How to putty drywall: seams, corners, preparation for wallpaper, painting

In order for the drywall construction to take on a finished look, it must be puttied. How to putty drywall, remove corners, seal joints – everything in this article. 

Do I need to plaster drywall?

Nobody wants to do extra work. In addition, puttying is a long, difficult process that takes a lot of time. The question reasonably arises – why putty a flat surface of drywall sheets. Maybe you can do without it when finishing? With some types of finishes it is possible, but not with all.

It is always necessary to close up the joints of sheets, corners and caps of self-tapping screws. For any type of finish. Be sure to putty GKL for painting. The drywall surface is far from perfect, and new irregularities are added during transportation and installation. If you paint the surface without prior leveling, they will all be clearly visible, especially if there is at least a slight degree of gloss.

The Knauf company, one of the leaders in the production of drywall, allows not to putty the entire surface of the sheets under tiles and wallpaper. Only joints, corners and screws. No one putty under the laying of tiles, but under the wallpaper – yes. And all because the wallpaper pasted without pre-treatment in places comes off along with the cardboard and sometimes – to plaster. So the second time putty is simply inevitable.

You can do without puttying the entire surface of the sheet using a primer. In this case, water-dispersion acrylic paint diluted with water serves as a primer. It creates a film on the surface with which the glue interacts well, but also this film does not damage the cardboard when tearing off the wallpaper.

So, it is absolutely necessary to putty drywall for painting, preferably for pasting wallpaper (at least in one layer) and seal only screws and seams for tiles.

Primer for drywall: why, what and when

The primer performs two different functions. The first is that it improves the adhesion (adhesion) of the two materials. As a result, when puttying, the chances of the formation of bubbles and delamination of the material are reduced. The second function is that it evens out the absorbency. The result is less material consumption and, when puttying, a smoother surface. So it is undesirable to skip the primer.

Priming during finishing work, in theory, is necessary before each new operation. For example, before puttying, a primer of gypsum boards is needed to improve adhesion with putty. Before painting or wallpapering – to reduce the consumption of paint and glue. You also need a primer before applying the finish layer – the starting one has to be leveled, which is why the surface turns out to be dusty. Without primer treatment, the finish layer does not fit well, rolls off and may even fall off.

What primers are needed? Depends on the stage and on the type of finishing material:

• Before puttying drywall (starting and finishing layer), a deep penetration primer is used or for porous, well-absorbing surfaces.
• The same composition can be used before painting and wallpapering.
• Under the wallpaper, the puttied GKL surface can be primed with wallpaper glue diluted with water. The proportions are indicated on the packaging with glue.
• For painting, you need to look at the recommendations of the manufacturers. Sometimes the primer is paint diluted with water. Unless otherwise indicated, use a deep penetration compound.

Summing up, it is worth saying that the primer is a necessary operation. It allows you to get a good result and reduce the consumption of materials.

Technology: workflow

After the GKL sheets are fixed on the frame, it is time to prepare the drywall for finishing. Consider the case with a full cycle – for painting. In this case, putty drywall must be at least two layers. For other types of finishes that are less demanding on surface quality, we simply remove unnecessary steps. The order of work is as follows:

• Coating with a deep penetration primer.
• Seal holes from self-tapping screws.
• Putty joints using sickle mesh or special paper tape.
• Sealing of corners – external and internal.
• Primer for drywall.
• Puttying the entire surface with the starting compound and grinding irregularities.
• Primer for hyposkarton.
• Puttying with a finishing compound and puttying irregularities.
• Coating with a primer for finishing.
  

A few words about which putty is better to use for drywall. Any one will do – based on gypsum or polymers (latex). Polymer putties are usually finishing – they give a very thin layer and a flat surface. Gypsum is both starting and finishing. difference in particle size. You can use any, as long as the quality is good.

There are two forms of drywall putty release – dry in bags and diluted in buckets. Before use, dry must be diluted with water in the indicated proportions and stirred until the lumps dissolve. The compositions in buckets are already ready to go, but they are more expensive. But they are guaranteed not to have lumps.

Primer coating

Before plastering drywall, prime the surface. Any primer is applied on a dry, clean base. Therefore, we first remove pollution from the surface, remove dust (you can use a vacuum cleaner or a slightly damp cloth). After that, we prepare the soil according to the instructions (sometimes it is necessary to dilute it with water, sometimes it is enough just to stir it), pour it into a container and apply it with a brush or roller.

