Wooden or metal dowel. Construction dowel - what is it? What are dowels for?

When building a house, everyone inevitably faces issues related to the use of various building materials. Wanting to help you in this important matter, we want to discuss one important aspect - the use of dowels in the construction of cottages and houses from profiled timber, as well as answer the most popular questions from beginners and more experienced builders.

Any wooden houses, even elements wooden log house, made from high-quality profiled timber, under the influence external factors may become deformed during operation. To prevent this from happening, builders use special parts - dowels. In fact, dowels are pins that are mounted perpendicular to the axis of the connected crowns.

The purpose of the dowels is to prevent the house from deforming, as well as to connect adjacent crowns to each other, preventing them from moving and giving the walls of the house greater strength.

Types of dowels

There are several types of dowels, which are classified according to the material from which they are made - plastic, wood and steel - and by shape - lamellar and cylindrical. Most often, builders use wooden dowels with square or round and cylindrical pins made of steel.

Steel dowels are usually made from rebar or pipes. When building houses from timber, it is undesirable to use pins made of reinforcement: they have a corrugated surface on which the timber can simply “hang”, and gaps form between the crowns.

Due to the fact that the load on the dowel mainly acts on bending, when connecting crowns it is better to use wooden dowels rather than steel. They are made from hard wood. Dowels made of birch or oak are considered to be of the highest quality. Most often, Russian builders use square birch pins with a side of 25 mm or round ones with a diameter of 24-25 mm.
IN Lately dowels with a square cross-section are used. They are recommended by world experts - Finnish construction companies, leaders in wooden housing construction. And this is not surprising: such dowels only partially touch the walls of the hole made in the timber, as a result of which the risk of the crown “hanging” on them during the shrinkage period is significantly reduced. But wooden dowels also have their drawback - they do not press the beams against each other, which causes bending of the lightly loaded upper crowns.

Installation of dowels

When mounting the pins, holes are drilled in the beams. They are made strictly perpendicular, in a checkerboard pattern in increments of 150-200 cm. For correct installation dowels, not only location matters drilled holes, but also the humidity of the dowels, which should coincide with the humidity of the profiled timber.

Basic concepts and purpose of dowel

Wood is a material of natural origin with a heterogeneous internal structure. When drying, not only a proportional change in volume occurs, but also some deformation. Its degree is determined relative position fibers tree rings and other factors. As a result, the material shrinks with the formation of gaps between elements, cracking and other unpleasant phenomena.

The dowel for timber is fastener round or square section. It is designed for detachable connection of two adjacent parts. The dowel can be made from hardwood or metal, preferably steel.

The geometric dimensions of the fasteners used must correspond to the timber. Its small cross-section and length will not provide the necessary rigidity of the structure, and too large it can lead to destruction.

The metal dowel can be solid or hollow, and its cross-section, as in the case of wooden dowels, can be square or round. Often, to save money, they are made from available or scrap materials: steel reinforcement, water pipe and rolled metal. Incorrect use This type of fastener can cause damage to such a fairly expensive material as profiled timber.

For dowels, blind holes of the appropriate diameter are drilled in both parts to be connected. The number and location of attachment points is determined in accordance with the requirements of governing documents, in particular SNiP 2.01.07-85. The work uses a special drill for drilling timber for dowels with the necessary fixtures and drills of the required diameter.

Production and use of dowels in the construction of timber houses

Important!
According to the craftsmen, the best material for dowels is birch.

Making dowels from wood

The cylindrical shape of this connecting element represents a classic body of revolution. Accordingly, it is most suitable for its production lathe with a set of corresponding cutters. Lumber dried to a certain moisture content is used as blanks. Preference is given to the outer parts of the trunk, where the density of the wood is higher, which means it can withstand heavy loads.

You can make dowels yourself if you have the necessary equipment in your home workshop.

The order of operations is as follows:

we select a workpiece of suitable size and shape, the wood should not have cracks, deep damage, knots, etc.;
we install it in the receiving device of the machine and carefully secure it in strict accordance with the instructions for use;
we start the engine and use a cutter to give the workpiece a cylindrical shape;

as the chips are removed, we measure the diameter using a caliper;
upon reaching the required indicator, we cut the workpiece to a certain length and make a chamfer; (see also article)
filming ready product from the machine and repeat all the described steps for the next workpiece.

It will take a qualified carpenter only a few minutes to make one dowel, if he has everything he needs. An inexperienced master will spend more time, but practice shows that the necessary skill is acquired quite quickly. Price of products self-made will be minimal.

Advice!
Please note that when working on a lathe, you must wear goggles to protect your eyes from chips.

The use of dowels in the construction of timber walls

The order of operations for assembling houses is determined by technology.

