Begin by installing the vertical pieces along door casings and corners. The boards next to the doors are 3-12" wide. For the corners, start with a 4-1/4" board ripped from 1x6 material.
Next to it, install a 3-1/2" board. Both will have 3-1/2" exposed. Secure them using a finish nailer with 2-1/2" finish nails.
Score any paint buildup on the edges with a utility knife to ensure the boards sit flush.
Repeat this process around the room until all corners and end pieces are installed.
Measure between the end boards, then cut the 1x6 baseboards to fit precisely against the vertical pieces. Nail them in place (Image 1).
For the top rails, position the 1x4s with toe kicks facing up. Measure, cut to length, and rout the ends on a router table.
Secure the top rails to the wall with 2-1/2" finish nails, just like the baseboards (Image 2).
Now measure each stile individually, as dimensions can vary slightly for a custom fit.
Take multiple measurements, cut to exact lengths, then rout the "female" ends on the router table.
Install by placing a stile, adding a nail, checking for plumb, and securing it to the wall. These cover seams where panels meet.
Align using guidelines drawn on the wall. Pre-cut stiles should fit easily.
Measure each wall section and cut chair rails to length with 45-degree mitered ends for corners (Image 1).
Attach to the top rail using 1-1/2" finishing nails, leaving a 1/2" overhang for a polished look (Image 2).
Complete the circuit around the room. With all woodwork in place, fill nail holes with wood filler and apply a durable polyurethane finish.
