How to connect wooden parts at an angle. Joinery and carpentry fastenings and connections

Making tight joints from wood

Professional layout with precision tools

Tight joints of wood products start with neat and precise markings. This is especially important if you are making connections by hand and marking lines serve as guides for tools. The accuracy of machining depends on the accurate setting of stops, stops, overhang and inclination of saw blades and cutters. The steps below will help you achieve great results. This does not require unique equipment, but should choose tools that guarantee accuracy and efficiency. Also, develop the habit of following rules when measuring and marking.

• Use precise tools. For example, try, if possible, to use an accurate steel ruler instead of a tape measure with a flexible tape in most cases. Good tools cost more, but they will last you a lifetime.
• Consistency is the key to success. Use the same measurement tools throughout your project to avoid small inaccuracies that affect the quality of your connections. For example, the 300 mm marks on the two rulers may not match.
• The main thing is the result, not the measurements. In most cases, measurements should be avoided when you can use an already finished part with connection elements to mark an adjacent part. For example, having made spikes on the front wall of the box, use them to mark the “dovetails” on the blanks of the side walls.
• Use the right markup techniques and the right tools. With good marking and measuring tools, it is easier to achieve the required accuracy.

It is not always possible to accurately align the end of the ruler with the end of the workpiece, so in such a situation it is better, as they say, to sacrifice zero. Align the next ordinal division with the end and mark the size in accordance with it.

To draw a thin line parallel to the edge of the workpiece, use a thickness gauge. Shows the outline of the nest on the post after determining the position of the end of the crossbar

The sharp knife leaves the thinnest line, providing high accuracy of a marking. In some cases, the recessed line also becomes the starting position for the chisel.

Fine-tuning of machines for precise machining of parts

Machine tools and power tools will provide great results only if they are correctly configured and adjusted. This page shows the main features of setting up three machines that are essential for most workshops: a saw and planer, as well as milling table. Having prepared them for work, remember the following rules.

• First of all, make blanks of the same thickness. Start any project by cutting all pieces to the same thickness. Any differences in thickness make it difficult to obtain accurate joints and necessitate additional adjustments in grinding and sanding.
• Reasonable approach. Long boards are inconvenient to process, so it is better to immediately cut them into blanks with a small allowance, which are easier to handle, achieving the necessary accuracy.
• Double check the dimensions. The actual thickness of plate and sheet materials, as a rule, differs from the nominal, so a caliper should be used to measure them. Only after that, cut the grooves, tongues and folds of the appropriate width.

Before cutting anything, check that the blade is parallel to the slots in the table, set the cross (corner) stop to 90°, and then set the rip fence parallel to the blade. When ripping, use a pressure comb to hold the workpiece firmly against the rip fence.

Align the rear table with highest point the paths of the cutting edges of the knives, as shown in the figure on the right. Then, using a checked square, make sure that the rip fence is set exactly at right angles to the back table. For best results, always press the workpiece against the fence when planing. Slowly feed the board onto the rotating cutterhead. When the front end of the board passes over the knives, move the downforce forward so that the board is pressed against the back table. For best results, adjust the rear table and rip fence.

Plan to do the most milling work over multiple passes, setting the fence to the final height or width for the last pass. Fix the position of the router after each change in the overhang of the cutter. When selecting grooves, tongues, folds and other elements of connections, use clamps similar to the clamping comb shown here. It is easy to do it yourself, it does not require a lot of material.

The final fit guarantees success

No matter how many connections you want to make on the machine, after each change in settings, always make test passes and connection samples using offcuts. Adjustment should be continued until a tight assembly of the test joint is achieved, and only then proceed to processing the details of the project. But despite all your efforts, sometimes you can find imperfections in the connections. Chips on the saw table or subtle warping of a previously planed workpiece can ruin the job and make assembly impossible. If the piece is too thick or too wide, resist the temptation to adjust the size with the help of lathes. Precise fitting is best left to hand tools.

• Little zenzubel. With its help, it is possible to quickly remove a layer with a thickness of 0.5 mm or more from a wide spike or comb. The low angle zener is especially effective when working across the fibers. The cutting edge protruding from the side allows processing inner corner close to the shoulder of the spike.
• Rasp or file. A flat rasp with a coarse cut quickly removes material, but leaves a rougher surface than a planer. A flat file is slower, but it works well for smoothing the surface.
• Sandpaper. If you need to remove very little material from a spike or other wide surface, glue a piece of 100 grit sandpaper to a suitable piece of board or cork block. Use self-adhesive sandpaper or stick a regular one with spray adhesive or double sided tape. This method allows you to process only one plane without affecting the adjacent ones, as happens if you just wrap the bar with sandpaper.
• Chisel. Blades of various widths will allow you to remove material from any hard-to-reach places. When scraping a flat surface, hold the chisel with the bevel up, pressing its flat front edge against the wood.

When using a rasp, chisel, or any other tool to remove material, take your time and regularly check the result by joining the parts.

Plan your build sequence carefully

You have carefully cut out all the details, achieved tightness in all joints and are now ready to start assembling. But before you open the bottle of glue, be sure to do a trial dry assembly (without glue). When assembling the product, determine in what order it is better to connect the parts, how many clamps are required to tightly compress all the joints, and how best to place the clamps so that there are no distortions.

assembly of large and complex projects it's better to divide it into several simple steps, instead of fussing around trying to glue all the parts together in one go. For example, when making a cabinet with paneled sides, first assemble the frames with panels, and then proceed with the main assembly. This approach gives you more time to check all connections and requires fewer clamps. Another way to buy time is to use glue with an extended setting time. For example, the regular yellow Titebond adhesive makes the entire assembly in 15 minutes, while the Titebond Extend variety allows you to align the bonding within 25 minutes.

