What size brad Nails for Baseboards?
The National Woodworking Association states that the preferred nail size for most baseboards is 1-5/8 inch “ 2 inch finishing nails to ensure maximum holding power.
Baseboards are prone to cracking, bowing, and pulling away from the wall if not secured properly. And when a baseboard starts to come away from a wall, it often looks much worse than it really is.
To hold baseboards in place, the "stud", or wall framing behind the baseboard, should be drilled and the proper size finishing nail driven through the baseboard and into the stud.
The only exception is where a nail is used to secure the baseboard to a piece of finished molding, like on transition molding between two rooms, or using miters for an L-Shaped room.
8d Finish Nails
The best size finishing nail for wood baseboards is the 8d nail, which measures 1-1/8" long.
What size brad nail for Trim?
When you are installing trim it’s important to take the time to make sure the nails are the right length and width. The nail must be long enough to pierce the trim and be secure, but not long enough to show from the other side.
A standard length nail to use for installing hardwood baseboard is 5/8-inch.
The best finish nail for trim is the 6d common nail. This nail is 1 1/4-inches long. Standard 6d common nails will work fine for installing trim and it’s a good solution if you’re not sure what size to grab.
Use 18-gauge brads when you are attaching material to particleboard, plywood, or non-structural walls. If you’re attaching to an exterior siding or another structural wall, use 16-gauge brads.