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Sometimes, when carrying out construction and other work using wood, it is necessary to make elements longer or wider, but very few people know how to do this correctly. That is why we will look at how to splice boards yourself and what methods and techniques exist. It is important to choose the option that is best suited in a given situation and requires minimal investment of time and money.
Before we begin to consider specific options for carrying out work, it is necessary to understand what factors will ensure that we obtain the expected result:
| Quality of material | Everything is simple here: it is impossible to make durable structures from low-quality wood, especially with regard to joints; if they have knots, damage from woodworms, mold and other problems, then there can be no question of any reliability and durability. Choose the most best elements so as not to waste energy and money |
| Humidity | Another the most important parameter, which should always be taken into account. Only dry elements are suitable for work, since high humidity, firstly, it reduces strength, and secondly, it reduces adhesion adhesive composition when using it, and thirdly, after completion of the work, no one will give a guarantee that in a week or month the structure will not move or it will not crack |
| Connection Loads | The choice of one or another connection option largely depends on this indicator; the greater the load, the higher the requirements for the quality of the connection and the more complex the process. Therefore, decide in advance which option will be used to ensure a good result. |
| Using a quality tool | A lot also depends on this, especially when it comes to complex options when the connection is cut with special devices. They must provide maximum cutting quality and maximum accuracy docking, since reliability largely depends on this |
Important!
Remember one simple rule that experts always use: to get best result It is necessary that the parameters of the elements being connected are similar; in other words, the same type of wood must be used.
All events of this kind can be divided into two large groups - joining boards in width and length; we will consider them separately and tell you which techniques are the most popular and how to implement them correctly.
Of course, the simplest solution would be a panel splice option, so we will start with it, first present a diagram of the main options, and below we will describe them in detail:
But if you want to connect the board more securely, then one of the following methods will do:
Important!
When working, a milling cutter is most often used, but cutters can have different configurations; you should monitor the condition of their cutting edges and sharpen or replace them in a timely manner, since the quality of the connection largely depends on the cleanliness of the processing.
Connecting the board correctly and securely means ensuring its maximum strength; it is important to follow all recommendations and use only high-quality materials. The video in this article will show some options for carrying out the work visually, and if you have questions or additions, please leave a comment.
Carpentry, construction and furniture products consist of various parts connected to each other in one way or another and mostly immovably. In some parts of collapsible and folding furniture, detachable connections are also used.
A part - a block, a board (plot), a shield - as the primary element of the product can be made from one piece of wood, from two or several pieces pre-glued together, and can also be veneered.
The connection of two or more parts forms a unit - a shield, a frame, a box, which are the structural elements of the product. From interconnected parts and assemblies, a simple carpentry product or a separate part of it is obtained - a plant, an assembly.
The parts are connected to each other by carpentry, glue or metal fasteners.
According to GOST 9330-60 "Wooden parts. Basic connections", the following groups of connections are distinguished:
The simplest product or part is formed from conjugated elements complex product(unit), depending on the purpose of which the method of connecting elements.
Splicing and extension. Due to the relatively short length of joinery parts, not exceeding the usual length of the boards and bars used, splicing and building up in joinery work is used mainly only in the manufacture of joinery and construction products (handrails, cornices, plinths, etc.), as well as when replacing unusable parts parts are new.
Splicing and extension is performed:
Bonding is used mainly for connecting narrow elements in order to obtain a part of greater width; much less often, bonding serves to increase thickness. The front sides of the product are veneered - covered with valuable wood. When bonding, the following methods of connecting elements are used:
Joining into a smooth fugue using glue can be done with both parallel and non-parallel edges of the boards being joined. The latter connection is more economical in terms of material consumption, since boards with edges sawn along the rung of the tree are used, but it is less beautiful and more difficult to implement.
Joining on tenons and dowels is usually performed without gluing, mainly to connect parts or parts of a product lying on top of each other in order to prevent their displacement. Performing this type of rallying, especially on spikes, presents some difficulties.
Joining in a quarter, in a tongue and groove and on a lath with glue is stronger, joining in a smooth fugue, as it gives large area gluing. Racking on a batten is more profitable than in a quarter or tongue, because the wood is not spent on forming a quarter or tongue, and the batten itself is usually made from waste.
