How to Install a Beadboard Ceiling Porch to Existing Plywood

Measure the length and width of the porch ceiling. Subtract 1/2 inch for wood expansion around the perimeter before recording the measurements. If the ceiling has angled corners, measure the angle using a bevel gauge.

Measure the width of a beadboard to determine its actual width. Divide the width of the porch ceiling by the actual width of a beadboard to calculate the number of full boards you need to cover the ceiling.

Cut the lengths of beadboard to length with a miter saw. If the ceiling is angled, rotate the miter saw to the required angle and cut the board accordingly.

Hold the beadboard against the ceiling with its grooved side 1/4 inch away from the wall. Insert a nail every 12 to 18 inches along the edges of this board to join it to the plywood directly below it.

Insert the grooved end of another board into the tongue on the previous board before nailing it to the plywood underlayment. Tap the seam lightly with a rubber mallet to ensure a secure joint. Continue this process of installing lengths of beadboard to the plywood underlayment until you complete the second-to-last row.

Trim the last beadbaord to size from its tongue side using a saw. Position this board over the exposed plywood and nail it in place.

Nail the decorative lattice trim to cover the expansion gap around the ceiling. Cut the lengths of lattice trim with a miter saw and tack each every 12 inches to the beadboard directly under it.