Dowel for concrete and aerated concrete: comparative characteristics of properties and applications

Fasteners for concrete walls

When determining which dowel is best for concrete, it is necessary to consider fasteners only for this material, since they differ in certain features. Thus, a brick dowel is not suitable for fastening into a concrete monolith and vice versa. The surface structure is also important - the porosity of the monolith and the presence of cavities in it must be taken into account.

The dowel-nail for concrete and brick is distinguished by a sleeve - classic smooth fasteners can simply be driven (hammered) into the monolith, efficiently and quickly, without the use of special techniques and the expenditure of time, effort, and finances. In brick or aerated concrete, for example, a sleeve without spacer elements will simply destroy the mounting hole due to the presence of cavities and looseness of the material.

The dowel marking always includes a description of the type of material for which the fastener is suitable: for concrete you need to select the appropriate elements and nothing else.

How to choose a dowel?

Content

What makes a good master? Nothing is too small for him! He also pays great attention to the choice of dowels. And this is no coincidence: an incorrectly selected or low-quality dowel can completely ruin the result of long-term work. Which dowel should I buy? How to choose a drill for a dowel? Let's find out!

Composition of concrete and its properties

If you intend to anchor the structure in concrete, it is important to understand what material you will be dealing with. Concrete can be of different quality, composition, and strength. This affects the loads that the surface can withstand.

Concrete is a building material based on cement, sand, crushed stone and water. After installation, the solution hardens, becoming a strong and reliable base. Concrete may contain more than just the components described above. In order to change the properties of the material, various binder components are added to the composition. For example, Portland cement, fly ash, slag and others.

The amount of water - up to 16% of the total volume of the mixture - hydrates the cement. When diluting the concentration, experts recommend using purified water. There are cases in production when water from non-potable sources reduced the strength of concrete.

The following types of chemical impurities may be found in concrete:

• air-entraining agents are used to stabilize air: a good option for improving the thawing of concrete after freezing, thereby increasing the service life of concrete;
• water reducers reduce the amount of added water, which also improves the quality of building materials;
• Set retarders help slow down the hydration process. This is convenient in cases where the finished concrete mixture needs to be transported.

Accordingly, in the process of preparing a concrete mixture, you can use components that improve its properties. It is also possible that errors can occur, due to which the material becomes porous and less durable. When creating a concrete anchorage, it is important to ensure that it will withstand the intended loads.

How to choose a dowel

When choosing dowels, it is important to consider the surface material. So, for fastening to drywall, Molly dowels are best suited, and for concrete walls, metal anchors

It goes without saying that when insulating a house you cannot do without umbrella dowels, and when attaching a plaster mesh to a wall, you cannot do without dowel nails (quick installation).

Also, when choosing dowels, it is important to consider whether their surface is galvanized or not. Galvanized dowels will last much longer than usual, they will not rust during operation

It is also important to consider the length of the dowels; it plays an important role when choosing them. However, here you should know not only the thickness of the wall, but also the materials used to make it, how strong and reliable they are, and whether they have voids inside.

Features of fastenings for concrete

When choosing fasteners for concrete structures, you should take into account the possibility of eventually removing the dowel and moving the desired object to another place.

Installing dowels in brick walls differs from working with concrete. Reinforced concrete structures allow the use of nails in the form of rods. For brick, studs, screws or similar tabs are more often used. It is important to consider the length of the fastener, as long lengths make installation difficult. Concrete fasteners are used in a variety of applications and are difficult to find replacements for. Dowels allow you to fix household appliances and interior items: hoods, wall cabinets and shelves.

What types of fastenings are there?

Chemical

This type of fixation is different from the others. The mounting system kit includes metal screws and ampoules with a chemical adhesive. When installing a dowel, the fasteners are not just screwed into the wall, but also glued into it. The glue becomes one with the concrete and it is impossible to tear off the fasteners. If you need to remove it, you will have to knock it out along with part of the wall. The metal rod cannot be used immediately after being inserted into the concrete. Installation takes 2-48 hours, which are necessary for the glue to harden.

Chemical dowels are often used for lightweight concrete. Porous blocks have low density, and even a small pullout force causes the wall to begin to crumble and the fasteners to fall out. For cellular building materials, a chemical version of dowels is also recommended. With its help, the hollow block will not collapse, and the fixed object will remain in place. The disadvantage of chemical fastenings is the installation time. Anchors have become widespread.