Primer for drywall is for dry and wet areas. For the bathroom and kitchen, choose a primer for wet rooms, for the rest, you can use any. When choosing a soil, pay attention to the presence of antibacterial components. They prevent the development of mold and fungus. This is especially true for the kitchen and bathroom.

Usually, for drywall primer, it is enough to apply the composition in one layer, but in the kitchen or bathroom, two can be used: to guarantee the result. After the soil has dried (the time is indicated in the instructions), you can proceed to the next step.

Sealing of screws and seams

For seams, there are special compounds Knauf-Fugen, Knauf Uniflot, Fugenfuller and their analogues. After the soil has dried, we dilute the putty to the consistency of thick sour cream. Please note that these putties dry quickly, so dilute a small amount at a time.

We take a small spatula, apply the composition to the installation sites of the screws, remove the excess. There should be just enough putty in this place so that the surface is even. Thus, we pass all the screws. They can be sealed in parallel with the seams, or you can – in the first place. It does not matter.

Drywall joints are of two types. Along the long side of the GKL, the edges are uneven – for easier sealing of this joint. But the sheets are also connected in height, where there are no ledges. You also have to cut the sheets and the connection is also obtained end-to-end. Such connections require special technology and about it a little lower.

Vertical joints

When puttying vertical joints of drywall with normal factory edges, they are first carefully filled, then glued.

After filling, while the composition is not yet dry, it is glued with a sickle mesh or paper reinforcing tape. This is necessary so that cracks do not form at the joints. If a tape is used, it is torn into the desired pieces, soaked in clean water for 10 minutes (while the seam is being filled).

After filling the seam, the tape is taken out, squeezed between the fingers, excess water is removed, glued to the seam. After that, they take a spatula 8 cm wide (necessarily such) and press the tape below the surface of the GKL. She “sits” on one of the factory ledges. Start pressing from the middle to the edges. When pressed, putty is squeezed out from under the tape, we collect it. As a result, if you put a wide hard spatula (at least 20 cm wide) on the surface, you can see that the tape is below the surface of the cardboard. Then they pass with putty again, leveling the joint to the level with the surface.

Cut seams

It is better to putty drywall in places of horizontal joints – where two plates are connected or on vertical ones, but without edges, it is better after pre-treatment. First, the surface is moistened with water – dip the brush into the water and grease the junction well. Walk several times – so that the plaster gets wet. Then cut the grooves at a 45° angle with a sharp knife. The processing of these joints can be carried out before priming. It’s even more convenient.

We coat the prepared joints with soil. In this case, it is more convenient to use a brush. After drying, fill the seam with a compound for puttying drywall joints. It is more convenient to work with spatulas 10 cm wide and 20 cm hard. We apply the composition with a small one, remove the excess with a large one. We fill well, pressing the composition into the seam. If everything is done correctly, a small roller is formed, slightly protruding above the surface.

Once again we pass the seam, applying fresh putty with a thickness of about 0,5 mm, take the soaked reinforcing tape and glue it to this composition. We take a spatula 8 cm wide and press the tape well against the surface, squeezing out the excess putty from under it.

In this case, a wave of paper is formed (it can be seen in the photo), we make sure that it does not jam, we catch up with it to the end, where it straightens out. We remove the excess solution in the tape and the adjacent area of ​​​​the sheet. And the last stage – again we take the putty and coat the glued tape on top with a thin layer. We make this layer as thin as possible, as they say – “on the shir”. Actually, the remaining putty is stretched with a very thin layer.

Second technology: first tape then putty

There is a second technology – first a sickle or paper reinforcing tape is glued onto the gypsum, then it is puttied. It turns out faster, but the disadvantage is the voids that remain under the tape. In these places, wallpaper may wrinkle or putty, decorative plaster may crack.

Instead of paper tape, they use a sickle mesh. It is more difficult to work with a sickle – it is hard and its edges often stick out of the solution. To make it a little easier, the mesh is pre-glued, after the glue has completely dried, it is puttied. In order not to think about glue and speed up the work, they use a self-adhesive sickle (there is one).

But, anyway, it’s more difficult to putty drywall – its surface is uneven, the spatula “jumps” on the fibers and a small wave is obtained, which is not at all easy to smooth over.

External and internal corners

External and internal corners on the walls and partitions made of gypsum plasterboard are made using:

• reinforcing paper;
• crescents;
• perforated aluminum corners;
• special metal corners Shitrok with paper.
  

Paper and sickle most often trim the inner corners – the junction of the walls, as well as the walls and ceiling. The technology is similar to sealing seams. A certain amount of putty is applied to the corner, paper or sickle is glued on it, the reinforcing strip is pressed into the composition with a narrow spatula, excess putty is removed. After that, they pass the corner again, applying putty with a thin layer on top.

