Quality.

    Pre-plaster inspection: what good looks like

    Final check before dry lining or plastering conceals the works.

    What good looks like

    Pre-plaster inspection: what good looks like

    The last honest look at everything that is about to disappear: structure, services, insulation, fire stopping and the air barrier, all checked in one pass.

    Pre-plaster is the highest-value inspection in the build, because every defect found here is cheap and every defect missed here is expensive. Once boards go on, the same fault costs a redecoration to reach. Inspect in layers rather than by trade: structure first, then services, then fabric, then fire. Look for the things that cannot be seen again — strap fixings, hanger nails, notch positions, cable depth and safe zones, insulation continuity, cavity barriers and penetration seals. Record it properly. Dated photographs against a plot and room reference are what settle a dispute two years later, and they are what the warranty inspector will ask for if a query arises after handover.

    Basis in regulation

    Before you start

    Before you start: pre-plaster inspection

    What to have in hand before you walk the plot, so the inspection is a decision and not a survey.

    Have the first fix test certificates, the insulation specification and the fire stopping schedule to hand. Confirm every trade has signed off their own work and that the plot is clean enough to actually see the details — an inspection through a floor of offcuts finds nothing. Give notice for any warranty or building control visit in good time, and hold the plasterer until the inspection has closed out. Take the photographs before the inspection, not after, so anything covered between the two is still on record.

    Basis in regulation

    Key requirements

    Timber moisture content for internal walls

    Timber used for internal wall framing should typically have a maximum moisture content of 20% when dry lining is installed to mitigate issues such as shrinkage, cracking, and nail popping in the finished surfaces. The structural performance of engineered wood products, including I-joists or metal-we

    Timber used for internal wall framing should typically have a maximum moisture content of 20% when dry lining is installed to mitigate issues such as shrinkage, cracking, and nail popping in the finished surfaces. The structural performance of engineered wood products, including I-joists or metal-web studs, must be assessed against relevant design standards.

    Basis in regulation

    Information Provision for Finishes

    Comprehensive design and specification documents for wall and ceiling finishes must be created and distributed to all relevant parties, including site management and specialist subcontractors. This documentation should detail material schedules, fixing methods, plaster specifications, tiling layouts

    Comprehensive design and specification documents for wall and ceiling finishes must be created and distributed to all relevant parties, including site management and specialist subcontractors. This documentation should detail material schedules, fixing methods, plaster specifications, tiling layouts, and the integration of air and vapour control layers.

    Basis in regulation

    Acoustic performance of light steel frame floors and walls

    Light steel frame (LSF) internal floors and walls must provide adequate resistance to the passage of sound, conforming to the relevant Building Regulations. Careful attention to detail is required to prevent acoustic flanking paths, such as sealing gaps in insulation, cavity barriers, lining boards,

    Light steel frame (LSF) internal floors and walls must provide adequate resistance to the passage of sound, conforming to the relevant Building Regulations. Careful attention to detail is required to prevent acoustic flanking paths, such as sealing gaps in insulation, cavity barriers, lining boards, and around service penetrations.

    Basis in regulation

    Internal insulation and fire resistance in timber frames

    When insulation, such as insulated plasterboard or a separate continuous layer, is applied to the inside face of a timber frame, the wall's fire resistance must be assessed and evidenced according to relevant building regulations. The entire wall system, including insulation and finishes, contribute

    When insulation, such as insulated plasterboard or a separate continuous layer, is applied to the inside face of a timber frame, the wall's fire resistance must be assessed and evidenced according to relevant building regulations. The entire wall system, including insulation and finishes, contributes to its fire performance.

    Basis in regulation

    Masonry chasing for services

    Chases in masonry walls for services must be cut carefully to avoid structural damage and should adhere to strict dimensional limits regarding wall thickness. Horizontal chases are generally limited to one-sixth of the leaf depth, while vertical chases are limited to one-third, and adequate residual

    Chases in masonry walls for services must be cut carefully to avoid structural damage and should adhere to strict dimensional limits regarding wall thickness. Horizontal chases are generally limited to one-sixth of the leaf depth, while vertical chases are limited to one-third, and adequate residual material must remain.

    Basis in regulation

    Sound Resistance of Walls and Floors

    Closed panel system walls and floors must provide adequate resistance to the passage of sound, particularly for separating elements as required by Building Regulations. Achieving sound performance relies on meticulous installation to avoid gaps in insulation, lining boards, cavity barriers, and arou

    Closed panel system walls and floors must provide adequate resistance to the passage of sound, particularly for separating elements as required by Building Regulations. Achieving sound performance relies on meticulous installation to avoid gaps in insulation, lining boards, cavity barriers, and around service openings.

    Basis in regulation

    Plaster bonding around gas pipework

    When plastering, it is standard practice to secure gas supply pipework that runs across a wall using solid dabs of plaster or adhesive. This measure prevents movement and rattling of the pipework and ensures it is fully encapsulated for protection.

    When plastering, it is standard practice to secure gas supply pipework that runs across a wall using solid dabs of plaster or adhesive. This measure prevents movement and rattling of the pipework and ensures it is fully encapsulated for protection.

    Basis in regulation

    CSST pipe protection behind dry lining

    Corrugated Stainless Steel Tube (CSST) gas pipework installed behind dry lining must be adequately protected. This protection typically involves encasement by building material or steel plates to prevent accidental damage.

    Corrugated Stainless Steel Tube (CSST) gas pipework installed behind dry lining must be adequately protected. This protection typically involves encasement by building material or steel plates to prevent accidental damage.

    Basis in regulation

    Key requirements: pre-plaster inspection

    The items most often raised at pre-plaster, in the order worth checking them.

    Structural fixings complete: hangers fully nailed, straps carried over joists, strutting fitted, and no cuts outside the permitted zones. Services tested and certificates recorded before boarding. Cables in safe zones and at sufficient depth, or protected by mechanical means or RCD as appropriate. Insulation continuous with no gaps, compression or bypass, and the air barrier sealed at junctions and penetrations. Cavity barriers and fire stopping installed and photographed. Plot dry, with timber moisture content checked before boards are fixed. Photographic record complete against plot and room references.

    Basis in regulation

    MVHR design and specification information

    Comprehensive and clear design and specification documents for MVHR systems must be produced and distributed to all relevant personnel, including site supervisors and subcontractors. This information should include detailed drawings, fixing schedules, and locations of all components to ensure correc

    Comprehensive and clear design and specification documents for MVHR systems must be produced and distributed to all relevant personnel, including site supervisors and subcontractors. This information should include detailed drawings, fixing schedules, and locations of all components to ensure correct installation and efficient operation. Adequate information supports energy-efficient use and prevents issues like overheating.

    Basis in regulation

    Preparation of Backgrounds for Plaster

    Prior to plastering, backgrounds must be appropriately prepared to ensure consistent suction, flatness, and adequate key for adhesion, avoiding excessive 'dubbing out'. Different background materials should be carefully managed to prevent differential movement, with measures such as metal lathing em

    Prior to plastering, backgrounds must be appropriately prepared to ensure consistent suction, flatness, and adequate key for adhesion, avoiding excessive 'dubbing out'. Different background materials should be carefully managed to prevent differential movement, with measures such as metal lathing employed where necessary. Metal beads should be used for edge protection and secured with manufacturer-recommended, corrosion-resistant fasteners.

    Basis in regulation

    Critical dimensions at this stage

    Browse all critical dimensions
    England
    Low-rise traditional

    Original editorial guidance based on publicly available Approved Documents. Not building control approval, a warranty determination, or a substitute for the full source document.

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