Rafter system of a gable roof of a brick house. Installation of a gable roof with hanging rafters. Types of gable structures

The roof of a building is an important and responsible structural element that performs several functions simultaneously. The main task is to protect walls and ceilings from rain or melt water, which destroys the materials of the walls and the entire structure as a whole. Additional features are the conservation of thermal energy, ensuring the operation of various life support systems at home, protection from wind, dust and other atmospheric and climatic manifestations. The roof structure is complex; the roof covering, which takes on all the main tasks of sealing and cutting off low temperatures, needs a reliable and durable supporting system.

Gable roof and its features

The roof is one or more planes covered with a roof and designed to cut off external weather or atmospheric manifestations. Each plane is called a slope, so a gable roof, by definition, has two protective planes. They can be symmetrical or asymmetrical, have the same or different angle of inclination. The configuration is determined by the architect’s plan, the climate in the region, the presence of strong winds, etc. The most common are symmetrical gable structures, as they create a uniform load on the walls and foundation.

Slope angle

The roof planes must have a slope that allows snow or water to drain away. The angle value is a calculated indicator; it cannot be chosen arbitrarily. Factors influencing the choice of slope:

The amount of snow falling in winter time, characteristic of this region.
The amount of rain, its strength and duration.
Prevailing winds, their strength and duration, the possibility of gusts or hurricane force.

The point of calculating the angle of inclination of the slopes is to determine the optimal position of the planes, ensuring timely melting of snow, drainage of rainwater and, at the same time, not creating excessive resistance to wind flows. Loads from snow in winter amount to tons, and gusts of wind create a significant impact on the load-bearing structures of the house and the foundation. You have to look for a “golden mean” that allows you to get a sufficient slope with low wind resistance. In some regions with certain prevailing winds and high precipitation amounts, the optimal choice is an asymmetrical roof shape, flat on the windward side and steep on the leeward slope. To achieve this shape, it is necessary to create two planes of different areas with a fracture line located outside the axis of symmetry of the building. When creating a house design, it is imperative to take into account the prevailing wind direction so that the load falls on the slopes of the roof and creates minimal stress on the load-bearing structures.

What is a rafter system

Gable roofs usually have vertical extensions of the walls at the end - gables. Small buildings may not have a rafter system at all, when the roof is laid on longitudinal strips laid on the slopes of opposite gables. For larger buildings it is necessary to have strong support. This is what it looks like to assemble a rafter system of two pitched roof with your own hands:

The roofing covering is able to ensure the tightness of the outer protective layer, preventing moisture or wind from passing through. At the same time, the roof has no load-bearing capacity; it needs a well-organized support system. These are rafters that perform several tasks:

create a supporting plane for the roof, form a frame;
form the roof configuration, create the required number of planes - slopes;
provide the necessary rigidity and strength;
connect the roof to the supporting structures of the building.

The functions performed place a lot of demands on the system, the main of which are strength and the ability to maintain shape despite a long service life and load-bearing loads. Here is an example of the simplest way to calculate the strength of each individual rafter:

Externally rafters gable roof look like two rows of inclined slats connecting at the top. To ensure the strength and rigidity of the structure, there are various elements that need to be considered in more detail.

Elements of the rafter system

The design of rafters is one of the most complex of all building systems. It includes:

Mauerlat. A strapping belt made of timber 100×150 or 150×150 mm, laid along the perimeter of the walls in the upper end part. Serves as a base for rafters and connects the roof to the walls.
Sill. It is laid along the longitudinal axis of the building and provides support for vertical support elements. Used only on buildings with an internal middle load-bearing wall.
Sprengel. Strengthens corner connections Mauerlat. It is a kind of strut laid horizontally and providing a diagonal brace.
Puff. Connects the opposite bars of the mauerlat, compensating for the bursting load from the inclined elements.
Stand (grandmother). Vertical piece that supports the ridge.
Skate (run). A horizontal beam (or board) that forms the upper edge of the roof, connecting inclined planes - slopes.
Rafters (rafter legs). Inclined strips forming the planes of the slopes. Their lower ends rest on the mauerlat beam, and their upper ends rest on the purlin.
Struts. Inclined elements that serve as additional supports for rafters at points of greatest load. Installed perpendicular (or at a slight angle) to the rafters.

Important! The above list is not exhaustive, there are many more various elements rafter systems, but on gable roofs they are, as a rule, not used.

What are rafters made of?

The material for making rafters is traditionally wood - timber and edged boards. Advantages wooden parts rafter system:

Relatively light weight, eliminating high loads on the supporting structures of the house.
Availability, prevalence of material.
Wood is easy to process, cut, and join.
High maintainability of the material. Any element can be replaced or put in order during operation.
Strength, reliability of the design.

There are also disadvantages:

Wood is susceptible to rotting, mold or mildew.
High susceptibility to water, ability to absorb and release moisture.
As wood swells, it changes its linear dimensions.
Wood is flammable.
Installation of rafters requires the use of material with high requirements for humidity and quality.

