The answer to 'why is my patio brown patches' is that the brown patches are likely caused by a fungal disease or excessive moisture. Patio pavers and concrete can develop brown or discolored patches due to fungi, mold, or mildew growth. This is often a result of poor drainage, standing water, or not enough sunlight exposure.
The symptoms include irregular brown or tan patches that can spread across the patio surface. In some cases, the patches may be slimy or have a fuzzy texture. Addressing the underlying cause is important to prevent the problem from getting worse and potentially damaging the patio material.