How to Repair a Shiplap Ceiling

1. Wearing safety glasses, a dust mask and work gloves, pry out rotting pieces of wood with the cat’s paw and hammer.

2. Using a back saw, cut away the rotted areas. Be sure to stop at a joist to ensure that you have a place to attach the ends of the replacement pieces.

3. If using new boards rather than salvaged ones, cut them to the proper width, and then use a router to cut out a lap on each side. Use the groove in an existing piece of shiplap to set your router-bit depth.

4. Cut the pieces to match the size of the openings. Wedge all the pieces into place.

5. Either pre-drill pilot holes for the nails or blunt the tips of the nails with a hammer to prevent the wood from cracking. Nail the pieces into place.

6. Cover the nail holes with wood putty.

7. Prime and paint the ceiling.