How Cleaning Exterior Surfaces?

Sweep off the surface. Remove any loose debris from the outdoor surface you are cleaning. If you are cleaning off a patio, use a large broom to sweep it off. If you are cleaning a small retaining wall or a monument, use a small broom to sweep the detailed areas. Removing the top layer of dirt and debris this way will help you assess what areas need to be deep cleaned and which just need a light scrubbing.

Wet the surface and allow the water to sit for about 30 minutes. Spray the surface with your hose so that it is all damp. A layer of water will start to loosen anything growing on the surface. Wait for the stone to soak for about 30 minutes before continuing on and your overall cleaning process will be much easier.

Tip: If the temperature is below freezing, wait for it to warm up before putting water on your sandstone tiles. Purposely putting water on sandstone tiles, especially older sandstone tiles that might have tiny cracks in it, can cause the stone to crack if water gets inside of it and freezes.

Scrub the surface with water and a plastic-bristle brush. Use a circular motion while scrubbing to get any organic material off of the stone. This often includes moss, lichen, and mold. Keep scrubbing until you are happy with the color of the stone. Most outdoor scrub brushes will work for fine for this. You can use a hand brush or a brush on a pole.

Just make sure that bristles are medium-firm, meaning that they bend when you push the brush across the surface. Never use a wire brush or extremely firm plastic-bristle brush on sandstone tiles. It will scratch the surface and speed up decay. Use a squirt of dish-washing soap, if necessary.