A concrete-slab patio is ideal for barbecues or just for relaxing. Concrete is durable and lasts a lifetime, but because of its constant exposure to weather elements, your slab patio gets dirty. Whether the concrete slab is plagued with just dirt and mud, or is stained with tree sap or moss, use the right products and methods to ensure it gets clean.
Remove all furniture, plants and other items from the concrete slab. Sweep off loose debris with a broom.
Fill a bucket with 1 gallon of water. Add a few squirts of mild dish soap.
Scrub the patio with a long-handled scrub brush and the soapy water. Rinse the soap off with water from the garden hose.
Cover plants, grass and landscaping around the concrete slab with plastic sheeting if it is still dirty or stained. Put on rubber gloves and protective eyewear. Combine three parts water and one part chlorine bleach into a clean bucket. Scrub the patio with the scrub brush and bleach mixture. Let the mixture sit on the concrete for 10 minutes, and then rinse the patio well with water from the garden hose.