How to choose self-tapping screws for drywall?

Drywall (GVL) is the most popular building material. One of the main elements of GVL-structures is fasteners, the quality of which directly affects the strength and durability of the entire assembled structure. Self-tapping screws are such fasteners - a kind of hybrid of a drill and a screw.

A self-tapping screw is a special fastener that is capable of simultaneously cutting threads during the production of fasteners. Functionally, it is a type of screw, but it has a thinner shank and a higher thread height. The safety of people depends on the quality of fasteners along with the strength of the structure. Therefore, when purchasing these products, it is recommended to require a certificate of conformity, which each manufacturer must obtain from specially accredited certification centers.

Self-tapping screws, anchors and screws are used to fasten drywall sheets. The most common type of fasteners are self-tapping screws, which is determined by simplicity, versatility and reliability (if performed correctly), especially if a screwdriver is at hand.

Installation, as a rule, implies the presence of metal or wooden frames, to which the drywall sheets are attached. It is the frame material that determines the type of fasteners to be used for installation. Self-tapping screws for wood are made with a rarer thread pitch than self-tapping screws for metal.

The main materials for the manufacture of self-tapping screws are steel and brass. The former have high strength, but are susceptible to corrosion. Therefore, they are covered with an anti-corrosion protective layer, oxidized or phosphated, which gives them a black color.

The dimensions (length and diameter) of the fastener largely determine its scope. In practice, depending on the purpose, fasteners with a length of 10-15 mm and a diameter of 3.5-5 mm are used. Such a wide range of product parameters determines the variety of types of models, their purpose, and hence the importance of the correct choice of fasteners for each individual case.

When working on drywall, special size tables are used for the selection of self-tapping screws. It indicates the nominal diameters of products, their lengths, including the head, and width.

An important issue in working with drywall is also the question of how much fastener goes to 1 square meter of the product. This parameter should be optimal: on the one hand, to ensure the proper strength of the structure, and on the other, to ensure the savings in material resources spent on work.

Self-tapping screws differ in many ways:

• high carbon steel;
• resistant types of steel to chemicals and water (stainless or alloy steel).

• frequent;
• rare.

• phosphate;
• oxidized;
• without cover.
• galvanized.

• sharp;
• drill-like.

• For the installation of gypsum board;
• for roofing works;
• woodwork;
• work with windows;
• metal work;
• work with concrete and brick.

In more detail, fasteners are subdivided into products with a universal thread, with a rare thread pitch and frequent. Fasteners with frequent threads are used for working with metal.

The presence of a drill at the end of the self-tapping screw eliminates the need for preliminary drilling of the material, which speeds up installation work.

Types of fasteners with infrequent threads are intended for working with soft textures: plastic, gypsum, asbestos, wood and other types. Universal fasteners are suitable for almost any texture.

Self-tapping caps are functional. They are produced secret, hemispherical, with large and small press washers, hexagonal, funnel-shaped for a hexagon.

Self-tapping screws for each type of work have different parameters and design features. For this reason, when buying a product, it is important to have a clear idea of ​​what types of work will be done and what textures will have to be dealt with.

When choosing the type of fasteners for gypsum board, it is important to know:

• frame material (wood, metal, other);
• what exactly is the fastener for;
• in how many layers will the plasterboard be laid;
• operating conditions of the structure (indoors, outdoors, humidity level, etc.).

If work is to be done in the "GKL-metal" system, then the fasteners are selected for work on metal - with "thick" threads. In the case of a timber frame, the fasteners should have a wider thread pitch.

If you just need to fix the shelf on drywall, then you can use a self-tapping screw with a butterfly dowel, equipped with a stop device that can be opened from the back and capable of withstanding high loads.

For laying sheets of gypsum board in 1 layer, the length of the fastener is 25 mm, in 2 layers - 35 mm. The thread thickness in both cases is 3.5 mm.

If a product made of gypsum plasterboard is to function at an elevated level of humidity, it is necessary to use moisture-resistant fasteners: alloyed or galvanized.

For work, the so-called "bugs" in everyday life - shortened screws with a drill used to fasten the profile, can come in handy. Fixing the profile directly to the wall or ceiling is done with anchor screws with dowels.

The consumption of fasteners directly depends on the quality of the screws, which is important to consider when choosing them:

• In appearance, self-tapping screws should be of the same size, with a uniform thread, not have thickenings and curvatures, which reduces its strength.
• The slotted hole must be clear and located strictly in the center of the screw head. Various types of nodules, bulges are a technological defect. A non-technological slot affects the quality of installation, it can deform the screwdriver nozzle.
• In color, the entire batch of self-tapping screws should be of a uniform dark or grayish-black shade, which indicates good quality when phosphating or oxidizing products. Otherwise, an increase in humidity leads to the appearance of rusty stains, for example, under the wallpaper, the elimination of which is extremely difficult.