Recently, an alternative type of rafters has appeared - metal. They are free from most of the disadvantages of wooden parts, are not afraid of water, are strong and durable. The only disadvantages include the possibility of corrosion (although the metal has protective covering), relatively high weight and increased connection complexity compared to wood. In addition, metal rafters are much more expensive, which limits their use in private housing construction. The main consumers of such parts are builders of large facilities that require strong roof large sizes. The loads experienced by the rafter system in such conditions are very high and require the use of reinforced parts.

The process of installing a metal rafter system is no more difficult than the process of assembling a wooden structure. You can see this for yourself:

There are combined rafter systems that use both metal and wooden elements. This option allows you to slightly reduce the weight of the structure, it is more economical and easier to install. The only critical point is the need to waterproof the joints of metal and wooden parts, since condensation formed on the metal can get on the wood, causing rot and failure.

Types of rafter systems

There are two design options for rafter systems:

With hanging rafters;
layered rafter system.

The fundamental difference between these options is the fulcrum of the rafter legs. The first option involves attaching the base of the rafters to the mauerlat and connecting them at the top point when the girder (ridge) rests on them. The second option provides a more durable girder with load-bearing functions, and the rafters are completely fixed to the mauerlat and to the ridge beam.

Both options are actively used. In practice, they differ little from each other, since the implementation features of one type or another directly depend on the size of the building and the design of the load-bearing walls. Construction of houses average size forces the use of structures that are more similar to the layered type, which provides greater strength and rigidity of the system. Let's take a closer look at both options:

Hanging rafter system

The traditional use of hanging rafters is in small houses, with maximum distance between supports up to 6 m. This is explained by the appearance of an additional load - in addition to the weight of the roof and the influence of atmospheric factors, the rafters acquire self-supporting properties. As the size of the house increases, the load becomes excessive and requires strengthening the structure.

A feature of hanging rafter systems is the bursting force applied to the Mauerlat. To compensate for this pressure and protect the walls from deformation and subsequent destruction, puffs located in the lower part of the rafter legs are necessarily used. During construction, they often resort to making so-called. trusses having the shape of an isosceles triangle. They are made on the ground or assembled directly on the top of the house and installed on the roof plate as a finished structure. This method somewhat speeds up the process of creating a roof, since the same type of elements are used, which allows you to repeat the same operations several times and obtain the required number of elements.

Layered rafter system

The construction of medium and large-sized houses requires the creation of a strong and rigid rafter system. The weight of the roof, snow and wind loads force the use of a layered type of system. It differs primarily in its installation technique. First, the supporting elements are installed - the Mauerlat, the bench, the racks and the girder. They have a high load-bearing capacity and are designed to bear significant loads, therefore they are made of timber. The rafter legs are installed with support on the Mauerlat at the bottom and on the purlin at the top, when long length they are strengthened by struts.

Experts note the greater reliability of the layered rafter system. During assembly, there are no ready-made parts of the structure, so all work is carried out directly on top of the building. No need to lift heavy ready-made elements, only the material is fed upward. Each strip is installed separately, which ensures the accuracy and tightness of the connection and avoids poor-quality installation or errors. Compared to structures with hanging rafters, layered rafter systems significantly improve in strength and allow you to obtain a better-quality and more durable support structure. In regions with large quantities precipitation, snowy winters, strong gusty winds, a layered rafter system for a gable roof is much preferable and more reliable.

How to choose the optimal design of gable roof rafters

The main selection criterion is the size and purpose of the building. Small houses, not having large area roofing, are able to make do with lighter supporting structures. Medium-sized buildings and large buildings must have a strong and powerful rafter system that can withstand the pressure of snow, wind, and withstand the weight of the roof. In order to decide how to properly make a roof, you need to find out the climatic conditions in the region, the amount of precipitation, the possibility and frequency of strong winds, heavy snowfalls, etc. These data are involved in the calculation; they are available in SNiP tables or in reference literature.

At the same time, you should not be too zealous and build an overly powerful rafter system for a small house. It must be remembered that power is additional material, and consequently - an increase in the weight of the structure. The optimal choice will allow you to get a fairly strong and lightweight system that does not overload the foundation and walls, but fully provides protection from external atmospheric manifestations.

Installation of a gable roof rafter system

Let's look at how to properly install rafters on a gable roof with your own hands. The task is difficult, but completely solvable. The main condition will be the possession of the necessary knowledge and accuracy, thoroughness in performing all necessary operations. A simpler option is a system with hanging rafters, but it is more correct to consider complex structures, since layered rafters on a gable roof are more reliable, and the technique for performing the work is almost the same.

Preparatory operations

First of all, you will need to make a thorough calculation of the system. For an unprepared person, such a task will probably be overwhelming, but the solution may be to use an online calculator, of which there are many on the Internet. They are easy to use - you just need to insert your own data (roof dimensions, other values) into the program windows and get ready-made parameters for the rafter system. To obtain more accurate values, you can repeat the calculation on another calculator.