When installing clamps, make sure that their pressure is on the middle of the joint. An incorrectly installed clamp can deform the parts so that a gap forms between them. Sometimes, despite your best efforts, the connections don't come out neat. An accidentally slipped tool, inattention or unnoticed filings near the stop lead to the fact that the connection is loose or a noticeable gap appears in it.

Assemble the locker in stages, first gluing the small side paneled frames. Then you can pay more attention to each connection. Then proceed to assemble the body

How can a seemingly ruined job be salvaged?

The gap can be covered with a mixture of fast-setting epoxy adhesive with sanding dust from the same wood (the mixture should have the consistency of a thick paste). It is better to use epoxy glue instead of PVA, since the putty is inevitably smeared on the surfaces adjacent to the joint and the epoxy glue hardens without being absorbed into the wood. Excess of such a composition is easy to remove by grinding, so that there are no problems when applying the finish. Use this filling method when it comes first appearance connection, not its strength.

If, during trial assembly, the spike dangles in the socket, such a connection will not be strong. Filling the gaps with glue won't do any good, so don't be lazy to reinforce a piece that's too thin with wood. Cut out two overlays to make the spike a little thicker than required, and glue them on both sides. After drying, re-adjust the spike to the dimensions of the nest.

Turn a disadvantage into a virtue

Sometimes it is better not to hide the traces of repair, but to make them visible. In a too narrow ash thorn, two cuts were made and thin cherry wedges were inserted into them, which tightly pressed the narrow cheeks of the thorn to the edges of the socket. In other cases, such as countersunk joints, small chamfers or roundings along the ribs of the shoulders will make the loose seam less noticeable.

Replace Part

This can happen to any of us. Some mistakes don't make sense to fix for two reasons: (1) if no matter your skill and effort, the unsightly defect remains noticeable, or (2) if it's faster and easier to make a new part to replace the damaged one.

It will be useful for beginner home craftsmen to learn about the methods of joining wooden parts. We devote a brief educational program to this topic, which will describe the main types of carpentry joints and rallying using glue, nails, screws or dowels, or without them at all.

Connection selection rules depending on the type of load

End connections are the simplest; they are used if necessary to build up a part. These joints are best able to withstand compressive loads, however, when punching specially shaped locks, good resistance to twisting, stretching and bending can be achieved. The standard version of the end connection is with trimming to half the thickness of both parts. The cut can be straight or oblique, if necessary, to prevent bending, stretching or twisting, a spike or an obtuse angle is cut at the end of each cut, or the cut is made stepped, forming a kind of “castle”.

1 - direct overlay half a tree; 2 - oblique pad; 3 - straight overlay with a stepped joint; 4 - overlay half a tree with an oblique joint; 5 - oblique overhead lock; 6 - half-tree connection with an oblique spike

Corner and side connections are used to connect straight parts into a truss or frame. Usually this part of the structure is supporting, so the main loads fall on displacement and compression. If the structure experiences the static load provided, a rectangular spike is cut on one of the parts, and a groove or eyelet of the appropriate size is cut on the other. If it is possible to act on the break of the structure, the spike and groove are cut in the shape of a trapezoid.

Corner joints: 1 - with an open through spike; 2 - with a deaf closed spike; 3 - with a through oblique spike

Overhead cross and T-shaped connections are used, as a rule, for additional connections between critical structural details. The main load in them is compression, displacement and rupture. The first two types of load are eliminated by cutting half a tree or less, followed by matching the parts. The shoulders of the notches take the main load on themselves, it remains only to fix the connection with screws or overhead brackets. In some cases, a dowel is used to strengthen the connection or a spike with a wedge is cut down.

1 - cross connection with an overlay in half a tree; 2 - cross connection with landing in one socket; 3 - T-shaped connection with a hidden oblique spike; 4 - T-shaped connection with a straight stepped overlay

A separate type of connections - box. They are designed to connect boards at right angles. Usually, for a box joint, teeth are cut on each board, the width of which is equal to the distance between them. On different boards, the teeth are cut with an offset, so when connected, the corner of the boards looks like one piece. The teeth can also be wedge-shaped, preventing the corner from breaking in one direction, or additionally fastened with glue or nails.

Box corner joints: 1 - with straight through spikes; 2 - with oblique through spikes

How to make a spike connection

To make a spiked joint, you need to circle both parts with a marking line along all faces at a distance from the end equal to the width of the joint. On two opposite sides and the end, the body of the spike is marked with lines, the markings on both parts are completely identical.

The spike is cut from the sides with a hacksaw for a transverse cut and the wood is chipped with a chisel. The width of the spike is made 2-3 mm larger for subsequent precise processing with a knife or chisel. The groove is cut with a hacksaw for a longitudinal cut and chipped off with a chisel, also leaving a small allowance for processing. This is followed by an adjustment, during which the parts are combined and achieve the most snug fit.

With a T-shaped spike connection, a central spike or groove is cut on one of the parts, and an eye is hollowed out on the other or two side cuts are made, depending on the type of the first part. To make an eye, a chisel is used, turning the inclined part of the blade into the hole. If the eye is not solid, I make the spike 8-10 mm more depth and cut off its end in the form of a developed wedge. So when driving, the spike will open itself, and the part will be firmly planted.

