Type M mortar mixes are ideal for patios that contact the earth directly, states DIY Advice. People can create their own Type M mortar mix by combining one part cement with 1/4 part lime and 3-3/4 parts sand.
Type N mortars are also commonly used and work well for patios, states Lowe's. Type N mortars are medium strength and the mortar mixes are combined with graded sand and cement. Different mortars work well with different materials, so consult a professional to ensure the correct mortar is used for the project.
Take proper safety precautions when mixing mortar as mortar is a caustic substance. Wear safety glasses, gloves, a respirator and long sleeves.