The second action will be the acquisition of material. Let's consider more difficult case- making a wooden rafter system with your own hands. She will need wooden beam sizes 100×150 or 150×150 mm, as well as edged boards 50 mm thick. You should pay close attention to the quality of the material. Wood should not have any defects:

rotten areas;
traces of insect activity;
cracks;
the number of knots should be limited; you should not choose material with dead (fallen out) knots;
Wood moisture content should be between 18-22%.

The selected and purchased material must be stored on the site under a canopy. It is impossible to lay boards or beams tightly on top of each other; spacers must be used to allow free air movement. An example of proper storage of lumber:

Important! The presence of resin in wood is of great importance. If tapping (resin collection) was carried out on the site, the material becomes lighter and dries faster. At the same time, the risk of fungal attack, rotting or absorption of atmospheric moisture increases.

In any case, the purchased material must be kept on the site for some time (at least a couple of weeks) to gain atmospheric humidity characteristic of the given region. If you start construction right away, there is a risk of the structure being distorted and causing unnecessary stress.

The next and final step of the preparatory operations must necessarily be the bactericidal treatment of purchased wooden materials:

Important! If you want your roof to serve you for at least 50 years without a single repair, you need to treat the wood with an antiseptic. This simple operation will avoid damage to lumber by bark beetles, and will also prevent rotting of the material.

Do-it-yourself installation of gable roof rafters

Let's look at how to make a rafter system for a gable roof with your own hands. The work is carried out in stages, in strict order. Since the installation of a structure with hanging rafters is somewhat simpler, we will consider a more labor-intensive option - installing a layered rafter system made of wood for a gable roof.

The first step in installing rafters for a gable roof with your own hands is to prepare the walls of the building without a Mauerlat. An example is shown in the photo:

The mounting surface of the walls is leveled with a small layer of mortar. After the solution has completely dried, bitumen waterproofing is applied on top of it, or one layer (strip) of roofing material is laid. Next, a board is laid on top of the “sandwich”.

The second step is the installation of the Mauerlat. How to do this is shown in detail in the photo below:

The timber frame is installed on a waterproofed base formed internal part the end of the walls. A brick or block edge is usually installed along the outer edge, providing protection against water from entering from outside. Sometimes the Mauerlat is made from edged boards, which is justified when small sizes buildings and roofs. For insulation, a double layer of roofing material is used, with an intermediate application of heated bitumen. The connection of the timber both in the longitudinal and transverse directions is made in half a tree. Pins are used to strengthen the strapping. Before finally putting the beam in place, holes are made at the end of the walls to deepen the ends of the studs or dowels and install anchor bolts.

Then the bed is installed. Installation is carried out in a similar way, on a waterproofed base. The connection to the Mauerlat is made in half a tree, reinforced with metal staples or nails.

Racks are installed. They are mounted on a bench and additionally reinforced with struts or spacers. A purlin is attached to the top of the racks.

The installation of the rafter legs begins. They are attached to the mauerlat and purlin using nails. For clarity, here are a few examples:

There are also metal fasteners for gable roof rafters, which ensure high-quality connection of parts. It must be remembered that between the wood and the metal there must be a gasket made of roofing felt or glassine. The installation step of the rafter legs is determined by calculations made in advance. The durability and reliability of the roof depends on the accuracy of the dimensions. Here is an example of assembling trusses on nail plates:

Upon completion of the installation of the rafter system of the gable roof, the sheathing is installed.

There are two types - the lathing itself and the counter-lattice. The first type is used in the absence of insulation, and if it is planned to install it, then both layers are installed. In such cases, the counter-lattice provides the necessary ventilation gap between the roof and the insulation and at the same time serves as a support for roofing material. The lathing performs the function of supporting the insulation and provides the necessary gap between the rafters and the counter-lattice.

In parallel with the sheathing, the roof overhang is made. It protects the ends of the walls from water. It is impossible to form an overhang immediately when installing the rafter legs, so the work is carried out on final stage. To form an overhang, an edged inch board is used, from which a continuation of the rafter line is made, taking into account the thickness of the sheathing, extending beyond the perimeter of the walls by the required amount.

Installing gable roof rafters with your own hands allows you to significantly save money, complete all the work at a time convenient for yourself and gain valuable experience in performing similar work. The main condition for obtaining a high-quality result will be accuracy, thoroughness in performing all actions, and preliminary familiarization with the rules and features of the installation of a particular element.

Video instructions

The rafter frame sets the geometric and operational parameters of the pitched roof. Due to violations in installation technology, due to flaws in the manufacture of its elements, system distortions, traditional leaks, and holes in the coating appear, threatening emergency situations.

In order to build a reliable and stable roofing structure, you need to clearly know how to cut and install rafters with subsequent fixation to the supporting elements.

Rafters, or rafter legs, are called wooden or metal beams, installed on the frame of the house at a given angle. They determine the configuration of the roof structure, take on and firmly resist the sum of permanent and temporary loads acting on the upper enclosing system of the building.

