Hang a Pre-Hung Door
Setting a factory-hung door plumb with an even reveal — the standard prehung sequence, the split-jamb variant, and the long-screw trick that stops heavy doors sagging.
Close a Gapping Inside Miter With a Shim Behind the Baseboard
When an inside 45 won't close, slip a shim between the wall and the back of the baseboard near the corner — it rocks the piece forward and squeezes the miter shut. Nail it off with the shim in place and the joint stays tight.
trim corners won't line up, crack opening at the corner, molding seam gap, fix a bad corner cut
The Problem
Inside corner miters on baseboard gap for a reason that has nothing to do with your saw: drywall corners are never a true 90, and mud builds up at the bottom of the corner, kicking the base away from the wall. The cut is right; the wall is wrong. (A coped joint sidesteps all this — but if you're mitering, here's the save.)
The Technique
- Dry-fit the two mitered pieces and find the gap at the miter face.
- Slip a shim behind the baseboard — between the drywall and the back of the board, near the corner. The shim rocks the top of the board forward, rotating the miter face closed.
- Adjust the shim depth until the seam closes tight, then nail the base off with the shim still in place. Score and snap the shim flush.
- Alternative with adjustability: drive a screw through the bottom of the base into the wall's bottom plate near the corner, and turn it in or out to fine-tune how far the board stands off the wall.
Pro tip: "Do your best and caulk the rest" is the joke for a reason — but a shimmed miter beats a caulked one because caulk in a moving joint opens back up. The shim removes the movement instead of hiding it.
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