To connect wide parts, you can use a box connection by cutting several spikes and grooves. The easiest way to fasten tenon connection- drill it through and through the spikes and hammer a wooden dowel into the hole (window corner connection).

How to glue boards together

A very popular method of joining boards and bars is longitudinal and transverse gluing. When connecting boards with a wide side, the end can be even, although in most cases a tongue-and-groove profile is used. It is very important to fit the parts tightly so that the adhesive layer is as thin as possible, only in this way it is possible to achieve maximum strength. Sometimes a small amount of cotton fiber is applied to the end smeared with glue, this improves the quality of the hitch.

The boards can also be connected in profile, but for this it will be necessary to perform a wedge-shaped gear cutting of both ends with a tooth offset to the floor for different parts. At home, such an operation can be performed using a manual milling cutter.

For gluing parts, casein glue or high concentration PVA is used; sifted wood flour is added to the adhesive to give strength. The surfaces are covered with glue and kept in air for 3-5 minutes, after which they are placed under oppression or squeezed with clamps. Such a connection is stronger than the tree itself and never breaks at the junction.

How to assemble elements of load-bearing structures

For load-bearing structures, two types of connections are used - extension and articulation. The easiest way to splice two parts is to make a cut with a hacksaw half the thickness at the same distance from the ends, and then chop off excess wood with an ax. After matching the two parts, the connection is usually fastened with two overhead strips nailed to the side of the cut. Bonding is also possible, but only if the parts are tightly fitted.

Half-cut ends can be brought together at almost any angle, this is the main method of connecting roof trusses. To fasten the parts, an additional tightening bond is required: the beam is applied to the connected parts on the side at a distance of 30-50 cm from the corner and cut to half the thickness at the points of contact, and then the structure is fastened with nails.

Often vertical and inclined structures need support, for example when connecting the truss system to floor beams. In this case, the landing slots on the horizontal beam are notched, into which the racks will be inserted. It is very important to observe the angle of inclination and make a hemming no more than a third of the thickness of the timber.

Connections with Special Links

Almost all carpentry connections are made with additional reinforcing ties. In the very simple example the role of such is performed by nails or self-tapping screws.

When building up parts, the assembly can be strengthened with a through bolted connection, clamps, staples and wood grouses, or it is simply wrapped with cold-rolled wire. It is enough to fasten the spliced ​​vertical supports with two overhead strips - wooden or metal.

Corner joints are most often fastened with staples, patch plates or corners. In cases where it is necessary to maintain a slight mobility of the connection, one through bolt is used, which either flashes across the place of the lining of the parts, or tightens them in the longitudinal direction with a minimum indent from the lining.

The place of fastening of the special connection must be removed from the edge by at least 10 diameters of the fastener and must not have defects. It is important to remember that often the bonds do not provide the overall strength of the connection, but only compensate for the unaccounted for load.

In any carpentry or furniture, corner joints are the most important node. They provide quality and durability. wooden products. Compared to dowel mount, classic way- spike connection on glue has greater durability and rigidity. Such connections are used in cases where the assembled frame must have a groove or fold for inserting a panel or glass.

In practice, they are represented by several options: two grooves and a spike inserted into them, one-sided or two-sided connection with a “mustache” and with a double spike. But most simple option for home master the use of an inserted (“foreign”) spike remains. Such a connection is nothing more than a tongue-and-groove connection.

The quality of the connection depends entirely on the exact correspondence of the groove and the tenon, which is achieved only by choosing measuring tool and a well-sharpened saw and chisel.

In case of a corner joint with one tenon, the thickness of the bar is divided into three equal parts (on a bar less than 25 mm, the tenon should be somewhat thicker than the cheek of the groove).

When marking, the width of the frame is first transferred to the inner edge of the opposite part. The risks are applied using a square with an awl. Since the wood around the spike is selected, its marking is done from any side. For the groove, marking is done only on its narrow side. Then the details are marked. It is customary to make grooves in the vertical elements of the frames, and spikes in the horizontal elements. The grooves are marked with a thickness gauge. A spiked bow saw is sawn along the falling part (for a groove to the base, for a spike - to a ledge). Then a groove is hollowed out with a chisel. To do this, the sawn part is fixed on a workbench. The chisel is placed with a sharpening cut to the detachable part and is driven with a mallet exactly into the mark with light blows. First, a wedge-shaped hole is hollowed out. The detachable part of the wood is left in place so that when working on the reverse side there is an emphasis. The spike is cut at a right angle with a miter saw.

The width of the frame is transferred to the opposite part, maintaining perpendicularity. Add 2-3 mm to the width of the cut.	Mark the groove and spike with a thickness gauge. This is the simplest and most accurate markup method.	Sawing is always from the side of the detachable part in the middle of the markup. A studded bow saw is designed specifically for such work.
A self-made auxiliary stop template will help you make accurate cuts and on circular saw. At the same time, be safe.	The grooves are hollowed out with a chisel. To do this, the connection parts are tightened with a clamp or fixed on a workbench. They weakly hit the chisel with a mallet.	A miter saw with a fixed angle adjustment will allow precise tenon placement. This work can be done on a circular saw.

Special options for corner connections

Special forms of grooves and tenons - double tenon and grooves on the "mustache". Double studs are used in products subject to heavy loads and thick frames. If the frame structure is profiled at the end, then the connection is made with a mustache. There are one-sided and two-sided grooves on the “mustache” (due to the insufficient area of ​​the contact surfaces, they are less durable).

