Lath and Plaster Ceiling Replacement and Wall Re-Skim by a Plasterer in Wandsworth

This project was carried out in a Victorian terraced house in Lambeth, South London, close to the Wandsworth borough boundary. The property retained much of its original construction, including a bedroom with a fully intact Victorian lath and plaster ceiling — a system that dates back well over a hundred years. The room featured dark navy-painted walls and original floral patterned wallpaper, indicating the space had not been significantly updated in many decades. The property was undergoing a wider refurbishment at the time of our visit.

The fourth image tells the full story of the ceiling's condition before work began: the original lime plaster had completely separated from the wooden lath strips, leaving the bare timber framework fully exposed across the entire ceiling span. Several lath strips showed signs of movement and one section had partially collapsed. The remaining plaster keys — the small nibs of lime that grip between the laths — had failed entirely, almost certainly due to age, vibration, and moisture ingress over many decades. The walls in the same room showed patches of old painted plaster that had lifted away from the substrate in places, with visible damage near the skirting line where plaster had been knocked during previous works.

The scope covered full ceiling replacement in the bedroom, removing all failed lath and plaster down to the joists, followed by the installation of new 12.5mm plasterboard fixed directly to the ceiling joists, taping all board joints with fibreglass mesh tape, and applying a full two-coat skim across the entire ceiling surface. The walls in the same room also required a full re-skim, with the existing painted plaster surface prepared and skimmed with Thistle multi-finish plaster to provide a clean, paint-ready surface. All board joints and screw fixings were covered with jointing tape and bonding compound before skimming commenced. The first image shows the plasterboard installation in progress, with all joints taped using orange fibreglass mesh tape and screw heads clearly visible across the new boards. The second image shows the re-skimmed walls mid-cure, already presenting a smooth, uniform surface. The third image shows the completed ceiling after the two-coat skim had been applied and was in its final drying stage, with the pendant light drop visible through the centre of the ceiling — confirming the full ceiling area had been plastered from wall to wall.

Before any plasterboard could be fixed, the entire failed lath and plaster ceiling was carefully stripped back to the joists. All loose lath strips were removed and the joist faces cleaned of any residual lime plaster or debris. The joist centres were measured and marked to ensure the new 12.5mm plasterboard sheets were fixed with a minimum of three screws per joist line. All board edges were butted tightly to reduce joint width. Once boards were fixed, all joints were taped with orange fibreglass mesh tape and joints filled flush with a bonding compound before the skim coats were applied. The walls were rubbed down to remove any loose painted plaster, and a diluted PVA solution was applied to stabilise the porous surface prior to skimming.

With the ceiling joists exposed and cleaned, 12.5mm tapered-edge plasterboard sheets were lifted into position and fixed using drywall screws at regular intervals along each joist. All board joints were reinforced with fibreglass mesh tape — as clearly visible in the first image — and the recessed tapered edges filled flush with a base coat compound. The screw heads were spotted over to sit flush with the board face before any finish plaster was applied. Once the base work had set and dried, Thistle multi-finish plaster was mixed to a consistent working consistency and applied as a first scratch coat across the full ceiling area. The scratch coat was ruled off flat and allowed to stiffen before the second finishing coat was applied, trowelled tight and polished to a smooth surface ready for decoration. The walls were treated in the same sequence: an initial scratch coat of multi-finish was applied to bring the surface to a flat plane, followed by a tighter finishing coat trowelled up to a smooth, even surface. The second image shows the re-skimmed walls still in the early drying phase, with the characteristic pale cream tone of fresh multi-finish visible across the corner junction. The third image confirms the completed ceiling in its final cream-drying state, with a clean, flat surface across the full room span.

The primary challenge on this project was the sheer condition of the original lath and plaster ceiling. Victorian lath and plaster ceilings are notoriously fragile once the lime keys fail — and in this case, the failure was total, with no remaining plaster adhered to the laths. Stripping the ceiling without causing damage to the surrounding walls and existing cornice detail required controlled removal, working methodically from the centre outward. A secondary challenge was the mixed substrate on the walls: old painted plaster of varying thickness and suction, which risked the skim coat drying unevenly if not properly primed and bonded before application.

The failed ceiling was stripped in sections to avoid shock loading the joists or disturbing the wall plaster at the perimeter. New 12.5mm plasterboard was fixed directly to the joists using appropriate-length drywall screws, with all joints and fixings taped and spotted before skimming. To address the variable suction on the walls, a diluted PVA bonding solution was rolled across all wall surfaces and allowed to become tacky before the first coat of Thistle multi-finish was applied. This controlled the rate of suction evenly across the surface, allowing the plasterer to work both coats without the plaster flashing off prematurely in drier patches.

The third image shows the ceiling after both skim coats had been applied and the plaster was moving through its drying phase — a uniform, flat surface with no visible joints, screw points, or board lines. The pendant light drop hangs cleanly through the centre, confirming the full ceiling was plastered in one continuous pass. The walls, visible in the second image, show an equally smooth re-skimmed surface at the corner junction, with a clean arris formed at the wall-to-wall corner. The room was left ready for the decorator, requiring only a light sand and a mist coat before final painting.

The client received a bedroom ceiling that had gone from completely failed, bare timber lath to a flat, smooth plastered surface ready for decoration — all completed within two working days. The walls in the same room were re-skimmed at the same visit, meaning the decorator could come in and treat the entire room in one session. The homeowner avoided the cost and disruption of a full ceiling replacement contract by having both the ceiling and walls addressed together by the same team, with no follow-up visits required before painting could begin.

Replacing a failed Victorian lath and plaster ceiling is not a straightforward task. The risk of bringing down surrounding plaster, disturbing original cornicing, or fixing plasterboard to undersized joists without correct screw spacing can create far bigger problems than the original failing ceiling. An experienced plasterer will survey joist centres before ordering boards, use the correct fixing lengths to avoid joist blow-out, and tape all joints correctly so they do not re-appear through the finish coat after decoration. On the wall re-skim, controlling suction on an old painted plaster substrate is critical — without PVA priming, the finish coat will crack as it dries unevenly.