for a successful project. We’re going to stroll through the most common sizes, shining a light on where they shine (and where they might fall short). Think of it as a Goldilocks guide, but for plywood!

1/8 Inch Plywood: Featherweight Champion

Applications: Think delicate! This stuff is your go-to for cabinet backs, drawer bottoms (especially in smaller drawers), model making, and any project where weight is a major concern.
Advantages: Super flexible, lightweight, and easy to cut. It’s the ballerina of the plywood world.
Disadvantages: Strength? Not its forte. This thin plywood is prone to warping and isn’t suitable for load-bearing applications. Definitely not for building a deck!
Limitations: Don’t even think about using it where it needs to hold anything heavy or withstand any significant stress.
Visual Aid: A photo of a beautifully crafted model airplane using 1/8″ plywood, showcasing its flexibility and lightweight nature.

1/4 Inch Plywood: The All-Arounder

Applications: A step up in strength, this is great for cabinet backing, some drawer bottoms (especially if reinforced), paneling, and craft projects.
Advantages: Offers a decent balance of flexibility and rigidity. It’s still relatively easy to cut and work with.
Disadvantages: Still not incredibly strong, and can still warp if not properly supported.
Limitations: Don’t use this for anything structural. Leave the load-bearing to its thicker cousins.
Visual Aid: A photo of a neat, organized cabinet, highlighting the 1/4″ plywood back panel.

3/8 Inch Plywood: Finding the Middle Ground

Applications: Now we’re getting a bit sturdier. Good for drawer sides, some furniture components (think lightweight shelving or decorative panels), and underlayment for flooring in low-traffic areas.
Advantages: Offers more rigidity and strength than thinner options, making it a better choice for projects that need a bit more support.
Disadvantages: Starting to lose some of that easy flexibility, can still be prone to warping if unsupported over long spans.
Limitations: Still not suitable for structural applications, but a good choice when you need something more robust than 1/4″ plywood.
Visual Aid: An image showcasing a simple shelving unit made with 3/8″ plywood.

1/2 Inch Plywood: The Workhorse

Applications: A very common choice for a wide range of projects. Think cabinet sides, shelving, furniture construction, and some wall paneling.
Advantages: A great balance of strength, stability, and workability. It’s strong enough for many applications, but still relatively easy to cut and shape.
Disadvantages: Heavier and less flexible than thinner plywood.
Limitations: May not be thick enough for heavy-duty structural applications or long unsupported spans.
Visual Aid: A photo showcasing a stylish kitchen cabinet made with 1/2″ plywood.

5/8 Inch Plywood: Stepping Up the Strength

Applications: When you need a bit more muscle! Good for subfloors, roofing, and some structural sheathing.
Advantages: Increased strength and rigidity compared to 1/2″ plywood. Offers better resistance to sagging and warping.
Disadvantages: Heavier and more expensive than thinner options.
Limitations: Less flexible and can be more difficult to work with.
Visual Aid: A close-up image of 5/8″ plywood being used as roof sheathing.

3/4 Inch Plywood: The Heavy Hitter

Applications: This is where things get serious. Ideal for structural applications, such as subfloors, roofing, wall sheathing, and heavy-duty furniture construction. It’s the choice for countertops and tabletops too.
Advantages: Excellent strength and stability. Resistant to warping and sagging. Can handle heavy loads.
Disadvantages: Heavy, expensive, and can be more difficult to cut and work with.
Limitations: Not suitable for projects where flexibility is required.
Visual Aid: A photo showcasing a robust workbench made with 3/4″ plywood.

1 Inch Plywood: The Unstoppable Force

Applications: Serious structural applications. Think industrial flooring, heavy-duty shelving, and specialized construction projects.
Advantages: The ultimate in strength and stability. Can handle extreme loads and resist warping even over long spans.
Disadvantages: Extremely heavy, expensive, and difficult to work with. Requires specialized tools and expertise.
Limitations: Overkill for most DIY projects.
Visual Aid: A photo of 1″ plywood being used in the construction of an industrial warehouse floor.

