Dowels for timber: types, advantages and features of use. Dowels for timber: step-by-step manufacturing instructions Which dowels are better than wooden metal dowels

Although “nail” means “nail” in German, it is a slightly different type of fastener. Unlike screws and screws in joints, it weakly resists external pressure, working more on shear and preventing bending of structures. Usually used during construction wooden structures from logs, timber or boards.

What is

Pins differ from most types of fasteners: they have no heads, no threads. Externally, these are straight wooden or metal pins 12–15 cm long and with a diameter of 10 to 30 mm. They are intended for working with wood, although there are pins for concrete structures. Rods placed in the drilled holes prevent horizontal movement of the fragments.

Wood tends to change in volume with fluctuations in temperature or humidity. This is especially true for fresh materials. Depending on the structure, timber or logs can increase or decrease in size. As soon as the wood fragments begin to move apart, the surface of their contact with the dowels increases: the pins bend slightly under pressure, and the resistance to further movement increases. When the wood dries out, the pin stops experiencing high pressure and again returns to the starting position.

To ensure that the fasteners are not destroyed during operation, it is necessary to correctly select the dowels, matching the diameter with the holes in the wood. As a result, the walls remain smooth and deformation does not occur. Dowel connections are more flexible than those provided by nails. Fastenings prevent the buildings from loosening and moving.

Kinds

Since dowels are used primarily for working with wood, they are often made from wood. Metal rods are also used. One or more types of fasteners from different materials are allowed.

Wood dowels

Wooden dowels or dowels are rods with a smooth cylindrical surface. Their cross-sectional diameter is from 10 to 35 mm. The length can be any: up to 1.5 m or more. When hammering into logs, pieces of 10–15 cm are usually used. Fasteners made from thin edged square or rectangular section. The best raw materials for the production of dowels are hard rocks: or . Due to the relative high cost of these materials, or is more often used. Coniferous species are not suitable for these purposes due to their flexibility. Dowels are turned only from dry material with a moisture content not exceeding 12%. Used for working with both soft and hard wood.

Advantages of wooden dowels:

Wooden dowels are suitable for building boats, rafts, outbuildings, bathhouses, one-story houses from logs, street furniture and other wood structures.

Disadvantages of wooden pins:

• low biostability;
• susceptibility to destruction;
• inability to withstand high blood pressure.

This type of fastener does not so much tighten structural fragments as serve as an embedded element, ensuring stability relative to each other. Working with wooden dowels takes a lot of time, requires certain skills, and is quite difficult to perform.

Dowels round shape create better adhesion to the surface, it is recommended to use it during construction load-bearing walls. Square fasteners are less durable, since they only rest against the material at the corners. It is used when assembling lightweight parts or walls that do not experience massive loads.

Metal dowels

To provide a more rigid connection that can withstand high loads, a material stronger than wood pins is required. When building walls of large structures, metal rods are used to fasten logs together. The production of a similar dowel from steel is almost impossible due to the high cost - dowel fasteners with a diameter of 25–30 mm for the construction managed at home would be several hundred thousand rubles. Iron rods of such volume serve as powerful bridges of cold when the temperature drops.

Greater strength than beech or birch dowels, metal rods can be used when working not only with wood, but also with concrete structures.

Metal dowels have more options by size and configuration, depending on the purpose:

• rods that are hollow inside round section resemble wooden dowels in shape, but have a smaller diameter;
• plate ones are designed for fastening several logs at once;
• hexagonal or star-shaped rods - fasteners special purpose, rarely used;
• spring-loaded screws: a type of galvanized self-tapping screws with a diameter of 10 mm, a length of 20 to 28 cm, the design of the fasteners involves the use of springs clamped with washers, which allows the elements to withstand a load at the joints of more than 150 kg per 1 cm²;
• U-shaped hardened staples and pins are used to tighten and secure logs from the end sides;
• dowels for working on concrete have the form of screws with variable threads, with a diameter of 7.5 mm, a length from 70 to 200 mm. They are screwed into the canvas with impact screwdrivers; pre-drilling of the material is not required when working with them.

Often during construction, ordinary pieces of reinforcement or pipes with a diameter of 10–12 mm are used as dowels.