The best and most durable look joining - connection with a trapezoidal tongue ("stitching"). Making such a connection with hand tools is extremely difficult and is rarely used. For this purpose, special stitching machines are currently used, receiving wide application in the production of furniture and packaging. A trapezoidal tongue connection can be made with non-parallel edges in both the longitudinal and transverse directions, which allows full use unedged boards with escape, giving a significant escape with other methods of rallying. The boards are arranged alternately in different sides the core side and the butt end, which prevents warping of the shield as a whole.
Corner connections. Connecting parts at an angle, i.e. knitting corners, is the most common type of connection in carpentry. The forms of these compounds are very diverse; they can be divided into two main groups: frame and box.
There are the following methods of corner connections:
Trimming corner joints in bars with figured processed edges (mouldings) are made in two ways: the tenon joint is processed rectangular shape with trimming the figured part into a miter or making a tenon joint according to the profile of the bars being connected. The first method, which is simpler (but produces a less durable connection), is applicable when manual processing, the second is used for machine processing of parts, ensuring the necessary accuracy of execution.
Nodal connections in products painted with opaque paint are strengthened with wooden nails (pins) driven into drilled holes.
Adjacent connections(Fig. 184) are a type of corner joint: the end of one bar is adjacent to the middle part of the other. They are made with an overlay (half-tree), with a straight and oblique tenon, through or semi-secret. Sometimes connections are made on inserted round tenons (dowels).
Rice. 185. Box corner connections: a - straight open spike; b - oblique open spike; c - open dovetail spike; g - into the tongue on the insert rail; d - into a tongue and groove with an open and closed end; e - on insertable flat and round tenons; g - with a dovetail spike; h - with a hidden dovetail tenon; and - on the mustache with an insert strip; k - on a mustache with a comb; l - with glued boss
Box corner joints(Fig. 185) boards or panels are widely used in carpentry and furniture. They are made with straight and oblique tenons of the “dovetail” or “frying pan” type. The number of spikes depends on the width and thickness of the parts or shields being connected. There are tenons at the ends of both connected parts, and the shield - the part with the eyelet on the edge of the edge - has one more tenon than the corresponding adjacent part.
Box connections They can be through, deaf, semi-recessed and deaf with a clear mustache. Through connections are used for parts located inside the product, also on its front sides if they are covered with plywood or opaque paint. Parts that are open only on one side are connected in a semi-flush manner, and parts that are open on all sides are connected in a recessed manner. Box corner joints are also made with plug-in tenons, but such joints are the least durable.
Box connections(Fig. 186) are made with straight through tenons and grooves with a ridge: triangular, rectangular, trapezoidal (reward). Groove connections are used in cases where outside It is undesirable to have protruding ends.
Glue connection. In carpentry and furniture production, adhesive joints are used relatively widely. The connection with glue alone is strong enough, provided that the parts are properly fitted and properly glued together.
This method is used not only for joining parts into a board with a smooth fugue, but also for preparing plywood boards (gluing boards onto the face) and gluing plywood onto a frame, veneering and cladding (gluing plywood and boards different breeds) for producing thick parts (stands, legs, etc.) from thin bars and planks, as well as for gluing small bars to finished products (mouldings, baseboards, cornices, glazing beads, etc.).
Veneering. Pasting of plain wood with thin planks (cladding) and veneering - pasting of sheets (plywood) more valuable wood is special kind adhesive connection to improve the appearance of the product and increase its strength.
Depending on the production method, sawn, planed (knife) and peeled plywood are distinguished.
The parts are veneered on one or both sides; double-sided veneering significantly increases the strength of the product. Plywood is glued in one or two or more layers.
With one-sided veneering, the plywood is glued with fibers parallel to the fibers of the base (frame, frame or frame), and with double-sided veneering - mutually perpendicular.
Due to shrinkage or drying of the glue and warping of the plywood that dries out after moistening, the base - a board or shield - warps (Fig. 187, a) and a concavity is formed on the surface covered with plywood. This warping is greater, the smaller the ratio of the thickness of the base to its width. Veneering a well-dried block, the thickness of which is at least half the width, does not at all entail its warping.
Gluing plywood to the right (core) side of the block reduces warping of the base and, by creating a convexity on the right side, it is possible to compensate for the arching resulting from shrinkage of the glue and warping of the plywood.
Double-sided veneering (Fig. 187, b) does not cause warping of the part. In this case, the internal, non-front sides of the part can be covered with plywood of simple species, and the front sides with plywood of more valuable species.
It is often necessary to cover timber parts on three or four sides. In this case, plywood is glued to the wide edges, and plywood or solid wood lining to the narrow edges (Fig. 187, c, d).
