Distinguish interior veneer plaster over gypsum base (blueboard) from conventional three-coat interior plaster for scope and licensing

Steps

1. For veneer plaster, install a gypsum base product compliant with current gypsum board standards (the historical dedicated veneer-base standard, C588, was withdrawn and superseded by gypsum board standard C1396) per ASTM C844 application requirements
2. Apply veneer plaster in one or two thin coats per ASTM C843, using the scratch-and-double-back technique where a single-coat product is used
3. For conventional three-coat interior plaster, use a full-thickness scratch/brown/finish build over lath per the applicable plaster application standard, similar in principle to exterior C926 but for interior gypsum-based plaster
4. Confirm which trade license classification covers the work being bid, since interior lathing/plastering scope can fall under the same classification as exterior stucco in some jurisdictions (e.g., California's C-35) rather than a separate drywall license
5. Communicate schedule differences to the GC: veneer plaster is typically a fast, low-dust, one- to two-day process versus the multi-day dry time of conventional three-coat plaster