Metal fasteners are stronger and more durable, stable, prevent warping of wood, and do not fall out drilled holes. The variety of forms of dowels produced allows you to choose them for any type of screed. The disadvantage of metal products is that the fastening is too rigid. Because of this, beams and logs can hang for some time, and cracks appear between them. Iron corrugated pins often split and spoil the surface of the wood; the difference in thermal conductivity leads to the accumulation of condensation.

Manufacturing

Industrial wooden dowel is produced from dry material of the highest or first grade, which does not contain twists or knots. The structure of the finished fastener must be completely homogeneous. The parameters of industrial pins are regulated conditionally.

Common sizes:

• diameter 20, 25, 30 mm;
• length 120, 150 mm.

According to GOST, during work the diameter of the dowels should be ⅙ of the diameter of the log. Pins standard length used to connect two logs; to connect several logs, longer dowels are required.

Upon completion of manufacturing, the dowels are treated with antiseptics.

In the presence of suitable wood Dowels can be turned yourself at home on a woodworking machine. Fasteners made in this way can have any parameters. It is recommended to make it long and later cut it as needed. It is better to use well-dried non-hygroscopic material.

Square dowels are made simply: the board is sawn along the grain into long bars 20–30 mm in diameter, and the edges of the segments are polished.

To obtain rounded pins, square bars are slightly larger required size fixed in a lathe and turned with a cutter. During the process, the specified diameter is checked several times with a caliper, otherwise there is a risk of excessively thinning the material. The sharpened bars are cut and chamfered at the ends of the pins.

Installation features

It must be remembered that the dowels must be stronger than the material being connected. For example, larch pins are suitable for fastening pine logs, and birch wood must be fastened at least heavy material: birch or oak. The logs and fasteners must be of the same degree of dryness, otherwise the mechanism for changing pressure and bending will be disrupted and the fasteners will crack.

Building a bathhouse or log house for a house alone is problematic. To work with dowels, you need to involve several workers.

Basic requirements to be observed during installation:

1. Holes in the central parts of the crowns are drilled strictly vertically - along the axis of the walls. The top log is usually stitched through, and the underlying log is stitched through ½ of its thickness. In cases where long dowel connections are used, 3 logs are drilled at once. The diameter of the holes should be such that the pins do not enter freely, but also do not get stuck, and penetrate with little resistance.
2. For the first hole, approximately 40–50 cm are removed from the corners of the building; further holes are made every 1.5–2 meters. At the next level they should be staggered.
3. The depth of the holes should exceed the length of the pins by 2–3 cm. This feature will protect the beams from hanging during seasonal swelling, and the dowels from deformation and destruction.
4. When hammering in fasteners, it is advisable to use a wooden mallet rather than a hammer, carefully driving the pins in with it.

The greatest difficulty in assembling timber structures is the correct direction or size of the holes to be made. Inexperienced builders often end up with them bent or not matching the diameter of the dowels. Execute correct connections in such cases it can be problematic.

Let's talk about dowels, which are widely used in construction. wooden houses from logs and beams. This special kind fastenings, the rules for choosing and using which you should know in order to build a reliable and durable house. Let's talk about the types of dowels and the cost of this type of fastener.

It is noteworthy that, despite German name(“dowel” translated into Russian simply means “big nail”), this type of fastening has become widespread in Russia. However, dowels were also used and are being used in Europe, because wooden house construction is also popular in Western countries.

Despite the name, the dowel bears little resemblance to a nail. It is more like a pin, without a point or head, smooth, even, very simple, but at the same time reliable and ideal for wooden houses, a type of fastening of individual beams and logs.

Pins and edgings can be not only wooden, but also metal and plastic. The latter variety is rare, as it is quite unreliable. Metal dowels in the form of an ordinary rod, string or pipe are most often used in the form of fittings and fastenings for concrete structures, but in wooden house construction they are used with caution. There are several reasons for this:

• The metal has high thermal conductivity. If a metal dowel is used to connect wooden parts, a cold bridge is guaranteed to appear;
• Due to the difference in the thermal conductivity of wood and metal, condensation will appear at the place of such a connection, and it will cause dampness in the wall;
• A metal pin may damage the wood;
• The metal holds the wood too tightly and rigidly, and we all remember that wooden houses shrink significantly.

