How to install gable roof rafters. Installation of rafters on a gable roof

At the heart of each roof is a large number of beams, rafters, racks and girders, which are collectively called the truss system. Over the centuries-old history of types and methods of its organization, a lot has accumulated, and each has its own characteristics in the construction of knots and cuts. More about what a truss system can be gable roof and how the rafters and other elements of the system should be attached, let's talk in more detail.

The design of the gable roof truss system

In the context of a gable roof is a triangle. It consists of two rectangular inclined planes. These two planes are connected at the highest point into a single system with a ridge beam (run).

Now about the components of the system and their purpose:

Mauerlat - a beam that connects the roof and walls of the building, serves as a support for the rafter legs and other elements of the system.
Rafter legs - they form the inclined planes of the roof and are the support for the crate under the roofing material.
Ridge run (bead or ridge) - combines two roof planes.
A puff is a transverse part that connects opposite rafter legs. Serves to increase the rigidity of the structure and compensate for bursting loads.
Beds - bars located along the Mauerlat. Redistribute the load from the roof.
Side runs - support the rafter legs.
Racks - transfer the load from the runs to the beds.

Filly may still be present in the system. These are boards that extend the rafter legs to form an overhang. The fact is that in order to protect the walls and foundation of the house from precipitation, it is desirable that the roof ends as far as possible from the walls. To do this, you can take long rafter legs. But standard length lumber of 6 meters is often not enough for this. Ordering non-standard is very expensive. Therefore, the rafters are simply grown, and the boards with which this is done are called “fillies”.

There are quite a few designs of truss systems. First of all, they are divided into two groups - with layered and hanging rafters.

With hanging rafters

These are systems in which the rafter legs rest only on the outer walls without intermediate supports (bearing walls). For gable roofs, the maximum span is 9 meters. When installing a vertical support and a strut system, it can be increased up to 14 meters.

The hanging type of gable roof rafter system is good because in most cases there is no need to install a Mauerlat, and this makes the installation of rafter legs easier: no need to make cuts, just mow the boards. To connect the walls and rafters, a lining is used - a wide board, which is attached to studs, nails, bolts, crossbars. With such a structure, most of the bursting loads are compensated, the impact on the walls is directed vertically downwards.

Types of truss systems with hanging rafters for different spans between load-bearing walls

Gable roof truss system for small houses

Exists cheap option truss system when it is a triangle (photo below). Such a structure is possible if the distance between the outer walls is not more than 6 meters. For such a rafter system, it is possible not to calculate the angle of inclination: the ridge must be raised above the puff to a height of at least 1/6 of the span length.

But with this construction, the rafters experience significant bending loads. To compensate for them, they either take rafters of a larger section or cut the ridge part in such a way as to partially neutralize them. To give greater rigidity in the upper part, wooden or metal plates are nailed on both sides, which securely fasten the top of the triangle (also see not the picture).

The photo also shows how to grow rafter legs to create a roof overhang. A cut is made, which should go beyond the line drawn from inner wall up. This is necessary to move the incision site and reduce the likelihood of a rafter breaking.

Ridge knot and fastening of the rafter legs to the backing board when simple version systems

For mansard roofs

Option with the installation of a crossbar - used when. In this case, it is the basis for filing the ceiling of the room below. For reliable operation systems of this type, the notch of the crossbar must be hingeless (rigid). The best option is semi-pan (see the picture below). Otherwise, the roof will become unstable to loads.

Please note that in this scheme there is a Mauerlat, and the rafter legs should extend beyond the walls to increase the stability of the structure. To secure them and dock with the Mauerlat, a cut is made in the form of a triangle. In this case, with an uneven load on the slopes, the roof will be more stable.

With such a scheme, almost the entire load falls on the rafters, therefore they must be taken with a larger section. Sometimes the raised puff is reinforced with a suspension. This is necessary to prevent it from sagging if it serves as a support for ceiling sheathing materials. If the puff is short, it can be secured in the center on both sides with boards nailed to the nails. With a significant load and length, there may be several such insurances. In this case, boards and nails are also enough.

For big houses

With a significant distance between the two outer walls, a headstock and struts are installed. This design has high rigidity, since the loads are compensated.

With such a long span (up to 14 meters), it is difficult and expensive to make a one-piece puff, because it is made from two beams. It is connected by a straight or oblique cut (picture below).

For reliable docking, the junction is reinforced with a steel plate mounted on bolts. Its dimensions should be larger than the dimensions of the cut - the extreme bolts are screwed into solid wood at a distance of at least 5 cm from the edge of the cut.

In order for the circuit to work properly, it is necessary to correctly make the struts. They transmit and distribute part of the load from the rafter legs to the puff and provide structural rigidity. Metal strips are used to reinforce the connections.

When assembling a gable roof with hanging rafters, the cross-section of lumber is always larger than in systems with layered rafters: there are fewer load transfer points, therefore, each element has a greater load.