The structural simplicity of the rafter legs is extremely deceptive. In fact, these are quite complex elements that require careful marking and careful cutting. Inconsistencies in the connections of the rafter legs with the Mauerlat, with each other and with other components of the system lead to a change in the shape of the slopes, disruption of the integrity of the coating and destruction of the nodes.

On the other side, competent installation rafter legs can correct some errors in the construction of the frame of the house, and not aggravate the situation by clearly repeating and increasing the differences in wall heights. True, in such situations, the frame elements are manufactured individually and scrupulously adjusted after the fact directly on site.

However, before understanding the specifics of installation, you need to find out what their design differences are, according to which rafter legs are divided into two groups:

Hanging. A type of rafters that do not have an upper support. At the top of the roof, the rafter legs rest against each other with their ends. So that under the weight of the components roofing pie and snow, this design did not burst the mauerlat beam; the hanging rafters were connected with a horizontally installed tie.
Layered. A type of rafter legs, laid on two supports of different heights. At the top, they most often rest on a ridge purlin installed in a cross to the rafters; less often, their ends, sawn at an angle, rest against each other. The bottom rests on the mauerlat beam or rests against it.

The scope of their application and installation technology depend on which group the rafter legs belong to. The hanging variety is assembled on the ground, and the trusses, made in the form of peculiar triangles, are lifted to the roof and mounted in a form fully prepared for installation.

The advantage of constructing a rafter frame using hanging technology is the safety of work and the ability to make node connections as accurately as possible. If the simplest version of a hanging truss with a tie at the bottom is used in the construction of the roof, you can abandon the installation of a Mauerlat, in the place of which a narrow leveling board is quite suitable.

The disadvantages of hanging technology accompany the advantages. For example, a truss assembled on the ground is much more difficult to transport to the installation site than boards and timber for layered rafters. There are restrictions on overlapped spans: the limit is considered to be 14 m, above which it is unreasonable to install those prone to sagging wooden beams without intermediate supports.

The rafter legs of the layered group, both top and bottom, rest on independent structures. Their tops are laid on a purlin structure, which is mounted on floor beams or on a beam that replaces the mauerlat on the inner wall. The bottom is either installed on the Mauerlat or rests against it, catching on the beam with a tooth or a support bar sewn in place of the tooth.

The advantage of layered systems is rightfully recognized as the ability to cover spans of almost any size. It’s just that as the overlapped space increases, the design becomes more complicated: it is supplemented with struts paired with racks, additional purlins coupled with beds, and contractions.

The layered structure takes longer to assemble and install, because it is built not from trusses, but from individual elements. However, this particular scheme has more opportunities for correcting defects in the frame or unevenly settled frame. Because Layered rafters are laid individually; it is possible to slightly change the position and size of the unit in order to ultimately form an impeccably leveled plane of the slope.

Specifics of manufacturing and laying rafters

It is clear that for the construction of the rafter system, lumber will be needed - long-length products from forest processing enterprises with clear geometric parameters. You will need a board or timber, which, naturally, does not have mounting cuts or notches for installation.

Why are cuts and cuts needed? The fact is that when placed on an edge, the boards and beams have too small a support area. They contact the Mauerlat with only one thin line, which is why, at the slightest load from above, they can simply “move out” from their occupied position and drag the entire structure along with them.

In order to increase the support area at the junction of the rafters and the mauerlat, or it and an additional purlin, a corner notch is selected in the beam or board, a tooth is cut out, or a support block is sewn on. If the top of the rafter is connected to a mirror-opposite analogue, then for a reliable stop you will need a cut, the plane of which must be clearly perpendicular to the horizon.

The basic rule in the construction of rafter frames is that the platforms chosen for support in the lumber are strictly horizontal and vertical. At the slightest violation of horizontality and verticality, stability is lost, structural parts shift under their own weight and the action of the load until the complete destruction of the system.

Let us note that the nodes of rafter systems are responsible for ensuring the possibility of slight displacement and rotation when the load is exceeded. These movements are necessary so that the structure bends slightly, moves slightly, but does not collapse and remains stable.

These subtleties should be known to both the craftsman who has decided to make and install rafters with his own hands, and the owner of a house under construction who does not want to pay for the poor-quality labor efforts of the construction team. Let's look at common options to understand the essence of the process.

Construction of a roof frame using hanging technology

Let's look at an example of constructing a rafter system over a log bathhouse. The span between the walls is small, it is easier and more reasonable to cover it with a hanging structure, the installation of which will be carried out on the bypasses of the ceiling beams - matits.

A log base is an almost ideal option for installing hanging systems, because it is easiest to cut it into the horizon, eliminating the need to adjust the rafters in case of violation of the foot geometry. There is no need to install a Mauerlat. However, the tie will have to be moved upward to bypass the upper crown of the frame and form a useful attic space.

