How to Install a Patio Against a Foundation

Insert wood stakes in the outer corners of the patio site and beside the home’s foundation. Connect these stakes by tying a long string around them to outline the border.

Dig out the grass and topsoil within the site using a shovel. Empty the dirt on a nearby tarp to use in gardening projects and low areas of the yard. Dig until the site is 8 inches below ground level. Pitch the subsoil away from the home by digging a smooth angle 1/4 inch deeper per every foot of length. Tamp the sloped subsoil with a manual tamper.

Clear the part of the concrete foundation that will meet the new patio. Use a stiff-bristled hand brush to sweep off loose dirt and debris.

Coat the foundation with waterproofing sealer using a paintbrush. Cover only the part of the foundation that will be below and level to the patio surface. This will prevent water damage and will help hold the expansion joint in place.

Measure the length of the side of the patio that will meet the home’s foundation with a tape measure. Cut a length of 1/4- to 1/2-inch-thick expansion joint equal in length and height to the patio base with a utility blade. The material can be made of cork, rubber or other semi-flexible, rot-resistant materials. Hold the joint against the home’s foundation and press it into the tacky sealer.

Pour 3/4-inch gravel over the subsoil in two, 3-inch-thick layers, tamping the first before adding the second. Set a board on the gravel so it's parallel with the drain slope, and lay a 4-foot bubble level on top. Shift the gravel with a shovel until one-fourth of the bubble sits out of the center lines, and tamp it.

Install the patio pavement. Pour an inch of bedding sand over the gravel and set pavers or stones in your pattern flush against each other. If you’re pouring concrete, line the inner perimeter with 2-by-4 inch form boards and screw the boards together. Blend the concrete in a mixer and pour it over the site. Drag a screed board across the surface to push excess concrete into low spots and level out the wet mixture. Keep the slab covered in a breathable drape cloth for seven days before removing the form boards.