Do-it-yourself attic roof: drawings and stages of how to build an attic roof for a house. Phased construction of an attic roof Installation of an attic roof for a wooden house 8x12

28.10.2023

When installing rafters for the attic, all technological requirements must be met so that the supporting structure can fully perform the tasks assigned to it. Trusses and other associated elements must be installed so that the finished structure can withstand wind and snow loads for a particular region. All these points are further clarified during the calculation process. If desired, you can install the rafters for the attic yourself, saving money on the services of third-party workers.

Rafter fastening diagram.

Basic information about roof rafters

An attic is a room under the roof; it is located on the attic floor of a building. This technique allows you to competently plan the growth of used areas without significant material costs. You can live in the attic no worse than in any other room. But to do this, it needs to be properly equipped and, in particular, the rafters for the roof must be correctly installed.

Mansard roof rafter system.

Before installing rafters for the attic, you need to choose the appropriate type of structure. Rafters can be layered or hanging.

Layered rafters for attic roofs are best installed in buildings that have a load-bearing intermediate wall. To install a layered rafter system for an attic roof, it is necessary that 2 load-bearing walls are located at a distance of no more than 7 m from each other.

If there are no internal walls, the only option is hanging rafters for the attic roof. The standard design includes rafters and a lower chord - a tie. The Mauerlat is used as a supporting element. Wire and staples are used to secure the rafters. Installation is carried out taking into account the expected load level.

Features of installation of the rafter system

Installation of roof truss system.

Before you begin installing rafters for the attic roof, prepare everything you will need during the work process:

Unedged board.
Wooden beams.
Thermal insulation material.
Nails.
Annealed wire with a diameter of 3-4 mm.
Leg-split.
The boards are 15 cm wide and 4-5 cm thick.
Moisture-proofing material.

There are several different types of attic roofing systems, namely:

Triangular.
Asymmetrical.
Symmetrical.
Broken.

One of the most important design aspects is the calculation of the roof slope angles. When performing this stage, the following features must be taken into account:

Climatic conditions of the region.
Type and characteristics of materials used for construction and finishing.
Personal preferences of the home owner.

Mounting points for the rafter system.

The greater the angle of inclination of the roof slope, the less free space there will be in the attic room. However, if the angle is too small, the roofing system will be more difficult to clean from sediment and dirt. Over time, this will lead to a decrease in system reliability. Therefore, it is very important to choose the optimal roofing material for the existing conditions.

Correct installation of rafters for the attic roof ensures the strength and stability of the roof. When performing this work, you must follow a number of rules. Firstly, the structure is constructed from wooden beams with a section of 100x100 mm or 150x150 mm. Secondly, the system is carefully waterproofed. Typically, roofing felt or roofing felt is used as waterproofing.

The frame structure is laid on reinforced concrete bases. To fasten the supporting unit, wire and metal brackets are used. Quite often a tongue-and-groove connection is used. It is important that the wood used to construct the rafters has a moisture content of no more than 15%. If possible, the choice should be given to coniferous species.

A disinfectant atmosphere must be created. It is strictly forbidden to use damp timber. Because of them, the entire rafter system can simply collapse. Therefore, the bars must be dried before use. Additionally, the wood is impregnated with antiseptic and fire-retardant compounds.

When marking the installation of supports, calculate the installation step so that all rafters are installed vertically in the same plane. A tool familiar to any builder called a plumb line will help you check the verticality of the installation.

To ensure that the parts are held in place as securely as possible, use braces or braces. Upholster vertical posts with suitable materials. Most often, double-sided cladding is performed using plywood and plasterboard. Insulation must be laid between the sheathing sheets.

Step-by-step instructions for installing rafters

Scheme of strengthening the rafters with additional struts.

The process of installing a rafter system for an attic roof begins with laying the top beam. To secure it, you can use nails, screws and metal staples. Bars with a cross section of 150x150 or 100x100 mm are used.

After this, the Mauerlat is installed. It is needed, first of all, to prevent the roof from tipping over in a strong gust of wind. The Mauerlat must be designed and installed in such a way as to withstand the loads that apply to both the roof of the house and its walls. The mauerlat itself is laid out from beams. It is best to use 100x150 mm bars. You can also use boards with a thickness of 50 mm or more.

The selected material should be laid horizontally, having previously calculated the size of the wall surface. A waterproofing material must be installed under each block or board, which will protect the elements of the Mauerlat from the harmful effects of moisture.