Now such dowels are given a special position - screws for concrete, and in the construction of houses made of logs and timber, wooden dowels are used, which we will continue to talk about.

Why did wooden dowels become so popular? Because the technology was tested many centuries ago on wooden boats. Impact wood fastening sea ​​water did not rust, on the contrary, it expanded and sealed the hole, there were no leaks. After such testing in the open waters, wooden dowels deservedly became widespread in construction and on land.

We wrote about the process of installing wooden dowels. Let us remember that small fasteners of this kind are called dowels and are used during furniture assembly.

The most common wood dowels are round, but square ones are also used. It is believed that such pins smaller area contact with the hole area, and this reduces the risk of rigid fastening of the log. There are pins in the shape of a hexagon, as an intermediate option, and also in the shape of a star, but they are extremely rare.

When using wooden dowels, it is very important to remember two conditions:

1. The dowel should be slightly smaller in diameter than the hole pre-drilled in the log or timber. In addition, the fastener should be slightly shorter than the hole. Only in this case will the wooden dowel ensure smooth shrinkage wooden house, will change dimensions along with it, otherwise the crowns may hang on the mounts;
2. The wood for the dowel must be stronger than the timber or log itself. If pine is used to build a house, then the dowel should be made of more durable wood, for example, beech or birch. Larch, oak, and ash are also used to produce dowels.

According to SNiP, during the manufacture of dowels, wood from the first or premium, without curls, knots and other wood defects. The moisture level of raw materials should not exceed 12%. It is advisable to treat the dowels with antiseptics.

There is GOST 30974-2002, which states that the diameter of the dowel must be at least 1/6 of the diameter of the log. That is, if we have a log with a diameter of less than 140 mm, then we need a dowel with a diameter of 22-25 mm. In this case, the length of the dowels is not regulated. Usually they take fasteners with a length of 120-150 mm.

As for the price, one birch dowel with a diameter of 22 or 25 mm and a length of 1.2 m costs about 18-20 rubles. One meter of oak dowel with a diameter of 21-25 mm costs about 32 rubles. Usually the fastening is sawed off the right size already at the site of construction of a log house or a house made of timber.

To build a house from timber, special guide elements made of wood or metal - dowels - are used.

Nagel is a small fastener, which can be either round or square in cross-section. Used when building a log house or bathhouse with materials of natural moisture.

Since the log house dries and shrinks for 12 months or more, with dowels it will not deform and will not move.

Description

Despite the fact that fastening options are different, dowels are most often chosen from wood. For this purpose, hardwood forest is used, often birch.

Sometimes reinforcement or pipes are used in construction, but the fact is that metal is too hard a material, and it does not give the natural shrinkage that a wooden dowel can give. It allows more flexibility for the walls.

In addition, the wood is not subject to rust, and even when wet it does not deteriorate, but rather provides better adhesion to the neighboring material.

Under no circumstances should you use screws or nails. They will only worsen the entire structure

The dowel is made slightly shorter than the hole drilled in the beams and of a slightly smaller diameter so that shrinkage occurs more evenly.

This design captures two beams at once and is installed around the perimeter in a checkerboard pattern.

What are they needed for

The fastener allows you to fasten the crowns to each other exactly along a given path. Some people think that the dowels tighten the frame of the house together, but this is not so. They make it possible, when drying and shrinking the timber, to keep it in its original state so that the structure does not move.

This installation method is used not only in the construction of houses, but also in the manufacture of furniture.

What negative consequences can the dowel combat:

• Drying and deformation.
• Loosening and displacement.

When installing fasteners, the structure remains stable and stable even after several decades. The main thing is to do it right.

Types and sizes of dowels

Pins come in round, square and rectangular sections. Naturally, they are most in demand round shapes, because it is very difficult to drill a hole for a square.

Kinds:

• Made of wood.
• Metal.

Metal - durable, but expensive

If preference is given to metal, then it can be either hollow inside or made of reinforcement, but it is difficult for a beginner to work with such material, and expensive timber can be damaged. Therefore, wood fasteners are increasingly preferred.

