Full bed with trundle is a good way to provide additional sleeping space for guests, while saving space because the bed is designed to slide under an existing, full-size bed. When necessary, the nest can be easily removed and used. These beds can also be easily built at home with a few materials and a little creativity. Place the double mattress on the floor and measure the length, width and depth of the mattress.
Measure the distance from the floor to the bottom of the full bed with trundle. Compare this to the height of the mattress. The mattress should be at least four inches shorter than the height of the bed so that it can be stored properly underneath. Measure and cut a piece of wood for the base of the trundle bed to the same measurements of the double mattress. Do not add more than one and a half extra inches to the width or length of the base.
Measure and cut two pieces of wood 2 inches by 4 inches so that it is the same length as the base of plywood. Cut two pieces of wood 2 inches by 4 inches the same length as the two shorter ends of the base. Sand each of the pieces with sandpaper so that the wood is smooth. Construct a rectangular frame on the plywood base using the four pieces of wood. Place the full bed with trundle frame pieces together using L-brackets and screws at each corner.