The veneered surface is prepared accordingly: knots are drilled out and the holes are filled with wooden plugs; cracks and chips are sealed with wooden inserts or putty; the surface is precisely leveled. The ends, which are usually difficult to veneer, are either glued and then (after the glue has dried) lined with zinubel, or pasted over with longitudinal blocks.
Plywood for front and inner layers cut into pieces of the required length, its edges are jointed and connected (pulled) into a sheet (set) according to the dimensions of the surface to be pasted.
Plywood screed produced on the table. The sheets are laid out with jointed edges one to the other, attached to the table with small nails, the seams and the surface of the plywood at the seams are wide 15 mm lubricate with glue and apply strips of paper the width of 15 mm. After the gluing has dried, the nails are pulled out, the set is removed and glued to the board.
Using the wood texture and applying the appropriate arrangement (set) of plywood sheets, you can get beautiful drawing and give the veneered product an artistic look.
In Fig. 188 shown different kinds set of plywood.
According to the specified veneering and set, plywood sheets are prepared.
Face plywood is selected after it has been cut to size (with allowance) and its edges have been smoothed. The selection is made in one of the following two ways: the sheets cut from the trunk are laid out, turning over every second sheet (as if unfolding the leaves of an open book) or simply shifted without turning over. In the first case, one sheet will turn out to be facing upward with the core (right) side, and the other sheet - with the sapwood (left). In the second case, all the sheets will turn out to be facing upward with one side - the core or sapwood - side.
The first method (unfolding) is used for plywood with tough wood that is less susceptible to cracking. Spiky wood (for example, oak) cannot be placed on the face with the left (sapwood) side up, since when drying, the plywood sheet will warp, bending upward, while the sheets facing the left side down will be pressed tightly against the base when warping, and in this case the cracks will be barely noticeable. Therefore, when picking up the plywood, they move the plywood, turning all the sheets with the left side towards the base.
Connection of elements from different materials. For the production of furniture, currently used, in addition to solid wood, are chipboards and fibreboards, wood and other plastics, non-ferrous metals, etc. The connections of such materials with solid wood differ from the above connections.
Elements made of particle boards and fibreboards, which have a higher sensitivity to moisture, lower strength and an unsightly surface, are usually combined with valuable wood. The following connections are used (Fig. 189): pasting front surfaces veneer and planed plywood, width joints on a smooth reveal and on a plug-in batten, miter corner joints with plug-in strips and dowels, with a plug-in pilaster made of wood on a smooth reveal and on a plug-in batten, middle joints on a smooth reveal and on a tongue and groove, sealing edges with wood. The connections are secured using resin adhesives, screws and special clamps.
Laminates are attached to wood using carbinol glue or screws and clamps.
Connections with screws, staples and nails.Screw connection used in dismountable products, as well as in products subject to moisture, in which the adhesive connection is unreliable. Screw connections are sometimes used to simplify work when gluing or knitting parts is difficult.
Almost all fittings are secured with screws: hinges, hinges, handles, locks and various decorations, as well as some wooden parts: glazing beads, trims, etc.
Fastening with dowels(Fig. 190) is used mainly for fastening tenon joints. To fasten parts made of soft wood, dowels are made wedge-shaped, with a pointed end, and are made from hardwood; To fasten hardwood, round dowels made of soft wood are used. Pin thickness from 3 to 12 mm.
The dowels are driven into the holes in a glued and pressed joint. Their ends are smeared with glue and hammered in with hammer blows, while the hard dowel is pressed into the wood of the joint, and the soft dowel is pressed into the hole. With one pin, it is placed in the center of the connection, and with two, each of them is placed at a distance of 1/4 diagonally from the inner and outer corners.
Connections with metal clamps are becoming more widespread. The clamps used are very diverse.
Stitching parts using wavy plates (Fig. 191, a) consists of driving (deepening) half of the plate lengthwise into one part, and the second half into another. This is most applicable when assembling bars into a frame for subsequent gluing with plywood (hollow panel) or when assembling a massive board panel for the same purpose.
Mustache connection made using a steel plate driven into the parts to be connected (Fig. 191, b).
Rallying on the rings(Fig. 191, c) consists in choosing a groove for the ring in the parts being connected, into which a special ring is placed that tightens the parts being connected.
Metal fasteners to strengthen the binding of wooden parts, it is most often used in the form of a metal square placed on top (Fig. 191, d).