So, there you have it! A whirlwind tour of common plywood thicknesses. Remember, choosing the right thickness is all about matching the material to the task. Don’t use 1/8″ plywood to build a deck, and don’t use 1″ plywood to make a model airplane! (Unless you’re building a very sturdy airplane.)

Units of Measurement: Inches vs. Millimeters Explained

Okay, folks, let’s talk about how we actually talk about plywood thickness. It’s not just “thin,” “medium,” or “chonky,” sadly. We use actual measurements! But here’s the catch: not everyone speaks the same measurement language. It’s like ordering coffee in Italy – you can ask for a “large coffee,” but you’ll probably get a raised eyebrow and a tiny espresso.

Inches: The American Way

If you’re in the good ol’ US of A, chances are you’re dealing with inches. It’s the system we love to love (and sometimes love to hate). When it comes to plywood, you’ll see thicknesses denoted like this: 1/4″, 3/4″, 1/2″ etc. That little double quote (“) is the secret symbol for inches. Easy peasy, right? You might also see these written as decimals (0.25″, 0.75”) depending on how precise things need to be. This is the way we’ve always done it, and by golly, we aren’t about to change anytime soon!

Millimeters (mm): The International Standard

Now, venture outside the US or delve into more technical specifications, and you’ll likely encounter millimeters (mm). This is the standard unit of measurement used in most of the world and in many industries. It is precise, reliable, and utterly confusing to those of us who grew up on the Imperial system. Don’t panic! It’s just a different way of slicing the pie.

The Inch-to-Millimeter Magic Conversion Table

Here’s your cheat sheet, your Rosetta Stone, your secret decoder ring to translate between these two languages:

Inches (“)	Millimeters (mm)	Common Use
1/8″	~3mm	Thin projects such as model making.
1/4″	~6mm	Cabinet backs, drawer bottoms.
1/2″	~12mm	Furniture, general-purpose projects.
3/4″	~18mm	Construction, shelving, sturdy furniture.
1″	~25mm	Heavy-duty construction.

Disclaimer: The tilde (~) means “approximately.” These are rounded conversions for easy remembering. If you need absolute precision (like, rocket-science-level precision), use a proper conversion calculator.

So, there you have it! No matter where you are or what the spec sheet says, you can now confidently navigate the world of plywood thickness measurements. Go forth and measure… accurately!

Plywood Types and Thickness: It’s a Match!

So, you know that plywood isn’t just one thing, right? It’s like the ice cream aisle – endless flavors (or, in this case, types!). And just like you wouldn’t put sprinkles on steak (eww!), you wouldn’t use just any plywood for just any project. That’s where thickness comes in, working hand-in-hand with the type of plywood to get you the perfect match. Let’s dive in, shall we?

Lauan/Meranti Plywood: Thin and Mighty (in its own way)

Think of Lauan or Meranti plywood as the lightweight champ. It’s typically available in thinner profiles, around 1/8 inch to 1/4 inch. Why so thin? Because it’s often used for things that don’t need to bear a ton of weight, like the backs of cabinets or the bottoms of drawers. It provides a smooth, clean surface without adding unnecessary bulk or cost. It’s a great option for adding a finished touch and a bit of needed support without going overboard.

Sheathing Plywood: Strong and Sturdy

Now we’re talking serious support! Sheathing plywood is the backbone of walls and roofs. You’ll typically find it in thicknesses like 1/2 inch, 5/8 inch, and 3/4 inch. The thickness you choose depends heavily on how far apart your studs or rafters are spaced. Wider spacing? You’ll need thicker sheathing to prevent sagging or flexing. Think of it like a bridge – the longer the span, the stronger the support needs to be.

Underlayment Plywood: Smooth Operator

Underlayment plywood is all about creating a smooth, stable surface for your flooring. It typically comes in thicknesses ranging from 1/4 inch to 1/2 inch. The goal here is to eliminate any imperfections or unevenness in the subfloor, ensuring your finished floor looks flawless and lasts longer. Thicker underlayment provides more stability, especially if your subfloor isn’t perfectly level.