Finally, the rafter legs are installed. These structural elements can be purchased ready-made or made independently. First, the pitch of the rafter legs is calculated, after which markings are applied to the mauerlat. To do this, you need to put marks on the rafter frame and the mauerlat. Professionals recommend installing rafters in increments of 1-1.2 m. Lay the outer rafters towards the front. It is important that the edge line of the gable and the top of the legs are at the same level.

Rafters are made of bars or boards. It is important that the boards are straight.

It is better to refrain from using material with knots; the maximum permissible number of knots is 3 pieces per linear meter.

Types of rafter structures.

Next, you need to take the twine and stretch it between the outer rafters. In this case, it will serve as a level for mounting the remaining legs. Finally, you will need to connect the upper parts of the rafters together in pairs and install the ridge beam. It will be needed if the roof is more than 7 m in length, and the rafter frame weighs relatively much.

If the roof is smaller, it will be enough to tie the top of the legs with guy wires. You can use the braces directly as attic ceiling beams in the future. In strong winds and snow, these elements will take on a certain part of the load.

Finally, the sheathing is installed, moisture insulation and thermal insulation material are laid, the roof is installed, and the walls and ceiling of the attic are finished.

If there are windows in the attic roof, the work is performed in the same sequence, but at the stage of installing the rafters, window openings are laid into which window frames will later be installed. Do not forget that the attic must have a size of at least 3x2.2 m. Otherwise, living in such a room will be extremely uncomfortable.

A mansard roof, made in accordance with all the rules, will be a wonderful decoration for any home and will serve for decades. Pay due attention to the design of the rafter system and approach this task with all responsibility. You will not only save money, but will also control every stage of the work, which will allow you to be completely confident in the quality of its completion. Good luck!

A house with an attic is not just additional living space, but also a presentable appearance of the entire structure. Even if the room under the roof is not heated and is used only in the summer, it still has a powerful “air cushion” that helps retain heat inside the entire building.

Making an attic on your own will be difficult, especially if you do not have the relevant experience, because it is a fairly massive and complex structure.

An attic room can be installed under various types of roofs, but the most popular is a broken or gable structure. According to their structure, they are slightly different from each other.

In order to decide which design will be more suitable for your home and will be easier to install, you need to consider both options in more detail. In addition, the master who will be involved in the construction of the attic roof must figure out which of the two types of rafter system structures to choose.

Any roof belongs to one of the existing two types of rafter systems; it is a layered and hanging structure. Each of them has a different feature, and which one to choose depends on how the load-bearing walls of the structure are located.

Hanging structure

A hanging structure is a rafter system that rests only on the outer main walls. This happens when in the house itself, except for the external walls, there are no major partitions.

This design can only be used if the distance between two main walls is no more than 8 m, since this system puts a high load on the foundation. To reduce it, various elements are used in the hanging system, such as tie rods and headstocks, struts and crossbars. For example, the headstock hangs the tie to the ridge connection, and the struts pull the beams to the rafters.

For floor beams in a hanging system, hewn logs or fairly thick bars installed on an edge are used. Their cross-section must be at least 100x200 mm. The floor in the attic should be as reliable as possible, and in order not to make mistakes in the parameters, it is better to entrust the calculations to a specialist.

Layered system

The layered system, unlike the hanging one, is supported not just by two external load-bearing walls, but also by permanent partitions installed on the foundation. Therefore, when planning the construction of an attic, it is necessary to think in advance about the design of the strip foundation on which the permanent partitions will be installed. The layered system is perfect for installing an attic because it can withstand high loads compared to the hanging version. It provides a good base for the floor beams and therefore for the attic floor.

If you make a broken version of the attic roof, then it makes sense to use a combined roofing system, that is, the side rafters are installed in a layered manner, and the ridge rafters are installed in the form of a hanging system.

Do-it-yourself mansard roof: video, photo

When building a house from blocks or bricks with an attic, its front side is often built from the same material. This is convenient because you don’t have to calculate the parameters of these roof elements and assemble them from bars to lift onto the wall. But it is important to understand that the walls of the building must be on a reliable foundation and have good thickness, since such a pediment puts a significant load on the main structure.

If the attic serves as another floor year-round, then a gable wall made of foam blocks or bricks is an excellent option for creating a living space under the roof.