Along with metal fasteners, they use wooden squares, bosses or crackers (Fig. 191, e), secured with glue and screws.
Reliability and aesthetics complex structures made of wood largely depends on the correct choice of method of connecting it components. This is especially true for frame products and load-bearing structures, where safety parameters come to the fore.
High-quality connection of wooden parts is the key to durability, the basis for an attractive appearance of the product, an indicator of the skill and professionalism of the carpenter and joiner.
In general, there are a huge number of types of joints of wooden blanks, so we can only talk about some of them, the most common.
One of the easiest ways to extend a wooden part (timber, log, board) and increase its width is an end connection. There are several options for its implementation. A simple and functional half-thickness (half-tree) method is often used. Depending on the expected load on the part, the cut can be straight or oblique. In some cases, the joint is strengthened using figured cutouts - locks. This type of connection prevents stretching, twisting, and bending. This is how the beams are spliced together for the purpose of lengthening.
Creating three-dimensional frames or wooden frames requires reliable connections at various angles. In this case, it is rational to use a tenon-groove or tenon-eye connection. The nodes at the junction of parts can withstand displacement, bending and compression loads. If the structure requires high tensile strength, the cutouts are made trapezoidal.
Additional connections of frame products, which impart rigidity to the structure, are implemented using T-shaped or cross-shaped connections. The main load at the joints is compression, displacement and rupture. IN special cases the structure is further strengthened metal corners, screws or nails.
To connect boards together into box-shaped structures at right angles, it is convenient to use a special box groove. As the name implies, this method is often used to create three-dimensional structures, including furniture boxes. A high-quality box joint looks monolithic, has an attractive appearance and can withstand impressive loads. While creating wooden furniture the connection is often used on dowels, dowels and dominoes (when the groove has an oblong shape, as opposed to a round dowel).
The simplest and one of the most reliable is the tongue-and-groove connection. It is widely used in carpentry. In a similar way, wooden parts of window frames are assembled into a single whole, a wide variety of cabinet furniture parts and plywood sheets are made. The essence this method consists in making a tenon at the end of one part being connected, which is inserted into the groove of another part and fixed in it.
For work, it is convenient to use a special lamellar router; in the absence of one, you can get by with a simple hand tool. You will need:
First, the blanks are marked. The parameters of the tenon and groove depend on the parameters of the wooden parts and the configuration of the product, however, it is worth considering several general recommendations.
Important! The thickness of the tenon should be approximately a third of the thickness of the part, the width should be 70-80% of the width, the length should be equal to the thickness of the workpiece being joined.
The groove parameters must also meet these criteria. In any case, it is important to ensure that the dimensions of the tenon and groove match. The parts should connect easily, without pressure, but not fall out under their own weight. There should be no backlash, cracks or distortion.
The groove is cut out first, this sequence is due to the fact that the tenon is much easier to fit into the groove than vice versa. Cuts are made using a saw, excess wood is removed using a drill, the bottom of the groove and the walls are leveled with chisels.
In most cases, only wood glue is enough to fix the parts; screws or nails will help ensure maximum strength.
Quite often used in carpentry various options half-wood joints (simple or straight lock). This type of assembly of wooden structures is characterized by ease of manufacture and high reliability. The following varieties are distinguished:
The first two methods are used to connect parts that intersect at right angles. Especially popular is the dovetail, in which the neckline is trapezoidal and the sides are not at right angles. The lock groove widens slightly from the end, providing a more reliable fixation. It should be noted that a tenon joint can also be called a dovetail if the tenons are cut in the form of trapezoids.
The second and third methods form a completed angle. Splicing is used if it is necessary to increase the length of the workpiece.
One of the simplest is the cross connection. It is easy to manufacture; even a novice carpenter can master its intricacies. The work is performed in the following order:
Now you can join wooden blanks. The connection must be tight, without backlash or gaps. If the product is one-piece, the joints are coated with wood glue, and the structure is additionally reinforced with screws.
One of the best ways creating corners of various volumetric products is a miter joint. It allows you to create monolithic structure, hide the fibers of the end, thereby providing an attractive appearance. This method is suitable for a wide variety of products, but is most often used for the manufacture of frames and cabinet furniture parts.
To create a connection, cuts are made at an angle in each of the wooden parts, equal to half the angle at which the workpieces meet. Most often, this angle is right, therefore, cuts are made at 45 degrees, however, the angle can vary widely. The work is performed according to the following algorithm.
First, mark out the details. It is important not to forget that the markings are made along the long side, otherwise you may not guess with the dimensions.
