How to Cut Logs Into Lumber With a Chainsaw

Whether you’ve felled a tree yourself or need to clear timber that came down in a storm, there’s something irresistible about milling your own lumber. With a chainsaw, you can turn even large logs into usable planks. I’ll show you two methods – with and without a mill – that make this project suitable for DIYers of any experience level.  

Cutting Logs Into Lumber With a Chainsaw

There are two basic ways to cut logs into lumber using a chainsaw. The safest and easiest way for inexperienced chainsaw users is to get a chainsaw mill, and run it along guide rails. If you’re already experienced with a chainsaw, you can forgo the mill and saw the log freehand. 

How to Cut Logs Into Lumber With a Mill

A chainsaw mill is a type of jig that makes it easier to cut logs into evenly-sized lumber. 

1. Set up the log. When using a mill, you’ll be cutting slices off the top of the log as it sits on its side. Ensure the log is stable and steady, and won’t roll from side to side. Props or chucks inserted where the log meets the ground are a great way to keep it in place. 
2. Attach guide rails. Set the guide rails on top of the log. Set a level on top of the guide rails and adjust the screws as necessary until the guide rails are perfectly flat, straight, and level. Use a mallet to tap the holding pins into place, ensuring that the guide rails don’t move with the vibration of the saw.
3. Attach the mill to your chainsaw. Slide the mill down the blade of your chainsaw and attach it tightly to the motor housing.
4. Adjust the depth of the cut. There are marks on the riser at the side of the mill. Decide how thick you want your planks, and adjust the riser accordingly. 
5. Start your chainsaw. Make sure you have sufficient fuel and that your blade is sharp and properly lubricated. Put on eye and ear protection. 
6. Start the cut. Keeping your body and fingers out of the path of the blade, use the handles on the chainsaw and on the mill to slide the mill onto the guide rails. With one hand on the chainsaw handle and the other hand on the mill, push the chainsaw away from your body, along the guide rails and through the log. 
7. Remove the first plank. When you’ve cut all the way along the log, turn off the chainsaw and wait for it to stop spinning before setting it down. Remove the first slice of log. Use a bubble level to check how straight and even your cut is. If you aligned the guard rails perfectly for the first cut, you can use the flat, level surface of the log top as a guide for subsequent cuts. 
8. Continue cutting. You can change the depth of your cut using the risers on the side of your mill, or keep it consistent to produce evenly sized lumber. Never force the chainsaw – apply gentle pressure only. If the chainsaw makes a funny noise or does something you don’t expect, immediately kill the power and stop sawing. 

Depending on how many cuts you have to make, your chainsaw might need to be refueled. You might throw a chain and have to replace it or reattach it.

If you’re interested, you could also upgrade to a portable sawmill.

How to Cut Logs Into Lumber Without a Mill (Freehand)

This method relies on cutting vertically through the log, rather than horizontally. 

1. Maintain your machine. Safe operation of a chainsaw includes proper lubrication and sharp blades. Perform any routine maintenance on your chainsaw before beginning this project. Even simpler small chainsaws need this maintenance.
2. Set the log up. Use supports or props with a concave shape, allowing the log to balance on its exterior curve. Shim as necessary to keep the log from rolling back and forth during the cutting process. Hitting the ground with the chainsaw will quickly dull the blade, so try to keep it out of the dirt as much as possible. 
3. Make a visual guide. You won’t be able to draw a cut line on a bark-covered log, but you’ll need a visual guide to direct your cut. Tie a string around the midpoint of the log, running along its length for the cut. As you cut, keeping the blade of the chainsaw a uniform distance from the string will help you get the flattest, smoothest planks possible. 
4. Divide the log into sections. Shaving off ultra thin lumber is an unrealistic goal. Instead, aim for planks that are at least two or three inches thick. Calculate how to cut the log to ensure each plank is roughly the same size. 
5. Put on protective equipment. Long pants and sleeves that are tight fitting protect your arms and legs without the risk of becoming snagged in the saw’s chain. Securely tie back long hair, and remove all jewelry. Ear protection is a must to protect yourself from the chainsaw noise. Safety glasses will keep your eyes clear of dust and splinters. 
6. Make an exit plan. Before you start cutting, visualize the path of the chainsaw through the log. Eventually, it will come out the underside. It’s difficult to predict when this will happen, so for your own safety, never place your feet underneath the log. 
7. Start the freehand cuts. Power on your chainsaw and firmly grasp both handles. Use a proper chainsaw stance to protect yourself from injury.  With the tool extended in front of you and under your complete control, introduce the tip of the chain blade to the log. Allow the tool to bite through the bark and into the log. Score the cut line for the first plank, going only two or three inches into the log at first. Repeat this process for the other planks. 
8. Continue cutting. The process of cutting logs into lumber is time-consuming and can become tedious. Work in short spurts, stopping whenever you become tired or sense your attention starting to lag. You can work on one cut at a time, or switch back and forth between cuts – just don’t cut all the way through the log. Harder wood will require a special chainsaw and will take longer.
9. Check your progress. Use a framing square to check how the cuts are progressing. Stick the framing square between two planks and move it back and forth. This will tell you how deep the cut is, if there are places where you’ve broken through the other side of the log, and generally give you a lot of good information about how to proceed. 
10. Separate the cuts with wedges. The chainsaw will remove a lot of material, giving you room between the planks to continue cutting. If you need more room to maneuver your chainsaw, tap wooden wedges into the gaps between the planks to help separate the cuts. 
11. Finish the side cuts. While standing out of the way, use the saw to cut away the outermost plank from one side. Allow the plank to fall away from the log. Check the stability of your log, then switch to the other side and remove the outermost plank from the other side. Continue on in this way to help keep the log balanced as you cut. 
12. Finish the center cut. The center cut is where the log is thickest, so it may be helpful to flip the log over, with the uncut side facing up. This also means you don’t need to worry about cutting into any props or chucks. Again, keep your feet clear and allow the planks to drop away freely. 

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• Chainsaws under $200
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Learn how much compression your chainsaw should have.

Conclusion

With sufficient time and patience, you can use a chainsaw to turn logs into usable lumber. Confident lumberjacks can cut freehand. For more predictable results and to avoid wasting wood, use a chainsaw mill and guide rail jig.