If you’ve been wondering how to cut large sheets of plywood with a circular saw, you’re in the right place.
A circular saw is a great tool for cutting plywood. In fact, it’s our favorite way to cut down plywood. Rather than having to maneuver a large sheet of plywood through a table saw, you can keep the plywood in place and cut through it with a circular saw. It’s much easier on your muscles and you can still get highly accurate cuts, especially when using a cutting guide.
Let’s dive in!
Choose the Right Blade
The first step to successfully cutting plywood with a circular saw is to choose the right blade. The blade that a circular saw comes with is generally meant for more rough construction and quickly cutting down things like 2x4s.
For cutting plywood, you need to choose a circular saw blade with more teeth. We personally use the Diablo 60-tooth circular saw blade. This blade is designed to give you a fine finish and the thin kerf reduces splintering and blowouts.
Though it’s an incredible blade for cutting plywood, it will not bring the splintering out to zero. More tips on reducing splintering and tearout are included near the end of this article.
Choosing the Right Depth of Circular Saw Blade
Now that you’ve decided on a circular saw blade, it’s time to set the depth of the blade.
You want the blade to be set deep enough to cut all the way through the plywood without being too deep. The depth you set it to will depend on the thickness of your plywood. The max depth your saw blade should be set to is about ¼” beyond the bottom of the plywood.
To determine the depth, I like to line the blade up with the edge of the plywood and adjust the depth while the saw is unplugged. The ideal depth is about one half of a saw tooth blade beyond the bottom of the plywood. This ensures you’re cutting all the way through the plywood while maximizing efficiency.
If you are using a cutting guide like the Kreg Accu-Cut where the saw actually sits on a track, be sure to adjust the blade depth while the saw is on the track. The track will lift the saw up slightly and if you set the depth without the track, you likely won’t cut all the way through your wood once on the track.
How to Support Plywood When Cutting
Since the circular saw blade drops down below the wood, you can’t cut directly on a workbench or the floor.
If you’ve been stumped on what to put under your plywood when cutting it with a circular saw, you’re not alone. This is one of the most common plywood cutting questions we receive. It’s also a very important one to address because improperly supporting plywood when cutting can increase the chances of kickback.
Rigid Foam Insulation Board
The way we most recommend is to get a sheet of 1” rigid foam insulation to make your cuts on. Yes, it adds a little more cost to your project initially, but this insulation can be used time and time again, so the cost is actually very minimal when spread out over several projects.
It also is one of the safest ways to cut plywood with a circular saw. Why? Because the rigid foam insulation board provides full support under the sheet of plywood. Since the plywood is fully supported, the wood is unlikely to collapse on itself, which is the main cause of kickback.
You can use the rigid foam insulation method on top of a large workbench or by setting it directly on the floor. As long as your blade depth is set correctly, the foam board will protect your floors or table from getting cut.
I would not recommend placing the rigid foam insulation board on top of a set of sawhorses. Though it’s called “rigid” the board would likely sag in the middle, defeating the purpose of using it.
If you are concerned about storing the foam insulation, you can cut it into small pieces and then use duct tape to connect the pieces again when you want to cut.
Some people don’t choose this option because it is bad to breath in dust from the foam, but whether you do this option or not, you need to take the proper precautions to protect your lungs. Saw dust itself is a threat to health, so always be sure to wear a good mask when cutting plywood or any wood, whether you cut on foam insulation or not.
2x4s or Construction Lumber
Another option to support your plywood when cutting is to use some scrap 2x4s. Like the rigid foam insulation board, you can reuse these scrap pieces over and over again. What exact boards you use don’t matter as long as they are all the same thickness and that your plywood is fully supported.
If you prefer to cut off the floor and don’t have a workbench, you can place the 2x4s on top of saw horses to support your plywood.
Clamping to a Workbench
If you have a large workbench and you don’t need to cut off too big of a piece, you can clamp the plywood so that the cut is made just off the edge of the workbench. The piece you’re cutting needs to be free to fall away to minimize the chances of kickback.
A caveat to this method is that the piece you’re cutting off shouldn’t be too large. The larger it is, the more likely it is to fall away before the piece has been fully cut through. If it does try to tear out prematurely, you can end up with a pretty large snap in your board.
Overall, I highly recommend sticking with the rigid foam insulation method to protect your plywood.
How to Cut Plywood With a Circular Saw Without Splintering
Now that we’re all set up to make our cuts, let’s quickly address how to minimize splintering and tearout when cutting plywood.
With the right blade, tearout will be minimized, but it won’t be fully prevented, especially when making cross-cuts. When making rip cuts (cutting with the grain), tearout should be minimal, but it tends to happen a lot when making cross-cuts.
Regardless of whether you’re making a cross-cut or rip cut, there are a few things you can do to minimize splintering.
First, you’ll want to place the “good” side of the plywood facing down. This will minimize the tearout on the good side, with the majority of the tearout occurring on the side that’s facing up.
If you need both sides to have nice clean cuts, there are a few options:
- The Accu-Cut guide has an anti-chip slip designed to minimize tearout
- Score the cut line with a utility knife before cutting. Be sure to score all the way through the top veneer layer.
- Add tape to the cut line to help reinforce wood fibers and get a cleaner cut.
- Cut slower. I would use this recommendation in conjunction with options 1-3 for the best results.
Cutting Straight with a Circular Saw
The best way to cut straight with a circular saw is to set up a guide. You can either clamp and scrap piece of wood to act as a guide or you can buy a pre-made guide.
Get a full breakdown of 5 different ways to get straight cuts with a circular saw in this post. We’ll breakdown the pros and cons of each method and which plywood cutting guide we use for certain situations.
Cutting Plywood with a Circular Saw Summary
A circular saw is a great way to cut plywood. Before cutting, you’ll want to select a circular saw blade with around 60 teeth for a smoother finish and then set your blade depth to cut about ½ of a saw blade tooth beyond the plywood
Place your plywood on a piece of rigid foam insulation board to fully support your plywood while cutting. Setting up a cutting guide can help you get straighter cuts.
You might also like:
- How to get plywood home without a truck
- Will Home Depot cut plywood for you?
- 5 ways to get straight cuts with a circular saw
- Circular saw vs miter saw: which should you get?
If you’re just getting started with DIY, you’ll want to grab our Beginner’s Guide to DIY. It’s the guide created to shorten your DIY learning curve so you can build more impressive things with less frustration.
It’s everything we wish we knew when we were just getting started: from lumber to tools, to making projects look more professional, we’ve got you covered. You can grab your Beginner’s Guide to DIY HERE.
We also have this super helpful woodworking for beginners post. We share how to get started and 7 things we wish we would’ve known when starting out! No need to make the same mistakes we did.