About Pressure Washers for Patio Slabs
For hard concrete and porcelain, 150+ bar with a surface-cleaner attachment is perfect. For soft Indian sandstone, drop to 130 bar and avoid turbo nozzles which pit the surface.
Top picks: Kärcher K5/K7 with T7 surface cleaner, Nilfisk Core 150 Pro, Bosch AdvancedAquatak 160. Pre-treat with a stone-safe patio cleaner for fastest results.
After cleaning, apply a patio sealer to lock out future algae growth — especially valuable on porous sandstone.