In order for attic rooms with a gable roof to be spacious and have a normal height, the angle of the roof slopes should be approximately 45-50°, depending on the width of the end part of the structure. If you take a smaller angle, the volume of the room will significantly decrease. Increasing the steepness of the slopes will make the roof unreasonably high, it will become heavier, will have greater windage under wind loads, and the cost of materials will be inappropriate.

Of course, the installation of a gable roof is simpler compared to a broken structure, since straight rafters are used without additional connections or any kinks. But the broken design allows you to make the room in this part more spacious, and the ceilings correspondingly higher.

The broken system is much more complex in design, calculations, and roofing, but it not only creates a more spacious space under the roof, but also gives solidity to the entire structure. Its main difficulty lies in the large number of complex connecting elements. All connections must be made in accordance with the technology, otherwise the roof will turn out to be unstable.

If the walls are built of brick or stone, then it is better to lay out the front parts in advance during the general laying. In this case, in order to create a unique rafter system, aligned with the finished gables, you can install intermediate rafters and special supporting fastenings to them.

Before purchasing and preparing material for a particular system, you need to draw up a design project with the appropriate dimensions - it will become the main guide for preparing and assembling elements during installation.

Video: rafter system for a sloping attic roof

Attic project

When developing a scheme for building an attic, it is better to do this in different projections in order to clearly understand how the elements of the rafter system will be placed. It is important to correctly calculate what the height of the roof ridge should be, since the size of the area depends on it.

When preparing a design diagram for constructing a roof for an attic, it is necessary to calculate the height of the ceiling, ridge and total area of the room.

The minimum height from the floor to the ridge is 2.5-2.7 m, but if this distance is smaller, then the room cannot be called an attic; the name attic is more suitable for it. This indicator is established by SNIP standards.

In order for all the elements to be accurately drawn and have the correct location in the overall system, it is necessary to start from a figure with right angles, namely a square or rectangle - a cross-section of the attic space being created. Based on the width and height of the future room, you will never be mistaken with the angles at which the roof slopes are located, with the location of the rafters, ridge and other supporting elements. Having found out these parameters, they must be immediately entered into the drawing.

First of all, you need to calculate the middle of the width of the front wall. Further from this point, the height of the ridge, the attic ceiling, the location of the walls (racks) and the size of the eaves overhang are determined.

Due to the fact that each of these structures has a certain number of connecting nodes with different configurations, it would be nice to draw each of these connections separately in order to understand in detail the features of the pairing of all the elements that are connected at this point.

All rafter systems include basic and additional elements, which may not be found in every structure. The main components of the attic roof include:

floor beams (the basis for the remaining elements of the system). They are laid on main walls.

A rafter leg consisting of two sections (in the case of a broken pattern) or straight in a gable system. The top rafter in this case is called the ridge rafter, since it forms the highest point of the roof - the ridge, and the rafters that form the walls of the attic are called side rafters.

Mauerlat is a powerful beam that is attached to the main side walls. It is necessary to install rafter legs on this element.

A ridge board or beam is an integral element for a gable roof, but is not always used when installing a broken roof.

Constructions are supporting elements that are required to strengthen a broken and gable structure. In the first case, the side and ridge rafters are attached to it, and in the latter, the stand acts as a good support for a long rafter. Moreover, the racks are the frame for covering and insulating the attic walls.

Diagonal connecting elements additionally fasten the longitudinal beams or posts and rafters, thereby making the structure even more durable.

Inter-rafter purlins are installed in the case of a broken roof for structural rigidity.

Attic floor beams are used in both versions of the system - they connect the racks with them, and they act as a frame for the ceiling.

In order to be sure that the project is developed without errors, it would be a good idea to show it to a specialist. It will determine how correctly you selected the attic parameters to the length and width of the walls of the building.

Video: calculating a mansard roof using software

Material parameters for the construction of an attic roof

When the graphic element is ready, then, based on the dimensions set on it, you will be able to calculate the amount of materials that will be needed for the construction of the attic roof. It is necessary to select materials according to their characteristics, which must meet environmental and fire safety requirements.

For wood, it is necessary to provide an antiseptic treatment, which will significantly reduce the flammability of the materials. For construction you will need:

boards for rafter legs, the cross-section of which is selected based on the results of calculations, which you will learn about a little below.

Beam of 150x200 or 100x150 mm - for floor beams, depending on the width between load-bearing walls, rafter system, as well as for purlins, valleys or diagonal legs - if, of course, they are provided for by the design.