Before installing the rafters, stage-by-stage preparation of the log house is carried out. On both sides of the foot, we align the bypasses according to the lace tied to the nails driven into the two outer beams. On top of the bypasses we cut off the slab so that the edge of each beam ends with a flat horizontal platform.

The layer formed after cutting off the upper convexity of the log along the edges of the beams is leveled to the horizon according to the level. We apply the specified control tool to three or more beams at the same time. If the level is not long enough to carry out such a check, use a long strip or board instead.

After trimming off all the excess, we mark the sockets for the rafter teeth. To do this, we again use nails and lace. Note that nest sampling sites can be marked on the crossings both before and after the construction of hanging trusses. However, it is much more convenient to make the nests before making the rafters. They will help with more high accuracy carry out a fitting.

To make your work easier, it is advisable to find the center of the log house on the side of the future tongs. At these points it is recommended to nail along a control strip, one of the edges of which will indicate the axis of symmetry. You can do without slats if you already have some experience in building roofs.

We sew two inch boards 10 - 15 cm longer than the designed length of the rafters at the top with a nail or bolt so that they can rotate around this connecting point.
On a strip installed in the center of the future gable, we mark the design height of the rafter system. We put another mark above it - this is the height of the tooth, more precisely, the length of the vertical line laid from the base of the tooth to its top.
We place the boards sewn at one point at the extreme bypasses so that the corner of each board rests on the future socket under the tooth.
We align the connection point of the boards with the top mark on the rail, which determines the length of the rafters with the tooth.
From the bottom corner of both rafters we set off the height of the tooth, return with the template blank to the ground and cut out the tooth according to the markings.
We return the template blank to its place, install it by inserting the teeth into the slots intended for them. It may happen that after installation the top of the workpiece does not coincide with the instructions of the staff. Then you need to pull out the nail and adjust the position of the top, making sure to mark a new point.
After adjusting the top, we draw a vertical line of their upcoming joint on both boards, measure the size of the crossbar and mark on the scraps of the board the shape of the overlays for the upper junction of the rafters.

If everything turned out exactly and no further adjustments are required, the template is ready. We return with him to earth. We disassemble the workpiece and make cuts along the marked lines. The parts obtained as a result of fitting and fitting will serve as a standard for the almost continuous production of roof trusses in the required quantities.

We will assemble hanging trusses on the ground. Their installation, as well as fitting, should be carried out by at least two people. One master simply cannot cope with such work. The person at the top will install the truss, and the second will change its position according to the instructions of the plumb line. The position of each leveled and installed truss should be fixed with temporary spacers.

To increase the stability of the system, we will install racks under the rafters:

Let's mark the mats for the installation site of additional supports using the already proven method: we hammer in a nail on opposite sides and pull the string tight.
We will hollow out nests in the logs according to the markings.
Let's try on a piece of timber for the installation site. Let's mark a line on it, taking into account the height of the tenon.
Let's make a stand and two pads for attaching it to the rafter.
We will install the support we have made and similarly secure the position of the truss on the other side. We continue to work according to the verified scheme until we equip each rafter with additional support.

To ensure rigidity hanging system trusses are connected by wind ties - boards, poles or slats nailed from the inside of the structure. WITH outside The rigidity of the rafter frame will increase due to the construction of the sheathing.

The rafter legs are attached to the mats with 200 mm nails or corner brackets. In this regard, metal corners and plates with perforations for fasteners are noticeably inferior to traditional methods. To the sides of the rafters we nail fillets made of boards, the width of which is half the size of the material used in the manufacture of the rafters.

The length of the fillies should be 70–80 cm greater than the designed width of the overhang. This distance is needed to securely connect them to the rafter legs. The fillies can be cut in advance, or you can nail scraps of narrow boards to the rafters without preliminary cuts, and then draw a line for the cornice. However, the first option is more convenient and economical.

In most cases, as in the example given, the fillies must be partially buried in the bypasses of the mats, for this:

We note the actual width of the filly at the bypass.
We make two cuts with a saw according to the markings for 2/3 of the thickness of the filly. We also use a saw to cut the log between the outer cuts. We refine the recess with a chisel accompanied by a hammer.
We install the fillies in the formed recesses and sew them to the rafters with nails 100 mm long.

Upon completion of the installation of all fillies, we hammer a nail into the outermost ones. Pull the control cord and mark where the excess should be sawed off.

Installation of a layered roof frame

The construction of a rafter frame using layered technology has much in common with the installation hanging structure. The fitting is carried out in almost the same sequence, so it makes no sense to describe the actions twice. The main difference is in the methods of forming the upper node, because the tops of the layered rafters have a support - a ridge girder.

If the layered rafters at the top simply rest on the ridge girder, they are laid either with a run, i.e. parallel to each other, or with a strictly vertical joint, similar to the joining of hanging legs. However, in most cases, they try to secure the upper part with a notch or a vertical cut, tightly abutting it to the ridge beam.

There are schemes according to which the layered rafters rest not on the ridge, but on the side girder. In such situations, the top is formed according to the hanging principle, and the point of support on the purlin is formed with a corner notch.

