It's cold and the house isn't heated yet.

For taping and finishing drywall, maintain the room temperature between 50°F and 70°F (10°C to 21°C) for at least 48 hours before starting and continuously during the process.

Key points:

• Minimum 50°F (10°C): Below this, joint compound dries too slowly, leading to poor adhesion, extended drying times, and potential mold growth.
• Ideal range 65–70°F (18–21°C): Optimal for even drying and workability.
• Duration: Keep the temperature steady for 48 hours prior to taping/finishing and throughout the entire process, including between coats.
• Humidity control: Pair with dehumidification if needed; high humidity slows drying even at proper temperatures.

Code reference: The Gypsum Association (GA-216) recommends maintaining temperatures above 50°F during application and drying of joint compounds. Local building codes often reference GA-216 for interior drywall finishing standards.

Practical tip: Use safe, temporary heating (e.g., electric heaters) and monitor with a thermostat. Avoid open flames or unvented gas heaters due to fire and moisture risks.

If you can’t maintain 50°F, delay finishing until conditions improve to avoid callbacks or rework.

Minimum 55°F (13°C) — ideally 65–70°F — for 48 hours before, during, and after each coat.

Code/Standard Basis

• ASTM C840 (referenced by IRC R702.3.5) requires 55°F minimum for application and curing of joint compounds.
• GA-216 (Gypsum Association) specifies 55°F minimum ambient and substrate temperature for 48 hrs pre/post each coat.

Practical Rules

1. Heat the space — not just the air. Cold framing/sheetrock sucks moisture from mud, causing bonding failure, cracking, or delayed shrinkage.
2. Maintain temp 48 hrs after final coat before sanding or painting.
3. No temporary heaters that add moisture (propane/kerosene). Use electric or vented gas.
4. Ventilate — but don’t create drafts that dry mud too fast.
5. Check substrate temp with infrared thermometer; if studs/bay are <55°F, mud will fail even if air reads 60°F.

If you can’t hold 55°F:

• Don’t tape. Wait.
• Cold-weather “quick-set” compounds (e.g., USG Sheetrock® Brand Easy Sand™) still need 55°F+ substrate. They set chemically but cure physically — cold stops cure.

Bottom line: No heat, no tape. Schedule the HVAC rough-in or temp electric heat before you mix mud.