How to Build a Cob Patio

Mix the cob in a mortar mixer. Begin with a 2-to-1 ratio of clay and sand. Add a small amount of water. The amount of water needed depends on the consistency of the clay. Add only enough to wet the mixture slightly. Begin adding straw. Add only approximately 10 percent of the amount of clay and sand. Mix until the cob forms into a clump.

Measure and lay out the patio forms. Use 2-by-4-inch boards to frame the area for the patio. Hold them in place on their sides with wooden stakes pounded into the ground with a rubber mallet on each side of the boards. This is just a guide since the cob will not run when put in place.

Pour the clump of cob into the framing and spread out. Use a hand-driven rolling paver and trowel to smooth and spread the cob. Use hands or the trowel to push the cob gently against the wooden forms.

Repeat the mixing and spreading process until the form is filled. Allow to dry for at least 24 hours prior to use.