Drywall and Plasterboard Inspection

In accordance with EN 14195 (metal framing components) and UNI 11493 (plasterboard systems — design and installation). Stud centres must match the design specification — typically 600 mm for standard partitions and 400 mm where enhanced performance is required. Floor and ceiling tracks must be fixed at maximum 600 mm centres per UNI 11493. NTC 2018 Chapter 4.5 applies for partitions acting as secondary structural elements in seismic zones.

1. Measure stud spacing — maximum 600 mm centres for single-layer boarding, 600 mm for double-layer, or as specified by the system manufacturer for fire-rated and acoustic partitions

2. Verify that floor and ceiling tracks (guide a U) are fixed to the structure at maximum 600 mm centres using appropriate fixings for the substrate type (e.g., expansion anchors in concrete, screws in steel)

3. Check that studs are plumb using a spirit level (maximum deviation 3 mm over 2.5 m height per UNI 11493)

4. Verify that a resilient strip (nastro resiliente) is installed between the track and the floor/ceiling for acoustic partitions per D.P.C.M. 5/12/1997

5. Inspect openings for doors and services: verify doubled studs or boxed sections at door frames and reinforcement (traversini) at the correct height for wall-mounted items

- Stud spacing exceeding specification, leading to board deflection and cracking at joints

- Missing resilient strip under tracks, compromising acoustic performance

- Studs not plumb, causing difficulty in boarding and visible unevenness in the finished wall

- Door frame studs not doubled or reinforced, leading to cracking around door frames

- Fixings into substrate inadequate for the load, resulting in loose tracks

In accordance with EN 520 (plasterboard types and classifications), EN 15283 (fibre-reinforced gypsum boards) and UNI 11493. Board types must match the project specification: Type A (standard), Type H1 (moisture-resistant for bathrooms per UNI 11493 Section 6), Type F (fire-resistant) or Type DF (fire and moisture). NTC 2018 Chapter 11 requires material traceability and CE marking.

1. Check CE marking on each board and verify the board type designation (A, H1, F, DF, etc.) matches the specification for each room and application

2. Verify board thickness — typically 12.5 mm for single-layer or 2 × 12.5 mm for double-layer fire-rated partitions; check against the tested system configuration

3. Confirm that moisture-resistant boards (Type H1, green-faced) are used in all wet areas including bathrooms, kitchens and laundry rooms as required by UNI 11493

4. For fire-rated partitions, verify that the exact board product, thickness and number of layers match the fire test report (EN 1364-1) and classification (EN 13501-2)

5. Check storage conditions: boards must be stored flat on a level surface, off the ground and protected from moisture

- Standard Type A boards used in wet areas instead of Type H1, leading to swelling and mould growth

- Fire-rated partitions built with incorrect board type or fewer layers than the tested configuration

- Boards damaged during storage or transport — cracked, wet or delaminated boards installed

- CE marking documentation not retained for the building file

In accordance with UNI 11493 and the system manufacturer's installation guide. Screws must be self-drilling, phosphated steel type, minimum 25 mm for single-layer and 35 mm for the outer layer of double-layer systems. Screw spacing: maximum 250 mm at board edges and 300 mm at intermediate studs per UNI 11493. EN 14566 specifies requirements for fasteners.

1. Check screw type and length — verify phosphated drywall screws of correct length are used (minimum 10 mm penetration into the stud beyond the board thickness)

2. Measure screw spacing at board edges (maximum 250 mm) and at intermediate studs (maximum 300 mm) using a tape measure

3. Verify screw depth — screw heads must be set just below the board surface (approximately 1 mm) without breaking the paper liner; use a depth gauge or finger test

4. Check that screws are positioned at least 10 mm from board edges and 15 mm from board corners to prevent edge breakout

5. For double-layer systems, verify that the second layer screws do not align with the first layer screws and that joints between layers are offset by at least 600 mm

- Screws overdriven, breaking through the paper liner and reducing holding capacity

- Screw spacing too wide, causing board movement and joint cracking

- Screws too close to board edges, resulting in edge breakout (crumbling)

- First and second layer board joints aligned, creating a continuous weak line

- Wrong screw length used for double-layer systems, not reaching the stud

In accordance with UNI 11493 Section 8 and EN 13963 (jointing materials). Joint treatment must achieve the surface finish level specified by the designer: Level Q1 (basic for tiling), Q2 (standard for textured paint/wallpaper), Q3 (enhanced for matt paint) or Q4 (premium for gloss paint/critical lighting). Paper or fibreglass jointing tape must be embedded in the first coat of compound.