On the edges that will be connected, draw a line at the required angle. Using a combination square, the markings are transferred to each side of the workpiece. Then the cut is made, for which it is better to use an electric miter saw, but you can also work with a hand tool. When working with a hacksaw, it is important to control the cutting angle; it would be useful to use a block as a guide.
The finished parts are placed next to each other, checking the accuracy of the fit. Unevenness will have to be smoothed out with a hand plane, and the angle will have to be adjusted using sandpaper. Wood glue is applied to both surfaces, and the product is fixed using clamps. Additional strength can be achieved using nails. When working with a hammer, it is important to control the impact force so that the workpieces do not move.
Particularly important connections are strengthened with the help of bars that are glued into internal corner. A joint that will not be visible can be additionally reinforced with a metal square.
The result of quality work will be a perfect seam. If a small gap has formed, it can be hidden by straightening the adjacent wood fibers using a smooth cylindrical surface. The shaft of a regular screwdriver is suitable for this.
Angle and T-joints (example: T-joint window frame) intersections are conveniently performed using the tongue-to-ridge method. IN in this case the eyelet is made at the end of the vertical part, the cuts for the tenon are made in its horizontal component.
The work begins with marking the eyelet. The thickness of the workpiece is divided by three. With a thin hacksaw, cuts are made to a depth equal to the width of the other workpiece. Excess wood is removed using chisels, and the walls of the eye are smoothed with sandpaper.
Mark the second workpiece. The width of the tenon should be equal to the width of the first workpiece, the thickness should be equal to the thickness of the tenon. The cuts are made hand hacksaw, carefully control the depth and angle of inclination. Remove excess with a chisel.
The final adjustment of thickness is carried out using sandpaper. The parts should connect with light force and not fall apart under their own weight.
A more complex connection is the tenon-to-socket method. It requires more skill, but is much more reliable and durable. The scope of use is the same as in the previous case, namely T-shaped joints. The difference between this method is that the tenon is made at the end of the vertical part, and a socket is cut out in the body of the horizontal part.
This is one of the most common furniture joints. There are connections with a through tenon and with a blind one. The difference is that in the first case a through socket is cut out, in the second the slot is made to a certain depth.
Carpentry art has reached unprecedented heights Japanese masters. Using traditional techniques, combining Various types connections, they create precise and reliable joints without the use of nails or other fasteners. The joining of various wooden parts is carried out solely due to the force of friction.
The reliability of these connections is based on precise cutting. The perfectly matched locking lines on both mating parts allow you to create a connection with impeccable precision. Complex lock configurations require a lot of experience, knowledge and ability to use the tool, but if you want, all this can be learned.
High-quality wood is expensive, and it is not always possible to buy a good board with the necessary parameters, and it is not always necessary. To make, for example, a tabletop, it is not at all necessary to look for a table-wide board; with carpentry skills, you can create the ideal wooden canvas with the necessary parameters.
There are many options for bonding. A board with a tongue and groove, the so-called lining, is widely used. It allows you to create smooth wooden surfaces of a large area. A simplified version of it is often used - a board with a quarter joint.
The simplest method that does not require additional elements. Side faces boards are jointed, it is better to do this in pairs, clamping both adjacent boards in a vice and processing them at the same time. This treatment will create a precise surface on which the unevenness of one board will be compensated by the unevenness of the other. Both boards are coated with glue and fixed until it hardens completely.
There are several ways to lengthen (build up) a board that is part of the supporting structure. The simplest and most reliable is a half-timber connection followed by overlaying reinforcing strips at the junction. Non-critical areas can be reinforced with plywood.
The same method is also used to join boards at different angles. Precisely made cuts of the jointed parts make it possible to do without reinforcing linings; it is enough to secure the boards at the joint with screws.
Cutting without residue means that the stacked logs will form an even angle, their ends will not protrude beyond the boundaries of the building; a separate type of it - warm corner. Cutting with the remainder, in turn, means that a weave of protruding ends will be formed at the corners of the building. The second method is more expensive in terms of the amount of material, but the building retains heat better and is more stable.
Exist various ways connecting wooden parts, the ability to determine the optimal one for a particular type of work will significantly diversify the range of products that a master can make. The right method will provide an attractive appearance product and guarantees the reliability of the three-dimensional structure.
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In this article we will review what options are available for joining wood products. And there are a great many such methods, from a simple butt connection to the most complex dovetail connection. It is important to remember that not all of them can be done independently, but the information below will definitely not be superfluous.
