How to Build a Porch on Top of a Patio

Attachment to House

• Unlike a patio, which merely butts up against a house, a porch usually attaches to the walls of a house. This attachment ensures that the porch doesn’t pull away from the house, creating a gap that may prove a hazard. To attach a porch to the house, begin the framing of the porch on the exterior wall. Measure up from the ground to the height that you want the porch at either end of the patio and install metal flashing and a wood board at this height, which serves as the back part of the porch frame.

Other Framing

• Once you install the back frame of a porch, create the front and sides of the frame. Begin by placing posts at the front corners of the patio and then every 8 to 10 feet along the perimeter of the patio if the patio stretches more than 10 feet in any one direction. Use 2-by-4 or 2-by-6 wood boards to connect these posts at the top, which creates a frame around the patio over which you install the main part of the porch.

Joists

• Like any floor surface, a porch requires joists to support the floor. Joists install between the boards that make up the frame with screws or joist hangers, and are the same size as the wood boards used to connect the posts, either 2-by-4 or 2-by-6 inches. When you finish installing the joists between the exterior boards that make up the frame, the tops of the joists and the top of the frame should sit at the same level, providing a grid for laying out the main floorboards of the porch.

Floorboards

• Just like the frame and the joists, the floorboards of a porch consist of standard 2-by-4 or 2-by-6 wood boards. These boards lay over the top of the porch frame and joists, perpendicular to the joists. Boards should be placed flush against each other to prevent gaps in the floor and be secured to both the frame and the joists with nails. Once installed, paint the floorboards of the porch any color that you like to finish the porch.