The groove should be located in the middle third of the thickness of the part. The sample around the spike is made less than the depth of the groove, otherwise there will be a gap in the connection. After assembly, the remaining cheeks of the groove are sawn off along the entire length. The reverse is also possible.

The rebate on the frame must be consistent with the division into three parts. This will save time on the spike. The width of the fold must be taken into account when marking out, otherwise gaps will occur here when milling.

After grinding the inner and outer surfaces of the groove and tenon, the frame is glued together. In this case, it is necessary to compress the gusset in two planes through the gaskets. The ends of the groove and tenon must be open for inspection and adjustment during assembly. The protruding adhesive is removed. When gluing, the right angle of the frame is controlled.

After the glue has dried, the clamps are removed and the protruding parts of the tongue or cheeks of the groove are ground down from the flanks to the level with outside products.

	Spike connection on the "mustache": one-sided and two-sided. The choice is determined by the design requirements for the product or its appearance.
	A double spike is made for especially loaded corners and thick frames. In this case, the thickness of the bar is divided into five equal parts.
	When selecting a longitudinal groove in the details of the frame, the spike is not affected. Otherwise, when gluing the knot, a hole will appear in its end face.
	The fold, even when marking, must have an appropriate increase, otherwise gaps will result. Depth is determined by dividing into three parts.
	The spikes and cheeks of the grooves protrude for an increase. When compressed, gaskets will be required. After that, the increase is sawn off.

Connections of wooden elements have the task of connecting mating Construction Materials, such as edged beams, so that they do not move relative to each other. According to the position and direction of the connected wooden elements, longitudinal joints and corner joints, as well as joints on branches and crosshairs, are distinguished. Spatial connectors from steel sheet and pre-drilled steel plate escutcheons often replace carpentry joints.

Connections that must transmit forces of a certain magnitude and direction, such as compressive forces, are also called joints of connected wooden elements as rods, such as compressed rods. Compressed rods connected at an acute angle can be connected at notches. Other connections of wooden structures are arranged at the expense of joints of wooden elements using connecting means.

According to the type of connecting means, such connections are called nail or bolt, dowel or dowel connections. In wood construction, glued building construction. Since they have particular advantages, the use of glued timber structures is of increasing importance.

Longitudinal connections

There are longitudinal connections on the supports and longitudinal connections in the span. Above the supports, perpendicular trunnions are used, a joint “in the paw” and a partially trunnion joint “in the paw” (Fig. 1). To reinforce these joints, building brackets made of flat or round steel can be driven in from above or from the side. Often, wooden elements are joined head-on and fixed only with building brackets. If, however, large tensile forces act at the joint, for example, at the girders on the roof rafters, then both elements are joined head-on on the support and connected by side plates made of boards or perforated strips of steel protected from corrosion.

Rice. 1. Longitudinal connections

Runs can also be made in the form cantilever-suspended(Gerber runs) or hinged girders. They have a joint located in a place determined by the calculation, not far from the support, in which the bending moments are equal to zero and where there are no bending forces (Fig. 2). There, the runs are connected with a straight or oblique overlay. The incoming purlin is held in place by a screw bolt, also called a pivot bolt. The swivel bolt with washers must bear the load from the suspended purlin.

Rice. 2. Longitudinal joints of Gerber girders

Gerber purlins with a seam lying on top are impractical, since there is a danger that the purlins at the edge of the seam will come off. With a suspended joint, having screwed up, there is no danger of separation.

To connect the Gerber purlins, spatial elements made of steel sheet are also used, which are also called Gerber connecting elements. They are attached with nails along the front butted ends of the runs (see Fig. 2).

Corner connections

Corner joints are necessary when two logs or beams in a corner are joined at a right or approximately right angle in the same plane. The most commonly used types of joints are cut-out trunnions, a smooth angular foot and a compressed foot (Fig. 3). With the help of cut-out trunnions and smooth corner legs, the ends of thresholds, girders and rafter legs lying on supports or protruding cantilevered are connected. Nails or screw bolts can be used to secure the joints. The compressed paw has planes obliquely entering each other. It is particularly suitable for connecting loaded, fully supported thresholds.

Rice. 3. Corner joints

Branches

When branching, a beam suitable at a right or oblique angle in most cases is superficially joined to another beam. In normal cases, a joint on the trunnions is used, and in secondary structures, the joint "in the paw" is also used. In addition, beams made of timber can be joined using metal spatial connecting elements. In trunnion joints, the thickness of the trunnion is approximately one third of the thickness of the timber. The trunnions are in most cases 4 to 5 cm long. The groove for the trunnion is made 1 cm deeper so that the compression force is transmitted not through the section of the trunnion, but through large area the remaining section of the bars.

When arranging trunnions, normal trunnions are distinguished, passing through the entire width of the beam, and protruding(hemp) pins, which are used for connections at the ends of the bars (Fig. 4). If the bars in the connection do not fit at right angles to each other, for example, at the corner struts, then the trunnion at the strut must be made at right angles to the horizontal (or vertical) structural element (see Fig. 4).

Rice. 4. Pin connections

When installing trunnions in wooden beams and runs, the trunnion must bear the entire load. It is more advantageous to make such connections using beam shoes from corrosion-protected steel (Fig. 9). These shoes are fixed with special nails in such a way as to prevent them from buckling and turning relative to the joint. Besides, transverse section beams are not weakened by pin holes.

