Surface Cleaning Guides: Concrete, Roofs, Siding and Decks

The correct pressure is different for every surface, and using the wrong one causes damage that costs more than the job paid. Concrete takes 3,000 to 4,000 PSI. Siding takes 1,000 to 1,500. Wood takes 1,200 to 1,800. Roofs take no pressure at all.

What pressure should you use on each surface?

How do you clean concrete properly?

Concrete is the most commonly pressure-washed surface and one of the most forgiving. Pre-treat with a sodium hypochlorite solution and Sticky Icky surfactant to kill organic growth, let it dwell 5 to 10 minutes, then clean with a flat surface cleaner at 3,000 to 4,000 PSI with 4 or more GPM.

A surface cleaner, such as the Whisper Wash line Ameritech carries, gives uniform results and prevents the striping pattern a wand alone leaves behind. Post-treat with a light SH rinse to slow regrowth.

How do you clean a roof without damaging it?

Roof cleaning requires a soft wash approach and never high pressure. Apply sodium hypochlorite, typically at 3 to 6 percent applied strength, with Sticky Icky surfactant using a 12V or gas diaphragm pump system at very low pressure.

Let the solution dwell and kill the algae, moss and lichen. Rain will rinse the dead growth away over time, or you can do a gentle low-pressure rinse. Using high pressure on a roof damages shingles, cracks tiles and voids manufacturer warranties.

How do you clean siding without forcing water behind it?

Apply an SH-based cleaning solution with surfactant from the bottom up, which prevents streaking, let it dwell several minutes, then rinse from the top down at moderate pressure of 1,000 to 1,500 PSI.

Vinyl and aluminum siding should never be cleaned at high pressure, because water can be forced behind the panels and into the wall cavity. Wood siding needs even more care, since excessive pressure will splinter or gouge it.

How do you clean a wood deck before staining?

Apply Ameritech Wood and Deck Cleaner, let it dwell, then rinse at 1,200 to 1,800 PSI with a wide fan nozzle held 12 to 18 inches from the surface. That restores the wood's natural colour.

Allow the wood to dry completely, 48 to 72 hours, before applying stain or sealant.

What do commercial flat surfaces need?

Commercial flat surfaces demand high GPM and a large-diameter surface cleaner for efficiency. Pre-treat with SH, a degreaser, or both depending on the contamination. Use a commercial machine at 3,500 PSI or more with 8 to 10+ GPM and a 24 to 28 inch surface cleaner.

Pay particular attention to dumpster pads, drive-through lanes and grease-trap areas, which often need hot water and a dedicated degreaser to come clean.