I was closing part of a room in my house for use as a workshop and had to add some doors. The two ways in were both about 47" wide so I couldn't use a 48" door and I didn't want to use a smaller door. I built two doorways- one a 48-inch slider and one with two 24-inch doors. The doors themselves are plain hollow-core doors with craftsman-style trim added. The hardware is actually pocket door hardware, installed on the outside.
Step 1: Door 1- big panel
This is the 48-inch door. It's two 24-inch doors stuck together. My plan was to stain it, but it was cold and rainy here for a few months, and now the pollen count is in the thousands (and I didn't want it to be yellow). I kinda like it the way it is, and might leave it this way.
Step 2: Starting door construction
For the 48-inch door, I started with two 24-inch hollow core doors, and screwed a piece of trim to the top and bottom. I used a table saw to rip a1x4 to the width of the doors (1-5/16 inches). This also gives the sliding door hardware a stronger attachment point on the top of the door.
Step 3: Adding Trim
For the trim, I set my table saw to the width of a 1x4 (3.5 inches) and ran a sheet of 3/16" plywood through it. Each set of doors used one 4x8 sheet of plywood and roughly two tubes of Liquid Nails. I used a nail gun to staple down the edges of the trim, and filled in above the staples with spackle.