Slippery Patio Finish? How to Tell if It Needs Cleaning, a New Sealer, or Drainage Repair

Slippery concrete patio with wet sheen and dark algae buildup along a shaded edge

Most slippery patios are misdiagnosed. The usual problem is not that the patio is simply “too smooth.” It is usually one of three patterns: a biofilm that keeps returning because the surface stays damp too long, a film-forming sealer that turns slick when wet, or water movement that keeps re-wetting the same area. Start with … Read more