Interior-Trim Transitions: Shim Trim and Fix Uneven Walls
Trim carpenter Tucker Windover demonstrates how to straighten a dip in existing drywall or plaster and shim a new chair rail or baseboard to match
So we’ve got a dip in the wall at a chair rail, and after this is painted it would be very obvious and very unsightly. It’s not terribly noticeable when the walls and trim are in white primer, but it will be once the wall is a different color than the trim.
This dip is more than 1/8-in. in less than 4 feet. We’re going to correct that with a shim behind the trim to push it straight, and then we’ll add some setting-type joint compound on either side of the shim to straighten out the wall.
Watch this video to see how it’s done.