Reliable coupling is the key to strength and reliability for any design
All of them are distinguished by their strength and complexity, for example, the cabinet body is assembled with a seam or butt joint, less often they use a “grooved” or “mitered” combination. But for the manufacture of a door frame or panel, the skill of tenoning is useful.
Below are the methods for joining wooden parts.
Butt registration is called securing the edges. For this purpose, fasteners and glue are usually used. But the butt joint is not very reliable, so it needs to be strengthened, which is not so difficult to do.
It is advisable to strengthen the butt joint metal fastening: corners and screws
This method is usually used when assembling the front frame of a cabinet, where strength does not play an important role, since the frame parts are securely attached to the cabinet itself. Butt joints of wooden structures are usually reinforced with lamellas or dowels, which are able to align the individual parts during gluing.
This combination has some differences from the previous one. When gluing the surface, the parts are beveled at an angle of 45° relative to the axis. The miter connection of wooden parts also needs to be strengthened using additional fasteners.
For your information! Typically, this method of combining is used when it is necessary to connect two pieces of molding in a corner.
As mentioned above, you can strengthen it using ordinary wooden dowels. Dowel reinforcements are usually made using two dowels glued into one and the other end of the crossbar, into vertical posts, and into their corresponding sockets. There are specific instructions for making such connections:
We mark the sockets for the dowels:
Advice! If you don't have a locking sleeve, you can replace it by placing a small piece of tape over the drill.
If we compare the types of connections of wooden structures, the lamellar connection certainly wins. Although the price of such connections will be a little higher, they are very easy and convenient to work with.
Lamels are compressed wood in the form of flattened balls. The nests for such balls are cut out using a special lamellar machine. This results in a perfectly shaped hole. And due to the fact that the lamellas are slightly shorter than the socket, the alignment of parts when gluing is more accurate. It is very uncomfortable.
The rafter system is the most complex and one of the most important elements of the house; the comfort and operating time of the building largely depend on the correctness of its construction. Calculation and design rafter system should only be done experienced builders or engineers with special training.
Designing a wooden rafter system is much more difficult than any metal structures. Why? In nature, there are no two boards with absolutely identical strength indicators; this parameter is influenced by many factors.
Metal has identical properties, which depend only on the steel grade. The calculations will be accurate, the error will be minimal. With wood everything is much more complicated. In order to minimize the risk of system destruction, it is necessary to provide a large safety margin. Most decisions are made directly by the builders on site after assessing the condition of the lumber and taking into account the design features. Practical experience is very important.
Construction boards
There are several reasons why rafters need to be spliced.
Important. It must be remembered that the strength of spliced rafters is always lower than that of whole rafters. You should try to ensure that the splice point is located as close as possible to the vertical stops.
There are several ways to splice, there is definitely no better or worse. Craftsmen make decisions taking into account their skills and the specific location of the joint.
Table. Methods of splicing rafters.
| Splicing method | Brief description of the technology |
|---|---|
| It is used on boards with a thickness of at least 35 mm. Enough complex method, requires practical experience performing carpentry work. In terms of strength, the connection is the weakest of all existing ones. The advantage is saving lumber. In practice, it is used very rarely on construction sites. |
| Length rafter legs increases with the help of an overlay. The cover can be wooden or metal. If the length of two sections of boards is not sufficient according to the parameters of the rafter system, then this method allows you to increase them. Butt joints have the highest bending strength and are widely used during the construction of various structures. |
| Overlapping. Two boards are fixed with an overlap. The simplest method is in the middle in terms of strength. Flaw - total length two boards should be greater than the design length of the rafter leg. |
In this article we will look at the two simplest and most reliable splicing methods: butt and overlap. There is no point in touching the oblique cut; it is almost never used because large quantity shortcomings.
Inept splicing of rafters along the length can not only sharply reduce their resistance to bending loads, but also cause complete destruction of the structure. The consequences of this situation are very sad. Building regulations provide certain patterns when choosing the size of the fastener, its installation location and the length of the pads. The data is based on many years of practical experience.
Spliced rafters will be much stronger if metal pins, rather than nails, are used to connect them. The instructions will help you make your own connection calculations. The advantage of the method is its versatility; it can be used to solve problems not only with lengthening rafters, but also with building up other roof elements. Specialized companies performed rough calculations and collected the data in a table, but only the minimum acceptable parameters are indicated in it.
