Moisture and mold prevention
Fix exterior water management before closing walls — gutters, grading, interior dehumidification. Do not trap moisture against concrete with plastic vapor barriers on the warm side in all climates; follow local building science guidance.
Fiber-resistant or moisture-resistant gypsum on lower walls in damp zones; never install standard paper-face board directly on below-grade concrete without a framed cavity and appropriate insulation strategy.
Framing and furring
Steel or pressure-treated bottom plates on slab, studs 16 inches on center, rigid or batt insulation in cavity, then drywall. Furring channels can save headroom versus full stud walls on perimeter concrete.
Soffits around ducts and beams eat sheet count — measure each boxed-out area separately in the calculator.
Egress and code for bedrooms
Legal basement bedrooms need egress windows and often smoke/CO alarms tied to house circuits. Fire separation from furnace rooms may require 5/8 Type X — sheet count and thickness vary by room.
Typical basement sheet quantities
A 1,000 sq ft open basement (30×33 footprint, 8 ft ceilings) might need 35–45 sheets for perimeter walls plus 30–35 ceiling sheets depending on layout — use room-by-room calculator entries for accuracy.