Spacer

This type of fastening has proven itself well when fixing heavy objects. All dowel options, except the chemical type, are suitable for solid building materials. Spacer fasteners differ in the shape and size of the insert screws. In most cases, they look like slate, allowing you to hammer the dowel into a concrete wall. The external part of the fastening system is in the form of a tube or cylinder, but other options are available. For fastening, they are equipped with spacers, of which there can be two or three. To ensure that the sleeve stays in the wall better, it is provided with spikes.

Metal nail

For household purposes, polypropylene and nylon dowel-nails are used. They secure objects weighing up to 75 kg. Consumables made of steel are more often used in industry.

Butterfly shaped

A distinctive feature of the fastener is its design. This is a non-expandable consumable, equipped with longitudinal projections that prevent the dowel from turning in the wall. To install the butterfly, you need to drill a hole for the dowel and insert a sleeve into it. During installation, when the screw is screwed in, the back side is rolled up. This is how fixation occurs. The folding ribs with which the fasteners are equipped increase the area of ​​contact with the concrete, and they cling to it like a hook. Typical butterfly sizes are 14x35 and 5x25 mm. These are good dowels for attaching baseboards, shelves and lamps.

Facade nails

Facade consumables are used to create a frame on walls made of brick and concrete. They have a number of properties similar to spacer options, but differ in longer length and larger cap size. The sleeve and the rod attached to it are made of alloys that are resistant to impact. They are used to design thermal insulation structures.

Universal

The fastening system is approved for use in everyday life and in production. It has similar properties to spacer options. The locking mechanism of universal dowels for concrete is similar to “butterflies”. Advantages of fastenings:

GB Mounts

If it is necessary to decorate a wall in which B25 concrete was used, quick-installation dowels with additional collars are used. In addition to concrete slabs, they are suitable for solid bricks and natural stones.

This type of fastening system is used when working with walls made of polystyrene concrete blocks. The main sleeve is similar to the spacer sleeve, but has a spiral shape. GBs have proven themselves well when it is necessary to secure heavy objects. They are used for stable mounting of hanging cabinets, hoods, shelves, household appliances and furniture on walls.

Dowels KVT

Designed to work with aerated concrete structures. A distinctive feature of the consumables is their wide thread, due to which they are securely fixed. Aerated concrete has low strength, since its structure is permeated with air bubbles. A thin anchor nail will not hold in gas and foam concrete, it will begin to loosen and paint the wall. Therefore, for porous materials, dowels and anchors with wide holding parts are needed.

Typical sizes

Let us present the main characteristics of universal products in the form of a table:

Table 1.

Here the lateral load is the weight that the dowel can support. This is a force directed vertically. That is, from the center of the edge of the fastener to the ground.

Materials

Which material is preferable? It would seem that what could be more reliable than metal? The advantages of this material are obvious: strength, durability, ability to withstand heavy loads. However, metal spacer fasteners also have disadvantages. First of all, their high price and, oddly enough, lack of universal use. As a rule, such dowels are used for mounting any structures to brick walls. It is perfect for hanging various large equipment: gas boiler, water heater, heating system elements, sports equipment, grilles, awnings, etc. A special type of metal consumables are frame fasteners designed for fastening window and door frames to brick walls.

In general terms, the design of a metal dowel is quite simple; in fact, it is a tube with an internal thread, at the working end of which slots are made, and its thickness becomes larger.

During the installation process, the dowel is inserted into a prepared hole of the appropriate diameter, and then a pin with an external thread is screwed into it. The pin expands the dowel petals, and they are securely fixed in the hole.

It is much cheaper to make dowels from plastic. This has resulted in a huge variety of plastic expansion dowels. The simplest of them have the same principle as described above for their metal counterparts.

A screw or self-tapping screw is screwed into the plastic sleeve; a special nail with a threaded notch can also be driven in. The introduction of a metal rod leads to expansion of the petals of the structure, which reliably fix the dowel in the material. Plastic dowels for hollow bricks have a special design.

During installation, their petals are twisted into tight “knots”, this helps fix them in voids. Reinforced plastic dowels can easily compete in terms of fastening reliability with some models of metal dowels. The use of plastic consumables is very widespread. From mounting pictures and mirrors to securing heavy equipment.

Material for making fasteners

A dowel for concrete can be made of metal or plastic. Metal guarantees strength and rigidity and has greater load-bearing capacity. Plastic fasteners are not subject to corrosion, have greater elasticity and viscosity, therefore they are easily deformed and even under such influences the fastener is not destroyed.

All plastic pins will burn even after the flame source is removed. Therefore, this type of fastener is not used in fire hazardous facilities.