Marine Plywood: Built to Last (at Sea!)

When it comes to boats, you don’t mess around! Marine plywood is designed to withstand constant exposure to water, and thickness is crucial for hull strength and water resistance. Typical thicknesses vary depending on the size and type of boat, but you’ll generally find it in the 1/2 inch to 1 inch+ range. Remember, your life might depend on this stuff, so don’t skimp! Its important to invest in the right marine plywood for the right application.

Hardwood Plywood: Beauty and Brawn

Hardwood plywood is the go-to choice for furniture and cabinetry where aesthetics matter. You’ll find it in thicknesses like 1/4 inch, 1/2 inch, and 3/4 inch. The thickness affects not only the look but also the structural integrity of your finished pieces. Thicker plywood provides more stability and strength, while thinner plywood can be used for decorative panels or non-load-bearing components. You need to balance form and function, people!

Plywood Quality and Thickness: Understanding Grades

Alright, let’s dive into the slightly mysterious world of plywood grades and how they play with thickness! Think of plywood grades like report cards – they tell you how pretty (or not so pretty) the face of the plywood is, and that impacts what thicknesses work best for your project.

Decoding the Alphabet Soup: A, B, C, and D

You’ve probably seen those letters stamped on plywood: A, B, C, and D. These aren’t just random; they signify the quality of the wood veneer used on the face of the plywood. “A” is the valedictorian—smooth, sanded, and ready for a beauty contest. “D” is more like the kid who showed up to school in pajamas—rough, with knots and imperfections.

“A” Grade: This is your show-stopper. It’s practically flawless, perfect for projects where the wood grain is visible, like high-end furniture or cabinetry. Because it’s so smooth, you can get away with thinner veneers and still have a beautiful finish.
“B” Grade: A step down from “A,” but still pretty presentable. It might have a few minor imperfections that can easily be fixed with some sanding and wood filler. Great for projects where appearance matters but doesn’t need to be perfect. Again, works well with a range of thicknesses depending on the underlying structure.
“C” Grade: Now we’re getting into workhorse territory. “C” grade plywood has more knots and imperfections, but it’s still structurally sound. This is your go-to for projects where the face isn’t as important, like sheathing or underlayment. You might opt for thicker plywood in this grade to compensate for the less-than-perfect surface.
“D” Grade: The “D” stands for “don’t judge a book by its cover.” This stuff is rough! Expect large knots, splits, and other imperfections. It’s primarily used for structural applications where appearance doesn’t matter at all, and it’s often paired with thicker plywood to ensure strength.

Face Value: When Looks Really Do Matter

Think about it: if you’re building a sleek, modern coffee table, you’re going to want a pristine “A” grade face. A thinner plywood in “A” grade can be laminated onto a stronger, thicker, but less aesthetically pleasing core. On the other hand, if you’re building a shed where nobody will see the plywood, you can save some money with a “C” or “D” grade, potentially opting for a thicker sheet to handle the elements. It’s all about matching the grade to the job, and then choosing a thickness that supports both the look and function!

Exterior vs. Interior Grades

Inside Out: For indoor projects, you’re typically shielded from the elements. Think cabinets, furniture, or interior walls. You can often get away with thinner plywood here, as it’s not battling rain, sun, or extreme temperature changes. Interior-grade plywood uses glues that aren’t waterproof, so it’s not a good idea to use them outdoors.
Brave the Outdoors: Outdoor projects are a whole different ballgame! Decks, siding, or anything exposed to the weather needs exterior-grade plywood. This type uses waterproof glues to resist delamination. And, because the outdoors can be tough on materials, it’s generally a good idea to go with thicker plywood for added strength and durability. The thicker the better when it comes to weather resistance! For example, marine-grade plywood (an exterior grade) often comes in greater thicknesses because it’s designed to withstand constant water exposure.

