White vinegar, a common household condiment, can be used as an effective stain remover while cleaning concrete patios. To make a cleaning solution using vinegar, simply mix equal parts of vinegar and water. Apply the solution onto the porch and scrub the stains using a hard bristled brush.

Add stone or wood detergent to your Kärcher pressure washer. Start with a low pressure setting, especially on wooden surfaces, engaging the trigger gun away from the surface initially. Using a sweeping motion, clean your deck or patio surface using long sweeps that overlap each other.

Use a stone-safe cleaner. There are products specifically developed for each type of natural stone. If these are not available, use mild dish detergent mixed with warm water. Use a non-wire brush to scrub patio and walkway surfaces.