Aligning the walls before laying tiles: plaster, gypsum board, tile adhesive

For a seamless and long-lasting finish, walls must be prepared before laying tiles. Over time, uneven surfaces may result in improper tile adhesion, which could lead to cracks or loose tiles. Achieving a polished appearance starts with making sure your walls are precisely aligned.

Depending on the kind of material and surface condition, there are multiple ways to align walls. Using tile adhesive, gypsum board, or plastering are common techniques that can assist you in creating a level surface for your tiles.

You’ll save time and effort if you can distinguish between these approaches and select the best one for your project. Preparing the walls is essential for a successful tiling job, regardless of whether you are working with recently constructed walls or old, rough walls.

What kind of plaster can you lay tiles on?

Option No. 1: gypsum and lime

It is generally not advised to use gypsum and lime plaster mixes for wet room finishing such as bathrooms, kitchens, and swimming pools. Plaster on gypsum or lime is also not the best choice for a base on which to lay tiles in any room. This material can be left if it was used to level the walls. Nevertheless, you must thoroughly prime the surface using a deep penetration compound.

Primer aids:

• increase adhesion;
• increase the strength of the coating;
• create a water-repellent film;
• reduce porosity;
• prevent the appearance of fungus and other bacteria.

Two or three layers of primer are applied. It is advised to use a waterproofing primer for the final layer.

It is advised to use a specific tile adhesive when adhering tiles to lime and gypsum plaster.

It is advised to use metal mesh as additional reinforcement for the surface coated with a plaster mixture based on lime. In order to accomplish this, tile adhesive is applied to the walls after two coats of primer have been applied and dried. After the glue has dried, a mesh is added and primed once more.

Let’s emphasize the key points: Tiles should be placed on high-adhesion glue after the plaster has completely dried and been primed.

Option #2: cement-sand mortar

Cement-sand mixtures are typically used to plaster the walls of rooms that experience high humidity and frequent temperature changes, as these are the areas where tiles are most frequently used for finishing. Plaster preparation of the necessary quality is challenging without experience. It is therefore preferable to purchase it already made, with a predetermined composition, and just mix it with water as directed on the package.

Sand-cement plaster has the advantages of strength and moisture resistance.

Cons: It takes a while for it to dry and become stronger, and it may crack.

You will need the following to prepare the solution yourself:

• cement M400 or M500;
• purified sand of medium fraction;
• plasticizer.

The ratio of one part cement M400 to four parts sand (five parts sand to one part cement M500) is used to mix the two materials. The coating will be stronger the less sand there is in the mixture. A plasticizer makes the solution more elastic and makes application easier. The amount indicated in the manufacturer’s instructions is added to the mixture. It’s common practice to use detergent or washing powder in place of a professional plasticizer.

By the way, you do not need to be concerned about lowering the vapor permeability of the blocks when plastering aerated concrete with a cement-sand mortar for tile laying. The aerated concrete will still be fully shielded from moisture by the tiles.

Option No. 3: tile adhesive

Any tile adhesive or screed mortar can be used beneath porcelain or ceramic tiles in place of the typical plaster mixture. The primary benefit in this instance is an increase in the leveling layer’s strength at the same or reduced thickness.

But because the mixture flows and does not remain in one plane, application is far more challenging. By mixing sand and cement with the tile adhesive, the amount of mortar that drips can be minimized. But even with beacons, you can still see imperfections in the plaster set. Following full drying, the wall is examined using a rule, and areas that protrude are leveled using a float.

Plasterboard is a finishing option for leveling walls beneath tiles. Only moisture-resistant gypsum board is used for wet rooms. It can be glued straight to the wall or attached to a metal frame the conventional way. Only the option with a frame is appropriate if the unevenness is noticeable. In other situations, it’s preferable to glue the drywall to the walls because the frame method "eats up" five centimeters of space on each side of the space.

In order to finish the task, you’ll need:

• a metal rack and guide profile, hangers;
• a level, a grinder or metal scissors, a screwdriver or a drill;
• GKLV sheets (green), masking tape, self-tapping screws.

Method:

1. Draw up a frame diagram. It consists of two horizontal guide profiles and rack vertical ones. Two sections of the rack profile are mounted at the corners, the rest are installed with a step of 60 cm. If you plan to hang cabinets on the wall later, then make the step smaller (up to 40 cm) and install additional horizontal cross sections of the profile in the place where the furniture is supposed to be attached.
2. Apply markings to the walls according to the drawn up diagram.
3. Cut the profile into sections of the required length with a grinder or metal scissors.
4. Use dowels to attach the upper guide profile to the ceiling.
5. Use a plumb line to determine the position of the lower guide profile and screw it in, also using dowels.
6. Attach hangers to the walls with self-tapping screws to fix the rack profile. Check their position with a level during work.
7. Install and secure the vertical profile with screws according to the markings. Check the correct installation of each element with a level.
8. Secure the gypsum board sheets to the resulting frame with self-tapping screws. The joints between the sheets should fall on the rack profile. They need to be sealed with serpyanka.
9. Corners are also covered with serpyanka.
10. Putty the seams and screw heads with a special putty for drywall.
11. The water-repellent properties of plasterboard can be enhanced by treating the sheets with a water repellent for drywall.
12. To improve adhesion, be sure to apply a primer for gypsum plasterboard under the tile adhesive.

If you choose to glue drywall without first building a frame, then follow these steps:

1. Apply primer to the walls.
2. Clean the surface from dust and dirt.
3. Apply handfuls of drywall adhesive onto the sheets or wall in 30 cm increments.
4. Attach the sheet to the wall and set it level.

To guarantee a smooth, long-lasting finish, the walls must be aligned before installing tiles. Plaster, gypsum board, and tile adhesive are three different techniques that, depending on the type of tile being installed and the state of the wall, each offer special advantages. In addition to making tiling simpler, proper alignment guards against uneven surfaces and loose tiles in the future, guaranteeing a durable and polished finish.

For a finish that is both aesthetically pleasing and long-lasting, walls must be prepared before tiles are installed. Creating a smooth and even surface is crucial, regardless of the material you choose—plaster, gypsum board, or tile adhesive.

A dependable and conventional choice, plaster offers a sturdy foundation for tiles. A quicker option that works well for covering large areas is gypsum board, but handling it carefully is necessary to prevent moisture problems. Tile adhesive is not a replacement for proper wall leveling; it should only be used for small adjustments.

The state of your walls and the particulars of your project will determine which approach is best. You can be sure that your tiles will stick correctly and last for a long time if you prepare the surface well.

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