Cross connections

Wooden beams can intersect in the same plane or with offset planes and be overhead or support. Bars intersecting in the same plane can intersect "IN THE LAPU" if the weakening of the section does not play any role (Fig. 5). It is advisable to tie the intersecting overhead thresholds on the support beams with round dowels (pins) made of hard wood or steel 10 to 12 cm long (Fig. 6).

Rice. 5. Connection "in the paw"

Rice. 6. Connection with round dowels (pins)

The beams joining on the side receive good support on the pole if their connection is made “In the groove” (Fig. 7). To do this, the intersection planes of both elements are cut to a depth of 1.5 to 2.0 cm. This results in an immovable connection, which is fixed with a screw bolt.

Rice. 7. Groove connection

When docking inclined and horizontal bars, as is usually the case when joining rafter legs with girders - thresholds, a cutout is made in the rafter leg corresponding to the slope, which is called sidebar(Fig. 8).

Rice. 8. Insert rafter leg

Insertion depth in rafter legs with a normal section height of 16 to 20 cm, it is from 2.5 to 3.5 cm. For fastening, one nail is used that penetrates the threshold for a length of at least 12 cm, or a special anchor for attaching rafters to girders.

Rice. 9. Steel shoe connection

cuts

When cutting, a compressed rod entering at an acute angle is connected to another beam using one or more force-transmitting planes on its front side. According to the number and position of the force-transmitting planes, a frontal cut, a cut with a tooth, and a double front cut with a tooth are distinguished.

At frontal cutting(also called a frontal stop) the receiving bar has a wedge-shaped cut that matches the shape of the end compressed rod(Fig. 10). The frontal plane should pass at an angle dividing the obtuse outer corner of the cut in half. The fastening bolt must also have the same direction, guaranteeing the joint from lateral displacement. To mark the cut, parallels are drawn at the same distance from the sides of the corner, which must be divided in half. The connecting line between the point of their intersection and the vertex of an obtuse angle will be the bisector of this angle (see Fig. 10). The position of the fastening bolt is obtained if the distance between the bisector and the end of the notch is divided into three parts parallel to the bisector (see Fig. 10).

Rice. 10. Frontal cutting

Under the action of a compressive force, the wood lying in front of the frontal part of the compressed rod works on slice(see fig. 10). Since the permissible stress on the cut of wood along the fibers is relatively small (0.9 MN / m 2), the plane of the wood in front of the cut edge (cut plane) must be large enough. Since, in addition, cracking due to shrinkage should be taken into account, with rare exceptions, the length of the cut plane should not be less than 20 cm.

At reverse or notched cut the cutting plane is cut at a right angle to the lower side of the compressed rod (Fig. 11). Due to the fact that due to an eccentric connection in a notched notch there may be a risk of splitting the compressed rod, it is necessary that the free end of the notch does not fit tightly against the support rod and a seam is provided between them.

Rice. 11. Serrated notch

double cut consists, as a rule, of a frontal cut in combination with a toothed cut (Fig. 12). The direction of the cutting planes is similar to that used for each of the cuttings of this combination. However, the notched cut in this case must be at least 1 cm deeper so that its cut plane is below the cut plane of the frontal cut. The fastening bolt should run parallel to the front of the notch approximately midway between the bisector and the top of the acute joint angle.

Rice. 12. Double notch

Cutting depth t v is limited according to DIN 1052. The decisive factors for this are the contact angle (a) and the height h of the cut rod (Table 1).

Pin and bolt connections

In the case of pin and bolt connections wooden bars or boards in contact with the sides are connected by cylindrical connecting elements, such as rod dowels, countersunk bolts and nuts, ordinary bolts with nuts. These rod dowels and bolts should prevent the wooden elements from moving in the connection plane, which is also called the shear plane. In this case, forces act perpendicular to the axis of the rod dowel or bolt. Dowels and bolts at the same time work on bending. In connected wooden elements all efforts are focused on inner surface holes for dowels or bolts.

The number of rod dowels and bolts installed at the junction depends on the magnitude of the transmitted force. In this case, as a rule, at least two such elements should be installed (Fig. 13).

Rice. 13. Connection with rod dowels

In one connection, many shear planes can be located next to each other. According to the number of cut planes that are connected by the same connecting elements, single-cut, double-cut and multi-cut dowel and bolted connections are distinguished (Fig. 14). According to DIN 1052, single shear load-bearing connections with dowel pins must have at least four dowel pins.

Rice. 14. Bolted connections

For bolted connections, mainly bolts with nuts made of steel with a normalized diameter of 12, 16, 20 and 24 mm are used. In order to prevent the head and nut of the bolt from cutting into the tree, strong steel washers should be placed under them. Minimum dimensions these washers are given for various bolt diameters in DIN 1052 (Table 2).

In order to prevent splitting of the wooden elements to be connected by rod dowels and bolts, these connecting means must have installed minimum distances between themselves, as well as from the loaded and unloaded ends. Minimum distances depend on the direction of the force, on the direction of the wood fibers and on the diameter of the dowel or bolt db and do (fig. 15 and 16). For load-bearing bolts with nuts, greater distances must be maintained between themselves and from the loaded end than in the case of rod dowels and bolts with hidden heads. On the other hand, rod dowels or bolts with hidden heads located close to each other in the direction of the wood fibers should be spaced apart from the cut line so that the joints do not crack (see Fig. 15).