Plastic dowels for concrete:

• Polyethylene - resistant to acids, lightweight, provide excellent viscosity, are not afraid of deformation, and act as a dielectric. Over time, the material may age and crack. Cold-resistant – fasteners can be used in temperatures down to -40 C.
• Polypropylene - less resistant to cold, but provides greater wear resistance and hardness. The material is resistant to heat - it deforms only at temperatures above +140 C. It can also crack.
• Polyamide (nylon) dowels for concrete are strong, rigid, viscous, resistant to vibration, are not afraid of mechanical damage, and have good wear resistance. Such dowels are considered the most reliable and durable, but have one drawback - they are hygroscopic, and therefore exclude the possibility of installation in frost and high humidity.

Metal dowels for concrete are not much different in structure and shape from plastic fasteners, but are presented in a smaller range. The metal is rigid and durable, but it has less viscosity and elasticity, so it loses its properties when deformed.

Metal dowel-nails for concrete:

• Galvanized and stainless steel are not afraid of corrosion and provide a reliable, rigid connection.
• Special alloys with chromium, titanium, bronze, brass are durable, particularly resistant to corrosion, and are expensive, so they are relevant only for certain cases, particularly important fasteners.

Peculiarities

The dowel for concrete differs from the brick version. It is not used on hollow brick masonry blocks, since in this case the dowel structure cannot provide reliable fastening. The concrete dowel is used for both external and internal work. It is used for fastening small shelves and large-sized structures, used for mounting a suspended frame for the ceiling, mounting for a chandelier, and so on. As a working surface, the dowel can be used for reinforced concrete, polystyrene concrete, and also for cellular foam concrete.

Externally, the mount looks like a plastic sleeve made in the shape of a cylinder, on the surface of which special retaining notches and protrusions are evenly distributed. With their help, the fastener is held within the boundaries of a hole prepared in advance in the material, and does not become loose or fall out. A long self-tapping screw or a special nail made of a durable steel alloy with alloy is inserted inside the cylinder.

Some models of concrete dowels may have a special steel collar or it is made of polymer materials - it protects the working surface of the wall, as well as the prepared hole and increases the strength of the fastening joint. Plastic polymer fasteners are good because they are not subject to corrosion, they do not conduct electric current through themselves, but at the same time they guarantee reliable adhesion to concrete, thanks to the features of their design.

Dowel fastening materials used for concrete surfaces can be completely metallic in composition and are not much different from fasteners made from polymer plastics. However, it is worth noting that the choice of metal fasteners is much smaller than that of their plastic counterparts. In addition, the metal material is considered too rigid, non-plastic and difficult to install, and during installation work this option is often subject to deformation due to improper handling and becomes unusable.

Material for making fasteners

Materials for the manufacture of dowels for concrete can be: plastic; metal. According to the installation method, fasteners can be: driven in with a hammer; install using a construction gun.

Plastic dowel in concrete

The fastener contains a cylindrical rod that expands when a nail is driven into its cavity, which ensures a strong fastening.

• At the upper end there is a cuff that prevents the fasteners from sinking into the pre-drilled hole. The cuff can be cylindrical or hidden.
• There are products with “whisker” spacers to increase the strength of fixation of fasteners in concrete.
• The dowel-nail can have a thread on the surface and a slot on the head. Screwdrivers are used to install such an element. The most common materials used for manufacturing are polyamide, polypropylene or polyethylene. The nail itself uses galvanized steel alloy.
• Plastic fasteners - their price is lower and are used for mounting small items. For heavy structures, their metal analogues are used.

Metal dowel for concrete

This type of fastener has a metal rod with a smooth surface without threads. The part expands when a nail is driven into a hole in the wall.

Tip: It should be borne in mind that metal dowel-nails are quite difficult to dismantle, so they are installed for a long period of use.

Doweled nails are installed when installing suspended ceilings and various metal frames. The greatest strength of fastening can be achieved on solid and hard materials.

Characteristics and types of dowel fasteners for concrete

The classic type of dowel for concrete is a cylindrical plastic sleeve with notches along the entire length and protrusions that prevent the fastener from turning and falling out. It is usually supplemented with a self-tapping screw or nail.

Design of a standard dowel for concrete

In addition to standard dowels, you can now find special chemical fasteners for porous concrete on the construction market. They are fixed in the finished hole by using an adhesive composition that fills all the pores. For their final fixation, it is necessary to wait until the composition hardens. This takes from two hours to a day.

