Ceiling Replacement & Full Re-Skim by a Plasterer in Hackney – Collapse Repair Case Study

This project took place in a Victorian terraced property in Hackney, E8. The ground floor open-plan living and kitchen area featured original timber joists and period-style six-panel doors with traditional skirting boards, typical of the housing stock found throughout this part of east London. The room had been partially modernised — a wall-mounted television and recessed downlights were already installed — but the ceiling had suffered a significant structural failure, leaving the timber joist framework fully exposed across a large central section of the room.

On arrival, a substantial portion of the ceiling had completely collapsed, exposing the raw timber joists above. The exposed section measured approximately 3 by 3 metres and revealed multiple joists, electrical cables running between them, and debris from the failed plaster and lath or board material. The surrounding ceiling area that remained intact showed visible stress cracks radiating outward from the collapse zone, and surface staining consistent with historical moisture ingress — likely the cause of the original failure. The existing intact ceiling sections appeared to be older plasterboard or lime plaster on lath, and were at risk of further failure without intervention. The room was still partially occupied, with furniture sheeted up and appliances in place.

The full scope of work involved stripping back the remaining unstable ceiling material around the collapsed section to expose clean, solid joists across the entire ceiling area. Once all loose and compromised material was removed, new 12.5mm tapered-edge plasterboard sheets were measured, cut and fixed directly to the timber joists using drywall screws at appropriate centres, ensuring the boards were staggered to avoid continuous joints running across the ceiling. All board joints and screw fixings were taped and filled with jointing compound before the entire ceiling surface received a full skim coat of multi-finish plaster. Recessed downlight apertures were carefully marked and cut through the new boards to align with the existing electrical drops. The perimeter of the ceiling where it met the original walls was also addressed, with any ragged edges made good prior to skimming. The scope did not include decorating, which was left for the client to arrange separately once the plaster had fully cured.

Before any new plasterboard could be fixed, the collapsed and unstable ceiling material was fully cleared and the joist bays were inspected for residual moisture and structural integrity. Any remaining loose debris was removed from the joist faces to provide a clean fixing surface. Electrical cables were carefully checked and temporarily secured out of the way by the client's electrician prior to plastering commencing. The floor and all remaining furniture were sheeted with dust sheets and polythene to protect the room. The exposed joist faces were checked for level and any proud fixings or nails were knocked flat before boarding began.

New 12.5mm plasterboard sheets were lifted into position and fixed to the existing timber joists using 42mm drywall screws driven at approximately 150mm centres along each joist. Boards were staggered so that no two board ends met on the same joist, reducing the risk of joint cracking over time. Once the full ceiling area was boarded, all joints between boards were reinforced with paper jointing tape bedded into a skim of bonding, and all screw heads were spot-filled and allowed to dry. The entire ceiling was then misted with a diluted PVA solution to control suction across the mixed substrate — new board alongside the older remaining surface. Multi-finish plaster was then applied in two passes: a firm scratch coat worked into the surface to build up coverage, followed by a tighter finishing coat laid on and trowelled to a smooth, flat plane. The finishing coat is visible in the third image, showing the fresh plaster across the full ceiling still wet and reflecting the room lighting evenly — confirming a consistent thickness and flat surface across the repaired and surrounding areas.

The principal challenge on this project was integrating new plasterboard into a ceiling where sections of the original surface were still intact. The height difference between the existing ceiling and the newly boarded area needed to be resolved within the skim coat alone, without the option of dropping the entire ceiling level. Additionally, the timber joists showed minor variation in level, meaning the boarding had to be shimmed in places to bring the new surface flush before skimming could begin. Managing the difference in suction between new plasterboard and older existing plaster also required careful priming to prevent the multi-finish from drying unevenly.

To resolve the level discrepancy between old and new surfaces, the boards were packed at specific joist fixing points using thin timber packers to bring the plasterboard face flush with the remaining original ceiling. Once boarded, the full ceiling — both old and new sections — was treated with a diluted PVA bonding agent to equalise suction. This allowed the multi-finish to be applied at a consistent working time across the entire surface without the new board pulling moisture from the plaster too rapidly. A heavier scratch coat was applied first to bridge any remaining level differences, with the finishing coat used to bring the full ceiling to a single flat plane.

The third image shows the completed skim coat across the full ceiling of the room — a large, open-plan ground floor space with the fresh multi-finish plaster still wet and reflecting the warm light from the pendants and recessed downlights. The surface reads as entirely flat and continuous, with no visible joint lines between the new and existing sections of ceiling. The perimeter edges where the ceiling meets the walls are clean and straight. The room, though still mid-refurbishment with furniture sheeted and tools present, clearly shows the ceiling has been fully restored to a sound, level, paint-ready surface.

The client in Hackney E8 had a fully collapsed ceiling section restored within two days, with the new boarding and skim coat blending into the remaining original ceiling across the full open-plan room. The ceiling was left flat, sound and ready for decoration, allowing the broader refurbishment of the property to continue without further delay. Recessed downlights were retained in their original positions, and the room's period features — skirting and panel doors — were left undamaged throughout the works.

A collapsed ceiling involving exposed joists, live electrical cables and a mixed substrate requires accurate boarding before a single trowel of plaster is applied. Fixing plasterboard to joists at incorrect centres, failing to stagger board joints, or skipping the PVA priming stage on a mixed surface can all lead to joint cracking or uneven drying within weeks of completion. The levelling work required here — packing boards to bring them flush with the existing ceiling — is the kind of preparation that determines whether the finished skim remains crack-free. Cutting corners at the boarding stage is the most common reason ceiling plasterwork fails prematurely.