Rice. 15. Minimum distances in case of rod dowels and hidden head bolts

Rice. 16. Minimum distances in case of bearing bolts

Holes for pins and bolts are pre-drilled perpendicular to the cutting plane. For this, electric drills with a bed with parallel movement are used. For pins when drilling holes in wood, as well as when drilling holes in wood and metal connecting elements, the diameter of the hole must correspond to the diameter of the pin.

Also, the bolt holes should match the diameter of the bolts well. Do not increase the diameter of the hole in comparison with the diameter of the bolt by more than 1 mm. With bolted connections, it is bad when the bolt sits freely in the hole. It is also bad if, due to the shrinkage of the wood, the clamp of the bolt in the hole gradually weakens. In this case, a play appears in the shear plane, which leads to even greater pressure of the bolt shaft on the boundary planes of the hole walls (Fig. 17). Due to the flexibility associated with this, bolted connections cannot be used indefinitely. For simple buildings, such as sheds and sheds, as well as scaffolding, they can, however, be used. In any case, in the finished structure, the bolts must be tightened many times during operation.

Rice. 17. Backlash when bolted

Dowel connections

Dowels are fasteners made of hard wood or metal, which are used together with bolts to connect smoothly joined wooden elements (Fig. 18). They are positioned in such a way that they evenly act on the surface of the elements to be joined. In this case, the transmission of forces is carried out only through the dowels, while the bolts provide a clamping action in the connection so that the dowels cannot tip over. Laths made of flat or profiled steel are also attached to wooden elements using dowels. For this, one-sided dowels or flat steel dowels are used. Dowels are various forms and types.

Rice. 18. Connecting wooden elements with dowels and bolts

When making dowel connections with pressed dowels, bolt holes are first drilled in the elements to be connected. After that, the wooden elements are separated again, and, if necessary, a groove for the main plate is cut. Depending on the construction technology, the dowel is completely or partially driven into the groove of one of the connected elements using a mallet. For the final clamping of an axially aligned connection, special clamping bolts with a large washer are used. Connections with many or large pressed-in dowels are clamped with hydraulic press. When connecting with a large number dowels, as is the case with the device corner connections in frames made of glued plank elements, it is more preferable to use round plug-in dowels, since with pressed dowels the pressing pressure may be too high (Fig. 19).

Rice. 19. Dowel connection in the corner of the frame

Each dowel, as a rule, should correspond to one bolt with nut, the diameter of which depends on the size of the dowel (Table 3). The size of the washer is the same as for bolted connections. Depending on the magnitude of the force acting on the connection, larger or smaller dowels can be used. The most common are diameters from 50 to 165 mm. In the drawings, the size of the dowels is indicated by symbols (Table 4).

Table 3. Minimum dimensions in dowel connections
Outer diameter d d in mm	Bolt diameter d b in mm	Distance between dowels/distance from dowel to element end, e db, in mm
50	M12	120
65	M16	140
85	M20	170
95	M24	200
115	M24	230
The values ​​are valid for the family of round push-in dowels type D.

Table 4. Drawing symbols for special type dowels
Symbol	Dowel size
	from 40 to 55 mm
	from 56 to 70 mm
	from 71 to 85 mm
	from 86 to 100 mm
	Nominal dimensions > 100 mm

At dowel placement it is necessary to adhere to certain distances of the dowels between themselves and from the edges of the wooden elements. These minimum distances according to DIN 1052, they depend on the type of dowel and its diameter (see table. 3).

Bolts with dowel nuts are almost always driven through the center of the dowel. Only with rectangular and flat steel dowels do they lie outside the plane of the dowel. When tightening the nuts on the bolts, the washers should cut about 1 mm into the wood. With dowel connections, the nuts on the bolts must be re-tightened after a few months after installation, so that their tightening effect remains even after the shrinkage of the wood. They talk about a connection with a constant transmission of force.

Bearing pin connections

Bearing dowel (nail) connections have the task of transmitting tensile and compressive forces. With the help of dowel joints, load-bearing parts can be fastened, for example, for freely supported trusses, as well as structures made of boards and beams. Nail joints can be made single-shear, double-shear and multi-shear. In this case, the size of the nails should correspond to the thickness of the lumber and the depth of the drive. In addition, when arranging the nails, certain distances between them must be maintained. In load-bearing dowel joints, holes must be drilled in advance. The drilled hole should be slightly smaller in diameter than the diameter of the nail. Since the wood does not crack as much, the nails can be placed closer together in this way. In addition, the load-bearing capacity of the nail joint will increase and the thickness of the wood can be reduced.

Single shear dowel joints are used when compressed and stretched rods from boards or beams must be attached to the beams (Fig. 20). In this case, the nails pass through only one connecting seam. They are loaded there perpendicular to the shaft of the hole and can bend with too much force. Since shear forces also occur in the connecting seam in the body of the nail, this sectional plane is called the shear plane. In the case of paired joining of plank rods on the planes of the main beam, there are two single-cut dowel joints opposite each other.

Rice. 20. Single shear dowel connection

At double shear dowel joints the nails pass through three connected wooden elements (Fig. 21). Nails have two cut planes, since they are loaded in both connecting seams with the same directed force. Therefore, the bearing capacity of a double-shear loaded nail is twice that of a single-shear nail. In order for the double-cut dowel joints to not disperse, half of the nails are hammered on one side, and the other half on the other. Double-cut dowel joints are mainly used if freely supported trusses consist entirely or mainly of boards or beams.

