Alkaline Cleaner
An alkaline cleaner is a high-pH detergent (typically pH 10-14) that dissolves oil, grease, fats, protein stains, and atmospheric grime by saponifying fatty acids and emulsifying petrochemical contaminants. The most common alkaline ingredients in exterior cleaning are sodium hydroxide (caustic soda), sodium metasilicate, and potassium hydroxide, often combined with surfactants, chelators, and dye. Alkaline cleaners are the counterpart to acid cleaners — pros reach for alkaline chemistry when the stain is organic or petrochemical, and acid when the stain is mineral.
In depth
In practice, alkaline cleaners are essential for restaurant grease traps, dumpster pads, fleet truck washing, oil-stained concrete, and heavy commercial kitchen exhaust work. They are almost never used on residential siding (sodium hypochlorite and surfactant do that job better and safer), but they are indispensable in commercial settings. Proper use requires dwell time, agitation (a deck brush or surface cleaner), hot water for best saponification, and a thorough rinse — alkaline residue attracts dirt if left behind.
How this shows up on our jobs
Our commercial division keeps alkaline degreasers on hand for restaurant back-of-house washes, dumpster pads, and oil-stained commercial concrete. Not used on residential siding.
Services where this matters
Related terms
Acid Wash
An acid wash in exterior cleaning is the application of a dilute acidic solution — most commonly muriatic (hydrochloric), phosphoric, oxalic, or a proprietary masonry blend — to dissolve mineral-based staining that bleach and surfactants cannot touch. Typical targets include efflorescence on brick, heavy rust from fertilizer or irrigation, mortar haze on new brickwork, mineral deposits on glass, and battery acid on concrete. Acid wash is not a general cleaning method — it is a targeted chemistry tool for specific stains on specific substrates.
Hot Water Pressure Washing
Hot water pressure washing uses a diesel-fired burner to heat the pressure washer's output to 180-200°F before it hits the surface. The physics is simple: hot water dissolves grease and oil, accelerates chemical reactions, lowers the dwell time needed for detergent to work, and kills biological growth on contact. Cold-water pressure washing relies on mechanical force and chemistry alone, which means longer jobs and lower performance on greasy substrates.
Surfactant
A surfactant (short for "surface-active agent") is a chemical compound that lowers the surface tension of water so it can wet, spread, penetrate, and cling to a dirty surface instead of beading up and running off. In exterior cleaning, surfactants are blended with sodium hypochlorite and water to let the mix "stick" to vertical surfaces long enough for the bleach to kill organic growth at depth.
Non-Ionic Surfactant
A non-ionic surfactant is a surfactant whose molecule carries no net electrical charge, making it uniquely tolerant of the extreme pH and high chlorine content found in a soft-wash mix. Ionic surfactants (anionic, cationic) often precipitate, react, or lose effectiveness when combined with 12.5% sodium hypochlorite; non-ionics stay stable, keep their foaming action, and continue to reduce the surface tension of the cleaning solution throughout the dwell period.
Organic vs. Inorganic Stain
Organic stains are caused by living or once-living things: algae, mold, mildew, lichen, tannins from leaves, berry drip, insect excretion, pet urine, and so on. They contain carbon and respond to oxidizing chemistry — sodium hypochlorite or hydrogen peroxide (percarbonate) — which breaks the carbon bonds and destroys the stain at the molecular level. Inorganic stains are mineral-based: rust, hard-water deposits, efflorescence, metallic irrigation over-spray, fertilizer streaks, and the like. They contain no carbon and will not respond to bleach at all — you need an acid or a chelating agent to dissolve the metal or mineral and carry it away.