You can also distinguish some other types of dowel elements for concrete:

1. Spacer. It is distinguished from the rest by the size of the screws and the execution of the latter in the form of slate.
2. A dowel-nail made of metal, driven into concrete with a hammer or a special gun.
3. Facade - dowel used for mounting the frame on concrete walls. This fastener is slightly longer than the expansion fastener, and its screw has a larger head. Resistant to material impacts.
4. KVT is a dowel with a wide thread, which allows it to be secured as securely as possible in a wall made of aerated concrete.
5. GB – fasteners for walls made of polystyrene concrete. Its sleeve is similar to a spacer sleeve, but has a spiral structure. Such fasteners will withstand maximum loads.

Variety of dowels for concrete

A dowel for concrete has a lot of differences from a similar one for brick. It is important to choose the right fasteners, as this affects the installation result. In most cases, a dowel-nail is used for concrete. Self-tapping screws or studs are not suitable here, as when working with brickwork. Thanks to the ability to easily hammer a nail into a concrete base, you can quickly and efficiently complete the job.

Dowel fastening for concrete is such a universal option that it is sometimes difficult to describe all areas of its application. It is used during repairs for attaching wall cabinets, hoods, curtain rods, TV brackets, household appliances and for solving other problems.

Application area

Wall shelves are attached to the wall using dowels.

The use of this type of fastener is advisable in various fields. It is an important part that is difficult to find a replacement for. When renovating an apartment, many household appliances and interior items - hoods, wall cabinets, kitchen furniture - must be hung and mounted on the wall. They are held in place thanks to the use of dowels - reliable mounting elements.

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What is a classic dowel?

The classic dowel for concrete and other solid materials has been preferred by specialists in the field of construction and repair for a long time. Consumers often call it a “dowel-nail.” Concrete fasteners can be made of metal, nylon and various types of plastic. Naturally, products made from different materials differ in their characteristics and, accordingly, in their area of ​​application.

Polypropylene dowel-nail with a hidden side

The load-bearing capacity of a dowel on concrete is determined by its design features. In the classic design, a dowel-nail is a sleeve, the entire outer surface of which has special notches that prevent such an element from turning in a hole in a wall or in any other building structure. Special whiskers, which, due to their elasticity, are constantly in a decompressed state, help prevent the fastening element from being pulled out of the wall. When a screw is screwed in, the fastening element expands due to longitudinal slots on its surface, which ensures high reliability of its fixation.

Parameters of dowel-nails with a mushroom-shaped edge used for through installation (click to enlarge)

In addition to dowel fasteners, which operate on a mechanical principle, the modern market offers dowels for porous concrete and other similar materials, fixed in the holes through the use of a special adhesive composition. By filling the internal cavities of the porous material, the adhesive composition reliably fixes such an anchor element in a previously prepared hole.

The classic dowel-nail intended for concrete is such a universal fastener that it is quite difficult to list all the areas of its application. With its help, they install frames for various purposes, attach furniture and interior items to the surface of walls, fix household appliances at the required installation location, and also solve a whole list of other important tasks.

Metal driven dowel nails can be made of steel or aluminum alloys

This is interesting: How to easily remove an anchor bolt from a wall: basic techniques

What is a dowel-nail

A dowel-nail is a metal fastener that is hammered or screwed into a plastic or metal body. The installation process looks like this:

• A hole is drilled in the material.
• Insert a bushing into the hole.
• They hammer a nail inside.

The expansion mechanism expands and the fastener gets stuck in the concrete or brick. This results in a reliable connection. It does not lose its properties for several years.

The service life depends on the type of materials from which the elements are made and on external conditions. High humidity will cause even a galvanized rod to oxidize, and direct rays of the sun will destroy the plastic sleeve.

If the length of the nail does not exceed 50 mm, then its maximum curvature will be 0.1 mm.

We invite you to watch a video about the types and characteristics of dowels:

The process of driving a dowel

During construction and repair, the dowel with a self-tapping screw or dowel-nail is most in demand; they can be fastened in different materials. In order to properly fix them in the wall, ensuring high-quality fastening, certain conditions must be observed. Only at first glance it seems that driving dowels into the wall is very simple. In order not to damage the material, you must follow the rule that the dowel body should not protrude beyond the edge of the wall surface.

A hole is drilled
A hole is made in the wall with a puncher, and the diameter of the drill must match the size of the dowel sleeve in the cross-section

It is important that the depth of the hole is 0.5 cm greater than the length of the dowel. After the hole is made, it must be cleaned with a long object at hand. To get rid of dust, the hole can be blown out with air or, for example, cleaned with a vacuum cleaner. Then you need to insert the dowel body into the hole and hammer it in until the edge of the part coincides with the surface of the wall. After this, the self-tapping screw is screwed into the plastic base almost all the way

In the version with a nail, the latter is driven in with a hammer. The core, after entering the body of the outer shell of the part, will have a bursting effect on the base in the hole, and it will be almost impossible to pull out the dowel. To install the dowel efficiently, you need to follow all the necessary rules.