Let us analyze the most popular option in private construction for constructing rafter legs based on the lower corner notch and on the ridge run through a vertical cut. Please note that the maximum cutting depth should not exceed 1/3 of the board width.

Option for marking with a construction square:

On the square we mark the height of the roof and half the span on a scale. These values display the slope of the slopes and set the main angles. The proportions must be kept exactly.
If further use of the square is not planned, then you can mark the deferred points with screwed bosses or short screws with screws; if you plan, then better paint, which can be removed with a solvent.
We apply a square to the laid flat board with the side on which the height of the roof is marked. We draw a line according to the readings of the square - this is the line of the upper cut of the rafter - the area where it connects with the ridge girder.
Cut along the marked line with a circular saw. We lay the board for sawing flat, as it should be when cutting wide. Longitudinal cuts are made on the edge.
From the top of the formed angle we set off the length of the so-called diagonal. This is the distance from the point of connection with the purlin to the outer edge of the Mauerlat or top harness, if a frame house is being built.
Move the square to this point. We draw a line parallel to the first one.
We turn the square over, move it along the workpiece so that 2/3 of the total distance is on the left, and 1/3 on the right. In the picture these are 8ʺ and 4ʺ.
The line of the smaller segment will mark the cut for us.

At the end, we draw the outline of the eaves overhang on the board, cut it along the outlined lines and use the rafter blank we made ourselves to cut the remaining elements of the roof.

You can apply the described method without a construction square and marking the roof parameters on it. It is enough to imagine the process to set aside the necessary distances with a conventional drawing tool. However, without experience, you can get confused in calculating angles and segments.

To help beginning builders, a template has been developed with options for forming corner notches. It will help you navigate the production of rafter legs from the most common lumber in this area.

In cases of laying rafter legs with notches in the upper and lower parts, it should be remembered that the depth of both notches must be the same so that the roof slope does not change during construction work. Usually, to create two equal notches, an auxiliary block is used, the thickness of which is no more than 1/3 of the thickness of the board.

The rafter blank is then installed edge-on on the mauerlat and on the purlin. The block is applied to the side in the area of the lower and upper node to outline the notch.

If a notch is needed only in the lower part of the rafter, and the top will rest on the purlin with a cut, the board is installed below on the mauerlat, and at the top on the purlin and block, so that as a result of cutting the angle of the slope does not change. At the bottom, a second block of a similar size is applied to the future node and, with its help, the outline of the future notch is outlined.

The same methods are used to form cuts with teeth. The only difference is in the shape.

The installation of layered rafters begins with the installation of two outer trusses. The elements are mounted one at a time, their position is carefully checked using a plumb level. Most often, the outer trusses are made from paired boards, because more load is distributed over them. They are fixed with temporary spacers, then connected with a lace or strip to indicate the plane of the slope.

Ordinary rafters located between the outermost load-bearing trusses are installed according to the instructions with laces. If necessary, adjust the position of the legs according to the actual situation.

Video about installing rafter legs

Installation of rafters with fastening metal corners:

How to make rafter legs with notches for mounting on the Mauerlat:

Construction of a rafter frame for a garage roof:

We have cited and described only part of the methods for constructing rafter frames. In reality, there are significantly more manufacturing and installation methods. However, analysis of the basic options allows you to perfectly understand how to properly make rafters and roof trusses, and how to saw them before installation.

A gable roof is a simple but effective roof that reliably protects the building from wind and precipitation. You can install the rafter system of a gable roof yourself, but first you should familiarize yourself in detail with the design and the basic rules of its design.

The rafter system consists of several parts, each of which plays an important role.

In addition, the rafter system of a gable roof may have additional elements necessary to strengthen the structure:

struts - beams located at an angle between the rafters and the tie;
headstocks - beams installed vertically in the center of the rafter system (necessary for roofs whose width is within the range of 6.0 - 7.5 m);
crossbar - a beam installed parallel to the tie that tightens the rafter legs (used for roofs up to 6 m wide).

About the types of rafter systems

The installation of a gable roof rafter system is carried out in two ways.

The hanging rafters rest with their upper parts on each other, and their lower parts on the mauerlat. To increase reliability in the lower part, the rafter legs are connected with a crossbar. This system suitable for use in roofing buildings whose width does not exceed 10 m. This is the only possible solution for projects that do not involve the construction of a load-bearing wall in the central part of the structure.
Layered rafters, in addition to the mauerlat and ridge beam, have an additional point of support - beams installed vertically on the middle load-bearing wall, called purlins. The installation frequency of the purlins coincides with the pitch between the rafters.

Calculation of the rafter system of a gable roof

The height of the ridge depends on the distance between the load-bearing walls on which the rafter legs rest, as well as on the planned slope of the roof. The latter is chosen based on local conditions: for snowy areas the roof slope angle should be large, and for windy areas it should be smaller. The optimal angle is considered to be within 35-45 degrees.
The height of the ridge is determined by multiplying half the distance between the rafter legs by the tangent of the slope angle (tabular value).
The distance between the rafter legs and the length of the rafters influence the choice of beam section (see table).

