Kitchen Extension Ceiling Replacement by a Plasterer in Islington, N1

This project took place in a Victorian terraced house in Islington, N1, within a rear kitchen extension that had been fitted with a large, multi-pane lantern-style rooflight and a ceiling fan. The kitchen itself featured fitted wooden cabinetry and a central sink unit, suggesting a well-used family home. The extension ceiling sat between the rooflight frame and the surrounding structural walls, forming an angled perimeter ceiling section around the glazed lantern that required full plastering attention.

When we arrived on site, the perimeter ceiling sections around the rooflight lantern were fully stripped back to bare timber joists. Celotex rigid insulation boards — clearly marked with the manufacturer's branding — were visible between the joists, indicating previous insulation work had been carried out but no plasterboard had yet been fixed over them. Sections of the ceiling showed exposed joist timber with no substrate whatsoever, making the space completely unfinished and unsuitable for decoration. The kitchen units and worktops were still in place, requiring thorough dust protection before any work could begin.

The scope of work involved a full ceiling board installation and skim coat to the angled perimeter ceiling sections surrounding the existing rooflight lantern in the kitchen extension. This included: - Fixing 12.5mm tapered-edge plasterboard directly to the exposed timber joists across all ceiling sections adjacent to the rooflight frame - Cutting boards accurately to fit the angled geometry around the lantern opening, ensuring tight board-to-board joints and clean edges against the rooflight frame - Applying jointing tape and scrim to all board joints prior to skimming - Applying a bonding or PVA mist coat where required to condition the board surfaces - Applying two coats of British Gypsum multi-finish plaster — a scratch coat worked into the board surface, followed by a finishing coat trowelled to a flat, paint-ready surface - Working around the ceiling fan electrical fixture and the rooflight glazing bars throughout the process - Protecting all kitchen units, worktops, and appliances with heavy-duty polythene sheeting secured with green masking tape throughout the duration of the works

Before any boards were fixed, all kitchen surfaces — including cabinet fronts, the sink, worktops, and a freestanding appliance — were fully sheeted in heavy-duty polythene and secured at the edges to prevent plaster dust and debris from causing damage. The Celotex insulation between the joists was checked to confirm it was flush and secure. Noggings were assessed to ensure there was adequate fixing support for the plasterboard sheets at all edges. A Makita site radio and cordless drill were among the tools on site, and a spirit level was used to confirm the joist line was consistent before boarding began.

Plasterboard sheets were measured and cut to suit the angled perimeter ceiling configuration around the rooflight lantern. Each sheet was lifted and fixed to the timber joists using drywall screws at the correct centres, with tapered edges aligned so that joints could be filled and taped flush before skimming. Scrim tape was applied along every board joint and the internal angles where the ceiling met the rooflight frame were carefully cut in. Once all boards were fixed, the surface was mist coated with diluted PVA to regulate suction across the tapered edges and board face. The first coat of British Gypsum multi-finish was applied with a steel float, working the plaster firmly into the board surface and across all scrimmed joints to build a consistent base. This scratch coat was allowed to stiffen before the finishing coat was applied. The final coat was laid on at a consistent thickness and then trowelled back progressively as it firmed up, bringing the surface to a flat, smooth finish ready for paint. Particular care was taken around the rooflight frame edges to keep lines crisp where the new plaster met the existing frame.

The primary challenge on this project was the geometry of the ceiling itself. Rather than a straightforward flat ceiling, the plasterboard sections had to be fitted around a large, multi-pane rooflight lantern with angled rebates and internal corners on all four sides. Cutting boards accurately to these angles — while maintaining tight joints and avoiding gaps at the rooflight frame — required careful templating and cutting before each sheet was lifted into position. Working overhead in a confined kitchen space, with existing cabinetry directly below and a ceiling fan protruding from the rooflight frame, added further difficulty to manoeuvring full-size boards into place.

Each board section was templated individually using offcuts and a straightedge before the full sheet was cut. This approach minimised waste and ensured each piece dropped into position cleanly without requiring excessive trimming once overhead. The internal angles against the rooflight frame were cut slightly back and filled with multi-finish during the skimming process to produce a tight, clean line. The ceiling fan wiring was carefully kept clear of all fixings throughout the boarding phase, and the fan canopy was temporarily removed and bagged in polythene to protect it from plaster splatter during the skim coats.

On completion, all ceiling sections surrounding the rooflight lantern were fully boarded and skimmed to a flat, paint-ready surface. The new plaster ran cleanly up to the rooflight frame on all sides, with no visible joint lines or steps between boards. The angled ceiling sections sat flush and consistent under natural light coming through the lantern glazing — which is a particularly demanding test for any plastered surface. The kitchen was left clean, with all dust sheeting removed and the units and worktops intact beneath.

The homeowner now has a fully finished kitchen extension ceiling that is ready for decoration without any further preparation. The rooflight lantern, which had been the centrepiece of the extension since it was built, is now properly framed by smooth plastered surfaces rather than exposed joists and insulation. The project was completed within two days, allowing the kitchen to be returned to full use quickly and the wider renovation to progress to the decoration stage without delay.

Plastering around a rooflight lantern in a kitchen extension is not a straightforward boarding and skim job. The angled geometry, the need to work accurately against a glazed frame, and the confined overhead working conditions all require experience to get right. Boards fixed out of alignment or with poorly cut edges will telegraph through the skim coat under natural light. Getting the plaster to sit flush against the rooflight frame without gaps or rough edges requires careful cutting and controlled finishing — mistakes at this stage would require the frame to be masked, filled, and repainted before decoration could begin.