With rafters

In gable roofs with layered rafters, their ends rest on the walls, and the middle part rests on load-bearing walls or columns. Some schemes burst walls, some do not. In any case, the presence of a Mauerlat is mandatory.

Bezporny schemes and knots of cuts

Houses made of logs or timber do not respond well to spacer loads. For them, they are critical: the wall can fall apart. For wooden houses the truss system of a gable roof must be non-thrust. Let's talk about the types of such systems in more detail.

The simplest non-spacer scheme of the truss system is shown in the photo below. In it, the rafter leg rests on the Mauerlat. In this embodiment, it works on a bend, without bursting the wall.

Pay attention to the options for attaching the rafter legs to the Mauerlat. In the first, the support platform is usually beveled, while its length is no more than the cross section of the beam. The depth of the cut is no more than 0.25 of its height.

The top of the rafter legs is laid on the ridge beam without fastening it to the opposite rafter. Two are obtained by structure shed roofs, which in the upper part are adjacent (but not connected) to one another.

It is much easier to assemble the option with rafter legs fastened in the ridge part. They almost never give a thrust on the walls.

For this scheme to work, the rafter legs below are attached using a movable joint. To fix the rafter leg to the Mauerlat, one nail is hammered from above or a flexible steel plate is placed from below. See the photo for options for attaching rafter legs to a ridge run.

If the roofing material is planned to be heavy, it is necessary to increase the bearing capacity. This is achieved by increasing the cross section of the elements of the truss system and strengthening the ridge assembly. It is shown in the photo below.

Strengthening the ridge assembly for heavy roofing material or with significant snow loads

All of the above gable roof schemes are stable in the presence of uniform loads. But in practice, this almost never happens. There are two ways to prevent the roof from sliding in the direction of greater load: by installing a brace at a height of about 2 meters or by struts.

Options for truss systems with contractions

The installation of contractions increases the reliability of the structure. In order for it to work normally, at the places where it intersects with drains, you need to attach nails to them. The cross section of the beam for the scrum is used the same as for the rafters.

They are attached to the rafter legs with bots or nails. Can be installed on one or both sides. The knot for attaching the bout to the rafters and the ridge run, see the figure below.

In order for the system to be rigid and not “crawl” even under emergency loads, it is enough in this embodiment to provide a rigid fastening of the ridge beam. In the absence of the possibility of its displacement in the horizontal, the roof will withstand even significant loads.

Rafter systems with braces

In these options, rafter legs, which are also called struts, are added for greater rigidity. They are installed at an angle of 45° with respect to the horizon. Their installation allows you to increase the span length (up to 14 meters) or reduce the cross section of beams (rafters).

The strut is simply substituted at the required angle to the beams and nailed from the sides and bottom. An important requirement: the brace must be cut accurately and fit snugly against the uprights and the rafter leg, excluding the possibility of its deflection.

Systems with rafter legs. Above is a spacer system, below is a non-spacer system. The nodes of the correct felling for each are located nearby. At the bottom - possible schemes strut mounts

But not in all houses, the average load-bearing wall is located in the middle. In this case, it is possible to install struts with an angle of inclination relative to the horizon of 45-53°.

Bracing systems are necessary if significant uneven shrinkage of the foundation or walls is possible. The walls can sit in different ways on wooden houses, and foundations - on layered or heaving soils. In all these cases, consider the installation of truss systems of this type.

System for houses with two internal load-bearing walls

If the house has two load-bearing walls, two rafters are installed, which are located above each of the walls. Beds are laid on the intermediate load-bearing walls, the load from the rafter beams is transferred to the beds through the racks.

In these systems ridge run do not put: it gives expansion forces. The rafters in the upper part are connected to one another (cut and joined without gaps), the joints are reinforced with steel or wooden plates, which are nailed.

In the upper non-expansion system, the expanding force is neutralized by tightening. Please note that the puff is placed under the run. Then it works efficiently (the top diagram in the figure). Stability can be provided by racks, or jointing - beams installed obliquely. In the spacer system (in the picture it is below), the cross member is a crossbar. It is installed above the run.

There is a variant of the system with racks, but without rafters. Then a stand is nailed to each rafter leg, which rests on the intermediate end with the second end. bearing wall.

Fastening the rack and tightening in the rafter system without a rafter run

To fasten the racks, nails for 150 mm and bolts 12 mm are used. Dimensions and distances in the figure are in millimeters.

The gable truss system is chosen by many owners of residential buildings. This is due to its high practicality and ease of creation. If you carefully study the structure of the gable roof truss system, then the process of its formation can be done by hand. The resulting design is different. high reliability and strength, and also guarantees excellent protection of the building from cold and precipitation.

