Concrete patio stones lend strength and style to an outdoor surface. You can reduce a significant expense and open up your design possibilities if you make the concrete blocks yourself. Creating concrete patio blocks entails pouring concrete into molds and working with care to ensure that each block has a flat, level surface. You can personalize a few decorative blocks by embedding shells, sea glass or other special items into the concrete before it hardens.
Choose which type and shape of mold you want to use. Commercial molds offer an array of shapes including natural stones, round and basic bricks. You can also create your own unique molds with pie tins, foil pans or plastic or polyurethane sheeting. Make or purchase multiple molds so you can pour more than one patio stone at a time.
Set the molds on an even surface and coat the inside with a light layer of petroleum jelly or another mold release agent.
Mix concrete in a bucket or wheelbarrow with an electric paddle mixer. Use concrete powder and water, and stir until it has a thick, batter-like consistency.
Use a trowel or scoop to add concrete into the mold, spreading it into every corner and filling to the top. Drag the trowel over the top of the mold to smooth the surface and remove excess. Tap the mold on a hard surface several time to release air bubbles.
Cover the molds with plastic and wait two days for them to dry, less if you use quick-setting concrete. Turn the molds upside down, tap on the bottom and they should slide out of the mold.