How to Prepare Walls for Wallpaper

Wall preparation before wallpapering includes a comprehensive set of measures and will be described in detail in this article.

Before detailing the preparatory steps, we conditionally divide all wall substrates (walls) into three major groups: plastered brick or block walls, monolithic concrete walls, and claddings made from sheet materials such as gypsum board or gypsum fiberboard.

Wall Skimming

The first and most critical step in preparation is wall skimming. Some believe it's unnecessary if walls will be wallpapered, but we’ll explain why this view is incorrect.

Russian concrete products, including slabs and block rooms that form part of apartment walls in multi-story buildings, have never been known for high geometric accuracy. As a result, one wall may have several hollows and several protrusions simultaneously. Full-surface skimming of such a wall aims to level the defects mentioned above and improve adhesive bonding of the wallpaper glue.

Plastered brick or block walls already have a proper horizontal level, especially if plaster was applied with guides. However, the plaster surface has a slightly rough micro-relief, which will inevitably appear on the wallpaper after application. Full-surface skimming of a brick wall resolves the issue of plaster layer texture and again improves adhesive bonding between the glue and wall.

Skimming is simplest with sheet materials, as gypsum board is naturally flat and ready for further coating. Joints between sheets and screw fastener points must be leveled with joint compound. Special attention should be given to the joints between two sheets – this is the most problematic area of the entire cladding structure. To reinforce the skim coat, reinforcing material based on fiberglass mesh is embedded into the compound. If joints and screws are not properly sealed, they may show through as dark spots on many wallpaper types, especially light-colored ones.

Removal of Old Coatings

If the wall intended for wallpapering has already been covered with paper or non-woven wallpapers, they must be removed, as old wallpapers tend to gradually detach from walls over time, negatively affecting the quality of new wallpaper adhesion.

Old wallpapers can be removed using various methods, such as wetting them with water or a special solution. To help the removal solution penetrate the paper base more effectively, a so-called 'wallpaper tiger' – a special tool for disrupting the integrity of the old wallpaper – can be used.

Wall Priming

Priming the wall is a crucial step in preparation. It can be done using any deep-penetration primer, evenly distributed across the wall surface with a brush or roller. Some professionals prefer to prime the wall with the same adhesive used to attach the wallpaper. The primer removes dust and seals pores, preventing moisture from the adhesive solution from penetrating the wall structure, thus improving adhesive bond strength.

A starch paste is prepared in a 1:7 ratio with water, but many modern wallpaper manufacturers strongly recommend using only factory-made specialized adhesives for both priming and adhesive application. These adhesives contain specific additives and plasticizers that prevent clumping and sedimentation in the adhesive.