In addition, there is a special spring unit “Strength”, which is also used as a dowel. However, its cost is quite high, and the house can cost a decent amount. (On average this is 46 thousand for a house measuring 6x6)

Why is it still a tree?

The finished material should not be made from raw wood and it is better if it is impregnated special composition from rotting. Otherwise, it will have to be dried. You cannot work with raw material; it must be harder and drier than timber.

Prices

Prices for these products depend on the diameter of the fastener. A lot depends on the volume of purchase, but on average:

• Dowels with a diameter of 25 mm up to 500 pieces will cost 16 rubles, and up to 1000 pieces will cost 11 rubles.
• If the diameter is chosen to be 30 mm, then the prices will accordingly be 25 rubles for 500 pieces and 18 rubles for 1000 pieces.

When purchasing in bulk, prices are reduced by up to 30%, but this is more suitable for construction companies. In one package finished products There are from 30 to 50 pieces of dowels.

Making dowels

• If necessary, you can turn them yourself on a lathe from premium or first grade wood.
• Please note that it is without large quantity knots and damage.
• Do not make dowels from hygroscopic material.
• The diameter of this rod must be greater than 2.5 cm.
• The length can be arbitrary, from 1.5 to 2 meters, in any case only part of the product is used.

Step-by-step guide to making from wood

To make dowels you need lathe and cutters of the required configuration. After which a suitable material is selected.

Manufacturing process:

1. The workpiece is selected required diameter and size.
2. Attached to the machine.
3. Using a cutter, the desired rounded shape is given.
4. It is necessary to constantly measure the diameter of the workpiece being turned with a caliper so as not to remove excess material.
5. The workpiece is cut to length and chamfered.
6. We repeat the same action with the other part.

You can make it even simpler - cut the board on a sawmill into thin blocks measuring 25x25 mm. Then use square dowels for construction.

How to use dowels when building a house from timber

• The dowel must not be hammered in completely to prevent cracks in the timber.
• The holes in the upper crown for fasteners should be slightly wider, this will prevent the beam from sagging.
• The pin itself must fit into the hole freely; this is necessary for the wood to shrink.
• The holes for them are drilled perpendicular to the surface and located along the axis of the beam.
• The distance between the pin fastenings is calculated according to the construction documentation.

Advantages of fasteners:

• Reliable grip and structural integrity.
• Ability to resist shrinkage and natural phenomena.
• Long service life of the house.
• Minimizing gaps between timber.

How to install correctly (drilling and fastening)

The number of fasteners is calculated based on the principle of 2 meters between each subsequent fastening.

To secure the timber with dowels you need to:

• Drill a hole along the diameter of the fastener to a depth of 1.5 times the size of the timber.
• The dowel should be 30 or 40 mm shorter than the depth; it is driven into this hole by 10 mm. A distance of 30 mm in the lower of the two beams will be needed for possible shrinkage so that the beam does not hang.
• We hammer in a checkerboard pattern, the distance is from 1 thousand to 1.5 mm.
• The distance from openings or bowls must be at least 300 mm.
• The moisture content of the fasteners should best be the same as the wall material.

Advantages and disadvantages of fastening timber with dowels

Dowels, like other fasteners, have their advantages and disadvantages.

The advantages include:

• The dowel prevents the crowns from sagging.
• It does not corrode like metal.
• They are more suitable for the construction of a residential building than for a log house for a country house.
• They work better in bending than nails or reinforcement.

However, there are also disadvantages:

• The assembly of the log house will be slower.
• An incorrect selection of sections will not ensure the strength of the structure, and a larger one can lead to the destruction of the timber.
• Without the proper skills, it is difficult to work with dowels; it is difficult to align the fastener with the hole; the help of 2-3 people is required.
• A lot depends on the quality of the product itself, which must be knot-free, impregnated and non-hygroscopic.

Professionals work best with this fastener; single craftsmen are better off using metal.

