Plasterboard plasterboard for painting and wallpaper: technology, sealing joints and corners
Having finished the walls and ceiling inside the apartment with sheets of drywall, not a single owner will stop arranging the rooms. Bare walls are just asking for decoration. Drywall sheets themselves are smooth and even, but, unfortunately, they are not monolithic, but have certain dimensions. After installation, the wall looks uneven. The resulting joints, the places where the drywall is attached to the frame - the screw heads - need puttying. Before the final finishing of the walls, do-it-yourself plasterboard puttying is done - the work is not difficult, but quite painstaking. First of all, you need to choose a suitable putty.
Choosing a putty for drywall
In building materials stores, there is a sufficient selection of dry building mixes. There are so many of them that you can’t immediately figure out what kind of putty to putty drywall. Some materials are designed for finishing ceilings and walls, others for cracks and chips. Still others are used solely for decorative purposes.
Dry mixes are more profitable to take, because they last for a long time. Both in warehouses and in shops, and after purchase. The quality of dry putties is not affected by temperature storage conditions. While finished putties are subject to all sorts of changes, far from for the better. In addition, dry mixes can be used in doses: grease somewhere, level somewhere, and leave most of it for emergency work.
Depending on the materials putty are:
- Cement;
- Gypsum;
- Polymer.
All three materials are suitable for puttying drywall, but not in every room. If it is necessary to putty a kitchen or bathroom, it is better to use cement putty, since gypsum cannot withstand changes in humidity: when it dries, gypsum putty will crack.
Polymer putties are universal and plastic. They are best suited for drywall putty. In addition, their consumption is much less.
Various characteristics of putties, which determine their price and scope, are not decisive for working with drywall at home. Such qualities as frost resistance or fire resistance are not so important.
The best option would be to buy a universal dry mix.
Primer
To prepare the drywall for further action, the wall is primed. Under the primer is applied evenly over the entire area of drywall. As a primer, water-soluble mixtures are used that impregnate the top layer of dry plaster without penetrating inside. This forms a moisture-resistant film that will prevent the absorption of wallpaper glue or paint.
Important: When priming drywall, alkyd primers are not used because they can cause deformation of the cardboard layer. Peeled paper forms bubbles that crack and hang in tatters. There is no need to talk about any fastening strength of clean finishing materials under such conditions.
The primer is diluted in a basin, then applied with a roller throughout the entire wall: from top to bottom. The thickness of the soil layer should not be less than 0.03 mm.
Preparing drywall for plastering
Before puttying, the plasterboard wall is leveled so that the surface becomes perfectly flat. It makes no sense to putty a wall with protruding heads of self-tapping screws. You need to screw them all up. However, do not apply excessive force so as not to drown the bolt heads. Then you get holes. If, during the installation process, the self-tapping screws are screwed in so that their caps are sunk deep into the drywall layer, the self-tapping screws are unscrewed and new ones are screwed in their place - longer ones.
At the joints of drywall sheets, there should not be any delamination of the outer sheet from the gypsum filling. If the paper has peeled off, you need to carefully tear it off with your hands and cut it with a knife under the very spine. Then clean the resulting wrinkle with sandpaper. Otherwise, the putty may peel off after the fallen off paper. In place of the formed bubbles after the putty dries, cracks will appear.
Plastering drywall for painting
The preparation of drywall is carried out according to a similar scheme, as well as for wallpapering. It is important that the wall is perfectly flat, without dents or protrusions.
cutting corners without edges
The seams between the drywall profiles are carefully leveled with putty, the surface is primed. Paint absorbs into cardboard in the same way as wallpaper paste. If this impregnation reaches the inner layer, the outer - cardboard - is deformed. Crack or blister.
The joints of drywall sheets that do not have a factory edge must be cut off independently at an angle of 45 0. Only under such conditions will a reliable reinforcement of the seam be obtained.
Putty technology
When the primer dries, it's time to move on to putty. A simple putty technology is carried out in several stages.
sticking sickle
First of all, a fiberglass mesh - sickle - is glued to all joints and corners. The joint tape has a self-adhesive surface, so this process does not take a long time. It is important to stick the sickle so that on both sides of the seam or corner, there is half the tape. That is, the seam was exactly in the middle of the sickle.
Putty is diluted in small quantities, because it dries quickly. Adding water to a dried mixture changes all its qualities. Having calculated the approximate volume of disposable putty, you need to dilute exactly this amount, and not a gram more. For half an hour of work. After that, the putty will no longer be suitable for use.
Sealing drywall joints
To seal the seams between drywall sheets, you need two spatulas: medium and wide. 12-15 cm and 30-35 cm, respectively. It is much more difficult to work with a trowel and a grater, and the work is not as neat as we would like. What works well for concrete doesn't go without a hitch with drywall.