Main elements of the system

The design of the gable roof truss system is considered simple. It consists of a variety of elements made from wooden elements having different lengths, configurations and cross sections. The main nodes include:

Mauerlat. Represented by a beam with a section in the form of a square. It is usually used to create softwood. Its dimensions vary from 10 to 15 cm. It is laid along all the load-bearing walls of the building. It is fixed to them with the help of anchors or special rods. If you make and attach it correctly, then it will evenly distribute the load from the rafter legs along all the walls of the structure.
Rafter legs. They are created from a bar with dimensions of 15x10 or 15x5 cm in section. With their proper connection, a roof contour is formed that has the shape of a triangle. It must be strong and reliable in order to withstand heavy loads from rain and wind. Rafter legs must be fixed at a distance of about 1 m from each other.
Sill. Made from square wooden beam, whose cross section is equal to . It is laid horizontally on a load-bearing wall inside the building. Due to it, the load coming from the roof racks is evenly distributed.
Puff. This element is used if a hanging structure is chosen. It is installed on top of the resulting triangle of rafter legs, which ensures its stability.
Racks. To create them, a square beam is used. They are in a vertical position. They bear the load from the ridge, after which it is transferred to the load-bearing wall inside the building.
Struts. The installation of these elements is necessary in order to obtain a special transmission element located between the rafter legs and various load-bearing parts. Due to their reliable connection with a tightening, the creation of a strong structure is guaranteed.
Crate. It is assembled from bars or boards. Installed perpendicular to the legs of the rafters. It provides the transfer of gravity from the roof of the roof to the legs of the rafters. It is advisable to use to create this element edged boards. If you plan to create a coating on the roof of soft roofing materials, for example, shingles, then the crate must be continuous.
Skate. It is represented by the topmost element of the entire roof. Due to it, its two slopes are connected. Its assembly is carried out by connecting the legs of the rafters at the top of the roof. It must be placed in a horizontal position.
Eaves. It protrudes from each wall of the building by about 40 cm. Its installation is due to the need to protect the walls from water flows as a result of precipitation.
Filly. Provides the ability to create a roof overhang. They are used exclusively in a situation where short rafter legs are used, so they are lengthened by fillies.

Important! The step between the legs of the rafters is chosen in accordance with the severity of the roof, since the more weighty it is, the smaller this gap should be.

Thus, the installation of a gable roof truss system is considered quite simple, so it is not difficult to make this design with your own hands.

Types of structures

The rules and features of the installation of this design depend on the selected variety.

Types of gable roof truss system:

All options have their own characteristics, so their characteristics are preliminarily evaluated. If you plan to install a gable roof truss system with your own hands, then a simple symmetrical design is chosen.

Important! The basis for obtaining the ideal result is competent calculations, and if they are incorrect, then the roof will not be reliable and durable, and it will also be dangerous to live in such a house.

How to choose the material to create the system?

When choosing a material, the following rules are taken into account:

rafters are created exclusively from quality wood which does not have any rotten areas, damage, knots or other defects;
edged boards are purchased to form the crate;
all wood should be well treated with antiseptics and fire retardants.

Important! Knots are allowed, but their length cannot be more than 1/3 of the thickness of the timber used.

Calculation rules

To make the gable roof truss system reliable and of high quality, a lot of attention is paid to competent calculations. They should affect all elements of the future design:

Load calculation. Any system is affected by two types of load. The constants will regularly act on the structure, and this includes the weight from roofing roofs, battens, thermal insulation material, waterproofing, extensions and finishing materials used for the attic. Typically, this load is 40 kg / m. sq. Variable loads can have different strengths, as they include wind, snow exposure and precipitation intensity. To calculate the load, the wind load of a particular region is multiplied by a special correction factor.
Determining the angle of inclination. A roof with two slopes may have different angle slope, and it is determined by the used roofing material. If a soft roof is mounted, then a slope of 5 to 20 degrees is selected for it, or metal tiles vary from 20 to 45 degrees.
Snow load calculation. In winter, a large amount of snow can accumulate on the roof. In order to avoid any problems with the structure, the frame must withstand these loads. The calculation requires the weight of the snow to be multiplied by the correction factor.
Definition . The gap between these elements is usually chosen in the range from 60 to 100 cm, and the final choice depends on the roof and the weight of the roof.
Definition . To do this, it is recommended to use the standard Pythagorean theorem.
Determination of the section of the rafters. This setting is affected by several important factors: roof loads, type of materials used, length of rafter legs, as well as a step between them.

Important! When calculating loads, the possibility of a storm or tornado is additionally taken into account, since if the house is located in a region where such loads can appear, then a margin of safety is made for the roof, read more:.

Types of rafters

Before direct work on creating a gable roof with your own hands, you should make a special plan, which will contain a drawing and layout of the entire structure. This takes into account which rafters will be used, since the following types can be used:

. Suitable for small buildings. Their installation consists in fixing the legs to the bearing wall of the structure, as well as to the ridge run. A feature of the use of these elements is that a bursting force acts on the rafter legs, and puffs are used to reduce this effect. They can be made from wood or metal.
Layered. Suitable for roofs of any shape and size. The layered design is used in conjunction with racks and lying down. The bed is laid parallel to the fixed Mauerlat, so a certain part of the load is transferred to it. This allows you to tilt the legs of the rafters, which are additionally supported by the rack, to each other.
Combined. They are used when using unusual gable roof configurations.

