Minimum coats by joint type
- Tapered edge seam: 3 coats (embed tape, fill, finish)
- Butt joint: 3–4 coats (wider feather each pass)
- Screw heads: 2 coats minimum (dimple fill + finish)
- Inside corner: 3 coats with corner tool
- Outside corner (bead): 3 coats over bead flanges
When to add a fourth coat
Critical lighting (window opposite a wall) shows every seam. A thin skim coat over the whole room — or a Level 5 skim on seams only — fixes telegraphing after the third coat sands through tape.
Dark paint and glossy sheens show flaws more than matte white primer. Budget extra compound and sand time if you are going from new drywall to a deep color.
Compound quantity per coat
A 1,000 sq ft hang (walls + ceiling) often uses 4–6 five-gallon buckets of ready-mixed mud for three coats, plus one roll of tape. High-coat-count butt-heavy jobs push toward eight buckets.