Beam from 100x150 or 150x150 mm, intended for laying the Mauerlat.

Typically, timber 150x150 or 100x100 mm is used for racks.

Unedged board for the subfloor, as well as some fasteners.

Annealed steel wire with a diameter of 3-4 mm - for fastening some parts.

Bolts, nails, staples of various sizes, angles of various configurations and other fasteners.

Lumber for counter battens and sheathing for roofing material - depending on the type of roof.

Vapor barrier and waterproofing membranes.

Insulation materials intended for roof thermal insulation.

Roofing material and special fasteners.

Rafter section

Rafters provide a roofing element that absorbs the main external loads, which means special requirements are placed on their cross-section.

The size of the required lumber depends on many parameters - from the step between the rafter legs, the length of these legs between the support points and ending with the wind and snow load that falls on them.

The geometric parameters of the rafter system are easily determined in the drawing. But to understand other parameters, you will have to refer to reference materials and perform some calculations.

It's no secret that snow load differs in different regions of our country. Below in the figure you will see a map on which all of Russia is divided into zones demonstrating the snow load.

In total, 8 zones are distinguished (the last one is considered extreme and can not be considered for the construction of an attic roof).

Sg is an indicator in the table (carefully study the map and the table attached to it).

μ is a correction factor that depends on the steepness of the roof slope.

For example, if the roof slope angle is less than 25°, then - μ=1.0; if from 25 to 60°, then μ=0.7; if it is more than 60°, then the snow will not linger on the roof, and the snow load is not taken into account.

If the attic roof is of a broken structure, then for its different sections the load may have different values.

The angle of inclination of the roof can be determined by a simple ratio of the height and base of the triangle (usually half the width of the span) or using a protractor according to the drawing.

This indicator also largely depends on the region where the structure was built, on the height of its roof and on the characteristics of the environment.

And again, for the calculation you will need to determine the initial data from the map and the table attached to it.

The calculation for this task will be carried out using the following formula:

Wp = W × k × c

W – value in the table, depending on the specific region.

k – coefficient taking into account the location and height of the building (see table).

The letters in the table indicate the following zones:

A - open areas, forest-steppes, steppes, tundra, deserts, forest-tundra, sea coasts, reservoirs and large lakes.
B – urban areas, areas with frequent wind obstacles, artificial or relief, at least 10 m high, wooded areas.
B – dense urban development, building heights from 25 m.

With– a coefficient that depends on the prevailing wind direction (wind rose of the region), as well as on the angle of inclination of the roof.

With this coefficient, the matter is much more complicated, since the wind can have a dual effect on roofs. So, it has an overturning, direct effect on the roof slopes. However, at small angles, the aerodynamic effect of the wind is of particular importance - it raises the slope plane due to the resulting lift forces.

As you have already noticed, the diagrams that accompany the tables indicate the areas of the roof that are subject to maximum wind loads, and also indicate the corresponding coefficients used for the calculation.

It is worth noting that at slope angles up to 30° (in the area of ridge rafters), the coefficients are indicated both negative (directed upward) and with a plus sign. They somewhat dampen the wind load, and in order to reduce the impact of lifting forces, you need to carefully secure the roofing material and rafter system in this area, using additional connections (for example, annealed steel wire).

Once the snow and wind loads are calculated, they can be summed up and, taking into account the design features of the system, the cross-section of the rafter boards can be determined.

Please note that these data are indicated for the most commonly used coniferous materials (spruce, pine, larch or cedar). In the table you can see the maximum length of the rafters between the supports, the section of the board depending on the pitch between the rafters and the grade of the material.

The total load value is indicated in Kilopascals (kPa). Converting this value into the usual kilograms per m2 will not be difficult. 1 kPa ≈ 100 kg/m².

As for the size of the board along its cross-section, it is rounded up to the larger side of standard lumber sizes.

What tools will you need to install an attic roof with your own hands?

Of course, during work you cannot do without a set of tools, the list of which includes:

screwdriver, electric drill;
building level, tape measure, plumb line and square;
chisel, axe, hammer, chisel;
jigsaw, circular saw, hacksaw;
carpenter's knife

If the work takes place surrounded by competent mentors, step by step and carefully, and the tools are of high quality, the process will be much faster.

Do-it-yourself mansard roof: main steps + video

It is important to strictly follow the sequence of work, because this is the only way the structure will be strong and reliable.

Mauerlat fastening.