After determining the main design parameters, the calculation of the required amount of material begins. Then you can proceed to the direct creation of the truss system.

Assembly of the structure

truss system do-it-yourself gable roof is created only after the preliminary formation of drawings and plans. The scheme of future contraction should be clear and correctly calculated. For this, it is recommended to use special computer programs.

Important! In the presence of Money it is allowed to contact specialized construction companies for the correct calculation.

Installation of a gable roof truss system is divided into successive stages:

to the walls of the building. Its installation is carried out along their entire length. If the house is made of logs, then the Mauerlat acts as its upper crown. If the building is selected cellular concrete or brick, then it is mounted on top of the load-bearing wall along its entire length. It is required to splice the Mauerlat, for which the bars are sawn at a right angle and connected with bolts. It can be fastened with an offset to the side of the wall or in its center. Laying is carried out on a waterproofing layer, for which roofing material is usually used.
Creation of roof trusses. To do this, it is allowed to install bars on the roof or form a structure on the ground, after which it rises to the roof. The second option is often chosen, since it is difficult to perform work on the roof of the house. But to raise the structure made, you will have to use special equipment. Before connecting the legs of the rafters, the correctness of their size and location is checked.
. The formed pairs rise to the roof, after which they are laid on the Mauerlat. For the competent performance of the work, special cuts are made from the bottom of the legs. The process begins with the ends of the roof, located opposite to each other. To obtain a perfect result, temporary fasteners are used when installing the elements. A rope is pulled between the fixed pairs, making the installation of subsequent elements simplified. All rafter legs are mounted, and the correct step between them is checked. Next, a special skate support is installed. Everything additional elements used in the rafter system are fixed by cutting and brackets. It is allowed to lengthen the rafter legs if necessary.
Skate installation. It is created with the help of a competent connection on top of all rafter legs. Different methods are used for its formation, and it is allowed to use a support bar for this or you can work without it. If a beam is used, then it is allowed to put a skate on it or use the cutting method.
The rafter system is considered to be done, but in order for it to be strong and reliable, it is necessary to thoroughly fix all the elements, therefore, all temporary fasteners are eliminated, in place of which they are applied quality products to fix all parts of the system.
Lathing installation. This design is intended for easy movement on the roof, and also serves as the basis for laying the roof. Its type and parameters depend on the chosen roof. Solid crate is created if a soft roof is selected. has a distance between the boards within 35 cm. For or slate, this parameter is 44 cm.

The erection of the roof is one of the most important stages of construction. From the reliability of the "umbrella" from above, from its resistance to precipitation and any external influences directly depends on the durability of the building itself and the level of comfort of living in it.

Of all the variety of roof structures, gable can be attributed to the most popular, simply because of the relative simplicity of its construction. However, behind this "simplicity" lies a lot of different nuances, the need to carry out certain calculations and follow technological rules. However, this publication has the main task: to show that installing the rafters of a gable roof with your own hands is a completely doable task, even for a novice builder.

Let's walk through the process of installing rafters for such a roof together, from the basics of preliminary design to an example of practical implementation.

General arrangement of a gable roof

Basic concepts

Structural elements of the gable roof truss system

Let's make a reservation right away that this scheme, of course, cannot reflect the entire possible variety of designs, but the main parts and assemblies on it are shown quite clearly.

1 - Mauerlat. This is a board or beam that is rigidly attached to the upper end of the external load-bearing walls of the building. Its purpose is uniform distribution loads from the entire roof system on the walls of the house, creating conditions for reliable fastening of the rafter legs at their lower fulcrum.

2 - rafter legs installed in pairs. They become the main load-bearing parts of the entire roof system - it is the rafters that set the steepness of the slopes, will be the basis for attaching the batten, roofing, and if the roof is planned to be insulated, then the entire thermal insulation "pie".

For the manufacture of rafter legs, high-quality boards or timber are used, and round timber can also be used. About the section of lumber, which will be sufficient to ensure that all possible loads can be guaranteed, will be discussed below.

The rafters may end on the Mauerlat, but more often they go beyond the perimeter of the walls of the house, forming a cornice overhang. However, lighter parts can also be used for this - the so-called "fillies", with which the rafter legs are increased to the required width of the overhang.

To form a cornice overhang, the rafters are extended with “fillies”

3 - skating run. It can be a beam, a board or even a composite structure. The run runs along the entire line of the ridge and serves to securely connect the upper points of the paired rafter legs, connect all rafter pairs in order to impart overall rigidity to the entire roof structure. V various options roofs, this run can be rigidly supported by racks, or tied only to the connection node of the rafter legs.

4 - puffs (contractions, crossbars). Horizontal details of the reinforcement of the system, additionally connecting paired rafter legs to each other. Several puffs located at different heights can be used.

5 - floor beams, which will serve as the basis for mounting the floor in the attic and the ceiling from the side of the room.

