Plastering & Drylining
QA inspection checklist

Metal Framing

1. 1.

   Stud and track sizes match specification
   What to look forStud size and gauge marked on flange — typically I-Stud, C-stud or shaft wall stud. Track depth matches stud. Acoustic mat or isolation strip on track at floor and ceiling for sound-rated walls. Manufacturer marking visible.
   Acceptable whenStuds to BS EN 14195 (steel framing). Stud width to suit wall thickness — typically 50, 70, 92, or 146 mm. Gauge 0.5-0.7 mm for general partitions, 0.8 mm+ for high partitions or shaft walls. System per BSI BBA / British Gypsum / Knauf "BWA" detail.
   StandardBS EN 14195:2014 — Metal framing components. BS 5234-2:1992 — Partition strength and stability. British Gypsum / Knauf system specifications.
   Common defectsWrong stud width — 70 mm used where 92 mm specified for fire/acoustic ratingStuds too light gauge for partition height — wall flexesTrack depth less than stud height — racking weaknessNo isolation strip on acoustic walls — flanking transmissionMixed manufacturer system — no warranty, fire test not applicable
2. 2.

   Stud centres correct

   Record: Centres (mm)
   What to look forStuds at design centres — measured centre-to-centre. Typically 600 mm for standard, 400 mm for higher loads or extra acoustic mass. Studs vertical, no twist. Web pre-cut for service penetrations only at indicated locations.
   Acceptable whenStud centres typically 600 mm for boards up to 1200 mm wide; 400 mm for high partitions, ceramic tile substrates, or higher acoustic ratings. Tolerance ±10 mm. Studs plumb ±3 mm in storey height per BS 5234-2.
   StandardBS 5234-2:1992. BS EN 14195:2014. British Gypsum White Book / Knauf installation guide.
   Common defectsStud centres at 600 mm where 400 mm needed for tile backerStuds out of plumb — visible bow in finished wallCut-out for services not at manufacturer's pre-punched locationLast stud > 600 mm from wall — board edge unsupported
3. 3.

   Acoustic insulation fitted
   What to look forMineral wool fits between studs without compression. No gaps at top, bottom, or vertical joints. Density and thickness as specified. Friction-fit so it does not sag. Continuous around services penetrating wall.
   Acceptable whenMineral wool to BS EN 13162. Density 10-60 kg/m³ depending on acoustic spec — typically 16-25 kg/m³ for partitions. Thickness typically full depth of stud. Sound rating to BS EN ISO 10140 — Rw of 40-55 dB depending on construction.
   StandardBS EN 13162:2012+A1:2015 — Mineral wool. BS EN ISO 10140 — Sound insulation testing. Approved Document E (England/Wales).
   Common defectsInsulation slumped to bottom — top of cavity void = direct sound pathWrong density — 10 kg/m³ used where 25 kg/m³ specifiedCompressed at services — local thermal/acoustic bridgeNot full stud depth — board cavity left = drum effectGaps at top/bottom track — flanking transmission

Boarding

1. 4.

   Board type correct for location
   What to look forBoard type marking on edge — Standard (white core), Fire (pink/red core, FireLine / Fireshield), Moisture (green core, MR / Aquapanel for tile backer), Impact (high-density). Thickness 12.5 mm typical, 15 mm for fire and acoustic.
   Acceptable whenBoard to BS EN 520. Wallboard Type A (standard) for general areas; Type F (FireLine, ≥12.5 mm) for fire-rated walls; Type H (moisture, MR) for kitchens/bathrooms; Type I (Impact) for high-traffic. Thickness for fire rating per manufacturer's test certificate.
   StandardBS EN 520:2009+A1:2018 — Gypsum plasterboards. Approved Document B (fire). British Gypsum / Knauf system specifications.
   Common defectsStandard board used in fire-rated wall — wall not compliant with FRAStandard board in bathrooms — board paper degrades, mould12.5 mm board where 15 mm specified for 60 min fire — rating not achievedType F board single-layer where double-layer specified — fire failCement-particle board (Aquapanel) needed for tiled wet areas — used MR instead
2. 5.