Dowel in the hole
It must be taken into account that the core must be twisted and not driven in with a hammer. Otherwise, the bushing may rupture and lose its fastening properties. This statement is only suitable for dowels whose core is a self-tapping screw. The nail must be driven in with a hammer until it stops.

Watch an illustrative video on installing a dowel-nail:

Installation features

To drive a dowel into a concrete wall, it is not necessary to invite craftsmen. You can do everything yourself. You will need the following tools and materials: the dowel itself of a certain design, a sharp nail, an electric drill and a Pobedit drill (you can use a hammer drill), electrical tape, a small hammer.

The main stages of fastening:

• The installation location is planned after careful design.
• Using a hacksaw, nail or anything else, make a small indentation in the marked area.
• A drill bit for an electric drill of the appropriate diameter is selected - it must exactly match the size of the screw and the required hole for it. The dowels must be inserted into the hole with force in order to securely fasten inside. It is advisable to make a mark on the drill with a piece of electrical tape along the depth of the hole with a small margin to limit drilling. The drill must be strictly perpendicular to the surface. A hole is made.
• You need to remove dust, debris, crumbs from the hole - it is better to do this with a vacuum cleaner, but you can use anything.
• Next, a plastic or metal dowel for concrete is carefully installed into the hole, driven with a hammer to the maximum stop with strong, precise movements, and a screw is screwed into it (if screws are supposed to be included in the construction kit).

How to drive a dowel nail into a concrete wall

The need to hammer a nail into a wall appears not only where repairs are being carried out. You may need to drive a nail to attach mirrors, paintings, framed photos, hanging furniture, electrical appliances, appliances, etc.

Any standard fastening requires the presence of two elements: a plastic dowel and a metal screw. Regardless of the purpose of the fastener, both elements are important because they complement each other well: there is no point in a dowel without a screw, and a self-tapping screw without a dowel will simply easily fly out of a solid base, since nothing will hold it there. The self-tapping screw is screwed into soft plastic and such fasteners are reliable and durable.

Before driving a nail into a concrete wall without a drill or using a special tool, you need to accurately mark the wall. To do this, choose a suitable place and make a cross with a pencil. You need to make a bag from a sheet of thick paper, attach it to the wall a few centimeters below the mark with masking tape - such a simple design will protect against the spread of dust throughout the room.

Next, you need to drill a hole in the wall with a hammer drill and a drill of the required size. For a brick wall, it is better to choose a powerful drill. The tool is installed strictly perpendicular to the base, a hole of the required depth is drilled so that the dowel can be completely buried in the material. If you don't drill enough, the dowel will stick out; if you drill too much, the plastic stopper may tear or fall through when driven in.

Having received a hole of the required diameter, you should carefully drive the dowel into the wall flush with the surface, then screw in the self-tapping screw, leaving the required length so that the fasteners can be used.

Which dowel for concrete is better?

The following types of dowels are suitable for concrete bases:

• A dowel-nail is a classic sleeve with grooved teeth on the sides, which ensures a tight grip in the hole. Hardware is hammered into the dowel;
• A self-tapping dowel differs in that it is screwed into concrete. Due to its high strength it has excellent load-bearing capacity. It is very difficult to dismantle it from a concrete base;
• expansion dowels – during installation the dowels expand and are driven in with a hammer;
• butterfly dowels – convenient for installing fasteners on thin concrete walls;
• universal dowels - such a dowel is suitable for fastening to almost all monolithic surfaces;
• dowels-nails - driven in with a hammer;
• façade dowel – designed for installation of thermal insulation materials. The design is made of materials resistant to mechanical damage.

What is a spacer dowel?

The expansion dowel is characterized by a metal or plastic sleeve. Moreover, its length can exceed the diameter up to 10 times. Installation of this building element is simple.

To do this, make a hole in the wall by inserting a dowel there. Which serves as the basis for the self-tapping screw.

• The product is manufactured in accordance with GOST 28778-90. The dowel belongs to construction fastenings.
• At the same time, its role in the decoration of interior and exterior spaces is very great.
• After all, thanks to him, necessary objects can be held in hollow spaces.
• All this happens due to spacer wedges in the product.

Polypropylene, nylon and metal are used to produce dowels.

Dowel selection

When choosing dowels for concrete, the operating conditions, expected loads, type of material, and other features of the fastener are taken into account.