Rice. 21. Double-cut dowel connection

Minimum timber thicknesses and minimum nailing depth

Since thin wooden elements easily split when hammering nails, boards for load-bearing rods, belts and planks must be at least 24 mm thick. When using nails from size 42/110, use even larger minimum thicknessesa(Fig. 22). They depend on the diameter of the nail. With pre-drilled nail joints, the minimum thicknesses of the wood can be less than with simple nailing, as there is less risk of cracking.

Rice. 22. Minimum thickness and depth of driving

The distance of the tip of the nail from the closest cutting plane is called the driving depth. s(see fig. 22). It depends on the diameter of the nail dn and has a different value for single-cut and double-cut nail joints. Single shear loaded nails must have a driving depth of at least 12d n. However, for certain special nails, due to the greater holding force due to the special profiling, a driving depth of 8d n is sufficient. For double shear connections, a driving depth of 8d n is also sufficient. With a shallower driving depth, the bearing capacity of the nails decreases. If the nails have a driving depth of less than half that required, then they cannot be taken into account for the transmission of forces.

Minimum spacing between nails

Fixing formwork, battens and fillets, as well as rafters, battens, etc. acceptable with less than four nails. However, in general, at least four nails are required for each seam or multi-shear nail joint intended for force transmission.

The uniform arrangement of these nails on the plane of the connection is made using nail marks(Fig. 23). In order for two nails located one after another not to sit on the same fiber, they are displaced relative to the point of intersection of mutually perpendicular nail lines by the thickness of the nail in both directions. In addition, minimum distances must be observed. They depend on whether the direction of the force is parallel or across the fibers. Further, it is necessary to monitor whether the ends of the rods or the edges of the wood are loaded by the force acting in the joint or not. Since there is a danger of cracking when the ends of the rods or edges are loaded, it is necessary to maintain large distances from the edges to the nails.

Rice. 23. Minimum distances between nails with a single shear connection

At single shear nail connection vertical or diagonal tensioned rod with nails with a diameter of d n ≤ 4.2 mm, the minimum distances shown in fig. 23. When using nails with a diameter of d n> 4.2 mm, these distances should be slightly increased. If the nail holes are pre-drilled, in most cases smaller distances are required.

At double-cut nail connections nails are arranged in ledges. Between the risks of a single-cut nail joint, additional risks are drawn with a minimum distance of 10d n (Fig. 24).

Rice. 24. Minimum distances between nails for double-cut joint

Nail connection device

When making nail joints, the nails must be driven vertically into the wood. In this case, the nail head should only be slightly pressed into the wood so that the wood fibers at the junction are not damaged. For the same reason, the protruding ends of the nails can only be bent in a special way. This should only happen perpendicular to the fibers. For drawing the location of the nails, as a rule, suitably drilled templates made of thin plywood or tin are used. In the case of plywood templates, holes are made of such a diameter that nail heads can pass through them. In the case of tin templates, the locations of the nails are marked with a brush and paint.

Nail connections with steel plates

Nail joints with steel plates can be divided into three types, namely, connections with embedded or externally laid plates with a thickness of at least 2 mm and connections with embedded plates with a thickness of less than 2 mm.

Overlays on the outside, as a rule, have in advance drilled holes(Fig. 25). They are superimposed over the connection of beams or boards to the butt and nailed with the appropriate number of wire or special nails. At embedded overlays with a thickness of at least 2 mm holes for nails must be drilled simultaneously in the wooden elements and in the overlays. In this case, the diameter of the holes must correspond to the diameter of the nail. Embedded linings less than 2 mm, of which there may be several at the junction, can be pierced with nails without pre-drilling (Fig. 26). Such connections may only be made with specially designed spline tools and only on the basis of special approval from the authorities.

Rice. 25. Connection with a perforated steel plate-lining

Rice. 26. Nail connection with embedded steel plates (Grame)

Connections with nail gussets

Nail gussets are used for the rational manufacture of wooden half-timbered trusses from single-row sections of wood (Fig. 27). To do this, wooden rods of the same thickness are cut to length, impregnated and adjusted exactly to each other.

Rice. 27. Connection with a nail gusset

In this case, the moisture content of the wood should not exceed 20%, and the difference in thickness should not be more than 1 mm. In addition, the rods should not have any cuts and edges.

Nail gussets must be placed symmetrically on both sides and, using a suitable press, pressed into the wood so that the nails sit in the wood for their entire length. Hammering of nail gussets with a hammer or the like is unacceptable.

Fastening with the help of nail gussets creates a connection or joints that are strong in compression, tension and shear at nodal points without weakening the load-bearing section of the wood. For the transmission of forces, the working area of ​​\u200b\u200bthe connection of the nail gusset is of primary importance (Fig. 28). It corresponds to the area of ​​contact of the nail gusset with the wood, with the exception of the edge strip with a minimum width of 10 mm.

Rice. 28. Working area of ​​the connection at the nail gusset

Trusses with connecting rods with gussets are industrially manufactured only by licensed enterprises, supplied in ready-made to the construction site and installed there.

Since ancient times, after mastering the tools of labor, a person began to build a dwelling made of wood. Having gone through evolution, a person continues to improve the construction of his home for thousands of years. Of course, modern technologies have simplified construction, given a wide opportunity for imagination, but basic knowledge about the properties of wooden structures is passed from generation to generation. Consider ways to connect wooden parts.

Consider the ways of connecting wooden parts that beginner craftsmen face. These are mainly carpentry joints passed down from generation to generation, these skills have been used for more than one century. Before joining wood, we assume that the wood has already been processed and is ready for use.

The first basic rule that should be followed when joining wooden parts is that a thin part is attached to a thicker one.

