PVC Marble Sheets: Where They Work

Everything about a PVC marble sheet installation depends on what is behind it. The adhesive needs a dry, sound, flat surface to grip. Loose paint, flaking putty, efflorescence and powdery plaster all give way, and the sheet comes away with them. Before fixing, we check external walls and bathroom walls with a moisture meter, look for salt bloom and tap for hollow plaster.

On laterite walls and in older houses, rising and penetrating damp are common. A plastic sheet stuck over that wall stops the masonry breathing into the room. The moisture has nowhere to go, gathers behind the sheet, softens the adhesive and feeds mould that you will smell before you see. Where a wall is damp, the source has to be dealt with first, whether that is a roof leak, a failed external coat or a plumbing line, and the plaster left to dry out.

Where the substrate is sound but uneven, we either correct it with a skim or fix the sheet onto a flat backing board on battens, which also keeps it off a wall that is slow to dry.

Joints decide whether the wall looks like stone or like plastic. Book-matched sheets must be fixed in the right sequence, cut square and butted tightly. On long runs, small expansion gaps at the ends and at junctions with other materials allow the sheet to move with temperature without bowing.

Exposed edges are the weak point for chips and for water getting in. Trims at outside corners, at the top of a dado and around windows protect them. Switch plates, sockets and cable entries are cut precisely before fixing, so plates sit flush rather than pressing on the sheet.

PVC expands and contracts with temperature more than plaster does. On a wall that takes direct afternoon sun through glass, a dark sheet can warm enough to move, and a tightly fitted run with no allowance can ripple. Pale and matt sheets cope better in sunlit rooms. Prolonged strong sunlight can also fade the print over the years, so a sheet facing a large west window is a gamble that a north-facing wall is not.

Humidity in the air does not hurt the sheet itself; PVC does not absorb water. The risk is behind it, in the plaster and the adhesive. In a house closed through the monsoon, keep some airflow in the rooms with sheet finishes and check bathroom joints when you reopen it.

In a kitchen, a sheet can work behind a sink or along a worktop used for preparation, provided it stops short of the cooking zone. Behind a gas burner, heat and flame will soften and scorch it within a season. That area needs tiles, stone, glass or stainless steel.

In a bathroom, the sheet suits the walls around a basin, a toilet and the space above a tiled dado. Inside a shower, water hits every joint daily and drains down the face. Unless the wall behind has its own waterproofing membrane and the sheet system is designed for wet use, tiles remain the better answer there.