DSS-R.01.04 — Mastic / Bitumen / Tar Transfer

Mastic/bitumen/tar transfer is an appearance change on glass from bituminous products (roofing asphalt, waterproofing mastics, tar-based adhesives/primers) contacting the surface during construction, roofing, façade waterproofing, or logistics. It presents as dark brown-black, tacky smears/bands, often edge- or frame-adjacent, with drag strings and heavy particulate/soot capture. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status. Treat active tack/residues per site safety.

• Thick, tarry bands or hand/finger prints near roof lines, flashing interfaces, waterproofing joints, hoist points, or material staging paths.
• In specular: high-contrast dark smear; in raking: viscous drag fronts, ropey strings, embedded grit, lint.
• Heat/sun can soften/flow residue, creating sags/legs below the origin.

Surface-catch class (MSRT)

• SC-0 on the clean glass substrate once residue is truly lifted (non-etch).
• Do not run MSRT across active tack; if a small test patch is safely cleaned without abrasion, confirm substrate SC-0 there.
• Use polymer stylus if a functional coating is suspected on the worked face. MSRT supports classification only.

Visual signature

• Opaque, dark brown-black smear with ropey edges, stringers, and heavy soil/soot catch; may show heat flow legs.
• No chip-flank sparkle (not mechanical scoring); no discrete fused nodules/pits (not hot-particle peppering).

Viewing / lighting

• Evaluate clean & dry surroundings at 12 / 36 / 72 in, normal incidence and oblique sweep (~60°-120°). Use raking to highlight drag fronts, stringing, and embedded grit. Record distances/angles in-frame.

Location / access

• Record pane ID and surface numbering (#1-#4; laminate-internal). If residue is observed inside an IGU cavity (by parallax on #2/#3), classify CAT-5 by location (out of in-place scope) and refer.

Mechanism cue (context)

• Nearby roofing/tar kettle work, bituminous membranes, flashing/seal courses, waterproofing primers, hoisting slings or gloved handling transferring tar.

Assign CAT by visibility impact under VIS geometry after a controlled reveal test confirms substrate SC-0 on a small patch. Depth values are indicative-field measurement not required.

• CAT-1 (Benign / non-relief): Thin optical smear; SC-0 on clean substrate; mainly angle/raking visible. Indicative relief: 0-10 μm (optical film).
• CAT-2 (Light): Persistent tar veil with soil/soot loading legible at standard view; SC-0 on substrate at test patch. Indicative relief: ~10-40 μm (film).
• CAT-3 (Moderate): Broad/opaque bands, ropey strings, heat-flow legs visible at standard distance; SC-0 on substrate where truly cleaned. Indicative relief: ~40-120 μm (film stack).
• Reclassify when: After true residue removal, any modeled micro-texture or SC-class > 0 persists on substrate → evaluate under chemical etch (Ch.04/.05) or mechanical families as indicated.
• 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 abrade to “force” removal during classification.

• vs. Butyl/PIB smear (R.01.02): PIB is usually edge-line/parallels spacers, tacky but less opaque; bitumen/tar is darker, more odoriferous, and often heat-flowed.
• vs. Polysulfide/PU smear (R.01.03): Polysulfide/PU tends amber/grey, shows elastic tails; tar is brown-black, more ropey with soot catch and heat sag.
• vs. Silicone smear (R.01.01): Silicone reads oily/iridescent, lighter, with corduroy tool lines; tar is opaque/dark with grit capture.
• vs. Mineral staining/etch (Ch.03): Mineral films are light/whitish and non-tacky; tar is dark/tacky, often with odor and particulate embed.
• vs. Coating anomalies (Co-family): Manufacturing rub/patchiness shows sheen/color shift on #2/#3 without tack or odor; tar is field residue on exposed faces, unless parallax shows cavity (CAT-5).

• Photo set (VIS): 12 / 36 / 72 in, normal + oblique; include raking macros resolving ropey edges, stringers, grit embed, and any heat-flow legs; add context frames (roofing/waterproofing work zones). Record distance/angle in-frame.
• MSRT result (substrate only): After lifting a small test patch without abrasion, perform one light, non-marring pass on the clean substrate; record SC-class (expect SC-0). Avoid stylus over active tack.
• 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.

• R.01.04 Mastic / Bitumen / Tar Transfer - Dark brown-black, tacky smear with ropey edges/stringers on surface #___; post-reveal test patch shows substrate SC-0; visible at [12/36/72 in] under VIS geometry. Morphology: opaque tar bands, grit embed, heat-flow legs; no chip-flank sparkle, no discrete pepper. Classification: CAT-[1/2/3] by visibility (film-only). CAT-5 if between-pane by parallax, or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.