How to choose dowels for concrete:

• For heavy structures, choose dowels with a mounting depth of at least 85 millimeters.
• Horizontal fixation requires a fastening depth of at least 30 millimeters, and an external dowel diameter of 7 to 11 millimeters.
• When arranging suspended ceilings and lighting fixtures, where the main load comes from below, fasteners must be made with transverse notches and spacer antennae of different lengths.
• When choosing a dowel for a finished hole, you need to ensure that the diameter (mm) of the fastener and the hole is the same. If the hole diameter is larger and the dowel goes in without force, the fastener may become loose.
• In weak walls, dowels act as a softening pad. The fastener must fit tightly to the fastener so that the load is distributed evenly throughout the product.
• Depending on the load, the sizes of dowel nails for concrete are chosen - the larger the diameter and length, the more reliable the fastening. The exact parameters can be viewed in special tables or in the product labeling.
• For old concrete, it is better to use universal fastening, since there may be voids in the monolith.

Selection rules

Before purchasing dowel fasteners, you need to find out what surface it will be mounted on.
An important parameter when choosing is the diameter and length of the fastener. The larger they are, the greater the load it can withstand. It also takes into account the thickness, surface density and the presence of voids. For example, for a plinth, the most popular universal dowels with a diameter of 0.6 centimeters and a length of up to 8 centimeters are suitable. This is one of the reliable mounts, but if the structure needs to be dismantled, problems may arise. It must be remembered that before installation, all the necessary markings are applied for mounting on the wall and under the holes on the baseboard, which will later be drilled in advance. The diameter of the holes must be equal to the diameter of the dowel.

For a toilet with small dimensions, installation using dowels will be the most practical option. Rubber washers or gaskets should be included with the hardware. Here you also need to measure the surface and mark where the fasteners will be inserted. Next, a hole is drilled in the tile with a drill, and then in the concrete with a construction hammer. Façade specimens are suitable for insulation and polystyrene foam; at their base there is a special serrated groove, thanks to which the dowel-nail is securely attached to the base.

As a fastener for a TV, for a wall-mounted hallway, for hanging a kitchen, shelves and other furniture that will be installed in a vertical plane, it is better to use metal nails for aerated concrete or frame ones.

In the next video you will learn about the types, characteristics and features of installing dowel-nails.

Types of dowels

Before driving a dowel-nail into a concrete wall, you need to carefully study the designs and features of all existing fasteners in order to choose the only correct option. The most effective and popular are: spacer, chemical, facade, nail, butterfly, KVT, universal, GB, etc. There are self-tapping screws for concrete without dowels.

Classic

This design consists of a plastic sleeve with notches along the entire length and antennae, as well as a special rod inserted into it, which guarantees the strength and reliability of the fastener. When the rod is driven into the sleeve, the plastic expands in the hole, ensuring high-quality fastening.

Self-tapping screw in concrete without dowel

The self-tapping dowel for concrete is made with a variable thread that is screwed directly into the monolith. First, as usual, a hole of a smaller diameter is drilled, then the dowel is tightened, during which the variable notch expands the cavity, and the thread secures the self-tapping screw.

The fasteners are distinguished by high load-bearing capacity, strength, and are very difficult to dismantle, and therefore belong to the type of stationary fasteners.

Spacer

This dowel is suitable for fastening rigid structures - usually made in the form of slate, driven into the monolith with a hammer. The fasteners may also be different (in the form of a cylinder or tubular shape), there may be 2-3 spacers, with spikes. The connection is strong, suitable for loose materials with voids.

Butterfly

This option is suitable when fastening with dowels and nails to a concrete wall that is very thin. The sleeve is attached to the hole, and its back side is folded during the process of inserting the screw into the concrete, which securely fixes the dowel.

Universal

Universal metal dowels for concrete resemble spacer dowels. In hollow walls, during the process of screwing in the nail, the sleeve is wrapped into a knot, securing the fastener in a “butterfly” fashion. The same fastening can be used for a variety of types of monolith.

Nail

Regular fasteners are simply driven into the wall with a hammer or a special gun.

Facade

Used for installation of various thermal insulation structures. Similar to a spacer, but has a longer length and a larger cap. The rod and sleeve are made of impact-resistant materials.

Chemical

This type of fastener is different from all others. The structure contains a capsule with glue and a metal screw. Usually such fasteners are used for aerated concrete.

First, a capsule corresponding to its size is inserted into the hole, broken, an adhesive substance comes out of it, and a metal rod is inserted into it.

KVT

Relevant only for aerated concrete monoliths. It has a wide thread, which guarantees high-quality fastening in porous structures.

G.B.