Application and Thickness Requirements: A Project-Based Guide

Alright, let’s get down to brass tacks! You wouldn’t wear flip-flops to climb Mount Everest, would you? Same goes for plywood – the right thickness is key to success. So, let’s break down some common projects and the plywood thicknesses that’ll have you saying, “Nailed it!”

Flooring: Laying a Solid Foundation

When it comes to flooring, you’re essentially building a stage for your life. You need something solid underfoot, and plywood thickness is a major player. For subfloors, you’re typically looking at 5/8-inch to 3/4-inch plywood, depending on the joist spacing. Think of it as the foundation of your floor, it needs to handle the weight of you, your furniture, and that midnight fridge raid.

Now, for underlayment (that smooth layer between the subfloor and your fancy vinyl, laminate, or tile), you’ll often see 1/4-inch to 1/2-inch. This is the finishing touch that ensures a smooth, even surface. And of course, always, always check those pesky building codes and standards. They’re not always fun to read, but they’re there to keep you safe and sound (and your floors from collapsing!).

Roofing: Keeping a Roof Over Your Head

Roofing is where you really don’t want to mess around. Picture yourself in a storm, cozy inside, all thanks to properly installed, appropriately thick plywood. For roof decking, the thickness depends heavily on rafter spacing and potential snow load. Generally, you’ll find 1/2-inch, 5/8-inch, or even 3/4-inch plywood being used. The wider the spacing, the thicker you need to go! This is where those span ratings become your best friend. Seriously, don’t guess – consult the span rating to avoid any unexpected skylights appearing during a heavy snowfall. And if you are going to DIY, you should also remember some key building codes and standards or even consider professional install from start to finish.

Wall Sheathing: Strong Walls, Safe Havens

Wall sheathing is the unsung hero that gives your walls their backbone. Think of it as the ribcage of your house. The thickness you need is determined by framing (stud) spacing and the loads the wall will bear. Typically, 3/8-inch to 5/8-inch plywood is used. Heavier loads or wider stud spacing? You guessed it – go thicker! Just like with roofing, those engineering guidelines aren’t just there for fun. They ensure your walls can stand up to wind, weather, and whatever else Mother Nature throws your way.

Furniture Making: Balancing Beauty and Brawn

Ah, furniture! This is where artistry meets practicality. The balance between thickness, weight, and aesthetics is crucial. You don’t want a coffee table so heavy you can’t move it, but you also don’t want one that collapses under the weight of your remote control.

Tabletops: Aim for 3/4-inch for a sturdy surface that can handle spills and everyday use.
Sides: 1/2-inch to 3/4-inch provides good support without adding excessive weight.
Shelves: Depending on the span and expected load, 1/4-inch to 3/4-inch will do. For longer shelves, consider thicker plywood or adding support.

Cabinetry: A Place for Everything

Cabinets are like furniture’s organized cousins. For cabinet doors, 1/4-inch to 1/2-inch keeps them light and easy to swing open. Cabinet sides benefit from 1/2-inch to 3/4-inch plywood for structural integrity. Shelves follow similar rules to furniture shelves, varying from 1/4-inch to 3/4-inch based on span and load. And for those cabinet backs? Often, 1/4-inch is sufficient, as they’re not usually load-bearing.

Construction (General): Building it Right

In construction, structural integrity is paramount. Skimping on plywood thickness is like playing Russian roulette with your building. Always ensure you’re using the appropriate thickness for the intended application. Using too thin of plywood can lead to flexing, warping, or even catastrophic failure. We are not trying to build for the long run.

Marine Applications (Boat Building): Ahoy, Matey!

Boat building? Now you’re entering a whole new level of seriousness. You’re dealing with water, which is relentless. Hull strength and watertightness are absolutely critical. Thickness requirements vary greatly depending on the size and design of the boat. Think about how hard the water will be hitting the side, the harder it hits, the thicker it needs to be. Always reference specific guidelines or standards for marine plywood use, and don’t even think about cutting corners here. Your safety (and the safety of anyone on board) depends on it!

