How to Build and Estimate a Porch Railing

Measure the space between the first two columns on your porch. Count the number of columns that your porch has and multiply by your measurements, which gives you an estimate on the number of railings. For example, if you have six columns along one side, you need five railings for that area.

Cut 2 2-by-4-inch wood boards down to the size needed to fill the gap between two columns. Apply your measurements to the wood and mark the wood where you need to make your cut. After marking the wood, place the saw blade against the wood and move it across your mark. Make the cuts with a circular saw, while wearing protective goggles.

Lay one of the boards flat on a work surface and set a wood baluster 4 inches from the end of the board. Turn the board over and sink a 3-inch decking screw through the wood and into the baluster. Measure 4 inches from the baluster and attach a second baluster. Attach the balusters every 4 inches across the board.

Turn the piece you made in the last step upside down so that the balusters point up. Place the second board on top of the balusters. Drill a 1-inch hole through the top board and into each baluster with a countersink drill bit. Sink a decking screw through the top. The countersink bit makes the screws sit slightly below the surface of the board.

Slide the railing between two of your columns and hold it flat against the porch. Set a finishing nail flat against the opposite side of the column and hammer into the railing. Use at least two nails for both sides of the boards, for a total of eight nails.

Finish the porch railing by sinking decking screws through the bottom of the railing and into the porch floor. Sink two screws through each end of the bottom board and sink two additional nails on each side of the balusters.