6 - and this beam simultaneously performs the role of a bed. This is a beam that runs along the entire length of the roof, which is a support for installing additional reinforcement parts for the truss system. The bed can be installed as shown in the figure (like a floor beam), or it can be rigidly laid on a capital partition inside the building.

7 - racks (headstock) - additional vertical supports of the rafter legs, preventing their deflection under the influence of external loads. Racks at the top can rest against the rafters themselves, or against an additional run, longitudinally connecting the rafter legs at a certain height.

8 - braces. Often with a large length of their rafter legs bearing capacity is not enough, and reinforcement only with uprights does not provide the necessary strength. In these cases, diagonal reinforcing elements are used, resting on the bed from below, creating an additional point of support for the rafters. The number of struts and their installation location can vary in roofs varying degrees difficulties.

Some differences between hanging and sloping gable roof systems

Gable roofs can be divided into two types of structures - with layered and hanging rafters. In addition, widely used combined systems, in which both principles of construction are combined. What is the fundamental difference?

Laminated rafter system

This design of the truss system is characterized by the presence of support on the internal capital partition in the building. On the upper end of this partition, a bed is mounted, on which drains are supported, supporting the ridge run. Thus, the rafter legs are “leaned” on a vertical support, which makes the entire system as strong as possible.

This scheme is the most popular because of its reliability and relative ease of implementation. If it is possible to create an additional point of support in the center, then why not take advantage of this? True, if it is planned to place a dwelling in the attic, then vertical racks can sometimes become a hindrance. However, their presence is also sometimes “beaten up”, using, for example, an internal light partition for mounting.

Depending on the number and placement of internal partitions, the design of the layered truss system may vary. Some examples are shown in the illustration below:

Fragment “a” shows the simplest option, which, by the way, on short rafter lengths (up to 5 meters) may not even have struts shown - a row of central racks under the ridge run is enough

With an increase in the width of the building, the system naturally becomes more complicated, and additional reinforcing elements appear - puffs and struts (fragment "b").

Fragment "c" clearly demonstrates that the internal main wall does not have to be located exactly in the center, under the ridge. Such an option as shown in the illustration is also quite possible, but with the condition that the displacement of the lying relative to the ridge does not exceed one meter.

Finally, fragment "d" shows how the system of rafters in the building can be supported. big size, but having two capital partitions inside. The distance between such parallel beds can reach up to a third of the width of the building.

Hanging rafter system

Graphically, this roof scheme can be depicted something like this:

It immediately catches the eye that the rafters rest only on the lower part, and then are connected to each other on the ridge. There is no additional support in the center, that is, the rafter legs seem to “hang”, which predetermines the name of such a system. This feature imposes certain restrictions on the use of hanging rafters - usually such a scheme is practiced with a distance between the bearing walls on which the Mauerlat is fixed, no more than 7 meters. Installed puffs only partially relieve the load from the external walls.

The illustration below shows several options for a hanging system. However, some of them already, rather, can be classified as combined.

Fragment "d" - hanging rafters are interconnected by a screed at the level of the Mauerlat or fixed to a powerful floor beam, forming a triangle with it. There are no other reinforcing parts. A similar scheme is permissible with a distance between walls of up to 6 meters.

Option "g" - for the same size house (up to 6 meters). The puff (bolt) in this case is shifted upwards, and is often used for filing the ceiling of the attic.

Options "e" and "h" are designed for a span between walls up to 9 meters. Multiple puffs may be used (or top puff in combination with bottom floor beam). Another approach is to install racks under the ridge run, by analogy with a layered system. Only as a lower point of support, it is not a bed on the main partition that is used, but the racks are supported by a puff or a floor beam. To call such an option purely “hanging” is already difficult, since here is clearly a combination of parts from both designs.

In still more such a combination of two schemes is expressed in the “and” variant, which is designed for large spans, from 9 to 14 meters. Here, in addition to the headstock, diagonal struts are also involved. Often, such trusses are generally assembled on the ground, and only then they are lifted and set in place, connected to each other, thereby forming the entire roof frame.

So, in preparation for the construction of a gable roof, it is necessary to study the principles of the device of a particular system, evaluate their advantages and disadvantages, choose the best one for your conditions and draw up a graphic working diagram. It will also be needed when purchasing. required material, and for the production themselves installation work. However, drawing up a drawing should still be preceded by some calculations.

Calculation of the basic parameters of the gable roof truss system

Let's take another look at circuit diagram gable roof devices to highlight those parameters that need to be calculated.

So, in the process of calculation, we need to decide on the following values.

The initial data is the length of the side of the house along the gable part (highlighted in blue - F), and the length of the house along the ridge ( purple– D). It is assumed that the owners have already decided on the type of roofing in advance - since there will be certain restrictions on the steepness of the roof slopes. (angle a).

