PVC Wall Panels for Damp-Prone Rooms

Every PVC job starts with the wall, not the panel. We test the plaster with a moisture meter at several heights, look for salt bloom near the skirting, check for hollow plaster by tapping, and ask where the water goes in the monsoon: which side takes the rain, whether there is a terrace or bathroom above, whether the outside face is cracked. Laterite walls in particular can hold a great deal of water after a heavy season and release it slowly into the room.

If the readings are high, the right first step is to find the cause, whether that is a failed external coat, a leaking pipe, a blocked gutter or rising damp, and give the wall time to dry. Panels fitted over a wet wall look fine for months and then reveal the problem as a smell, black spotting at the joints or plaster crumbling when the panel is eventually removed.

On a sound, dry, flat wall, panels can be glued directly. On most older walls we prefer a frame: PVC or aluminium battens fixed with plugs, set out level and packed true. A frame bridges the waves in old plaster, gives a cavity for wiring, and leaves a small air space between the wall and the back of the panel. In Goa we avoid untreated timber battens altogether, because they become termite food the first time the wall gets damp.

That air space is worth keeping open. Leaving a small gap at the top and bottom of the lining, hidden by the trims, lets the cavity breathe rather than sealing the wall into a box. In a bathroom the base trim is sealed against splashing, but the cavity can still vent at ceiling level.

PVC grows and shrinks with temperature more than almost any other wall lining. A run of panels across a sunny wall can lengthen enough over a hot afternoon to push against a corner and bow outwards. The answer is simple but often skipped: leave an expansion gap at every end and every abutment, hide it behind a trim, and fix with clips rather than rigid glue across the whole back so the panel can slide.

Colour matters too. Dark panels absorb far more heat than pale ones, and dark laminates on a wall that takes the evening sun are the ones we most often see distorted. Glass in front of the wall makes things worse, so a window wall or a room with a big west-facing sliding door needs paler finishes and extra allowance for movement.

Salt does not attack PVC itself, but it does attack plated steel screws and clips, and rust stains bleed through joints within a season near the sea. We use stainless or plastic fixings in coastal homes. In a house closed for the monsoon, PVC is a forgiving lining because it does not grow mould on its face, though condensation can still collect behind it if the room is sealed tight with no air movement at all.

Fire sense is the other part of a responsible specification. Keep PVC well away from hobs, tandoors, heaters and any light fitting that runs hot, use fittings designed for enclosed ceilings, and do not use it to line escape routes in commercial premises without checking what the local rules require.

Most of what makes PVC look like a stopgap is avoidable. Choose a thicker panel with a matte or textured face, run the joints vertically so they read as a deliberate rhythm, and finish every edge with a matching trim. Plain colours almost always age better than printed timber or marble, whose repeat becomes obvious once you notice it.

Planning the layout also helps. Centre the panels on the wall so the cut pieces at each end are equal, align joints with windows and switches, and mark socket positions before the panel goes up so the cut-outs are neat. Small decisions like these separate a lining that looks built-in from one that looks added later.