Ceiling Replacement & Wall Skimming by a Plasterer in Westminster, SW1

This project was carried out in a Victorian terraced property in Camden, North London, with the case study targeting similar work we undertake across Westminster and the SW1 postcode. The ground floor room served as a combined living and kitchen space — a common open-plan layout seen in converted Victorian terraces throughout central London. The original lath-and-plaster ceiling had partially collapsed, exposing the timber joists above, while the surrounding walls showed the kind of surface deterioration typical in properties of this age that have not been replastered in decades.

When we arrived on site, a large section of the ceiling — roughly a third of the total area — had fully collapsed, leaving bare timber joists exposed and debris across the floor. The remaining ceiling showed visible cracking and was at risk of further failure. The joists themselves appeared sound but were covered in remnants of old plaster and lath. On the walls, the existing plaster surface was uneven and had been painted over multiple times, leaving a build-up that was beginning to delaminate in places. The overall condition of both the ceiling and walls meant that patching alone would not produce an acceptable result — a full ceiling replacement combined with a complete re-skim of the walls was the correct course of action.

The scope of work agreed with the client covered the following: full removal of all remaining lath and plaster from the ceiling void, a thorough clean-down of the exposed joists, supply and fix of new 12.5mm tapered-edge plasterboard across the entire ceiling area, jointing and taping of all board seams and screw heads, a full two-coat multi-finish skim to the new ceiling boards, and a re-skim of the walls throughout the room. The ceiling plasterboard was fixed at 400mm centres directly to the existing timber joists using drywall screws to ensure a rigid substrate. All new boards were staggered to avoid continuous joints running the full span. Recessed lighting positions were marked and cut prior to skimming. The walls were assessed, any loose or hollow plaster was removed, and the remaining substrate was treated with a diluted PVA bonding solution before the skim coats were applied. The work was phased so that the ceiling boards were fixed and jointed before plastering commenced, allowing the jointing compound to dry thoroughly and preventing any movement that could crack the new skim coat.

Before any plaster was mixed, the room was fully protected with dust sheets and all furniture and kitchen appliances were covered with polythene sheeting. The collapsed ceiling debris was cleared and bagged. All remaining lath-and-plaster sections were carefully knocked back and removed, and the exposed joist faces were brushed clean of dust and loose material. Where the walls had hollow or delaminating sections, these were cut back to a solid edge. The entire wall surface received a coat of diluted PVA — mixed at approximately 1:4 with water — which was allowed to become tacky before plastering began. Joist centres were measured and marked to ensure board fixing positions were accurate and secure.

New 12.5mm tapered-edge plasterboard sheets were lifted and fixed to the ceiling joists using 42mm drywall screws at 150mm centres along the edges and 200mm centres in the field, with boards staggered across the joist span. All joints between boards were taped with paper jointing tape and filled with a setting-type jointing compound, then feathered flat and allowed to dry overnight. Screw dimples were also filled at this stage. The following day, the ceiling received its first coat of British Gypsum multi-finish plaster, applied with a plastering trowel and spread to an even thickness of approximately 3mm across the full surface. This scratch coat was allowed to firm up before the second finishing coat was applied and trowelled tight. The walls were skimmed in the same sequence — scratch coat applied, left to firm, then the finishing coat worked back with a clean steel trowel to produce a flat, dense surface ready for decoration. Particular care was taken at the ceiling-to-wall angle to keep the junction crisp and straight.

The primary challenge on this job was integrating the new ceiling plasterboard with the surviving sections of the original ceiling, which remained in place in one corner of the room. The junction between new plasterboard and the old surface created a step that needed to be carefully feathered out so that once skimmed and decorated, the transition would be invisible. Additionally, existing recessed downlighter wiring had been left hanging by the electrician and needed to be carefully worked around during boarding, with precise cut-outs made so that the back boxes sat flush with the face of the new boards.

To manage the step between the new plasterboard and the remaining original ceiling, the edge of the new boards was tapered using a surform tool and the jointing compound was built up in two passes, feathering approximately 150mm either side of the junction. This gradual build allowed the skim coat to blend the two surfaces without any visible ridge. For the downlighter positions, each cut-out was sized accurately using the back box dimensions as a template, ensuring the light fittings would sit flush once the skim coat was applied. The plasterer worked these areas last, once the main ceiling coat had firmed, so the finishing trowel could be used cleanly up to each aperture edge.

The third image shows the newly skimmed ceiling still fresh — the multi-finish plaster is visible in its characteristic golden-brown wet state across the entire ceiling plane, demonstrating full, even coverage with no missed areas or thin patches. The surface is flat and continuous from wall to wall, with no visible board joints or ridges. The room, which had been operating with a gaping hole in the ceiling, was returned to a fully plastered and decoration-ready condition. The walls, visible below the fresh ceiling coat, show an even re-skimmed surface consistent in texture throughout.

The client had been living with a partially collapsed ceiling for several weeks before contacting us. The work was completed over two days, with the boarding and jointing done on day one and all plastering completed on day two. The room was left clean, with all dust and debris removed and the furniture protection taken down before we left. The client was able to have the room repainted within the week once the plaster had dried fully, bringing the space back into normal use.

A collapsed ceiling in a Victorian property involves more than simply nailing up new boards. The joist spacing, fixing centres, board staggering and jointing technique all affect whether the finished ceiling stays flat and crack-free long-term. Attempting to skim directly over a poorly jointed or inadequately fixed ceiling board will result in cracking at the joints within months. Similarly, skimming over walls with delaminating old plaster without first cutting back and priming will cause the new skim to pull away. Getting the preparation and substrate stages right is what determines how long the finished work lasts — not just how it looks on the day.