The height of the ridge above the Mauerlat plane (H - green color), or, conversely, determine the angle of the slope, starting from the planned height of the ridge.
The length of the rafter leg ( blue color- L), and if necessary - and elongation of the rafters to form a cornice overhang of the required width (l).
Calculate the total loads falling on the rafter system in order to determine the optimal cross-section of lumber for the manufacture of rafters, their installation step (red color - S) and allowable length spans between anchor points. All these parameters are closely interconnected.
When these calculated values \u200b\u200bare in hand, it is already easy to compose graphic diagram, determine the need and optimal arrangement of reinforcement elements, calculate the amount of material for their manufacture.

chainsaw prices

chainsaw

We calculate the steepness of the slope and the height of the ridge

The slope angle of the slopes can be determined by the owners by different criteria ratings:

For purely aesthetic reasons - when "at the forefront" becomes appearance buildings. Many people like roofs with a high ridge, but at the same time, one must not forget that the wind load increases sharply on such a roof. Yes, and materials for the manufacture of a high roof will go immeasurably more. At the same time, on steep slopes, the snow load is reduced to almost zero - it is possible that for "snowy" regions this assessment parameter may become decisive.
For reasons of useful use of the attic space. With a gable roof scheme, in order to achieve maximum area attic, it is necessary to build slopes with a very steep slope, that is, with the same consequences as mentioned above.

Finally, there may be a completely opposite approach - for reasons of economy, make a roof structure with minimum height in a skate. But in this case, you will have to focus on the minimum allowable slope angles for a particular type of roofing. To reduce the steepness below the indicators recommended by the manufacturer is to “plant a bomb” in your roof, both for reasons of its strength and durability, and from the standpoint of the waterproofing qualities of the coating.

It is not difficult to calculate the height of the ridge above the floor plane (Mauerlat). At the heart of the vast majority of nodes of any roofing system is a triangle, which, in turn, obeys strict geometric (more precisely, trigonometric) laws.

So, in our case, the width of the roof along the gable line is known. If the roof is symmetrical, then the ridge will be located exactly in the middle, and for calculations, you can simply divide the width F by two (the base of the triangle f=F/2). With asymmetrical slopes, you will have to project the top of the ridge onto line F, and measure the distances f1 and f2 from it to the edge of the triangle (to the Mauerlat) on each side. Naturally, in this case, the slope of the slopes will be different.

H =f × tga

In order not to force the reader to look for the values of tangents and carry out calculations manually, a calculator is placed below, in which the necessary tabular values \u200b\u200bare already entered.

double roof - the best way for an inexperienced builder, which you can do with your own hands. It is simple in execution, but at the same time reliable and can withstand significant loads from both wind and precipitation. She, of course, is not very beautiful, but in the baths she looks quite organic.

To do everything consciously, it is necessary to understand the structure of a gable roof and the purpose of all its elements. Let's start in order.

Mauerlat

This is a large bar attached to the load-bearing walls around the perimeter of the building. It is this element that accounts for most of the load from the roof. And it is the Mauerlat that transfers it to the load-bearing walls.

For this element, square bars with a size of 100 * 100 mm or 150 * 150 mm are used. They are connected to the walls with embedded studs. If the bath is wooden, then the upper crown usually serves as the Mauerlat. For all other types of walls, a belt is made of reinforced concrete in which the studs are embedded. Then the beam of the selected section is “put on” on the studs and attracted with nuts. Sometimes it is additionally fixed with long pins.

Since the thickness of the walls is often greater than the width of the mauerlat, it can be laid with bricks from the outside of the beam. This will make the system more reliable. Only wood needs to be wrapped with two layers of roofing material - to protect it from moisture and decay.

Rafter legs and skate

The horse is horizontal wooden block located at the top of the roof and connecting two slopes. Rafter legs or rafters rest on it and on the Mauerlat. Since the ridge has a rather large load, it must be made of a considerable section and wood of durable species should be chosen.

The height of the roof ridge is determined based on the slope of the roof and the width of the building. The angle of the roof slope is a value that depends on climatic factors: if there is a lot of snow in winter, then you need to make the slopes steeper. They will snow well. If in the region strong winds, a high roof will experience heavy loads and can be damaged.

For medium conditions, the optimal roof slope angle is about 35°-45°. They will not be heavily loaded by the wind, and the snow will not accumulate much. In addition, with such an angle, you can choose any type of roofing: any of the tiles, soft roofing, slate, metal tiles.

Also remember, the higher the ridge is raised (the steeper the slopes), the larger the roof area will be. And this will lead to the fact that the cost of purchasing roofing materials and the amount of work will be large.

Knowing the slope angle and the width of your bath, you can calculate the height of the roof ridge. To do this, the width of the building must be divided by two (if the ridge is in the middle, and not shifted to one side or the other) and multiplied by the slope angle tangent (the first formula in the figure). In order not to look for the necessary coefficient in mathematical tables, it is written out and summarized in a simple table.