Installation of dowels in timber is carried out as follows:

Attachment point marks are applied to the lower part, their number and the distance between them are calculated in accordance with the regulatory documentation;
the holes for the dowels must be located strictly along the centerline of the beam and be perpendicular to its outer surface;
For drilling, a drill with a drill is used; during operation it should be held with both hands, and the body position should be stable;
It would be optimal to use a tool with a special attachment, which ensures its required position in relation to the beam, this will significantly speed up the work;
the total depth of the holes should be slightly greater than the length of the dowel, which will provide the necessary thermal gap. (see also article)

The assembly of profiled timber on a dowel is carried out as follows:

Connecting elements are inserted into the pre-drilled holes in the lower beam and pressed down using wooden hammer– mallets;
The next prepared part is lifted by two people and an assistant by the edges and turned over with the holes down;
Having aligned the holes with the dowels, the timber is put on them and pushed down until it stops.

Helpful advice!
When performing such an operation as assembling timber onto dowels, it is difficult to ensure alignment of the holes with the fasteners.
To simplify the action, attracting another assistant who will guide the beam with great accuracy will help.
To reduce friction during assembly experienced craftsmen use a soap solution.

Reliable fastening of timber with dowels, however, must also have a certain degree of freedom. When wood dries, a change in shape and a decrease in volume are inevitable, as is thermal expansion when heated. The material is left with a certain degree of freedom to compensate for changes in linear dimensions.

Conclusion

Dowels for hardwood timber are the most best option connecting element for the construction of buildings. They provide the necessary strength of the enclosing structure and prevent warping of its individual elements.

The video in this article will help you get an accurate idea of the manufacturing process and use of this type of fastener.

Nagel - what is it and where is it used? In fact, this word means a pin (fastener) that prevents wall elements from sliding and moving wooden house. A timber structure, no matter how well dried it is, is always subject to deformation and subsidence. Pins are round and rectangular shape, they can be made of either metal or wood.

A dowel installed in a timber wall prevents the logs from rotating during the shrinkage of the house.

The only condition that is mandatory when installing fasteners is that it must be smooth and not have a corrugated surface, potholes or inserts. Its length must be suitable.

Selection and installation

Since the main purpose of the dowel is to hold the beam in the correct position and prevent it from bending, then when choosing a material you need to take into account the nature of the construction. Wood copes best with this task, since the bars on which the pin is attached are also made of wood.

In addition, fasteners made of wood material not so susceptible to changes in shape as a result of sudden temperature changes. They do not rust and do not form condensation due to changes in humidity. Wooden fasteners do not interfere with the planned subsidence of the walls, since they are made of the same material.

Wooden pins and the parts they hold together usually have the same moisture content, which promotes uniform pressure distribution and the natural process of soldering the fasteners into the wall material.

If the beams are made using soft types of wood, for example, pine, it is strongly recommended to use pins of harder species. That is why birch fasteners are now very popular. They are harder than most other types of wood and therefore are used almost universally.

We can conclude that the choice of pin if it is being built wooden house, must be birch. This can guarantee stable behavior of fasteners during sudden fluctuations in weather conditions.

Metal dowels

But metal pins also have their advantages.

Almost all modern construction companies claim that it is impossible to build a reliable wooden house without the use of metal fasteners.

They give the following reasons:

wooden dowels cannot keep the top layers of wood from twisting;
during the process of natural shrinkage, the pins begin to come out of the holes and wobble;
a wooden dowel prevents the normal installation of insulation;
in the case of using wooden fasteners, the possibility of using spring ties, which have proven themselves very well when assembling timber structures, disappears.

The metal dowel can be either solid or empty inside; very often the pins are made right on site from construction waste - pieces of reinforcement and pipes.

You should carefully study the installation technique iron structures so as not to damage the material. You need to keep in mind that too thin pins will dangle in the holes, and too thick ones will lead to cracks and breaks. Dowel for timber - extremely important component construction, this stage must be approached carefully.

Installation of dowels during construction

Most often, when building houses from timber, the first layer is attached to the next one using dowels. Then holes are drilled in the third layer in order to connect it with the previous two. There should be no additional obstacles between the dowels.

When using pins, you must strictly follow these recommendations:

You only need to drill holes for structures vertically, so that the fasteners do not become an obstacle to the natural sliding of the beams;
the distance from the corner must be at least 40 cm;
the hole for the pin must be located strictly in the center of the wooden beam;
Do not apply great force when driving in the dowel to avoid its deformation;
the length of the pin should be 2-3 cm shorter than the depth of the pre-drilled vertical hole (this is necessary so that during the planned natural subsidence, gaps do not form between the beams);
installing wooden pins will help avoid wood torsion and gaps between layers of beams.

