How to Remove Wallpaper Without Damaging the Plaster Underneath

Plaster gets wrecked during wallpaper removal for two reasons: people scrape before the paste has properly softened, and they attack the wall with a sharp blade held nearly flat against it. Soak the paper until the adhesive lets go on its own, then use a wide blunt-ish scraper at a shallow angle and let the tool slide rather than dig. That combination strips almost any paper without leaving craters behind you.

Work out what you are dealing with first

Before you wet anything, find out what is on the wall and what is behind it. Lift a corner with a scraper near a skirting board or socket. If the top layer peels away dry and leaves a paper backing stuck to the wall, you have a strippable vinyl and the job just got easier. If it resists and tears into small flakes, it is likely a painted-over paper or a woodchip, and it will need soaking.

The wall itself matters more than the paper. Solid plaster over brick or block is fairly forgiving and takes a decent amount of moisture. Plasterboard is not, because the paper face of the board is what the skim is bonded to, and saturating it makes the board swell and the surface come away in sheets. Tap the wall: a hollow, drummy sound in a modern house usually means plasterboard, so keep water use light and controlled.

Also check the condition of the skim. Press your fingers across the wall in a few places. If it flexes, crunches or sounds hollow in patches, that plaster is already blown and it will come off with the paper no matter how careful you are.

Protect the room and kill the power

This is a wet, messy job and the water goes everywhere. Cover the floor with plastic sheeting, put old towels or dust sheets on top, and tape it down at the skirting. Cardboard along the base of the wall catches the sodden lumps that would otherwise get walked into the carpet.

Switch off the lighting and socket circuits for that room at the consumer unit before you spray or steam near a socket or switch. If you are not comfortable loosening faceplates, tape them over and cut the paper cleanly around them instead.

Score the surface, but only as much as you need to

Water cannot reach the paste through a vinyl or painted face, so you need to open the surface up. A scoring tool with small spiked wheels is the usual answer. The mistake is bearing down hard and rolling it over the same patch repeatedly until the wall looks like it has been shot with birdshot. Every one of those punctures goes into the plaster and every one has to be filled later. Use light pressure and a random overlapping pattern, just enough to break the face. Skip scoring altogether on plain paper backings.

Soak in stages, not all at once

Wet a section of about a square metre and leave it alone for five to ten minutes, then wet it again. The second soak does the real work, because the first pass mostly dampens the paper face while the second gets through to the adhesive. You should then be able to push a scraper under an edge and feel the paper release with almost no effort. If it still fights you, wet it a third time and wait. Patience here costs minutes, impatience costs a plastering bill.

Steamers work on the same principle but faster and with less standing water, which is why they are the better option on plasterboard. Hold the plate flat for fifteen to twenty seconds, then move along and scrape the section you just did while the next one steams. Do not park the plate in one spot for a minute or more. That is how you cook the skim.

Scrape at a shallow angle with a wide blade

Use a stiff scraper at least 100mm wide. Narrow blades concentrate force into a small area and that is exactly what gouges plaster. Hold it at roughly 30 degrees to the wall and push with a steady sweep, keeping the blade moving. If you have to lever or stab at it, the paper is not ready and you should re-wet it rather than force it.

Run a file over any nicks in the blade edge before you start, because a burred scraper leaves tramlines. Work from the bottom up on each section so the water you applied above keeps running down into the paper you have yet to remove.

• Start at a seam or a lifted corner, never in the middle of a sheet
• Keep the blade flat and moving; if it stops, re-wet rather than push harder
• Clear the sodden paper off the floor regularly so you are not standing on it
• Change your scraper blade or file it if it starts leaving marks

Get the last of the paste off

Once the paper is gone the wall will still be coated in old adhesive, which feels tacky when damp and dries to a shiny film. Paint over it and the finish will eventually flake, so wash the wall down with warm water and a little sugar soap, then rinse with clean water and a fresh sponge. Change the water often or you are just spreading dissolved paste around.

Let the wall dry fully, which can take a day or two after a heavy soak. Only then fill any dinks, sand back flush, and mist coat bare or patched plaster before decorating.