Perforated corners are used to decorate external corners – slopes, ledges, etc. First, a piece of the desired length is cut off. The metal is very thin, it can be cut even with ordinary large scissors, but if there are metal scissors, it is easier to work. Edges are cut at 45° or less, not 90°. So, when puttying drywall, the edge will not wrap.

Putty is applied to the outer corner on both sides in small islands approximately every 10 cm (it can be in a checkerboard pattern). A perforated corner is pressed into the solution, the verticality or horizontality of its installation is checked, and corrected. The excess solution is picked up with a spatula, aligning the edges in the same plane with the surface of the sheet. The installed corner is left for a while – until the putty dries, after which it is sanded, puttyed again if necessary.

What is the difference between the metal corner Shitrok (Sheetrock)? Thin strips of metal are applied to the paper base. They are more rigid than simple reinforcing paper, but it is more convenient to work with them than with ordinary perforated ones, since due to the presence of paper, the transition to the plane is smoother.

Grinding seams and corners

If the layer is well leveled during grouting on drywall, sanding can be minimized. Why is it better to grind less? Because firstly, it’s long, and secondly, it’s dusty. Moreover, the dust is very fine, it flies in the air for a long time and rises again from any movement. To reduce the amount of flying dust, wet rags, wet sawdust, etc. can be placed on the floor. The doors leading out of the room are closed with a wet cloth; it should be larger than the size of the door – so that dust does not fly into other rooms.

To begin with, you can walk with a sharp, even spatula, cut off all the most protruding irregularities. Next is the grinding process. Since the corners and seams at this stage do not need to be cleaned to perfect smoothness, they take a grinding grid with a 180-200 cell and a wooden block. A mesh is attached to the bar (you can use staples from a construction stapler, but the staples should not stick out). This tool is used to level the surface. When working, it is desirable to highlight with oblique light – so all the irregularities are more visible. But puttying drywall under the wallpaper can not be so thorough.

One point – it is better to grind in a respirator and goggles. Gloves will not be superfluous. The dust is very fine and penetrates literally everywhere. After the seams and corners are sanded, the surface is primed again. Moreover, all completely, since dust also settled on the untreated areas, and it worsens the grip.

The most inconvenient places for puttying and grinding are internal corners. See the next video for the secrets of fast, high-quality grinding of corners.

How to putty drywall: align the plane

To putty surfaces, you will need a large spatula – with a blade of 40 cm or more and narrow – by 10 cm. The first layer is applied with a starting putty. It is placed in a layer of about 5 mm (the maximum should be looked at in the instructions for a specific putty) and hides all the irregularities. Dilute it with water to a state of thick sour cream, stir thoroughly so that there are no lumps.

The technique of puttying the surface of drywall is simple: we take a large spatula, at its end with a small spatula, lay out a putty roller. We press the blade to the surface and stretch the composition. We repeat several times, filling some piece of the wall or ceiling. Then we clean the blade, and draw it over the freshly puttied surface, leveling it. It is necessary to align as carefully as possible – it will take less time for grinding.

When you have finished plastering the drywall, wait until it dries. Then you take an already familiar tool – a bar with a grid and align all the flaws. Grinding is finished, remove dust, pass the surface again with a deep penetration primer. After drying, start applying the second layer.

Next, putty drywall with a finishing compound. As they wrote, it can also be based on gypsum, like the starting one, or maybe based on polymers. Both are suitable, but some are more difficult to work with – they quickly begin to roll and harden.

Finishing putty is made more liquid and applied in a thinner layer. The application technique is the same, nothing changes. In addition to the fact that it is more difficult to work, it spreads worse, but you need to stretch it with a thin layer and quickly level it. As for the primer, everything is much better, and without it, the bottom layer quickly draws moisture from fresh plaster and it begins to roll. After applying the finishing putty, they again wait until everything is dry, then they begin to level it. But this time they do not use a grid – noticeable grooves remain from it, but sandpaper with fine grains. It is not so convenient to work with it – it clogs quickly, but the surface is smooth. If you prepare the surface for painting, we do the backlight from below or from the side and you can use not an incandescent lamp, but an LED one – all the flaws are visible. Even very small ones.

It is difficult to describe in words how to putty drywall – it is difficult to describe the movements. In the video you can see how to hold the spatula, how to move it, how to apply or remove the solution. See the video for details on the technology.

And more.