Preparing the walls for finishing is a crucial stage in the repair of the premises. Only a thorough cleaning of the entire surface of the walls from old wallpaper, paint, tiles, plaster or whitewash will subsequently make it possible to carry out high-quality finishing work. And although this is a laborious and dirty process, it will not be possible to avoid it. Regardless of which finish option is chosen, the walls must be cleaned to the ground. The only exception is plasterboard sheathing.
We clean the walls from old wallpaper
For work you will need:
- spray gun, roller or sponge;
- respirator, goggles;
- spatula narrow and wide;
- scraper;
- a bucket of warm water;
- wallpaper remover.
Different types of wallpaper differ in properties and quality, so they require a different approach when cleaning walls from old wallpaper.
Sometimes remove old wallpaper can be done effortlessly by simply pulling on the lagging edge. But if the wallpaper holds well, you must first soak it with warm water or a special agent that dissolves wallpaper glue. Paper wallpaper should be generously soaked with water, left for 20 minutes, then removed.
A waterproof layer of non-woven or washable wallpaper will not allow water to soften them so easily, so you need to break its integrity by making cuts and notches, and then moisten it with plenty of water with a sponge. After the glue dissolves, the wallpaper easily moves away from the walls.
When removed, vinyl wallpaper does not tear into pieces, but lags behind the wall in whole strips. If a part of the paper base remains on the wall, it can be easily removed by moistening it with water and prying it with a spatula.
Liquid wallpaper can be removed with a spatula, having previously treated them with water with the addition of a primer. If removing wallpaper by hand is difficult, you will need a sander with an abrasive nozzle.
How to clean walls from paint
In order to cleaning painted walls was successful, you need to know two things:
- What is the basis of the surface with which to work: brick, concrete, cement or plastered.
- What kind of paint are the walls painted with: oil, water-based or acrylic.
The most difficult thing is to remove oil paint from a concrete surface. But even with such a difficult task, you can cope if you have at hand all the necessary tools and means. Can be used:
- grinder with a nozzle;
- spatulas, chisels, scrapers;
- puncher or electric drill with a nozzle;
- paint thinners;
- axe;
- construction dryer.
There are three ways to clean walls from old paint, each of which has its pros and cons.
Mechanical
The mechanical method is the most dusty, but the least toxic compared to the next two. You can remove the paint manually: beat off individual sections of the surface with an ax or a hammer with a chisel. If you choose the right angle of inclination of the ax, the paint will be easily removed.
When working with a grinder there will be a lot of dust, so it is better to use a hammer drill or a drill with a chain attachment. The tool with chain links knocks down the paint, which flies off in pieces and does not dust.
Chemical
This method is less labor intensive. It is necessary to apply a special reagent to the surface, under the action of which the paint softens and is removed with a scraper.
Thermal
This method is simple, but toxic, like a chemical one. Its essence is to heat the surface with a building hair dryer until the paint begins to bubble, and remove it with a scraper.
Important points:
- To make it easier to remove water-based paint from concrete, it is necessary to moisten the surfaces with iodine solution (10 ml of iodine per 1 liter of water).
- You need to remove acrylic paint by first spraying the wall with water with the addition of alcohol or acetone.
- Oil, water-based and acrylic paints are successfully removed by all three methods.
Getting rid of old whitewash
Old whitewash can be removed in two ways - dry and wet.
Dry way to remove whitewash
You will need:
- respirator;
- Sander.
A lot of dust during operation is a significant disadvantage of this method. All furniture must be taken out of the room or wrapped in a protective film. The advantage is that the grinder will quickly clean the walls of whitewash without damaging them.
wet way
Tools needed to remove whitewash:
- putty knife;
- bucket with water;
- sponge;
- brush.
In this case, the old whitewash will need to be washed out by wetting the walls with plenty of water with a sponge. The whitewash that has become pliable is removed with a spatula, and the remaining places are treated with a brush and washed off with water to the ground.
Removing old plaster
To decide whether to remove all the plaster or not, you need to tap it with a spatula handle. In those places where there is emptiness, a dull sound will be heard.
To remove old plaster, you will need one of the following tools:
- putty knife;
- scraper;
- perforator;
- Bulgarian;
- plaster remover.
Algorithm plaster wall cleaning simple:
- Beating old plaster with a spatula or hammer. If it does not move well, use a grinder, puncher or a special machine with abrasive discs. Before this, the wall should be moistened with water so that there is less dust.
- Cleaning with a metal brush. To eliminate irregularities, the wall must be worked out with a brush or sandpaper, and then wiped with a wet cloth.
Tip: in order for the old plaster to come off easily, it must first be wetted with water with the addition of starch (2 tablespoons of starch per liter of water).
Cleaning the wall from mold
Get rid of mold needed in the most radical way. If mold has appeared on the wallpaper, they will have to be completely removed, and the wall surface should be thoroughly dried. Remove the mold with a spatula to the very base of the wall and apply an antiseptic primer to the cleaned wall.
Advice. Regular table vinegar copes well with mold. It is applied to mold-infected areas and washed off after an hour. In order to prevent, repeat the procedure several times. Baking soda is also effective in the fight against mold, an aqueous solution of which is sprayed onto surfaces. And ammonia in half with water will get rid of mold no worse than a purchased antiseptic.
