Masonry Cleaning Dilution, Coverage, and Rinse

Acid-based cleaners attack the cement paste in the mortar and the surface of many units, so the correct dilution is the WEAKEST that removes the soiling, established on a test panel -- and strengthening it because the wall is dirty is the standard way to burn a facade. The damage looks like efflorescence or a colour change, it appears after the scaffold is down, and it is permanent. One part concentrate to N parts water is one part in N plus one of the mix, which is the arithmetic people get wrong in the direction of too strong. PREWETTING IS WHAT KEEPS THE CLEANER ON THE SURFACE. Dry masonry draws the solution into itself, where it attacks the mortar from within and leaves salts that migrate back out for years afterward. Saturating the wall first means the cleaner works on the face and rinses away, and skipping it is the difference between a cleaned wall and a damaged one -- so the prewet water is counted here as part of the job rather than as an optional step. RINSING IS A QUANTITY AS WELL AS AN ACTION. Residual cleaner keeps working after the crew moves on, so the rinse volume and pressure are specified, and an inadequate rinse produces damage that appears days later on a wall that looked finished. The total water is what the site has to supply and what the runoff control has to handle. THE UNITS THAT MUST NEVER SEE ACID ARE A SHORT LIST WORTH CARRYING: polished stone, limestone, marble, many coloured and glazed units, and anything with a metallic finish or with metal below that the runoff will reach. Aluminium windows under an acid-cleaned brick facade get etched by the rinse water alone, which is why masking and runoff control are part of the job rather than housekeeping. Dwell time belongs on that list too: a stated dwell is a maximum as much as a minimum, because a cleaner allowed to dry in place has to be removed mechanically. Quantities from a dilution and a coverage rate the reader takes from the manufacturer for the specific unit. It does not select a cleaner or a dilution, evaluate the soiling, or replace a test panel, which is required rather than advisable. It does not address containment, runoff collection and disposal, which are regulated; personal protective equipment and the hazards of the concentrate; pressure and equipment; or the temperature and weather limits on application. Efflorescence, mortar smears, and construction staining have different treatments, and some of them are not acid. The cleaner manufacturer's instructions for the specific unit, the project specification, a test panel, and the applicable environmental rules govern.

diluted solution = area / coverage; one part concentrate to N parts water is one part in N+1, so concentrate = diluted / (N+1) and water is the remainder; prewet and rinse water are counted at their own rates per 100 sq ft.

The dilution and coverage identities by name. NO CLEANER, DILUTION OR COVERAGE IS SHIPPED: all three come from the manufacturer for the specific unit, and a test panel is required rather than advisable. Acid attacks polished stone, limestone, marble, many coloured and glazed units, and metal the runoff reaches. The cleaner manufacturer's instructions, the project specification, a test panel, and the applicable environmental rules govern.

Two divisions on a dilution and a coverage rate the reader has; no product data is reproduced.

Estimate. AHJ and licensed professional govern.

Field names used by the API: area_ft2, dilution_parts_water, coverage_ft2_per_gal, prewet_gal_per_100ft2, rinse_gal_per_100ft2, acid_safe_unit, diluted_gal, concentrate_gal, water_gal, concentrate_pct, prewet_gal, rinse_gal, total_water_gal

• Dilution and coverage are the manufacturer's for the specific unit, and a test panel is requiredthe cleaner manufacturer's instructions
• Some units must never see acid polished stone, limestone, marble, coloured and glazed units, and metal belowthe project specification
• Containment and disposal are regulated and are not addressed herethe applicable environmental rules