• Nails, screws and other metal will spoil the wood from the inside, so if possible, it is better to use wood. Otherwise due to different thermal conductivities
• materials, condensation accumulates, and this leads to rust on the fittings and rotting of the wood. It’s not for nothing that ancient ships were built entirely of wood, and examples of architecture speak of the same thing. The temple in Kizhi, built without a single nail, has stood for many centuries, and, nevertheless, is still just as strong. Don’t forget about the staggered order of installing the dowels
• , this is why you need a house design in order to calculate not only the amount of fasteners, but also the location of its installation. To avoid hanging logs and the entire structure of the house, it is better not to use metal and square wooden dowels. Experienced craftsmen It is recommended to use a round one mounting structure
• standard type made of birch. This will allow you to achieve not only strength, but also the beauty of the building as a whole. In addition to dowels, for uniform shrinkage of the log house, you can use such structures as: screw jacks
• and sliding fastening of metal rafters.
• The moisture content of the fasteners must match the moisture content of the timber.

To reduce friction when driving the rods, professionals use a soap solution.

If such work seems too labor-intensive, then it makes sense to turn to professional construction companies specializing in construction. They will help you build a house quickly and competently, and will also be able to guarantee that it will be completed in accordance with all necessary standards.

Due to its high strength and durability, concrete is one of the the best materials for walls, partitions and ceilings. However, it does have some disadvantages. For example, it is inconvenient to install any hanging parts on such enclosing structures - chandeliers, shelves or a regular cornice.

A special solution will help solve this problem. fastener, called a concrete dowel. Inexpensive in price and easy to install, these items will allow you to save a lot of time spent trying to use other methods of fastening to concrete.

Features and purpose

Screws or dowels for concrete are rods with variable threads and sharp tips. As a rule, the product is equipped with a countersunk head with internal notches, to work with which you will need a special bit made in the form of a six-pointed star. The notches allow the screws to stick to the base even more tightly.

Basically, dowels are designed to fasten various designs to substrates such as concrete. Among them are cabinets, frames, door jambs, heating radiators and various communications. However, the same fasteners are also suitable for bricks (solid or hollow). And the reliability of fastening with the help of the product is explained by the unevenness of its thread, which reliably fixes the dowel screw in any suitable surface, including concrete.

Classification of dowels

The main classification according to which they distinguish different kinds dowels, depends on the shape of their heads. There are several other options for separating products, although all of them are of less importance when installing mounted products - the type of fastener coating, size and price.

According to the shape of the head, dowels for concrete are:

• secret, i.e. conical and having cross-shaped slots;
• rectangular or in the form of a hook (loop), sometimes round;
• hexagonal with internal thread and a cross-shaped slot designed for ring and open-end wrenches;
• in the form of a stud having a threaded fitting for a nut.

The features of their installation depend to some extent on the shape of the heads. For example, a dowel ending with a hook or pin can only be installed in pre-drilled holes with a dowel installed. The remaining options can be screwed in without pre-drilling.

For screws with a countersunk or hex head, preparation of landing holes is not required, although this may not be possible for every concrete.

Coverage type

Depending on the type of coating, dowels can be:

• galvanized;
• copper-plated;
• blackened.

The choice of type of dowel coating for concrete depends on how it will be used. The first option has a silver color and is suitable for installation in any place, both outside and inside. Copper-plated screws are used only for interior works. And the blackened dowel is suitable for conditions with low humidity levels and, naturally, cannot be installed either outdoors or in basements.

Despite the fact that each dowel screw has a variable thread (this differs from other fastener options) and the same diameter of 7.5 mm, there are differences in the length of the products.

It varies from 70 to 200 mm (72–202 mm taking into account head dimensions) in 20 mm increments, except for a 30 mm gap between 150 and 180 mm. The length of the screw depends on the length of time it takes to tighten the screw into the wall, and, accordingly, the strength of the product mounted on it.

Cost of materials

The cost of concrete dowels depends mainly on their length and coating parameters. For example, copper-plated products will cost more than blackened ones, and you will have to pay more for 150 mm than for 70 mm. In any case, purchasing screws will not cause much damage to your budget, since the dowel is inexpensive, and for construction work You usually need only a few of these products.

There are only three main stages of installing dowels. This - preparatory work, calculation of the quantity and dimensions of the product and direct installation.

