Ceiling Replacement & Re-Skim by a Plasterer in Wandsworth – Full Ceiling Strip and Plasterboard Installation

This project took place in a Victorian terraced property in Kensington, typical of the period housing stock also found across Wandsworth SW18. The room — most likely a hallway or stairwell given the angled ceiling line and sash window visible — featured the original lath and plaster ceiling construction common in properties of this age. The walls retained their existing painted plaster, painted in a distinctive yellow ochre. The property was mid-refurbishment at the time of our visit, with electrical cables already partially re-routed through the ceiling void.

When we stripped back the existing ceiling, we found the original Victorian lath and plaster construction beneath — thin horizontal timber laths nailed across the joists with lime-based plaster keyed between them. This type of ceiling has a limited lifespan, and in this case it had reached the end of it. The laths were dry and brittle, several had snapped, and the plaster keys had failed across large sections, causing the ceiling to become structurally loose. Exposed electrical wiring was running through the ceiling void with no containment, which needed to be managed safely before any boarding could begin. The ceiling perimeter showed old staining consistent with minor historic water ingress, further confirming the need for full replacement rather than repair.

The full scope covered complete removal of the failed lath and plaster ceiling, followed by installation of new 12.5mm plasterboard fixed directly to the exposed timber joists, and a two-coat multi-finish skim to bring the ceiling to a flat, paint-ready surface. The work included the following stages: full strip of all existing lath and plaster to expose the joist structure; inspection and clearance of the ceiling void to allow safe access for the electrician to re-route and secure all exposed cabling; cutting and fixing of new 12.5mm tapered-edge plasterboard sheets to the underside of the joists using appropriate screws at 150mm centres; taping and jointing of all board junctions and screw heads with joint tape and filler to prevent future cracking at joints; application of a PVA bonding coat to stabilise the new board surface prior to plastering; a scratch coat of British Gypsum multi-finish plaster applied across the full ceiling area; a finish coat of multi-finish worked to a flat, smooth surface ready for decoration. The ceiling junction with the angled wall section — visible in the images — required careful mitring and boarding to maintain a clean internal angle throughout.

Before any plasterboard could be fixed, the ceiling void was cleared of the stripped lath debris and inspected for the condition of the joists. All joists were confirmed sound with no signs of rot or movement. Exposed electrical cables running through the void were temporarily secured out of the working area to allow safe boarding — the electrician attended site separately to clip and contain all cabling before the ceiling was closed. The new plasterboard sheets were measured and cut to fit the room, with board joints staggered across the joist span to avoid continuous seams. All screw fixings were driven flush without breaking the paper face. Once fully boarded, joints were taped with fibreglass mesh tape and filled with jointing compound, then left to cure fully before the PVA wash and skim were applied.

With the boards fully taped, jointed and dried, a diluted PVA bonding solution was applied across the entire ceiling surface and allowed to become tacky — this is critical on new plasterboard to control suction and give the first plaster coat something to grip. Once the PVA reached the correct tack, the scratch coat of British Gypsum multi-finish was applied using a wide plastering trowel, working from one end of the ceiling to the other in firm, overlapping passes. The plaster was spread to an even thickness of approximately 2–3mm across the full ceiling area, including the angled section running down toward the window wall. This coat was laid up and left to stiffen before the finish coat was applied. The second coat of multi-finish was brought on while the scratch coat was still green — this allows the two coats to bond together and prevents delamination. The finish coat was trowelled tight and polished back using a dampened trowel in circular passes to close the surface. The completed ceiling was left to dry naturally, with the sash window used to provide ventilation without creating a direct draught across the fresh plaster.

The primary challenge on this job was the presence of live and unsecured electrical cables running through the ceiling void. The original lath and plaster construction had been in place for over a century, and the electrical installation had been chased in at various points over the years with no consistent routing. Once the laths were stripped, cables were found hanging loose across the joist bays with no clips or containment. This could not be boarded over safely, and the project required a hold on boarding works until the electrician attended and secured all cabling properly. A secondary challenge was the angled ceiling plane — where the ceiling dropped toward the window wall — which required the plasterboard to be cut and fitted at an angle to maintain a flush, continuous surface.

Works were paused after the strip-out to allow the attending electrician to route, clip and contain all cables within the ceiling void before any boarding was started. This added time to the programme but ensured the ceiling was safe and compliant before being closed. For the angled ceiling section, the plasterboard sheets were scribed and cut on site to follow the pitch of the slope, with a continuous internal angle formed at the junction between the flat ceiling and the angled drop. The joint at this angle was taped with fibreglass mesh tape and filled prior to skimming, ensuring the skim coat could be applied across both planes in a single pass without the risk of cracking at the junction.

The completed ceiling — as visible in the top-right image of the collage — is a flat, smooth, fully skimmed surface ready for mist coat and decoration. The junction between the flat ceiling and the angled section is clean and continuous, with no visible joint lines. The ceiling rose aperture has been left open for the light fitting to be reinstalled by the electrician. The surface shows an even, consistent tone across its full area, with no trowel marks or hollow patches. The bottom-left image shows the bare joist structure before boarding, giving a clear before-and-after reference for the scale of the transformation.

The client — who was part-way through a wider refurbishment of this Victorian property — was able to continue with decoration immediately after the plaster cured, keeping their overall project timeline on track. The new ceiling removed a long-standing concern about the structural state of the original lath and plaster, and the electrical void is now clear, accessible and safe. The room now has a flat, even ceiling plane across both the horizontal and angled sections, which the client confirmed was exactly what they needed ahead of painting.

Replacing a Victorian lath and plaster ceiling is not a straightforward boarding job. The joist spacing in period properties does not always conform to modern standard centres, meaning plasterboard sheets need to be cut and fixed carefully to land on solid timber. Failing to stagger board joints correctly, or over-driving screws so they break the paper face, will cause cracking and hollows in the finished skim. The presence of electrical cables in the ceiling void also means a competent plasterer needs to recognise when work must be paused for a qualified electrician — something an inexperienced contractor may overlook. Getting the PVA timing right on new board is also critical: too wet and the plaster will slide; too dry and suction will be uncontrolled.