A reliable manufacturer, as a rule, marks products not only on the packaging, but also on the product itself. For example, the letters X, T, W, G, Z on the head of the self-tapping screw. So, the letter X stands for OMAX, which is one of the most reliable manufacturers of fasteners.

For work on aerated concrete, a special group of self-tapping screws is produced, which takes into account its porosity and fragility, which is called dowels - universal types of fasteners, its "Christmas tree" varieties.

Without dowels, fasteners for aerated concrete are practically not used due to its special structure and are usually used for fastening lightweight structures. For example, for the equipment of a reinforced network on an aerated concrete wall, before plastering it, fasteners with a wide thread pitch and a length of at least 100 mm are usually used.

For large amounts of fastening work the professional set of tools necessary for the installation of gypsum board includes:

• hammer drill or hammer drill;
• screwdriver, with which you can conveniently and quickly fasten fasteners;
• level;

• special knife for cutting sheets;
• roulette;
• needle roller for bending the gypsum board;

• a roughing planer for processing the edges of the gypsum board;
• grinder and special shears for profile cutting;
• special pliers in order to fix the profile (with their help, they easily connect the profile to each other, similar to the rivet system);

• gas gun for mounting gypsum board;
• tape screwdriver reduces installation time, since self-tapping screws are fed automatically thanks to a special tape;
• special corners for cutting holes for sockets, lamps or junction boxes;

• disc cutter for cutting even strips of material;
• punch for the production of holes in the profile;
• a set of self-tapping screws of various lengths, with frequent and rare threads, with serifs on the back and other types of fasteners.

Complete with professional tools, there are usually a number of different devices that significantly speed up the process of installing the gypsum board and profile.

To perform one-time work for the home, it makes no sense to purchase expensive equipment (punchers, pistols, etc.), since it is not difficult to always find some alternative and more economical option. However, when hiring installers, it is necessary to pay attention to their professional equipment.

Correct installation of gypsum board requires compliance with a number of rules:

• Preliminary and accurate marking of the location of the holes for connecting the drywall and the profile to each other not only improves the aesthetics of the product, but also increases its strength.
• The approximate consumption of fasteners for one sheet of plasterboard of standard sizes is no more than 70 pieces (with the generally accepted step of fasteners between the holes - 300-350mm).
• It is more practical and efficient to install the gypsum board using a screwdriver, using various nozzles (bits) for different self-tapping slots.

• In the course of fastening, the first half of the self-tapping screw should be screwed in at the maximum speed, the second half must be screwed in at the minimum speed in order to fully control the degree of immersion of the self-tapping screw into the drywall sheet.
• Drywall is a fragile material, and therefore accuracy and accuracy are important when working with self-tapping screws. If the sheet was deformed during the fastening process, it is necessary to unscrew the screw, putty the deformed hole and screw in a new one at a distance of about 50 mm from the old hole.
• The head of the screwed-in self-tapping screw should not go deeper into the material by more than 1 mm, and its location should be strictly perpendicular to the surface of the sheet.
• At the end of the work, it is important to check how correctly and efficiently all the screws are screwed in.

For fastening 2 wooden elements, it is recommended to use black screws with rare threads. In this case, pre-drilling is not performed. For fastening other elements to the tree, yellow or white self-tapping screws are used. Silver self-tapping screws are used for a more durable fastening of sheet material.

The consumption of self-tapping screws per 1 m2 of gypsum board sheet depends on the optimal size of its step, which is selected based on the following features:

• practice shows that a structure of medium strength has a step rate of 300-350 mm (distance between holes);
• to strengthen the plasterboard structure, the distance between the holes can be slightly reduced, sometimes up to 100 mm;
• the self-tapping screw should not be brought closer to the edge of the sheet by less than 10 mm in order to avoid chipping.

When working with a reinforced profile (for example, 2 mm thick), self-tapping screws with a drill should be used, which will eliminate the additional operation - pre-drilling - and significantly reduce the operating time.

For hanging various elements of the interior, it is better to use a butterfly dowel, which, after installation, opens and forms a reliable stop.The installation of such a dowel is carried out as follows: a hole with a diameter equal to the diameter of the dowel is drilled in the wall, 5 mm longer than the fastener. After cleaning the hole, a dowel is inserted, and then the fasteners are installed. One such "butterfly" is able to withstand up to twenty-five kilograms of weight.

For working with wood, self-tapping screws are used, usually 24 mm long. For a metal frame, experts recommend using self-tapping screws with a small cap, since it is more convenient to hide them under the finish.

After completing the markings, it is advised to pre-drill the hole with a thin drill no more than 3 mm deep. In the future, this provides a high-quality and reliable fastening.

It is recommended to install the gypsum board to the ceiling profile using a special nozzle that limits the drilling depth to the specified size. The cap of the finally screwed in self-tapping screw should be flush with the surface of the sheet.

You can find out how to properly tighten the screws in drywall from the video below.