Roof slope angle	5	10	15	20	25	30	35	40	45	50	55	60
Tg A (skate height calculation)	0,08	0,17	0,26	0,36	0,47	0,59	0,76	0,86	1	1,22	1,45	1,78
Sin A (rafter length calculation)	0,09	0,17	0,26	0,34	0,42	0,5	0,57	0,64	0,71	0,77	0,82	0,87

Multiply half the width of the house by this factor. Get the height of the ridge for your bath. For example, the width of the bath is 4 meters, the angle is 35 °. We consider: 4 m / 2 * 0.76 \u003d 1.52 m - the height of the ridge from the ceiling.

Now about the rafter legs. They are made from pine or spruce bars, or better - larch. Section 50*150 mm or 50*100 mm. The choice of bar thickness depends on:

The length of the rafter leg is also calculated according to the mathematical formula: the height of the ridge is divided by the sine of the angle of inclination (the second formula in the figure). The sines of the tilt angles are also in the table. Find desired value and think. For example, for the ridge we found is 1.52 m and the angle of inclination is 35 °, the rafters will need 1.52 m / 0.57 = 2.67 m.

Roof overhang and filly

But the roof does not end exactly above bearing wall. It extends beyond the walls by about 40 cm. This ledge is called the roof overhang. This is done so that the water flows further from the foundation, does not wash it away. Therefore, the rafter legs are taken longer. If their length is not enough, they are grown with boards, which are called "fillies".

To organize the overhang of the roof, boards are added to the rafters - filly

Types of truss systems

Rafter systems come with hanging or layered rafter legs. The hanging ones rest only on the outer walls of the building (on the Mauerlat or the upper crown). In order to increase the reliability of the system, so as not to ruin the walls, they are connected by puffs (also called a jumper or crossbar). This type of rafter system is suitable for buildings of small width (less than 10 m) and in cases where there is no load-bearing wall running in the middle.

Two types of truss systems - with hanging and layered rafters

The second type of system is with layered rafters. They rest on a ridge beam and a mauerlat, but the load from the roof is also distributed to the middle load-bearing wall, through vertical bars - girders, which are installed with the same pitch as the rafters and rely on the lower puff.

Do-it-yourself installation of gable roof rafters

For most of the baths, the system is made with hanging rafter legs - the dimensions allow this. In this case, less consumption of lumber and less time is required for its arrangement. In this case, most of the work can be transferred to the ground.

They make one triangle from the rafters according to all the rules and sizes. Try it on and then make it right amount its exact copies. Finished rafters with puffs and crossbars, fastened and measured, are raised to the roof. There they are set strictly vertically in the designated places and are fixed to the Mauerlat and the ridge.

An example of how you can do gable roof with hanging rafters, see the video.

With a roof slope length of more than 4.5 meters, to increase the reliability of the system, vertical racks are installed, which support the rafter leg at one end, and rest against the floor beam with the other. This is done regardless of the type of installation of rafters: both hanging and layered. They also install slopes that make the structure even more rigid.

In any case, the rafters will need to be attached to the ridge beam, as well as to the Mauerlat. The figure below shows the mounting options for the ridge.

It will also be necessary to attach the rafters to the Mauerlat. How to do this - see the photo below.

Lathing device

Making a gable roof with your own hands ends with the installation of a crate for roofing material. For this, by outside rafters, a waterproofing film or membrane is rolled out. Lay it in a horizontal direction. Starting from the bottom, moving up. The second and all subsequent rows are laid with an overlap of at least 15-20 cm. They are fixed with small nails or staples from a staple gun.

After installing the truss system, a film or waterproofing membrane is fixed on it, and on top - a crate

There are two ways - with or without a counter-crate. The counter-lattice is stuffed along the rafters, and on top there are already lathing bars. So between the waterproofing and the roofing material is formed air gap. This option is better from the point of view that such a roof will dry out better and faster. And this is very important for baths.

Without a counter-lattice, the bars are packed immediately over the waterproofing. There is also a gap here, but it is smaller, therefore, ventilation will be worse. But this option is also acceptable: less consumption of materials and work, too.

After the manufacture of the crate, it remains only to fix the selected roofing material.

Results

Now you know how to make a gable roof with your own hands. Of all types, this is the simplest option that a non-specialist can make.

The truss system is the basis of the roof, the reliability and strength of the roof, its ability to withstand precipitation and wind depends on it. The design of the truss system is determined by the shape of the roof and the features of the layout of the house, as well as the materials used. A do-it-yourself truss system is usually made of wood, but other materials, such as a metal profile, can also be used.

Types of rafters and their application

The choice of a truss system is a crucial step that requires knowledge of the design of each type of roof. Rafters can be:

Laminated rafters based on a ridge run and Mauerlat. They are used in the construction of a single-pitched, simple gable roof, as well as one of the elements of a hip and broken roof. mansard roof.
Sliding rafters - a type of layered rafters used for wooden buildings, giving big shrinkage. Their difference is the sliding fastening of the rafters to the Mauerlat, which allows you to compensate for the shrinkage of the walls without deformation of the roof.
Hanging rafters - a system of rafters tied with crossbars or puffs, usually used in the construction of a simple gable roof, as well as the upper rafters of a mansard roof. In the hanging rafter system, there is no ridge run, and in the upper part the symmetrical rafter legs rest directly on each other.
Sloping rafters, otherwise called angular or diagonal. They are used to perform three-slope or hipped roof, as well as for roofs with complex geometry.