Fasteners and Plywood Thickness: Finding the Perfect Match

So, you’ve nailed down (pun intended!) the right plywood thickness for your project. Awesome! But hold your horses, partner, because the story doesn’t end there. Choosing the right fasteners – nails or screws – is just as crucial as the plywood itself. Think of it like this: you wouldn’t put cheap tires on a race car, right? Same principle here! Using the wrong fasteners can lead to wobbly shelves, creaky floors, or even structural failures. Let’s get it right.

Nailed It! (Or Not?): Choosing Nails for Plywood

Nails are the classic, tried-and-true fasteners. They’re quick, relatively inexpensive, and work well for many plywood applications. But here’s the skinny: not all nails are created equal. You need to consider both the length and the gauge (thickness) of the nail.

Length Matters: As a general rule, you want a nail that penetrates at least halfway into the underlying material. So, if you’re attaching 1/2″ plywood to a 2×4, you’ll want a nail that’s at least 1 1/2″ long (1/2″ for the plywood + 1″ into the 2×4). *Pro-tip: Err on the side of slightly longer rather than shorter.* You want that holding power! Nothing worse than a nail that barely grips.
Gauge Considerations: The gauge of the nail refers to its thickness. Thicker nails (lower gauge numbers) provide more holding power, but they can also split thinner plywood. For thinner plywood (like 1/4″ or 1/8″), use a thinner gauge nail to avoid damage. For thicker plywood (like 3/4″ or 1″), you can use a thicker gauge nail for a stronger connection.
Application is Key: Consider what you are building. Are you attaching non-structural items like trim? Or is this a structural component that will require support? *Always consult a professional if you are unsure!*

Screws: The Strong, Silent Type

Screws are like the dependable friend who always has your back. They offer superior holding power compared to nails, and they’re less likely to loosen over time. This makes them ideal for projects where strength and durability are paramount.

Length Guidelines: Just like with nails, length is crucial. You want the screw to penetrate at least two-thirds of the way into the underlying material. So, for that same 1/2″ plywood attached to a 2×4, you’d want a screw that’s at least 2″ long (1/2″ for the plywood + 1 1/2″ into the 2×4).
Gauge and Thread: Screw gauge also matters, with thicker screws providing more strength. *However, using too thick of a screw in thinner plywood can cause splitting, so be cautious!* Consider the thread. Finer threads are best for hardwoods while coarse threads are best for softwoods and plywood.
Pre-Drilling: For hardwoods and thicker plywood, pre-drilling pilot holes is often recommended. This helps prevent splitting and makes it easier to drive the screws straight. *It’s an extra step, but your project will thank you for it!*

So, whether you’re team nail or team screw, remember that choosing the right fastener for the plywood thickness is essential for a successful and long-lasting project. Don’t be afraid to experiment and see what works best for you. Happy building!

Building Codes & Standards: Don’t Be a Rebel Without a Cause (Or a Permit!)

So, you’re ready to unleash your inner carpenter and build something awesome with plywood! That’s fantastic! But before you go all wild west on your project, let’s have a little chat about something that might not sound as exciting as power tools, but is way more important for keeping you safe and sound (and out of trouble with the building inspector): building codes and standards.

Think of building codes as the rulebook for construction. They’re there to ensure that everything is built safely and durably, so your creation doesn’t, you know, fall down. And guess what? Plywood thickness plays a major role in meeting these codes. Ignoring them is like driving without a license; you might get away with it for a while, but eventually, you’re going to get pulled over (or worse).

Why Should I Care About All This “Code” Stuff?

Simply put, because it matters! Local building codes dictate the minimum plywood thickness required for various applications, such as flooring, roofing, and wall sheathing. These requirements aren’t just pulled out of thin air; they’re based on engineering calculations that consider factors like load-bearing capacity, wind resistance, and even seismic activity (earthquakes, for those of us who aren’t architects). So, before you even think about picking up a sheet of plywood, do yourself a favor and consult your local building codes. Your city or county’s website is usually a good place to start. Or, better yet, give your local building department a call—they’re usually happy to help.

