DSS-E.03.01 — Algae / Biofouling Film

Algae / biofouling film is an appearance change on glass resulting from microbial colonization (algae, cyanobacteria, biofilms) under persistent moisture and nutrient availability (organics, dust). It presents as green to brown films, strand/filament colonies at gasket/edge zones, and wetting anomalies where biofilm alters surface energy. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Greenish film in shade-damp exposures; brown/olive in sun-exposed, nutrient-rich areas.
• Edge-biased colonies: along gaskets, sealant joints, weeps, and horizontal ledges where water dwells.
• Filamentous/spot clusters; may co-present with runoff patterns (E.01.04) and salt or mineral residues.

Surface-catch class (MSRT)

• Typically SC-0 (soft biofilm).
• SC-1 localized where entrained grit or repeated wiping created very shallow micro-texture; SC-2 suggests misclassification-check M.02 abrasion fields or Ch.03.03 mineral etch if matte persists post-reveal.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use polymer stylus if a functional coating is suspected. MSRT supports classification only.

Visual signature

• Chromatic film (green/olive/brown), stringy colonies at edges/weep paths, beading/sheeting changes after misting due to biofilm wetting effects.
• No chip-flank sparkle, no fused pits/nodules.

Viewing / lighting

• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°-120°); raking macros to show colony edges, filaments, and wetting contrast. Record distances/angles in-frame.

Location / access

• Record pane ID and surface numbering (#1-#4; laminate-internal). Common on outboard (#1) in shady, damp zones; can appear on inboard (#4) in natatoriums/greenhouses. Between-pane by parallax on #2/#3 → CAT-5 by location.

Mechanism cue (context)

• Persistent moisture, overspray/irrigation, blocked weeps, organics deposition (trees, pollen), near landscaping.

Assign CAT by visibility at acceptance geometry and MSRT after a small reveal patch. Depth values are indicative-field measurement not required.

• CAT-1 (Benign / non-relief): Thin chromatic biofilm; SC-0; angle/raking visible; lifts on reveal patch. Indicative relief: 0-10 μm (optical).
• CAT-2 (Light): Persistent film/colonies with localized SC-1 from grit entrapment or prior wiping; limited standard-view impact. Indicative relief: ~10-40 μm.
• CAT-3 (Moderate): Wide-area growth clearly legible at standard distance with edge blooms and recurring wetting anomalies; SC-1 scattered. Indicative relief: ~40-120 μm.
• Reclassify when: Post-reveal, if non-directional matte persists without biofilm → evaluate E.01.02 atmospheric matte; if white crystalline rims/etch dominate → Ch.03 mineral system; if linear abrasion remains → M.02.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, 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 abrade to “force” a response during classification.

• vs. Algae-like mineral staining (Ch.03.02): Mineral films are inorganic, whitish/grey, with crystalline rims; biofilm is chromatic (green/brown) and organic, often slimy when wet.
• vs. Kitchen/HVAC films (R.04.03/04): Those are oily/amber and track air/grease paths; biofilm tracks moisture dwell and nutrient load.
• vs. Mold on sealants (off-glass): Mold resides on sealant/frames; confirm on-glass presence before classification.
• vs. Coating anomalies (Co-family): Coating issues show color/patchiness on designated coated faces; biofilm responds to reveal and aligns with moisture patterns.

• Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of colonies/filaments, wetting anomalies, edge blooms; context of moisture sources/landscaping/weep details. Record distance/angle in-frame.
• MSRT result (substrate): After a small reveal test patch, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
• 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; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

• E.03.01 Algae / Biofouling Film - Green/brown biofilm with edge colonies and wetting anomalies on surface #___; post-reveal test patch shows [SC-0/SC-1]; visible at [12/36/72 in] under VIS geometry. Morphology: chromatic film, strandy colonies, no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify to Ch.03 or E.01.02 per persistence/chemistry; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.