Length rafter beams is calculated by dividing the ridge height by the sine of the slope angle.

The calculations use the formula below.

So, the actions when calculating the roof come down to three points:

calculate the length of the slopes (the distance from the bottom point of the ridge and the edge of the overhang);
we make adjustments for additional elements: parapets, roof windows, firewall walls;
We select roofing material and calculate its quantity.

Note: the amount of roofing material and the time required to lay it depend on the height of the ridge.

How to make a rafter system for a gable roof

Before proceeding with the installation of the rafter system, it is necessary to check the level of the load-bearing walls: the horizontal discrepancy should not exceed 5 mm. All angles must be right (unless otherwise provided by the project). In places where the Mauerlat is attached, studs made of steel rods with a diameter of 10-14 mm are installed in advance in increments of 1-1.5 m. The lower ends of the studs are laid with bricks in three rows.

Do-it-yourself rafter system for a gable roof: installing a Mauerlat

Installation of a gable roof truss system begins with laying and fastening the Mauerlat. Your attention - step-by-step instruction installation

In the place where the Mauerlat is laid, 2-3 rows of roofing material are laid for waterproofing.
The distances between the studs are measured, all dimensions are transferred to the mauerlat bars.
Holes are drilled in the wood at the marked locations.
A beam with a cross section of 100×100, 150×150 or 200×200 mm is laid on top of the load-bearing walls on studs, which should protrude by 30-40 mm. There should be some distance between the Mauerlat and the outside of the walls. This gap can be filled with bricks.
The Mauerlat bars are attached to the studs using large diameter washers and nuts. Welding of nuts is allowed.

Note: in cases where fastening with studs is not possible, use tying the Mauerlat with wire or wooden staples. A long wire with a diameter of 3-4 mm is embedded in the wall 3 rows before the end of the masonry. Wooden brackets are used in wooden houses.

Installing rafters: basic rules

At this stage, it is important to maintain the accuracy of the location of the parts and ensure their secure fastening. For this we use:

steel corners;
studs with washers and nuts;
brackets;
metal plates.

The rafter system of a gable roof requires compliance with the following rules during preparatory work.

Well-dried, seasoned wood is selected for rafters. The moisture content of the material should not exceed 2.5%, otherwise the boards and beams may become deformed.
Grade 3 wood is suitable for struts and posts, but the number of knots must be minimized.
All parts made of wood should be treated with fire retardants and antiseptics.

Sequence of actions during installation.

Some nuances of installing the sheathing

The sheathing parts are fastened with self-tapping screws perpendicular to the rafters. Based on density, the following types of lathing are distinguished:

solid: OSB or moisture-resistant plywood boards are laid on top of the rafters with a small compensation gap at the joints (used for rolled and other flexible roofing materials);
sparse: the distance between the beams is 450 mm or more (for example, for slate);
standard: there should be 200-400 mm between the sheathing elements (for tiles and metal tiles).

Important: the sheathing is attached to all rafter legs. Select wood without knots or grooves. “Bluishness”, rot and damage by insect pests are not allowed.

Gable roof rafter system. Pediment: tying methods

Pediment finishing can be done various materials. We bring to your attention the rafter system of a gable roof (photos and descriptions of some techniques for decorating the pediment).

Rafter system of a sloping gable roof

In order to enlarge the under-roof space and make it habitable, they build a gable broken roof. This design can be presented in the form of three triangles, one of which is located above the attic ceiling, and the other two on the sides.

The technology for creating a sloping gable roof requires a certain sequence of actions.

IN ceiling beams prepare inserts for mounting racks. In the case of an overlapping device using concrete slabs- beds are laid on them.
Install vertical posts and attach struts. The structure can be assembled without struts.
Lay the side purlins.
The legs of the layered rafters are mounted one by one. If necessary, contractions are additionally strengthened.
Hanging trusses are made on the ground, all parts are connected and then lifted to be installed in place.
When layered rafters are used, the side purlins are connected by beams that serve as parts of the ceiling of the under-roof room. Inserts are made in the beams for fastening the ridge beam posts.
Install the ridge beam.
The layered rafter legs are attached.
The sheathing is installed, the type of which is selected depending on the roofing material.

At the end of the article about how the rafter system of a gable roof is created, a video with comments from a specialist.

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When constructing private households, the most popular are house designs with a gable roof; they can be seen in the photo. The design of such roofs is simple compared to hip roofs (they are also called hip roofs). To create the frame of a gable roof, wooden beams and boards are used, the light weight of which allows you to build a rafter system with your own hands.

