HarborGemWhich chemicals clean concrete oil stains, house stains and faded exteriors?
The right product matters as much as the equipment. Different problems call for different solutions.
Match the product to the problem
Oil, algae, rust, oxidation and sun fading all look like “dirt” but behave differently. Using the wrong chemical, or the wrong strength, can damage a surface and still leave the stain behind.
Concrete oil stains
Because concrete is porous, oil is usually treated with a concrete-safe degreaser, given time to work, agitated with a stiff brush if needed, and then rinsed with a pressure washer or hot water. Fresh spills respond far better than old, set-in ones, which may only lighten.
Algae, mold and mildew on siding and stucco
Green and black growth on a house is usually treated with a soft wash. A cleaning solution, commonly one based on sodium hypochlorite, breaks down the growth, and low pressure is used mainly to rinse it away. This is gentler on paint and siding than blasting the surface.
Black streaks on roofs
Streaks on asphalt shingle roofs are typically algae. They call for a soft wash with a suitable solution rather than high pressure, which can strip granules or lift tiles.
Faded exteriors
Some fading is dirt, algae or a chalky layer of oxidation, and cleaning can make a big difference. Permanent loss of pigment from sun exposure usually cannot be cleaned away and may need oxidation removal, a coating or repainting.
More pressure is not always better
Higher PSI does not guarantee a better clean. The right solution, dwell time and pressure for each surface does.
A safety note
Never mix cleaning chemicals, and keep products away from plants, pets and children. If you are not sure what is causing a stain, a professional assessment before you start can save you from making it worse. Ask us for a free quote.