S F Johnson Consulting, LLC
Services all contractors need since 2010

Division 09

Division 09

🎨 Division 09 — Finishes

Gypsum Board • Ceilings (ACT/GWB/Specialty) • Flooring (Resilient/Carpet/Tile/Wood) • Painting & Coatings • Wallcoverings • Acoustics. Follow project specs, manufacturer data, and tested assemblies.

🧭 Scope (What Div 09 Covers)

  • GWB partitions/ceilings; levels of finish; taping/textures; corner beads/trim.
  • Ceilings: ACT, metal, wood, stretched, specialty baffles/clouds; access panels.
  • Flooring: resilient (VCT, LVT, sheet), rubber, carpet/tile, ceramic/porcelain/stone, wood.
  • Coatings: paint systems, epoxy/urethane, intumescent (coord. Div 07), clear coats.
  • Wallcoverings: vinyl/fabric/FRP; acoustical wall panels; tack/marker surfaces.
  • Acoustics: NRC/CAC/STC/IIC targets; sound sealants; resilient details.

📑 Coordination & Pre-Checks

  • Confirm substrate flatness/levelness & moisture/pH tolerances before finish.
  • Locate control/expansion joints; maintain continuity of WRB/air/vapor (Div 07).
  • Schedule access doors, backing/blocking, and MEP penetrations before close-up.
  • Mockups for color/texture/pattern alignment and sheen acceptance.

🧱 Gypsum Board (GWB)

  • Thickness: 1/2" interior; 5/8" Type X for rated & most ceilings; moisture-resistant in wet zones; cement board at wet walls/tubs.
  • Levels of Finish (GA-214): L0–L5. L5 for critical light/high sheen. L4 common for painted flat/eggshell.
  • Control joints ~30' o.c. (or per GA-234) & at changes in framing; back-to-back with building joints.
  • Beads/Trim: metal/vinyl; L-bead/J-bead reveals; corner bead type per durability/exposure.

🧭 ACT & Specialty Ceilings

  • ACT grid: 15/16" or 9/16"; hanger wires ~4' o.c.; splay braces as required; perimeter angles = room perimeter LF.
  • Tiles: 2×2 (4 SF) or 2×4 (8 SF); NRC (absorption) & CAC (blocking) ratings per spec.
  • Clouds/baffles: verify suspension hardware, seismic bracing, service access.
  • Access: coordinate panel size & location with MEP equipment clearances.

🧪 Substrate & Moisture (Concrete)

  • RH (ASTM F2170) & MVER (F1869) to manufacturer limits (e.g., RH ≤ 75–85%; MVER ≤ 3–5 lb — spec governs).
  • pH typically 8–10. Flatness: 1/8" in 10' for resilient; self-level where needed.
  • Prep: shot-blast or grind; repair cracks; primer per adhesive; test slabs with patch/SLU compatibility.

📦 Resilient / Carpet / Wood

  • LVT/VCT/Sheet: acclimate; trowel notch per adhesive; roll seams; transitions ADA compliant.
  • Carpet tile: check dye lots/arrow orientation; cushion vs direct glue per spec.
  • Wood: acclimate to space RH; verify moisture content; use vapor retarder over slab if required.
  • Base: rubber/vinyl 4" or 6"; outside corners pre-formed or wrapped; clean substrate for adhesion.

🧱 Tile (Ceramic/Porcelain/Stone)

  • Mortars: ANSI A118.1 (non-mod), A118.4 (mod), A118.15 (improved). Grout: cementitious, high-performance, or epoxy.
  • Wet areas: waterproofing ANSI A118.10; slope showers ¼"/ft; movement joints per EJ171.
  • Layout: balance cuts; avoid slivers (<½ tile); expansion breaks at perimeters & transitions.

🎨 Painting & Coatings

  • New GWB: prime + 2 coats (spec sheen); critical light → Level 5 + high-build primer.
  • Masonry: block filler + 2 coats; Steel: clean → prime (zinc/epoxy) → finish.
  • Sheen guide: flat ceilings, eggshell/satin walls, semi-gloss trim/doors.
  • Coverage ROM: 350–400 SF/gal/coat (smooth). Dark colors/high-build vary.
  • LRV: light colors improve daylighting; coordinate with acoustics/glare.