The installation of any rafter system should begin with attaching a powerful support beam - Mauerlat - to the end of the side walls of the buildings. It is convenient to install rafter legs on it. It is made from high-quality timber 100x150 mm. The Mauerlat is laid on roofing felt waterproofing laid along the upper end of the wall (regardless of the material).

Thanks to the Mauerlat, the load is evenly distributed across the walls and transferred to the foundation. It is fixed to the wall using metal studs, which are previously embedded in a crown or concrete belt running along the upper edge of the wall of the structure or with 12 mm anchor bolts. They must go into the wall at least 150-170 mm. If the Mauerlat is installed on a wall made of wood, then the beams are attached to it using wooden dowels.

Installation of the rafter system.

Installation of the rafter structure begins with the installation of floor beams, which can be mounted on top of the mauerlat (if you plan to move the beams outside the room, increasing its area). In this design, the rafter legs are fixed directly to the floor beams.

Otherwise, they can be laid on waterproofed walls and secured with brackets or corners to the inner edge of the Mauerlat. This option is used if the rafter legs need to be fixed directly to the mauerlat.

The posts should be at the same distance from the middle of the floor beam. In the future, they will determine the location of the walls of the room, namely its width.

The bars for the racks must have a cross-section corresponding to the size of the floor beams. The racks are attached to the beams using wooden plates and special corners. But first, they are fastened with nails, after which they are leveled using a plumb line and a building level, and only then are they thoroughly secured with the expectation of upcoming loads.

As soon as the first pair of racks is installed, they are fastened on top with a block (tightening). It, in turn, is connected using metal corners to the racks.

When the tie is secured, you will have a U-shaped structure. On the sides, layered rafters are installed on it, which are laid on the mauerlat or attached to the floor beam with the second end.

A groove (special notch) is cut into the installed supports for the timber or in the rafters. With its use, the rafters are installed on the mauerlat beam and secured with metal brackets.

To ensure structural rigidity, struts can be installed from the base of the rack to the middle of the side rafters. If this turns out to be not enough, and you do not mind the material, then it would be a good idea to strengthen the overall structure with contractions and additional racks.

Then the middle is calculated on the puff. A beam will be attached to this place, which will support the ridge connection of the upper hanging rafter subsystem.

The next stage is the installation of ridge rafters. They can be fastened with various connections - these can be powerful bolts with metal washers or plates, or a metal plate.

After installing them, the headstock is attached to the middle of the tightening and the ridge.

Upon completion of work on one part of the truss structure, it is necessary to do the rest according to the same principle. The distance between adjacent rafters in such a system should be no more than 900-950 mm, but the best option would be an interval of 600 mm, which will give the structure the necessary stability and rigidity and will be convenient for insulation using standard mineral wool mats. But this significantly makes the structure heavier and increases the cost of materials.

First, the side parts of the system assembly are installed, then the intermediate parts. They are connected to each other by purlins, which are installed between the upper ends of the racks and work like spacers. So, we get a rigid structure of the attic rafters, where there will already be a ready-made frame for finishing the walls.

Waterproofing attic roof

As soon as you have built the rafter system, you can begin finishing it with insulation and other related materials.

It is worth noting that the first coating on top of the rafters should be a waterproofing and windproof film. It is attached to the rafters using a stapler and staples, starting from the cornice. The canvases are laid with an overlap (200 mm), and then the joints are glued together with waterproof tape.

A counter-lattice is placed on top of the waterproofing, which will better fix the film on the surface and create a ventilation distance between the roofing and windproof material. Typically, the counter-lattice is made of boards 50-70 mm thick and 100-150 mm wide.

A sheathing is fixed perpendicular to it, on which the roofing material is laid. As for the pitch between the slats, it is calculated depending on the size and type of sheet roofing material, taking into account the overlap required for it.

If you are using a soft roof, then plywood sheets are usually attached to the counter-lattice.

How the roof covering is installed

The roofing material is fixed to the prepared plywood or sheathing. Typically, its installation begins from the roof eaves and then one by one, from one of the edges - depending on the type of roof. The roofing sheets themselves are installed with an overlap. If metal tiles or a metal profile are used for the coating, then this material is secured using special self-tapping screws with elastic gaskets. Typically, fasteners are matched to the color of the material.

The most difficult stage in covering a sloping roof is the transition from layered side rafters to ridge rafters. Some difficulties may also arise if the roof has projections for arranging the roof above windows or balconies.