For each of them you should know some features.

Preparatory work

When installing a dowel screw, you cannot do without drilling additional holes. The diameters of such passages in concrete should be approximately 15–20 percent smaller compared to the threaded area of ​​the fastener. After the holes are drilled, they must be cleaned of dust.

Size and quantity calculations

The sizes of concrete dowels are most often selected based on the load they need to withstand. For example, a weight of 100 kg will require the installation of self-tapping screws about 150 mm long. A small shelf weighing up to 10 kg can easily be held by small dowels, the length of which does not exceed 70 millimeters. Not worth hanging new design on dowels designed for hanging a lighter object.

The number of dowels is determined by the distance between them. It is usually taken to be 70–100 mm in each direction. That is, for example, for a cabinet measuring 60x90 mm, you will need to install 4 screws in the corners, and for a structure with sides 120x150 mm - already eight pieces.

Installation

A dowel of the appropriate size is inserted into the hole intended for installing the dowel on concrete. The material for its manufacture can be plastic or wood, and main characteristic– the ability to withstand fasteners and securely fasten in the ceiling or wall. To screw in, you should use a special screwdriver, the parameters of which depend on the shape of the dowel head.

Correctly screwing in the screw will prevent it from breaking off. Therefore, this should be done carefully, without over-tightening. You should also avoid screwing in too quickly, which leads to overheating of the screw head and its destruction.

When ordering a log house made of natural wood, buyers first of all pay attention to the wood from which the building is being erected, the shape and type of timber, and the layout. At the same time, such a detail as connecting materials is missed, while it is this factor that affects the further operational characteristics of the structure. Wooden and metal dowels are used as fastening elements for a wooden house. Which of these options is preferable from the point of view of ensuring optimal qualities object?

Technology for fastening timber in a wooden house

To avoid displacement of logs relative to each other, in addition to fastening “into the bowl” and the shrinkage groove, dowels are used. Their use allows you to ensure the necessary verticality of the walls. The part is a wooden or metal rod that holds adjacent logs from moving. The element is installed in a checkerboard pattern, in increments of approximately 2 m, into pre-drilled holes. The length of the part should be 2-3 cm less seat, the thickness is such as to provide a slight interference fit.

The assembly of timber using dowels is carried out in the following order:

• holes of a given diameter are drilled in the laid timber;
• dowels are driven into the prepared holes to a depth of at least 2 cm;
• the next log is added with holes corresponding to the arrangement of dowels in the previous row.

Metal dowels: pros and cons

Products are pieces of reinforcement of a given length and diameter. They can be smooth or grooved. In some cases, metal bunches are used as pins. The advantages of this type of product include:

• simplicity and speed of installation and, as a result, reduction in the cost of construction;
• strength and durability;
• low price.

The reasons why you should abandon the use of metal fasteners are:

• Heterogeneity of structures. Wood will dry out and become deformed over time, metal will not. When rigidly fastened, the beams forming the wall may “hang” on the reinforcement, or, conversely, begin to dangle.
• Susceptibility to corrosion. Temperature changes, changes in humidity levels lead to rusting of the element and deterioration of the material around it. In the future, brown spots may form on the surface of the log house.

Wooden dowels: time-tested

Traditionally, wooden dowels were used in the construction of log houses. The part was made of wood with high strength - oak, birch, beech. It is recommended to give preference to this fastening option for the following reasons:

• prevention of timber deformation during further operation;
• uniform shrinkage of the walls of the house;
• resistance to warping and temperature changes.

When purchasing a part, you should pay attention to its quality. The wood of the dowel must be well dried and free of traces of mold. Hammer the product into the holes using a mallet.

Which option to choose

Metal dowels are optimally suited in situations where Special attention The focus is on the reliability of the timber tie. To minimize negative influence parts for the structure as a whole, it is recommended to use dowels made of corrosion-resistant steel. The inability of the product to cope with the bending load will be compensated by purchasing dowels of the “spring assembly” type - a fastening element consisting of a bolt with a spring.

In all other cases preference is given wooden connection. It will ensure uniform shrinkage of the entire house, good thermal insulation buildings.