Expert: Daniel Humphrey - 12/27/2007

Question
What size nails do I use to put trim around windows and doors? I have a air gun?

Answer
As you know, your nail gun determines the gauge; but you have quite a choice in lengths, and you can make custom lengths by cutting the stick of nails with shears. The two lengths of finish nails I keep on hand are 2-1/2" and 1-1/4". I can cut the longer nails when I need something in between; or if it's a big job, I just buy a box the length I need. I have both 16 Ga and 18 Ga trim nailers.

Around windows and doors, you nail the casing trim to the finish door jamb itself, and then to the trimmer in your door framing. On doors, the nails in the casing tie the jamb to the trimmer, which reinforces the entire door jamb.

For nailing into the jamb, use nails just long enough to pass through the casing and into the jamb about an inch. If the nail is too long, you risk a nail bending and popping out the surface of the jamb.

The nails holding the casing to the wall trimmer can be a bit longer--probably the longest you can find for your gun--because they need to go through the casing and sheetrock and get into the trimmer.