Moreover, if a chimney pipe goes onto the roof, it requires a separate design of the hole in the insulating layer and rafter system, and on the roof - a device around reliable waterproofing. It is worth noting that the work of constructing any roof, including such a complex one as an attic roof, is very important and dangerous, and therefore requires increased safety measures. If you do not have experience in such construction processes, then it is better to entrust their implementation to specialists or invite an experienced craftsman, under whose supervision, perform all actions carefully and carefully.

There are several roof options under which you can place a comfortable living space. In order to ensure the maximum volume of the attic space under the roof, it is necessary to select the optimal angle of inclination of the slopes and not to forget about the snow and wind load on the roof. We will look at the most popular designs of attic rafter systems in the middle zone.

The design of the attic roof truss system

A mansard roof makes it possible to obtain additional usable space with a relatively small financial investment, which is why this architectural solution has gained great popularity. So what is called an attic?

Attic (from the French mansarde) is an usable attic space (both residential and non-residential premises), formed on the top floor of a house, or the top floor of a part of a house, with an attic roof.

Wikipedia
https://ru.wikipedia.org/wiki/Attic

The attic is located within the load-bearing walls of the building and rests on them through the mauerlat, horizontal beams (strings) and rafters. The larger the attic space, the greater its useful volume, which is achieved by increasing the angle of inclination of the slopes and is formed by a more complex rafter system. The location of the rafters of the attic roof depends on the structure, which can be of different types, namely:

Tent or pyramidal structure with a minimum volume of under-roof space.
The slopes of the tent structure rest on the side rafters and the central post, so the volume of the under-roof space here is minimal
A hip or half-hip roof, in which the main living space is located under trapezoidal slopes.
The rafters of the hip roof form two triangular and two trapezoidal slopes
A gable structure, which is a symmetrical gable roof with gables cut in at right angles, which provides a significant volume of attic space.
The multi-gable roof allows you to equip a full attic floor
A gable symmetrical roof with an attic is a classic option, characterized by ease of installation and resistance to wind influences due to its rigid structure.
A gable roof requires the least amount of working time and low consumption of building materials
The rafter system of an attic sloping roof provides the maximum volume of living space at a relatively low cost.
A sloping roof is the optimal solution in terms of the ratio of the cost of construction to the volume of usable space in the attic

The rafter system must withstand constant loads, which consist of the weight of structural elements, insulation and roofing. In addition, there are variable loads depending on the strength of the wind and the weight of the snow on the roof. The choice of the cross-section of load-bearing elements and the method of connecting them should be aimed at creating the most durable and rigid structure that evenly distributes the load on the walls of the building.

Depending on the width of the building, different types of attic rafter systems are used, which are divided into hanging, layered and combined.

Hanging rafters are those that rest on the walls of the building through the mauerlat and tie, and form a ridge in the upper part. With this connection method, there is no intermediate support, and the bursting pressure on the walls of the house is reduced with the help of crossbars, racks and struts. The hanging rafter system is usually used when the building width is no more than 6 m.
To compensate for bursting forces in suspended rafter structures with a span of up to 6 m, tie rods and crossbars are used
Layered rafters are called rafters with intermediate support on the internal wall of the house. They are used when the width of the building is from 6 to 16 m. The larger it is, the more elements are used to evenly distribute the load.
Layered rafters have one or more supports inside the house
The combined type of rafter system is used in mansard roofs with variable slope angles. The most typical example is a broken mansard roof, where the lower rafter legs are layered and supported by a post and a mauerlat, and the upper ones are mounted as hanging rafters supported by a tie rod and a headstock. When constructing mansard roofs, all types of rafter systems are used, and their choice depends on the structure in which they are used.
In the design of a sloping roof, the upper rafters are hanging, and the lower ones are layered

Scheme of the rafter system of the attic roof

To erect a roof, you must have a project that specifies the list and size of structural elements, as well as the method of connecting them. To understand the principle and sequence of installation, you need to know the purpose of the elements of the rafter group and the way the roof adheres to the walls of the building. The attic roof consists of the following elements:

the connecting element between the wall of the building and the rafter group is the Mauerlat, which is attached to the walls of the house with studs, brackets or anchors;
strings are attached to the Mauerlat parallel to the short wall of the building, and beds are installed along the long side;
vertical posts are mounted on the central floor;
the ridge girder rests on the posts;
the upper part of the rafters rests on the ridge girder, and the lower part is connected to the tie, forming a cornice overhang;
the rafter legs in the upper part are connected by crossbars;
on hip roofs, diagonal rafters and shortened eaves are used;
trusses serve as additional support for the diagonal rafters;
for intermediate fastening of rafters, racks and struts are used;
if necessary, the rafters are lengthened with fillets.

