Cleaning
Cleaning
The Cleaning domain tests whether you can remove soil without harming the substrate. Questions typically target pH selection, dilution control, dwell time, mechanical agitation, water temperature, cleaning sequence, PPE, and chemical compatibility.
Core rules
- Match the product to both soil and floor. Alkaline cleaners cut grease and protein; acidic products dissolve mineral scale; neutral cleaners are safest for routine maintenance on most finishes.
- Dilution is a concentration, not a suggestion. Over-strength solution leaves residue, dulls finish, and increases slip risk; under-strength wastes labor.
- Dwell time does the work. Agitation starts the clock, but chemical action needs contact time, commonly 3–10 minutes for routine soil and longer for heavy build-up.
- Rinse or extract dirty solution. Leaving cleaner residue attracts soil and can interfere with sealer or finish adhesion.
- Control cross-contamination with color-coded tools, fresh solution, and changed mop water.
Worked example
A label specifies 1:256 for an auto-scrubber. One U.S. gallon is 128 fl oz, so 128 ÷ 256 = 0.5 fl oz per gallon. For a 5-gallon tank: 5 × 0.5 = 2.5 fl oz. If the floor is heavily soiled, do not double the concentration; instead pre-scrub or use a longer dwell time, because doubling may leave residue that dulls the floor and requires a rinse.
Traps that cost marks
- “Stronger is better” is usually false.
- Skipping dwell time and scrubbing harder.
- Mixing bleach with ammonia or acid products, which can release toxic gas.
- Using hot water on wax or heat-sensitive resilient floors.
- Failing to rinse before applying finish.