DSS-Ch.02.02 — Concrete Splash / Run-Off Etch Pattern

Concrete splash/run-off etch is alkaline (high-pH) attack on the exposed glass surface resulting from fresh concrete wash-out, saw-cut slurry, or rain-driven run-off carrying cement fines. It presents as splash constellations, vertical curtain-run bands, and pooling shelves that can leave grainy micro-texture (etch) after residues are removed. 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: Handle fresh residues per site safety.

• Speckled splash fields (near grade, slab edges, saw-cut lines, or mixing stations).
• Vertical “curtain” bands below slab edges, parapets, or jambs, sometimes with edge ridging where flow slowed/pooled.
• After reveal, interiors read as milky/grainy frost; run edges show higher contrast; pooling shelves at gaskets/sills may remain dull.

Surface-catch class (MSRT)

• SC-0 when only residual film was present and clears at reveal.
• SC-1 (slight) to SC-2 (clear) where alkaline etch produced micro-texture. Perform one light, non-marring pass; polymer stylus if a coating is suspected. MSRT supports classification only.

Visual signature

• Gravity-organized geometry: splash → constellations; runoff → contiguous vertical bands; pooling → horizontal shelf with duller tone.
• Under raking: non-directional, grainy micro-texture (no chip-flank sparkle; no discrete nodules/pits).

Viewing / lighting

• Evaluate clean & dry at 12 / 36 / 72 in, normal incidence and oblique sweep (~60°-120°) with raking light to resolve grain and edge contrast. Record distances/angles in-frame.

Location / access

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

Mechanism cue (context)

• Evidence of saw-cutting, wet curing/hosing, pump splatter, wash-out areas, or rain-carried fines from new concrete work above/adjacent.

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

• CAT-1 (Benign / non-relief): Cleaning film only, clears at reveal; SC-0; visible mainly in raking. Indicative relief: 0-10 μm.
• CAT-2 (Light): Subtle etched splash/run bands, SC-1; limited impact at standard view. Indicative relief: 10-40 μm.
• CAT-3 (Moderate): SC-2 over larger curtain-run fields; grainy frost legible at standard distance; edge ridging/pooling shelves apparent. Indicative relief: 40-120 μm.
• CAT-4 (Severe): Pronounced matte/frosted swaths with broad coverage or repeated events; distinct at standard & wide-field; may show opaque ridges at run terminations. 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. HCl brick-wash fallout (Ch.01.02): HCl runs show cleaner frost with sharper run edges; alkaline concrete leaves grainy/milky interiors and can show powdery edge build-ups.
• vs. Organic-acid footprints (Ch.01.03): Biogenic patches are localized organic ovals with pool centers; concrete shows splash constellations and continuous curtain bands tied to work zones.
• vs. Mechanical scoring (M.01): Scoring is directional lineation with chip-flank sparkle; alkaline etch is non-directional grain arranged by flow.
• vs. Hot-particle damage (Th.01.xx): Slag/sparks produce discrete fused nodules/pits with bright rims; concrete etch lacks discrete pepper.
• vs. Coating anomalies (Co-family): Coating rub/patchiness gives 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 grain and edge build-ups; add context frames showing splash source/runoff path (saw-cut lines, wash-out, slab edge). Record distance/angle in-frame.
• MSRT result: One light, non-marring pass on representative splash/band/pooling shelf; record SC-class (SC-0/1/2). 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.02.02 Concrete Splash / Run-Off Etch - Splash constellations / curtain-run bands / pooling shelves with [SC-1/SC-2] on surface #___, visible at [12/36/72 in] under VIS geometry after Non-Invasive Reveal. Morphology: grainy micro-texture with edge contrast; no chip-flank sparkle or discrete pepper. 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).