How to Build Your Own Floating Porch

Lay three piers snug against the home foundation if the doorway allows it, with the center of the piers three feet apart. Add four piers to each row to make three columns of five piers each, with the additional piers in the columns spaced two feet apart. The wooden substructure is placed on these piers.

Lay an 8-foot rail stud across each of the rows and center the studs. Do a quick check on the proper placement of the piers by holding the side board to the end of the rail studs. The ends of the side boards should make a perfect square with the ends of the first and last rail stud. If not, adjust the placement of the piers to allow the four boards to be square.

Measure the level of the piers by place a bubble level in the center of the studs. If the bubble is tilted toward one direction, raise or lower the piers by adding soil underneath until the bubble reads level. When the rows are leveled out, place the studs along the column and check the level in the same way. If you adjust a pier to ensure the columns are level, go back and double-check to see if the row is still level. Continue to adjust the rows and column piers until the entire field is level, and then place the rail studs back along the rows.

Place two nails or screws through the side board into each rail end on both sides of the porch substructure. The end result should be a square with three inner rails to hold the center weight.

Place the first top plank on the substructure, with the plank running perpendicular to the rails. The outside corners of the plank should match the outside corners of the square perfectly. Nail or screw the plank to the substructure at both corners and every 24 inches along the plank length. Place the next plank down and attach it to the substructure. Put two nails through the plank and into each rail it passes over. Continue to add planks until you reach the edge of the far side of the porch.