In addition, dowels, or dowels, as they are also called, help eliminate causes that may lead to cracks in the wood in the future. The principle of building a house from wooden beams using dowels is very reminiscent of assembling a children's construction set.

Wooden dowels can also be made at home. To do this, you need to take material without knots and cracks, place it in a woodworking machine and use a cutter to give it the required shape. It’s simple, the main thing is not to be afraid to create and build!

Dowel is an element for creating a movable connection between adjacent parts, in particular between beams and logs when building a house. Also found in window production, shipbuilding, etc. Not many people have heard of such a device, but construction is not complete without it. wooden houses and the creation of elements of familiar structures even though these connections are not visible to us.

What you need to know about the dowel

Another name for a dowel is a dowel. The word "nail" is of German origin, meaning "nail", which, in fact, is what it is. “Dowel” came into our speech from Vyatka, where about 300 years ago the active construction of wooden houses from logs began. Even then, carpenters introduced into the usual technology the use of wooden fasteners for the stability of the log house, which are not visible when the structures are assembled.

Initially, the dowel was made of wood, but nowadays fasteners made of wood and steel are used. They serve at facilities with different levels of responsibility, since they can take different loads.

The dowel has a round or square cross-section different sizes, which is determined by calculation.

Making dowels

The best wooden dowel is birch or oak. These types of wood are hard and rigid enough to support a frame of any size. The material must be thoroughly dried, ideally matching the water content of the timber for uniform shrinkage of the volume after assembly. It is recommended to use force-dried wood to reduce the risk of shrinkage causing the joint to weaken.

The square dowel is made using sawing machine strictly according to established sizes, since in the future they will need to make a hole in a beam or log according to similar parameters. Often they use standardized dimensions: for example, they order a log house with ready-made holes for dowels, and order fasteners separately, but of the same cross-section. Matching parameters is necessary for normal and fast work so that products do not have to be adjusted on site.

To make a dowel with a round cross-section, it is rational to use a lathe. With its help, you can make fasteners yourself. For this we use wooden blank of a suitable size, attach it to the turning mechanism of the machine and gradually remove the excess layers of the barrel. In order not to remove excess, we constantly check the diameter of the semi-finished product with a caliper. It is also important that the workpiece is processed evenly along its entire length so that the product can easily fit into the hole prepared for it.

The metal dowel is made of steel different brands and from finished products by casting or rolling. The cross-sectional shape of the product can be different: round, square, polygonal. Steel dowel is more suitable for assembling metal and concrete structures. Made from reinforcement, the fasteners, when wood shrinks, injure the log; mold and rust subsequently develop at the site of loosening, which significantly reduces the load-bearing characteristics of the structure.

Which dowel to choose

The dowel for timber can be metal or wood, square or round. Which one to choose for building a house from logs and timber?

Wood or metal

For logs it is better to use a wooden dowel. Although metal has a large margin of strength, it still rusts over time and spoils the wood. Humidity is supplied to the rusty spots by the log itself, which dries out for several years, and then begins to get wet and dry intensively.

A wooden dowel has the same characteristics as a log, so there will be no dissonance between the elements.

Circle or square

The cross-sectional shape can be determined by calculation method. In short, the round dowel is suitable for installation on small houses lightweight design, square is more reliable, therefore it is used for fixing timber and logs large cottages. The minimum diameter that should be selected is 25 mm, but more is possible.

Drilling holes for dowels

Distance between internal fastenings should be no more than 1.5-2.0 meters. In the designated places on a log house assembled in several belts, a hole is drilled through. It can be done powerful drill with two handles and with a drill attachment large diameter on wood.

In practice, they often fix 2 logs in a checkerboard pattern, but it is better to put the dowel to a depth of 3-4 logs. It turns out that one log is connected to both the upper and lower neighbors through a step.

The width of the holes in the log for round and square dowel sections should be 2-3 mm less than the actual one. For a 25mm square dowel, the hole is 32mm. The reserve is taken taking into account the expected amount of shrinkage of the fasteners and the wall. After drilling, driving the dowels into the holes will not be easy, especially in the case of a square cross-section: there is always the risk of even a slight displacement of the timber relative to the belt by 1-2 mm, then the driving process becomes more difficult. If you plan to internally fix 3-4 logs, it is better to order a log house in advance with holes already cut at the factory.

Assembly on a dowel: important nuances

When the fasteners are ready and the holes are drilled, it's time to start assembling the main structure. Important to remember:

There is no need to lubricate or lay the socket with anything before inserting the dowel.
It is prohibited to use wood glue so that the beam and dowel can move relative to each other during shrinkage.
The dowels must be installed strictly vertically so that the strung timber is fixed in one plane and does not change its position when shrinking in the horizontal axis.
Hammering should be done with a wooden or rubberized mallet. The metal head of the hammer will damage the wood and deterioration processes will begin in it.