   Boards fixed at correct screw centres
   What to look forSelf-tapping screws (drywall screws) — type 1 (sharp) for studs ≤ 0.7 mm, type 2 (drill point) for thicker. Screw heads sit just below paper surface, no torn paper. Screws into stud face, not edge. Alternating offset on double-board.
   Acceptable whenScrew centres per board manufacturer / system: typically 200 mm to perimeter, 300 mm to intermediate studs (single layer); 300/400 mm for second layer. Screws ≥ 25 mm into stud (12.5 mm board) or ≥ 36 mm (double board). Screw 10-15 mm from board edge.
   StandardBS 8212:1995 — Code of practice for drylining. British Gypsum White Book. Knauf Drywall Manual.
   Common defectsScrews missed studs — pushed through into cavity, no fixHeads driven through paper — no holding power, popping laterScrew centres > 300 mm — board waves under shrink/expandScrews too close to edge — board crumblesWrong screw length — does not engage stud properly on double board
3. 6.

   Joints staggered on double-boarded walls
   What to look forVertical joints offset by minimum 600 mm between layers (or one stud bay). Horizontal joints offset by minimum 450 mm. No coincident joints between layers. Layer 1 fully fixed before layer 2 applied.
   Acceptable whenVertical joint offset ≥ one stud bay (typically 600 mm), horizontal offset ≥ 450 mm. Per fire test report — coincident joints in tested system. Layer 1 typically uses fewer screws than layer 2.
   StandardBS EN 520:2009. BS 8212:1995. British Gypsum / Knauf installation manual. Approved Document B.
   Common defectsCoincident joints between layers — fire pathLayer 2 fixed before layer 1 fully complete — boards liftHorizontal joints aligned across two layersLayer 1 partially screwed (intended to be temporary) — never finished

Jointing & Finishing

1. 7.

   Joints taped and filled seamlessly
   What to look forPaper or fibreglass tape bedded into first coat compound. Three-coat system: tape coat, fill coat, finish/skim coat. Each coat sanded smooth before next. No tape edges visible. Joints invisible under raking light.
   Acceptable whenThree-coat tape and fill per BS 8212 — tape coat, fill coat with feather edge ≥ 200 mm, finishing coat ≥ 300 mm wide. Joint compound to BS EN 13963. Surface finish to BS 8000-8 / Level 4 or 5 finish.
   StandardBS 8212:1995 — Drylining. BS EN 13963:2014 — Joint filler/finisher. BS 8000-8 — Workmanship — Plasterboard finishing. PSA Specification ASF.
   Common defectsTape edges visible after paint — only two coats appliedTape bubbling — not pressed into wet compoundCracking along joint — tape missed or compound shrunkSandable finish coat used in wet area — degrades with moistureJoints "skim coated" without tape — cracks within months
2. 8.

   Surfaces flat

   Record: Deviation (mm)
   What to look forWall flat under 2 m straightedge — no waves, ridges, or hollows. Sudden steps at boards mean fixings inadequate. Skim plaster (if applied) flat with even sheen.
   Acceptable whenBS 8212 / BS 5234-2: surface flatness ±3 mm in 2 m straightedge for plastered finish (Level 5), ±5 mm for taped joint finish (Level 4). Wall plumb ±5 mm in storey height. Plaster overall thickness 2-3 mm typical for skim.
   StandardBS 8212:1995. BS 8000-8. BS 5234-2:1992. NHBC Standards 8.1.
   Common defectsJoint compound visible as raised ridge — over-built, not featheredHollows at studs — boards bowed between supportsCratering on skim — over-trowelled or wet trowel pullingWall not plumb at corners — installer not checking
3. 9.

   Corner beads straight and undamaged
   What to look forBeads firmly fixed, straight along edge, no twist. External corners protected with metal angle bead — galvanised or stainless. Ends of beads neatly mitred at junctions. Filled with at least two coats of compound, feathered out 100+ mm.
   Acceptable whenMetal angle beads to BS EN 13658-1/2 (internal) or BS EN 14353 (drylining). Straightness ±2 mm in 2 m. Fixed with screws at ≤ 250 mm centres or compound-bonded per manufacturer. Filled with three-coat finish.
   StandardBS EN 13658-1:2005 — Metal beads internal plastering. BS EN 14353:2007 — Metal beads drylining. BS 8212.
   Common defectsBeads bowed — fixed loose, then filled, no straight edgePlastic beads in fire-rated walls without test dataBead corners not mitred — gap at ceiling junctionSingle-coat fill on bead — bead "ghost" visible after paintDamage from impact during follow-on works — bead dented

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