Elements of gable roofs

The design of a gable roof includes the following elements:

rafters . They consist of inclined struts and vertically located racks;
rafter leg . To make it, you need boards with a cross-section of 100x150 or 50x150 millimeters. Using rafter legs, a triangular contour of a gable roof is formed. The loads resulting from weather conditions and the weight of the roofing are transferred by the rafter legs to the Mauerlat, which is transferred to load-bearing walls buildings. When installing a gable roof on a house, the installation step of the rafter legs should be a minimum of 60 centimeters and a maximum of 120 centimeters. The heavier the roof covering, the more often they should be installed;
struts . Such an element from cutting boards is mounted at a certain angle and thereby transfers the load to the load-bearing elements down from the rafters. Rafters, several struts and a tie together are the constituent parts of a truss, which withstands loads and transfers them in the presence of wide spans to the walls;
racks . They are vertical rafter elements that transfer the load from the roof ridge to the load-bearing internal walls of buildings. They are made from timber with a cross-section of 150x150 or 100x100 millimeters;
Mauerlat . This is the name of a wooden beam, which is installed and secured on load-bearing walls on threaded rods or on anchors mounted into the surface. necessary to transfer loads from rafter legs to load-bearing walls. The manufacturing material used is timber made from softwood lumber and square section size 150x150 or 100x100 millimeters. The Mauerlat beams located on opposite walls should be located parallel so that the dimensions of the rafter legs are the same length;
horse . This horizontally located element is necessary to connect the slopes in their upper part. It is formed by connecting the rafter legs at the top point when installing a gable roof;
fillies . They are used if the length of the rafter legs is not enough to create an overhang on the roof. They are part of a board that has a smaller cross-section than the boards that were used in the manufacture of rafter legs. Installation of a gable roof can be greatly facilitated if this element is used, since then the legs for the rafter structure are made shorter;
sill . It is a horizontally fixed beam with a cross-section of 150x150 or 100x100 millimeters. It is located on the internal load-bearing wall and its functions include distributing loads from the roof racks after;
puff. This is one of the elements of a hanging rafter structure, which with the rafter legs forms a geometric figure - a triangle - and thus helps them stay in place and not move apart;
eaves . It is necessary to protect the walls from getting wet as a result of rain; its outer edge must protrude by at least 40 centimeters;
sheathing . The installation of a gable roof involves the installation of roofing material; to lay it, you need to make a sheathing. To do this, bars or slats are attached to the rafters perpendicular to their direction. Thanks to the presence of the lathing, the load from natural phenomena and the roof’s own weight is evenly distributed across the rafters. Also, the lathing, which can be solid or sparse, holds the legs of the rafters together into a single one. For soft roof, for example, from bitumen shingles, this element is made from sheets of moisture-resistant plywood.

The roof of the house is created using lumber from coniferous wood, and so that they do not become unusable during operation due to rotting, before building a gable roof, they are first treated with antiseptic compounds.

Rafter systems: their types and differences

There are two types of rafter systems: hanging and layered.

Hanging rafters, together with floor beams, are used as tie-downs to construct an attic when building a gable roof of a house with your own hands (read: ""). In addition to the bottom tightening, an upper tightening is also required at a distance of at least 50 centimeters from the ridge. Hanging rafter systems are created when the distance between two external walls is no more than 10 meters, and there is no internal load-bearing wall dividing the internal space of the building into two halves.

Layered rafters are installed when there is a support beam that transfers the weight of the roof from the ridge to a load-bearing wall located in the middle between the outer walls of the house. If instead of a load-bearing internal wall there are columns, different types of rafters alternate. Layered rafters will rest on the columns, and they will be mounted between the columns.

Installation of gable roof rafters, detailed video:

Features of creating a gable roof

For proper construction, use drawings of a gable roof and project documentation, which indicates all its dimensions (in more detail: "").

When the walls of a house are built of logs or timber, the function of the mauerlat is performed by the upper beam. But, if the walls of the building are made of brick, to attach the mauerlat to the load-bearing base before installing a gable or hipped roof, metal threaded rods of at least 10 mm are mounted into the masonry and bolts with washers are used. When performing, an interval of 1-1.5 meters is maintained between adjacent fasteners. To avoid getting the walls wet, waterproofing is laid from two layers of roofing material.

The types of gable roofs are varied, but in any case, the slope angle on them should be 15-20 degrees in areas with strong winds, and where there is a large amount of precipitation, 35-40 degrees, then snow and water will quickly roll off the roof surface . These nuances must be taken into account even before.

When layered rafters are used, first of all a beam is installed, and supports are mounted on it, on which the ridge beam is placed. To secure the structure, jibs are used. Then the rafter legs are mounted on the ridge beam, and their length should be slightly longer than necessary so that after twisting the two rafters together, the protruding ends can be cut off. The use of this technology can significantly speed up the construction of a gable roof.

After completing the installation of the rafter system, the gables and overhang are sewn up and the installation of the roof covering begins. To purchase material, you need to know how to calculate the area of a gable roof and thus not make a mistake with its quantity. To do this, determine the area of each of the two slopes by multiplying its length (height) by the width (length of the ridge). Note that it is very important to initially calculate correctly.