🧵 Wallcovering / FRP

  • Substrate smoothness: Level 4–5 for thin vinyls; prime/seal walls.
  • Seam layout away from direct light; roll seams; maintain pattern repeat.
  • FRP: approved adhesive, trims, expansion gaps; clean, dry, flat substrate.

🔊 Acoustics (Quick)

  • NRC (absorb), CAC (ceiling attenuation), STC (partitions), IIC (impact floor/ceiling).
  • Use acoustic caulk at perimeters/penetrations; stagger studs/resilient channel per tested assembly.
  • Seal back-to-back outlets; extend walls tight to deck for high STC partitions.

🧮 Quick Math & Takeoff Shortcuts

Paint Gallons (per coat)

Wall Area ≈ (Perimeter × Height) − Openings.

Gallons ≈ Wall Area ÷ 350 (smooth). Multiply by # of coats.

ACT Tile Count

2×2: tiles ≈ Area ÷ 4 • 2×4: tiles ≈ Area ÷ 8 (+ waste & border cuts).

Carpet / Base

Carpet SY = SF ÷ 9. Rubber base LF = room perimeter (− door widths) + waste.

LVT Boxes

Boxes ≈ Area ÷ CoveragePerBox (common 24–36 SF/box) + 5–10% waste.

Tile Count

Tiles ≈ Area ÷ TileArea + waste (7–15% field; more for patterns/diagonals).

GWB Sheets

4×8 covers 32 SF • 4×12 covers 48 SF (choose to reduce horizontal joints).

Transitions (ADA)

Vertical ≤ 1/4" ok; 1/4"–1/2" beveled at 1:2; >1/2" requires ramp.

Floor Flatness Targets

Resilient/Tile: ≤ 1/8" in 10'. Wood/Carpet more forgiving; stone more stringent.

✅ QA / Submittals

  • Color/sheen schedule; drawdowns; elevation/finish key coordination.
  • Flooring: product data, adhesive, acclimation, moisture/pH reports, warranty terms.
  • Tile: mortar/grout data; membrane type; movement joint details.
  • Acoustical ceilings/walls: NRC/CAC targets; suspension details; seismic bracing where required.

🦺 Safety Notes

  • Silica control when cutting tile/concrete underlayment; use wet saw/HEPA vacs.
  • Ventilation & PPE for adhesives, primers, epoxies, coatings (check SDS).
  • Ladder/scaffold safety; fall protection at atriums/edges; material handling ergonomics.

📝 Self Test

  1. Which GWB finish level is recommended for critical light with semi-gloss paint?
  2. Compute paint gallons (2 coats): Room 12×20, height 9', 2 doors @ 21 SF, 2 windows @ 15 SF each. Use 350 SF/gal/coat.
  3. How many 2×2 ACT tiles for 3,600 SF (add 5% waste)?
  4. RH/MVER/pH checks belong to which ASTM tests?
  5. Tile waste % to carry for a running-bond layout with many cuts?
  6. Minimum slope to drain for showers?
  7. Carpet quantity for 2,250 SF (in square yards)?
  8. List two ways to improve STC in a partition.
  9. ADA rule for a 3/8" flooring transition?
  10. Flatness requirement for resilient flooring?

Answers: (1) Level 5. (2) Perimeter=2×(12+20)=64 ft; Wall area=64×9=576; openings=21×2 + 15×2=72; net=504 SF. Gallons/coat=504÷350≈1.44 → ×2 coats ≈ 2.9 gal (buy 3–4 gal depending on color). (3) Tiles=3600÷4=900; +5% ≈ 945 tiles. (4) F2170 (RH), F1869 (MVER), F710 (prep/pH guidance). (5) 10–15% (use higher for diagonals/feature cuts). (6) ¼" per foot. (7) 2250÷9 = 250 SY. (8) Add resilient channels/staggered studs; seal perimeters/boxes; increase layers/mass. (9) Bevel at 1:2 (since >¼" and ≤½"). (10) ≤ 1/8" in 10' (tighter for stone).