Stripping Old Wallpaper, Paint and Plaster

How to test and strip old wallpaper, paint and weakened plaster, and how to decide which layers can stay and which must come off.

New paint or wallpaper is only as sound as the layer underneath it. Working straight over an old finish looks like a shortcut, but a year or two later blistering paint, lifting seams and crumbling filler show what that shortcut really cost. So before any demolition starts, each layer on the wall deserves its own assessment.

Diagnose first: what is there and how well it holds

A wall usually carries several layers: plaster, skim coat, one or more coats of paint and sometimes wallpaper on top. A few simple checks tell you what can stay.

Tap the wall with your knuckles: a dull, hollow sound means there is a void behind the plaster.
On painted areas, score a small grid with a knife, press strong tape over it and rip it off sharply. If paint comes away on the tape, the coat is weak.
Wipe with a damp sponge: old distemper that leaves a chalky trace will not hold anything applied over it.
Pull at a wallpaper edge: if it comes away easily, the rest will not put up much of a fight either.

Test in several places rather than one, especially under windows, in corners and behind radiators. Problems usually start in zones exposed to damp and temperature differences.

How to remove wallpaper

Trying to pull paper off dry tends to take the skim coat with it. The right approach is to soften the paste. First the surface is perforated with a scoring roller or a knife so water can get behind the paper. Then warm water with a little detergent, or a ready-made stripping solution, is applied with a sponge or sprayer.

With vinyl and non-woven papers, the top layer often peels off on its own, while the backing paper left behind is soaked and lifted with a scraper. For multi-layer or painted wallpaper, a steamer makes the job much easier. Once the paper is off, wash the wall with clean water to remove paste residue; otherwise new filler and paint can stain over it.

Before wetting the walls, remove or tightly cover sockets and switches and switch the circuit off at the board.

Old paint: keep it or strip it

Water-based paint that adheres well and shows no cracking does not always need to come off. It can be washed, sanded, primed and taken forward with a new system. In some cases, however, stripping is unavoidable:

the paint is blistering, flaking or fails the tape test;
old distemper or limewash is powdering;
a water-based system is going over oil paint and a high-quality finish is expected;
tiles will be fixed and the adhesive is not rated for painted surfaces.

Oil paint is removed mechanically, with a heat gun or with a chemical stripper. When using chemicals, ventilate the room well and wear gloves and eye protection. Where firmly bonded oil paint cannot be fully removed, the surface is often densely notched and treated with a suitable bonding primer. Whether that is acceptable depends on the instructions of the manufacturer of the next material.

In older buildings where you do not know what the paint contains, avoid dry sanding. Some old paints may contain harmful metals; wet methods and a proper respirator reduce that risk.

Plaster: local repair or full replacement

Areas that sound hollow are cut back to sound material. Small patches can then be filled with a compatible product. But if hollow zones cover a large part of the wall, the plaster crumbles or the wall is badly out of true, removing the plaster completely and applying it again is more reliable and gives a neater result than patching.

Look closely at the surface once it is exposed: cracks in the masonry, old cable runs or damp stains are issues to solve before replastering. New plaster does not fix a problem; it only covers it for a while.

Dust, debris and site organisation

Stripping is the dirtiest stage of any renovation. Sealing doorways with plastic sheeting, protecting the floor with a heavy cover and bagging debris straight away keeps neighbouring rooms and the stairwell clean. A respirator, goggles and gloves are essential at this stage.

When stripping is finished, the wall is dusted down and given time to dry. Only then is it right to move on to primer, plaster or skim coat.

Zaferoğlu İnşaat assesses the condition of walls before demolition on apartment and office renovations and builds the decision about which layers to keep into the work plan. If you have questions about old finishes, you can contact our office at Babək Plaza.

News