The main load-bearing elements of the attic roof are rafters, beams and tie rods, as well as vertical posts and a ridge girder.

The diagram indicates the dimensions of the elements of the rafter system, their location, angles of inclination and methods of insertion at the connection nodes. Information about the location of double rafters, the presence of additional supports, and the dimensions of eaves and gable overhangs is also required.

The diagram is the main document for assembling the rafter system; it reflects all the necessary parameters. However, before cutting the material, it is necessary to check the calculations again and create templates for the main parts. If there is no project, you need to carry out calculations and create a diagram yourself.

Mansard roof rafter spacing

Before starting work, you need to select the pitch of the attic roof rafters. The distance between the rafters and the eaves (in the case of a hip roof) depends on several factors:

building size;
type of rafter system;
constant and variable load on the roof;
sections of rafters, racks and slopes;
type of roofing;
type and pitch of sheathing;
insulation sizes.

For rafters, sheathing and counter-lattens, softwood material is selected in accordance with SNiP II-25, and the load on the rafters is calculated according to SNiP 2.01.07 and ST SEV 4868. Based on what is stated in the building codes and regulations, we can say that for rafters less than 9 m applicable beam cross-section from 50X150 to 100X250 mm with a pitch of 60 to 100 cm. The size of the building affects the design of the truss and the presence of racks, struts and crossbars, the use of which increases the strength of the rafter legs and allows you to increase the pitch between the rafters to 120 cm or more . Usually, to select a step, reference tables are used, which contain recommendations taking into account the length of the rafters and the cross-section of the beam.

Table: dependence of the pitch between the rafters on the section of the beam and the length of the rafters

The type of roofing used also affects the choice of rafter spacing, because different materials have different weights:

tiles, depending on the type, weigh from 16 to 65 kg/m2, slate - 13 kg/m2. Such heavy coverings imply a reduction in the pitch of the rafter legs to 60–80 cm;
the weight of metal coatings and ondulin does not exceed 5 kg/m2, so the pitch of the rafters can be increased to 80–120 cm.

On hip roofs, in any case, the step of the roofers is chosen to be 50–80 cm to give the slope greater rigidity.

In addition, the installation step of the rafters depends on:

The length of the rafters and sheathing of the attic roof

When doing independent calculations, the dimensions of some structural elements of the roof have to be calculated based on the existing dimensions of the building and the angle of inclination of the slopes. The length of the rafters sometimes has to be adjusted for different types of attic roofs, selecting the optimal dimensions of the entire structure as a whole.

Let's assume that the main dimensions of the building are known and it is necessary to calculate the length of the rafter joists for several proposed options for the angle of inclination and type of roof. Let half the width of the building L be 3 m, and the size of the eaves slope be 50 cm.

Additional calculations show that increasing the angle of inclination of the lower slope from 60 to 70 o will increase the width of the attic by 10%.

The length of the sheathing connecting the rafter legs is determined taking into account the gable overhangs that protect the facade walls from precipitation. The length of the gable overhang depends on the height of the building and is selected in the range from 40 to 60 cm. Therefore, the total length of the slope will be equal to the length of the house, increased by twice the length of the overhang.

Let's assume that the length of the house is 10 m, and the gable overhang is 0.6 m. Then the dimensions of the sheathing must be calculated taking into account the length of the slope, equal to 10 + 0.6 ∙ 2 = 11.2 m.

The parameters of the sheathing should be calculated taking into account the length of the gable and eaves overhangs

Any adjustment to the project requires a careful recalculation of the parameters of the rafter system, taking into account the changes that have arisen.

Video: calculation of the attic roof

Knots of the rafter system of the attic roof

The nodes of the roof truss system represent the junction of individual elements into a single structure, which allows you to evenly distribute the load on the walls of the building. The connection is made with nails, self-tapping screws or bolts using overhead wooden elements or metal squares and plates, as well as by connecting to a groove. To construct a gable roof, the following main components are used:

A ridge unit that provides a connection between the rafter legs and the ridge purlin.
Places where the crossbar connects the rafters to give greater strength and rigidity to the trusses.
Attachment points for struts and posts that provide additional support to the rafters.
A cornice assembly in which the rafters are attached to a tie rod or mauerlat, forming a cornice overhang.