Who Makes These Rules Anyway?

Besides your local government, there are also industry organizations that set standards for plywood. One of the big kahunas is the APA – The Engineered Wood Association. These folks are the plywood gurus, and they develop standards for plywood manufacturing, grading, and application. Their stamp of approval on a sheet of plywood means it meets certain performance criteria, which is often referenced in building codes. So, keep an eye out for the APA stamp when you’re shopping for plywood. It’s like a gold star for quality and compliance!

Span Ratings: Decoding the Plywood’s Secret Language

Ever wondered how plywood manages to hold up your roof, floor, or walls? Well, span ratings are a big part of that story! Think of them as the plywood’s way of bragging about its load-bearing superpowers. Basically, a span rating tells you the maximum distance a sheet of plywood can stretch (span) between supports without buckling under pressure (load). It’s all about the thickness of the plywood, naturally: the thicker it is, the longer it can span.

Imagine plywood as a tightrope walker. The span rating is like saying, “Hey, this acrobat can walk this far across the rope before it snaps!” These ratings are usually displayed as two numbers separated by a slash (e.g., 24/16), which might look like a secret code but they are not.

Breaking down that code, the first number refers to roofing applications, stating the span rating in inches that the plywood can handle when used for roof sheathing with supports spaced accordingly. The second number refers to flooring applications, again in inches, indicating the maximum recommended spacing for floor joists when the plywood is used as subflooring.

For example, let’s say you’re picking out plywood for your roof, and you see a span rating of 24/16. That means if your roof rafters are spaced 24 inches apart, this plywood is strong enough to handle the load. But if you are using it for a subfloor and your floor joists are 16 inches apart, then it’s good for that too. Think of it like choosing the right size bridge for a stream – you wouldn’t want it to collapse mid-crossing!

When you are out at the lumber yard and you are choosing plywood, pay close attention to those span ratings! They are not just numbers; they’re your guide to a safe and sturdy structure, be it for your roof, floor, or walls. Ignoring them is like playing structural roulette – and nobody wants that!

Economic Factors: Balancing Cost and Performance

Alright, let’s talk about the green stuff – money! We all know that a successful project isn’t just about nailing (pun intended!) the technical aspects; it’s also about keeping your wallet happy. So, when it comes to plywood thickness, how does your choice impact your bank account?

Generally speaking, the thicker the plywood, the higher the price tag. Think of it like this: more material equals more cost. A beefy ¾-inch sheet is going to set you back more than a slender ¼-inch sheet. But hold on, don’t go reaching for the thinnest option just yet!

While it’s tempting to save a few bucks upfront, consider the long game. Thicker plywood often brings better durability, stability, and overall performance. This means it can withstand more wear and tear, resist warping, and provide a stronger foundation for your project. Skimping on thickness might lead to premature failure, requiring costly repairs or replacements down the road.

So, how do you strike that sweet spot between cost and performance? It’s all about understanding your project’s needs. Ask yourself:

What kind of load will this plywood need to bear?
How long do I want this project to last?
What are the environmental conditions it will face (moisture, temperature, etc.)?

For example, if you’re building a bookshelf for light reading material, a thinner plywood might suffice. But if you’re constructing a heavy-duty workbench or exterior sheathing, you’ll want to invest in thicker, more robust plywood.

Think of it as choosing between a bicycle and a pickup truck. A bicycle is cheaper and great for short trips, but it won’t haul a load of lumber. A pickup truck costs more, but it’s built for the heavy lifting. The same principle applies to plywood thickness.

Ultimately, the goal is to balance your budget with the performance characteristics required for your specific project. Don’t be afraid to do your research, compare prices, and consult with a knowledgeable salesperson to find the best value for your money. Sometimes, spending a little more upfront can save you a whole lot more in the long run.

So, whether you’re building a bookshelf, a treehouse, or something else entirely, knowing your plywood thicknesses is half the battle. Take a look at your plans, measure twice, cut once, and you’ll be just fine! Happy building!