When preservative treated lumber is cut, what happens to the cut end?

When preservative treated lumber is cut, the cut end is no longer treated. The treatment process typically involves infusing the lumber with preservatives to protect it from decay, insects, and other environmental factors. This treatment cannot penetrate through the entire thickness of the wood, especially at the ends.

When the lumber is cut, the inner untreated wood is exposed. While the surrounding uncut portions of the lumber remain protected by the chemical treatment, the freshly cut surface lacks that protective layer. This means it can be susceptible to moisture, pests, and rot unless properly addressed, such as with additional sealing or treatment. Therefore, the correct response highlights the loss of treatment effectiveness at the cut end of the lumber.