DSS-Ch.01.02 — Muriatic / Brick-Wash Fallout (HCl)

Muriatic/brick-wash fallout is acid exposure from hydrochloric acid (HCl) solutions used for masonry cleaning or concrete etch. It typically presents as flow films, drip legs, and splash constellations that leave etched micro-texture and tone/shine shift on the exposed face. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status on Forms: Treat any fresh residue as hazardous; do not touch-document visually per site safety protocols.

• Vertical runs and drip legs beneath masonry interfaces, parapets, or slab edges; splash flecks near grade or scaffolding lines.
• Soft-edged flow fields with higher contrast at run boundaries; in raking light, affected zones read as modeled micro-texture (non-directional).
• May show streaked patterns from over-application, wind drift, or rinse shadowing; adjacent metals can show acid burn or discoloration.

Surface-catch class (MSRT)

• SC-1 (slight) to SC-2 (clear) within etched run/film areas; SC-0 if only a residual cleaning film remains (reveal should remove film). Perform one light, non-marring pass; polymer stylus if a coating is suspected. MSRT supports classification only.

Visual signature

• Flow-organized morphology: continuous bands/legs/sheets tied to gravity; no chip flanks or continuous abrasive tracks.
• Boundary contrast strongest at flow edges, drip terminations, and pooling shelves; interiors read as low-contrast frost (modeled, not directional).

Viewing / lighting

• Evaluate clean & dry at 12 / 36 / 72 in, using normal incidence and oblique sweep (~60°-120°) with raking light to reveal micro-texture and run edges. Document distances/angles in-frame.

Location / access

• Record pane ID and surface numbering (#1-#4; laminate-internal). If fixed parallax indicates a between-pane presentation, classify CAT-5 by location (out of in-place scope) and refer.

Mechanism cue (context)

• Recent/ongoing masonry acid cleaning, brick-wash rigs, acid spray/fog drift, or rinse-down above the lite; note windward/leeward orientation.

Assign CAT by appearance + MSRT + morphology (three-part cueing). Depth ranges are indicative-measurement is not required.

• CAT-1 (Benign / non-relief): Tone/shine shift only, SC-0 after reveal; visible primarily in raking at close/standard view; suggests residual film, not etch. Indicative relief: 0-10 μm.
• CAT-2 (Light): Subtle etched flow film, SC-1, limited impact at standard view; edges soft. Indicative relief: 10-40 μm.
• CAT-3 (Moderate): Clear detect (SC-2) across run/film; modeled micro-texture visible at standard distance with legible flow geometry. Indicative relief: 40-120 μm.
• CAT-4 (Severe): Pronounced frost/matte along drip trains or pooling shelves; distinct at standard & wide-field; may exhibit localized whitening. Indicative relief: 120-300 μm+.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators (active cracks, pane movement), or confirmed functional-coating loss on the surface to be worked → CAT-5.

CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not “probe” with MSRT.

• vs. Acid-etch graffiti (Ch.01.01): Graffiti presents intentional stroke geometry with drip legs from stroke ends; brick-wash fallout shows gravity-organized sheets/runs without letterForms:
• vs. Alkaline cement/mortar etch (Ch.02.01/.02): Alkaline attacks may leave grainy crusts or efflorescence residues and often produce chalky film; HCl fallout more often yields cleaner frost with sharper run edges after reveal.
• vs. Mechanical scoring (M.01): Scoring shows continuous lineation with chip-flank sparkle; chemical runs are non-directional micro-texture within flow bands.
• vs. Residue films (R-family): Paint/mud/detergent films remove at reveal and read SC-0; persistent SC-1/SC-2 indicates etch.
• vs. Coating anomalies (Co-family): Coating rub/patchiness shows sheen/color shift but no etched relief; on a worked coated surface any anomaly is not permitted at acceptance (VIS §6.2.e).

• Photo set (VIS): 12 / 36 / 72 in, normal + oblique; include raking macros resolving flow edges/drip legs and modeled micro-texture; add context frames showing masonry/cleaning source and runoff path. Record distance/angle in-frame.
• MSRT result: One light, non-marring pass on a representative run/film; record SC-class (SC-1/SC-2 if etched; SC-0 if film only). Prefer polymer stylus if a coating is suspected.
• Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
• Acceptance split: Post-restoration acceptance per VIS-A §6 at 12/36/72 in; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e.

• Ch.01.02 Muriatic / Brick-Wash Fallout (HCl) - Flow-organized etched film with [SC-1/SC-2] on surface #___, visible at [12/36/72 in] under VIS geometry after Non-Invasive Reveal. Morphology: runs/drip legs/pooling edges with modeled micro-texture; no chip-flank sparkle or linear scoring. Classification: CAT-[2/3/4] by relief/visibility; CAT-5 if between-pane, integrity cues, or coating-side loss on the surface to be worked. Forms + photo set completed; acceptance per VIS-A §6 (separate).