To properly putty drywall joints, it is necessary to evenly apply a reinforcing layer throughout the entire seam. It is easier, of course, to first pick up a small amount of putty with a narrow spatula and apply it to the seam. Then, with a wide spatula, stretch the putty to the possible distance. Once you get used to it, you can immediately pick it up with a large spatula and spread it all over the seam. If it turns out to carefully fill the joint, the reinforcement process goes as it should.
An important condition for primary putty is the correct reinforcement of the joints, as a result of which no irregularities and roughness should form. Otherwise, after drying, it is very difficult to sand powerful streaks. Sandpaper and a rasp will not help. More serious abrasive tools can destroy not only dried putty, but also a drywall sheet.
Screw putty
Puttying screws is done in a crosswise way. Putty is applied along and across, so the grooves of the self-tapping screws are better filled and their heads are completely hidden.
Putty corners
Puttying the corners is a little more difficult, because this is not a flat vertical surface, but drywall sheets converging at a right angle. It is not immediately possible to bring out both sides of the corner evenly. In this regard, the sealing of corners is carried out in two stages.
- First, one side of the corner is puttied according to the usual rules.
- After half the seam has dried, the second side of the corner is puttied.
So, having endured for some time, we get an even, neat seam. A few drops of patience in the process of puttying corners saves a lot of nerves and energy that could be spent on rework.
Basic puttying technique
Actually puttying begins after the roughing of the seams has dried and the corners have been sealed.
often aluminum profiles for drywall corners are supplied with a reinforcing mesh
Smooth outer corners: window and door slopes - are fixed with an aluminum construction corner. It is attached to putty or a construction stapler, which is much more convenient and accurate. Without unnecessary splashes and construction debris under your feet. The corner is cut to the specified dimensions and attached along the perimeter of window and door openings.
Having strengthened the metal corners, the putty is pressed into the corrugated holes of the profile with a small spatula so that all the holes are filled. This achieves rigidity and hardness of the outer corner, which subsequently guarantees its strength to mechanical stress. Then the surface of the solution is leveled with a wide spatula. To do this, it is necessary to carry out a spatula along the edge of the corner and the surface of the drywall sheet.
If you have to putty arched passages, a special plastic corner is used. It is somewhat thicker than aluminum, so after the corner is fixed with a stapler, it is necessary to putty it in two stages. You should not try to stick putty as much as possible, then you get an uneven surface. It is recommended to apply the first layer, filling all the holes, wait for the drying time, and then apply the putty layer again, leveling the junction of the corner with the drywall surface. The putty layer with this approach turns out to be almost perfectly even.
Finishing drywall putty
The final stage of preparing plasterboard walls allows you to achieve perfect evenness of surfaces for subsequent finishing.
All irregularities and roughness must be cleaned with sandpaper. When working, you must use a respirator. The surface of the wall is also processed with an emery cloth - "zero". After stripping, the contact of the finishing putty with the wall, which was previously treated with a primer, is improved.
Fiberglass or the same putty that was used at the starting stage is suitable for finishing. The spatula is used wide. It is necessary to dilute the finishing putty to the consistency of sour cream. This will allow the putty to be applied evenly over the entire surface of the drywall. It is necessary to apply a layer of finishing putty as thinly and evenly as possible.
Putty consumption per square meter of drywall
The consumption of putty depends on the nature of the treated surface. If there are a lot of defects, then more putty goes away. Given the preliminary priming of the wall, the putty consumption per square meter of drywall is calculated one to one, plus one hundred grams. It is easy to remember: 1.1 x 1 m 2. This formula is suitable for dry cement-based putties.
- When using gypsum putty it is even easier: one to one when puttying walls and ceilings.
- Glue-based putty is consumed even less - half a kilogram per square meter is enough.
To calculate the approximate amount of putty, you need to know the surface area of all the walls in the room. It's easy: each sheet of drywall has certain dimensions, they are indicated on the label. All the numbers are summed up, and the total area for the finishing putty is obtained.
For starting putty, the same amount of material is taken, with a small margin. However, in any calculations, it is important to follow the technology. It is necessary to dilute the mixture in such an amount that it is enough to work for half an hour or less. If you hesitate or get distracted from work, then it is recommended to dispose of the dried putty. It's not worth using it. It is undesirable to redo work already done. Either the surface of the wall will not be smooth, as expected, or in the long term, finishing materials will begin to fall off the drywall due to the lack of a strong coupling.
Finishing putty is not the end of the matter. After the wall has dried, it must be primed again.
Only after completing all the stages of preparing drywall for a fine finish, you can be sure that it will be securely fixed. In addition, the finished drywall sheets are easily cleaned from the old wallpaper. Nothing falls off or cracks. After removing the old canvas, it will be possible to stick new wallpaper. There is no need to re-putty drywall walls.