Typically, such products are used when working with polystyrene concrete blocks. The sleeve is somewhat reminiscent of a spacer sleeve, but is made in the form of a spiral. The dowel is capable of withstanding heavy loads, so it can be used for fastening hoods, hanging cabinets, various types of shelves and household items with heavy weight, and equipment.

We take into account what we will attach

Some building materials and structures cannot be fastened with conventional dowels. They require special, highly specialized fasteners, otherwise all the work may go down the drain. Let's look at such examples.

Thermal insulation and waterproofing

The most common option is a mushroom dowel (plate-shaped). Its large head allows you to attach polystyrene, polystyrene and other similar materials as firmly as possible and at the same time accurately.

Plastic or metal nails can be supplied with these dowels. Fasteners with plastic nails are suitable for lightweight structures and do not place unnecessary load on the wall. Its main advantage is that it is not subject to corrosion, so it can serve for a very long time. In addition, it has low thermal conductivity, so heat loss will be minimal.

Dowel dowels with metal nails can support more weight. Unlike plastic ones, they do not break or bend during installation. However, they are susceptible to corrosion and can freeze. dowels with a thermal cover were developed . They are distinguished from standard ones by the presence of a plastic plug that protects the nail from cold and moisture.

Facade profiles, brackets, battens, etc.

Typically , anchor or façade dowels . They can be installed in concrete, hollow and solid bricks, foam concrete, etc. Due to their design, they provide reliable fastening even for heavy materials.

Cables and wires

Dowel clamps are suitable - plastic staples with teeth at the ends. These teeth securely hold the dowel in the wall, and the clamp securely fixes the wire. Working with such dowels is very simple: no need to use nails.

Painting, photo frame, decor

Nail or screw?

Both options are similar in design. Consist of a rod and a sleeve. But there is a difference. This is a fixation method. The dowel-nail is driven in with a hammer, and the dowel-screw is screwed in with a screwdriver or electric tool. Let's consider the performance characteristics:

Dowel screw:

• Long installation.
• Easy dismantling.
• Reliable fastening.
• It is difficult to damage the facade.

Dowel nail:

• Quick installation.
• Difficult to pull out.
• Average holding power.
• Risk of disruption of the facial surface.

By working with nails, you can finish a renovation or construction project sooner. But there is a danger of damaging the front part of the material, for example, with a strong blow from a hammer. The screws hold tightly in the dowel, but take a lot of time to tighten.

Dowel

The part is a spiral-shaped bushing with ribs on the surface. At the moment the screw is screwed in, they expand, due to which they firmly fit into the soft surface of the base. Such fasteners can be made of galvanized steel or plastic.

The first option is the most common and is considered the most expensive. It is used when installing profiles, installing attachments and furniture, and fixing various pipelines. Such fasteners have become widespread in fire-hazardous spaces.

Metal dowels for aerated concrete are produced in 2 modifications, which differ in design features and installation methods. The parts can either be screwed into the base or driven into it. The latter option is used if the aerated concrete floor is planned to be equipped with a collet.

Based on the shape of the fixation ribs, fasteners with a classic helical spiral and dowels in the form of a cone, equipped with spiral blades, are distinguished. The design of metal elements also provides for the presence of a locking flange or cuff, thanks to which the part will not rotate.

Corrosion resistance is the main advantage of plastic products. The materials used for them are polypropylene and polyethylene. The positive characteristics of the parts include their efficiency, environmental friendliness, and immunity to aggressive environments. Such dowels are not intended for outdoor work, since with the onset of cold weather the plastic may burst.

A separate group consists of fasteners for aerated concrete made of nylon. They are more wear-resistant, so they can be used for cladding facades. Together with them, galvanized screw elements with 2 types of heads are used - countersunk or hexagonal. The disadvantage of this type of fastening is the high price.

Depending on the scope of application, there are several types of dowels:

1. Universal. It can be mounted in any concrete surface. In a solid base, fixation occurs in a standard way. In a cellular coating, the product is rolled into a persistent knot. However, the load-bearing capacity of universal dowels is lower than that of spacer elements.
2. A dowel-nail that has a wide range of applications. At the moment of fixation, a nail is inserted into the fastener, rather than a screw being screwed in. In order to avoid turning the part, use a sleeve.
3. The “pancake-like” structure of the frame dowels allows you to reduce the load on the porous surface of the block.

Features of dismantling

When choosing which dowel is good and which is not suitable for the task at hand, it is necessary to take into account the possibility of dismantling. If there is a possibility that the mount will need to be removed in the future, it is advisable to think about this before installing it.

To quickly and correctly perform dismantling, you will need a variety of tools that are usually in the arsenal of any master. Some types of dowels (chemical, for example) cannot be dismantled).

