4 Tips For Cutting Treated Lumber

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  • Beginner

Pressure-treated lumber is wood that has been treated with chemicals so that it can stand up to environmental wear. You will see barns, sheds, outdoor furniture and even boat docks made out of treated lumber. Using treated lumber is the same as using any other type of lumber but cutting requires additional steps to avoid splintering and chipping. The following information will share with you several tips and tricks for properly cutting treated lumber.

1. Let the Saw do the Work

When you cut wood the typical approach is to either place the wood on the table saw and pull the saw toward the wood or pull the wood toward you. When working with treated lumber you run the risk of it splintering and chipping if you use either of these methods. The saw generates momentum which you can use to help you cut the wood. Instead of pulling the treated lumber toward you push it toward the blade. The spinning blade will pull the lumber toward it.

2. Tape It

If you're cutting out sections from pressure-treated lumber to build with you'll notice that each cut you make is potentially the one that splinters or chips the wood. This is not a pleasant thing because you cannot repair the piece of wood. You will either have to work with the piece as it is, or try to cut the same part out of the same piece, or re-cut it from a new piece of lumber.

To minimize the potential of chipping and cracking use 2-inch wide blue painters tape. Draw clear cut lines on the treated lumber and place tape over the lines so that the tape is center evenly over the line. Turn the lumber over and cut it from the other side through the tape.

3. Seal the Lumber

The idea behind using treated lumber is that it is relatively waterproof and stands up to harsh elements. Treated lumber can also withstand attacks by insects and mold. Once you cut the treated lumber you have effectively rendered it nearly as useless as interior plywood used outside. After you cut treated lumber you need to seal the cut ends. Purchase a waterproof sealer and apply several coats to the cut ends. Place the lumber in a dry area while the sealer cures.

4. Dry it Out

The process that makes treated lumber protected against insects, water and mold also add a lot of moisture to the wood. This moisture can make it difficult for someone to cut the lumber. The added moisture can cause the saw blade to slip, the cut to not be clean or for the wood to splinter and chip.

The solution is to dry out the treated lumber. All you need is a dry room, a hairdryer, and a dehumidifier. You want to place the lumber to dry out in the dry room with the dehumidifier. The dehumidifier will leach the moisture from the air and eventually the wood. Use the hairdryer to hasten the drying. You can also place the wood outside under direct sunlight.


To cut a perfectly straight line with a Skilsaw, set the edge of the saw's leading guide on the line, pull the blade guard back carefully, mind the blade. With the saw running set the blade's cutting edge on the line being mindful of which side of the line you wish to keep as this will change the length perceptibly enough that it can stall a fitting, waste time and materials, and even ruin a project where absolute tolerances are close. As you make the cut keep the guide on the line and push the blade smoothly through the cut. You can follow the line by sight once the guide is past the end of the line. When you can cut a pencil line in half lengthwise and cut it square then you know you've got it down pat.