The most common ways of joining wood, which will be needed in the construction of homestead buildings, are of several types.

End connection

This is one of the most simple ways connections (rallying). With this method, it is necessary to fit the surfaces of the two elements to be joined as closely as possible. The parts are pressed tightly against each other and fastened with nails or screws.

The method is simple, but to obtain the quality of the product, several conditions must be met:

The length of the nails should be such that, having passed through the entire thickness of the first workpiece, they would enter with their sharp end into the base of another part to a depth equal to at least ⅓ of the length of the nail;

Nails should not be located on the same line, and their number should be at least two. That is, one of the nails is displaced from the center line upwards, and the other, on the contrary, downwards;

The thickness of the nails should be such that when they are driven into the wood, a crack does not appear. Pre-drilling holes will help to avoid cracks in the wood, and the diameter of the drill should be equal to 0.7 of the diameter of the nails;

To receive best quality pre-lubricate the joints, the surfaces to be joined well with glue, and it is better to use moisture-resistant glue, such as epoxy.

Invoice connection

With this method, two parts are superimposed one on top of the other and fastened with nails, screws or bolts. Wooden blanks, with this method of connection, can be placed in one line or shifted at a certain angle relative to each other. In order for the angle of connection of the workpieces to be rigid, it is necessary to fasten the parts with at least four nails or screws in two rows of two pieces in a row.

If you fasten with only two nails, screws or bolts, then they should be placed diagonally. If the nails have a through exit through both parts, with the subsequent bending of the protruding ends, this connection method will significantly increase strength. The connection to the invoice does not require a high qualification of the master.

Half tree connection

This method is more complex, it requires already certain skills and a more scrupulous approach to work. For such a connection, in both wooden blanks, wood is sampled to a depth equal to half their thickness, and a width equal to the width of the parts to be joined.

You can connect parts in half a tree at different angles.

It is important to observe the following rule:

So that the sampling angle on both parts is equal, and the width of both samples strictly corresponds to the width of the part. Under these conditions, the parts fit snugly against each other, and their edges will be placed in the same plane. The connection is fastened with nails, screws or bolts, and glue is still used to enhance strength. If necessary, such a connection may be partial. That is, the end of one of the workpieces is cut at a certain angle, and the corresponding sample is made in the other part. Such a connection is used for angular rallying. Both spikes (samples) in this case are cut at an angle of 45 degrees, and the joint between them is located diagonally.

Splicing to length

Such splicing of bars and beams along the length has its own characteristics.

For vertical supports, splicing is simple.

But it’s a completely different matter when a beam or beam at the splicing point is subject to bending or torsion loads, in which case you can’t get by with simple fastening with nails or screws.

The parts to be joined are cut at an angle (into an oblique overlay) and compressed with bolts. The number of bolts depends on the applied loads, but there must be at least two.

Sometimes additional overlays are installed, for example, metal plates, it is better on both sides, top and bottom, for strength, you can additionally fasten with wire.

Cleat

Such a connection is used when laying the floor or for sheathing boards. To do this, a spike is made in the face of one board, and a groove in the other.

With this splicing, gaps between the boards are excluded, and the sheathing itself takes on a beautiful appearance. Appropriately processed sawn timber is delivered to trading network where they can be purchased ready-made.

Examples of such materials are batten or lining.

Connector "socket-thorn"

This is one of the most common joints of wooden parts.

Such a connection will provide a strong, rigid and neat rallying.

It goes without saying that it requires certain skills and accuracy in work from the performer.

When making this connection, you need to remember that a poor-quality spiked connection will not add reliability and will not have a beautiful appearance.

A spike connection consists of a groove hollowed out or drilled in one of the wooden parts, as well as a spike made at the end of another attached element.

The parts must have the same thickness, but if the thickness is different, then the socket is made in the thicker part, and the spike is made in the second, thinner part. The connection is carried out on glue with additional fastening with nails, screws. When driving a screw, remember that pre-drilling will facilitate this process. It is better to hide the head of the screw, and the pilot hole should be ⅔ of the diameter of the screw and be 6 mm less than its length.

One of the very important conditions, is the same humidity of the connected parts. If the elements to be joined have different moisture content, then when dried, the spike will decrease in size, which will lead to the destruction of the entire connection. That is why the parts to be joined must have the same humidity, close to the operating conditions. For outdoor structures, humidity should be in the range of 30-25%.

The use of wood to decorate buildings.

Choice of wood.

In carving, to perform large crafts with large elements, they often use coniferous wood as the main one. They are available, and the striped texture can be used in ornaments.

As background for invoice and slotted thread, used fir.

The valuable material is cedar, its soft, with beautiful texture and a pleasant yellow-pink or light pink wood core. The wood is easy to cut, cracks little during shrinkage and is resistant to decay.

Wood pears used for highly artistic carving details, as it is durable and warps little from atmospheric influences.

Poplar, the wood is very soft and light - it is used to make a carved decorative column or background shields for attaching false threads.

It is good to use wood to make chains from round rings. apple trees. This wood is used in small crafts, in applied carvings. In this case, the springy properties of the apple tree are used.

Wood is also used lindens. Very light, well planed, well drilled and polished.

carving from oak difficult to manufacture due to its hardness.

But oak is not afraid of moisture, it does not warp. Products from natural wood very beautiful, but too expensive. Veneering is used to reduce the cost of the product. For example, veneered doors are made, by order of the client, "under the oak". We get beautiful doors, outwardly similar to natural ones, but at a much lower price.