How to dismantle the dowel:

• To remove an ordinary plastic dowel, it is enough to find a self-tapping screw of the appropriate size. The self-tapping screw is screwed 2/3 into the dowel itself, the screw head is carefully clamped with pliers, then pulled out of the monolith together with the dowel. In some cases, a corkscrew will be enough.
• The head of the self-tapping screw, which is inserted into the dowel, can be pryed off with a nail puller. Here you need to ensure that the working part of the screw fits tightly in the hole itself.
• Homemade wooden dowels are removed in parts - first, a piece of wood is crushed (easiest along the grain) into separate pieces using a chisel (preferably with a thin blade) and a hammer. After the dowel is destroyed, it is pryed with an awl, a sharp knife or a nail and pulled out of the socket.
• In some cases, it is easier not to dismantle a dowel that sits firmly in the monolith at all - it is better to cut off the part that comes to the surface, carefully cover the recess with plaster and carefully level it.
• If part of the screw is stuck in the dowel, you will need a heated soldering iron. First, the plastic base of the dowel carefully melts, then the piece of fastener is pryed off with round nose pliers or wire cutters and removed.
• A metal dowel, which was hammered into concrete with a construction gun, is first treated with strong frequent blows of a hammer, affecting the protruding part of the product from different sides. Typically the anchor will become loose during the process and can be easily removed. If it is difficult to loosen, you can make a recess nearby with a drill with a carbide tip or a metal punch. Thanks to the circular funnel, the area of ​​contact between the fastener and the wall will be reduced, making it easier to remove.

Dowels for concrete today in the construction market of Moscow and the region and other regions are presented in a wide variety, so finding fasteners that exactly meet the requirements and operating conditions is not difficult. The main thing is to choose reliable suppliers and focus on product quality.

How to pull a chopstick out of the wall?

Nowadays, plastic dowels are widely used, which are considered stronger, more durable and reliable. However, some people still use wooden dowels instead of plastic dowels the old fashioned way.

The difference in dismantling plastic and wooden dowels is not so great. You can also try screwing a self-tapping screw into it and pulling it out with pliers, a nail puller, or another suitable tool at hand.

Another popular way to get rid of a wooden dowel is to break it apart and pull it out piece by piece. Using a chisel and hammer, divide the dowel along the grain into several parts, then pick out the fragments using a knife or screwdriver.

You can also try drilling out the cap using a drill. However, if the chopik was made of hard wood, this process will take quite a long time. Instead of a drill, you can use a hammer drill if you have one. However, do not overdo it, otherwise you will end up with holes in the wall that are much larger in diameter than you would like.

Types of fasteners for hollow materials

But do not think that such materials are too fragile. You can even lay various types of communications through them.

A large number of different fasteners have been invented and created for this building material. For example, this is a dowel for hollow bricks. And this is just one of the types. There are many types of fasteners. Below we will look at the features of each of them.

Which one is better to use?

It can be difficult to determine which type of dowel fastener is best suited for certain jobs, primarily due to the enormous variety. When purchasing dowels, of course, it is always advisable to consult the store so that you do not have to go to the store again. Let's try to give general recommendations. For solid brick, almost the same dowels are suitable as those recommended for concrete. If the walls are made of such material, you can say that you are in luck. Most universal dowels will work just fine. You can securely secure even heavy and bulky objects, not to mention shelves and cabinets.

It's a completely different matter if the brick is hollow. For hollow bricks, most universal dowels are completely unsuitable. Driving a dowel-nail into such a wall is dangerous, as it can cause the formation of cracks not only on the surface, but also in the partitions inside the brick; in this case, it will be simply impossible to fix anything in the same place, and the hole in the wall will have to be repaired.

For slotted and hollow bricks, special plastic dowels that roll into a knot are required, or metal anchors with petals that rest against the partition from the inside. You should work with such consumables very carefully, since, unlike solid bricks, those with voids are usually more fragile. Facing bricks, which combine strength with some decorativeness, require special care. The appearance of chips and cracks in this case is simply unacceptable. It is also important to remember that such bricks usually have voids to reduce their weight, which greatly limits the use of some anchors and dowel-nails.

For facing porous bricks, it is preferable to use elongated plastic dowels, which during installation form complex units that can securely fix them in the voids of such structures. The fasteners for red and sand-lime bricks are somewhat different. Red is usually softer, and there is a danger of turning the dowel in the hole if the diameter of the drill is incorrectly selected or during the drilling process the master failed to maintain the perpendicularity and the hole turned out to be slightly larger.

Sand-lime brick is more tolerant of minor flaws during installation.