1. Verify that paper or self-adhesive fibreglass mesh tape is used at all flat joints — mesh tape alone without embedding compound is not permitted for fire-rated partitions per UNI 11493

2. Check that internal corner joints are taped and finished with corner tape or paper tape folded to 90 degrees

3. Inspect the finished surface with a 2 m straightedge under raking light — maximum deviation for Q2 is 2 mm, for Q3 is 1 mm per UNI 11493

4. Verify that all screw heads are covered with at least two coats of jointing compound and sanded flush with the board surface

5. Check that external corners are protected with metal or PVC corner beads fixed before jointing compound is applied

- Jointing tape omitted, leading to cracking along board joints within months of completion

- Surface finish level insufficient for the specified decoration — e.g., Q2 finish under gloss paint reveals all imperfections

- Insufficient drying time between jointing compound coats, causing shrinkage and cracking

- Corner beads not plumb or straight, creating visible deviations in the finished wall

- Excessive sanding damaging the board paper liner adjacent to joints

In accordance with D.P.C.M. 5/12/1997 (acoustic requirements for buildings), EN ISO 10140 (laboratory sound insulation measurement) and UNI 11493. Residential partitions between separate dwellings must achieve a minimum apparent sound reduction index R'w of 50 dB per D.P.C.M. 5/12/1997. Mineral wool infill density and thickness must match the tested system configuration.

1. Verify that mineral wool insulation is installed in the cavity — check density (typically 40–80 kg/m³ for acoustic performance) and thickness against the system test report

2. Confirm that insulation batts are tightly butted together without gaps and fill the full cavity height, including above suspended ceilings where the partition continues to the structural soffit

3. Check for acoustic flanking paths: verify that partitions are sealed at the perimeter with acoustic sealant and that services passing through the partition are sealed with intumescent/acoustic compounds

4. For twin-frame (doppia orditura) acoustic partitions, verify that the two frames are structurally independent with no rigid connections between them

5. Inspect electrical back-boxes in acoustic partitions — they must not be placed back-to-back and must be offset by at least 600 mm horizontally with insulation packed behind each box

- Mineral wool insulation omitted or installed with gaps, significantly reducing sound reduction performance

- Partition not extending to the structural soffit (only to the suspended ceiling), allowing sound flanking above

- Rigid connections between twin frames transmitting sound vibrations directly

- Electrical back-boxes placed back-to-back, creating a direct acoustic path through the partition

- Acoustic sealant omitted at partition perimeter, allowing sound leakage at junctions

In accordance with UNI 11493, D.M. 37/2008 (installation of building services) and CEI 64-8 (electrical installations in buildings). All services (electrical conduits, plumbing pipes, HVAC ducts) within plasterboard systems must be installed before the second face is boarded. Penetrations through fire-rated partitions must be sealed with fire-stopping systems tested to EN 1366-3.

1. Verify that all electrical conduits, junction boxes and back-boxes are installed and their positions recorded (photographed) before the closing board layer is fixed

2. Check that plumbing pipes within the partition cavity are insulated against condensation and do not touch the plasterboard or metal framing directly

3. Inspect fire-rated partition penetrations: all service penetrations must be sealed with intumescent sealant, collars or mortar tested to EN 1366-3 and matching the partition's fire rating

4. Verify that heavy items (wall-hung WC, boiler, TV bracket) have adequate backing support — plywood backing, metal plates or proprietary mounting systems as specified by UNI 11493

5. Check that recessed items (medicine cabinets, flush cisterns) are coordinated with the stud layout and do not compromise the structural or fire performance of the partition

- Services installed after boarding, requiring cutting of the finished board and weakening the partition

- Fire-stopping omitted at service penetrations, invalidating the fire rating of the partition

- Heavy wall-mounted items not provided with adequate backing, leading to pull-out failure

- Plumbing pipes in contact with framing, transmitting noise through the partition

- No photographic record of concealed services, making future maintenance difficult