In timber construction there is another technology for installing logs and frames:

1) On a tier bottom trim Holes are drilled into which dowels are inserted.
2) Subsequent rows of binding are strung on installed dowels. To do this, you need to pre-drill holes for installation in the timber or log.

Dowels for a house made of timber or logs are a necessary thing. They may not be visible in the volume of the tree, but you can feel the strength of the structure and be completely confident in it.

Translated from German, a dowel is a nail. A wooden dowel is a cylindrical or square fastening element. It is often used in construction industry in the process of assembling houses and baths from wood, timber, logs.

Under the influence of various negative factors, the aesthetic appeal of wooden buildings deteriorates, and heat is poorly retained in the house. To reduce the influence of such factors, wooden dowels made from hard wood are used.

Dowel for timber

The dowels can have a diameter of 24-25 mm or a cross-section of 25x25 mm, as well as a length of 1.2 m. Such a fastening element prevents the crowns of a wooden house from moving relative to each other. Most important characteristic dowel can be called its smoothness. The surface of the dowel must be perfectly smooth so that individual beams do not hang on it or rise, causing gaps to form between the crowns.

The main task of the dowel is to reduce the curvature of the timber during shrinkage, due to the fact that it works well in bending. Experts achieve high joint strength by using dowels with the same level of humidity as the timber or a little drier. Thus, it turns out that during the drying of the timber, the dowel is reliably wedged between the crowns.

For log houses made of soft types of timber, for example, pine or spruce, birch dowels are used. Birch has hard wood, and the tree itself is very widespread in Russia, for this reason it is not expensive to create fastening elements from it. In addition, birch has a low natural humidity and dense structure. Naturally, the cost of a birch dowel will be an order of magnitude lower than that of oak, hornbeam or beech.

The use of wooden dowels can be called a universal option when assembling wooden log houses, because the main difference from metal fasteners is that they are not subject to corrosion and do not affect the structure of the wood. On final stage produced, pins are necessarily impregnated or treated with antiseptic solutions against rotting.

Dowel connection

The installation of the dowels takes place in a checkerboard pattern at a distance from the edge of the beam of 200-600 mm and between the wooden rods of 1.5-2 m. The hole for the dowel must be made the same diameter as it or slightly smaller. For shrinkage to occur correctly, the axis of the holes on the dowels must be in vertical plane. In this case, the holes must have a depth when connecting two crowns of at least two-thirds of the thickness of the beam; if the holes for the dowel are made at the enterprise, then the dowel can be mounted in three or four rows. The length of the wooden rod, most often, is no more than 1.25 m. We also note that at the enterprise, it is not always possible to create an exact axis of the holes, because during the drilling process directly during the assembly of the log house, the logs laid on top of each other give a load and lie flat in relation to each other. Whereas logs enter the machine one at a time and often have a curvature that affects the axis of the hole.

Using a wooden mallet, workers hammer the dowel into the timber. It is necessary to leave a small gap of 8-10 mm at the bottom of the hole so that during the shrinkage process the dowel does not rest against the crown and cracks do not form on the beam. Wooden rod it is necessary to recess 4-5 cm into the beam, or leave it protruding this distance so that the next beam can be attached to it.

Assembly sequence on dowels:

three crowns are placed on top of each other
then holes are created and dowels are mounted
then the next two rows are placed
holes are made to the depth of three crowns and the dowels are hammered in again
These steps are repeated until the roof is installed.

Calculation of dowels

Wooden dowels are calculated for bending, and the edges of the parts connected by them are calculated for crushing. This option involves installing dowels in straight rows or in a checkerboard pattern. If the design involves the presence of tension elements, then at least three tension bolts must be installed on each side of the joint.

Craftsmen drill holes for wood dowels through all wooden parts that need to be connected. Before drilling begins, it is necessary to tighten such elements with bolts or other fasteners. Otherwise, the craftsmen will not be able to mount the dowels tightly. The cross-section of the holes for the tie (non-working) bolts must be made 1-2 mm larger than the diameter of the bolts.

The purpose of using dowels is to prevent the beams (or logs) from moving in the transverse direction. In this case, under no circumstances should the dowels interfere with their movement in the vertical direction. Otherwise, gaps may form between the logs (or beams). Specialists drill holes for wooden dowels strictly vertically.

The distance between the bottom of the hole and the edge of the dowel should not be less than 10 mm. The length of the dowels is selected in such a way that it is possible to easily connect two (or better yet, three) crowns.

There are two types of dowels:

with round section
with a square section.

Pins are selected in each specific case according to the characteristics of the cottage or other structure.