Elements of the truss system

Any rafters are designed to distribute and transfer the load of the roof to the walls of the house. The main elements on which the rafters rely are:

Mauerlat - a beam fixed on the upper plane of the walls around the perimeter of the whole house;
Beds - support bars laid on internal load-bearing partitions or columns;
Beams of the ceiling of the upper floor;
Racks and supports;
Runs - horizontal supporting elements laid along the roof axis on racks.

The truss truss consists of the following elements:

Rafter legs - boards or beams that form the contour of the roof and are laid with a certain step;
Puffs or crossbars - horizontal elements that pull paired rafter legs together;
Struts - supports set at an angle and supporting the rafter legs;
Filly - boards fixed at the lower end of the rafters and forming roof overhangs;

Narozhniki - short rafters resting on diagonal rafters in a hip roof.

All these elements in private construction are usually made of wood - timber or coniferous boards, naturally dried. The tree is impregnated with an antiseptic, which allows you to extend its service life. The thickness and section of the elements is determined by calculation.

Laminated rafter technology

Before construction begins, it is necessary to sketch the roof and calculate its dimensions. The cross section and pitch of the rafters, as well as the need to install additional supports and struts, are also determined by calculation.
Support elements are laid and exposed: mauerlat, beds and floor beams, racks, ridge and intermediate runs. These operations are described in detail in the articles on different types roofs:
Make a rafter template. To do this, take a board with a width corresponding to the estimated length of the rafters, with the same width, but with a smaller thickness - it is lighter and easier to fit exactly in place. The board is applied to the installation site of the extreme rafter with one end to the ridge run, the other to the Mauerlat.
At the top of the template mark the top gash. The shape of the cut should be such that the board lies on the ridge run and at the same time fits snugly against the opposite rafter. The depth of the cut should be no more than 1/3 of the width of the board.
After sawing out the upper cut, the template is once again applied in place and the lower cut is marked out - it should rest on the Mauerlat, without leaving large gaps. The end of the template is filed at an angle so that the cut is in a vertical plane.
The resulting template is applied at the installation site of all rafter legs, checking whether it will be necessary to fit in place. If the template fits perfectly (which rarely happens), you can immediately make required amount rafter legs. If adjustment of the lower notch is needed, then only the upper part of each rafter is cut out according to the templates, and the lower notch is done in place each time.
The rafters are placed with established calculation step. Usually it is from 50 to 120 cm and depends on the type of roofing, namely on its severity, and on the expected snow load. The heaviest coatings are slate and ceramic tiles but they are now rarely used. More often, the choice is made in favor of more modern, light and reliable materials: metal tiles, ondulin, soft roof. For them, the pitch of the rafters can be chosen about 100 cm without performing complex calculations.
First, rafters are installed from the side of the gables. rafter leg they rest on the ridge run and the Mauerlat and fix it on two nails 100-150 mm in each attachment point. Having installed the rafter pair, they additionally fasten it: in the upper part with the help of metal plates and self-tapping screws on one side and corners with a stiffener on the other, in the lower part - with brackets or also on the corners.
After installing the rafters from both gables of the roof, a twine is pulled between them and the rest of the rafters are aligned along it. Rafters are fastened in the same way.
Install struts, if required by the results of the calculation. The struts are made from the same material as the rafters. A board of suitable length is applied at the desired angle to the rafter and the bottom cut is marked. It is important to consider what the brace will rely on: on the floor beam or on the bed, the shape of the lower gash depends on this. After completing the lower cut, the brace is put in place and the cut line along the rafters is marked. The prepared brace is placed at a distance between the beams and rafters and secured with metal plates or corners.

Roof strut installation

Technology for the implementation of hip diagonal rafters

Since the rafters for hip roof installed diagonally, the usual methods of fastening them are not suitable. In addition, the load on diagonal rafters is much higher than on layered or hanging ones, so the material for their implementation must have a larger cross section. You can use a beam with a thickness of 100 mm or more, but practice shows that it is more convenient to make these rafters from two folded and fastened boards of standard thickness.
The diagonal rafters are supported by the upper end on the racks, the lower end - on the Mauerlat bars converging at right angles. They are marked in place, and their main feature is that the cuts are not made perpendicular to the plane of the board, but at an angle of 45 degrees. When making rafters from spliced boards, first one side is performed with oblique cuts, then the second, in a mirror image.
Boards are pulled together by screws, nails or studs. Fasten hip rafters using pads and screws.

A video will help you better understand the basic techniques for building a truss system with your own hands.

When doing any truss system with your own hands, it is important to carefully secure all knots and connections and remember that the roof is the main protection of your house from bad weather. Therefore, it is important not only to make a high-quality frame, but also to choose the right one, for example, corrugated board, and lay it correctly.