Nodal connections of the rafter system must be made in such a way as to ensure the most rigid fastening of the elements to each other

A characteristic feature of a gable sloping roof is the knot where the upper and lower rafter joists, the vertical post, the crossbar and the purlin are connected. Such a complex connection requires the use of mortises, bolts, steel plates and construction staples.

In the most complex unit of a broken mansard roof, five rafter elements are connected

The most complex component of a hip mansard roof is the junction of the side or diagonal rafters with the mauerlat. The side rafter in the lower part rests on the corner beam of the mauerlat and on the embedded beam; in another option, a vertical post or truss is placed between the embedded beam and the rafter leg. The upper part of the hip rafters is attached to the ridge purlin using bolts or nails.

The corner rafters of a hip roof bear the greatest load, so their connection to the Mauerlat must be thought out most carefully

The described units are used most often when installing rafter systems of various designs and allow you to install load-bearing elements on your own. For efficient and high-quality assembly, drawings and production of templates with verified angles of joints and inserts are required.

Video: rafter system components

Calculation of the rafter system of the attic roof

The rafter system is the basis of the roof, so it is important to choose the design that is most suitable for the climatic conditions of the region and the existing requirements for the size of the residential attic. After selecting the design, the angle of inclination of the slopes and the height of the ridge are calculated for the required dimensions of the attic room. Calculations are made taking into account the size of the cornice using the following formulas:

The meaning of trigonometric functions can be found in reference tables.

Table: values of trigonometric functions for different slope angles

The most difficult thing when designing mansard roofs is counting lumber. Calculating the number of rafters required and matching them with a standard length of 6 m can sometimes be quite difficult. Let’s assume that we have chosen the hip roof, the most difficult to calculate, measuring 10X13 m, taking into account the eaves overhangs 80 cm long and the slope angle of 45 degrees. Then the side rafters will have a length of 5 / sin 45 o = 7.04 m. Therefore, the standard six-meter beam will have to be lengthened. Typically, for rafters a little more than 6 m long, a 100X200 mm beam or a 50X250 mm board is used.

If the building is large, it requires rafters longer than the standard size of 6 m, so the beam has to be extended

As for the horizontal floor beam, since the width of the building is 10 m, the tie rods should consist of two parts, which either rest on the internal wall of the building, or are joined together by reinforcing elements and rest on the purlin. For tightening and purlins, use timber with a cross section of at least 50x200 mm. Along the perimeter of the building there is a mauerlat, for which timber 150X150 mm or 200X200 mm is used. According to the scheme we have chosen, the perimeter of the building is 39.6 m, so installing the Mauerlat will require seven six-meter beams. The dimensions of all other elements of the rafter system will not exceed 6 m.

The weight of the lumber of the rafter system is calculated by summing the lengths of all elements with a certain cross-section and converting their quantity into cubic meters. This is necessary to determine the mass of the entire roof, and is also necessary when purchasing and transporting material. The calculation is made according to the table, and then the obtained values are multiplied by the weight of 1 m 3 of lumber.

Table: calculation of the amount of lumber in 1 m3 and the volume of one unit of material

Pine lumber weighs 505 kg/m 3 at 12% humidity, and 540 kg/m 3 at transport humidity 25%. Here are some examples of calculations:

If 1 m 3 of material with a cross section of 50X200 mm contains 16.6 boards, then the weight of one board will be 540 / 16.6 = 32.5 kg.
If 25 m 3 of lumber is purchased, then it will weigh 25 ∙ 540 = 13,500 kg.
If 100 boards 25X200 are required, then you need to buy 100 / 33.3 = 3 m 3 of wood, which will weigh 3 * 540 = 1,620 kg.

It is important to note that it is advisable to purchase edged lumber with the lowest moisture content so that after installation it does not warp or crack, especially for large-section timber. For the construction of a rafter system, the wood moisture content should not exceed 18%.

Installation of attic rafter system

Installation of a rafter system with a residential roof space requires careful preparation. It is necessary to install convenient scaffolding, decking and ladders, as well as provide workplaces with safety ropes. Workers must be provided with protective clothing, protective equipment and working equipment. It is necessary to select a flat place on the ground for pre-assembling the trusses, marking the corners and making templates. All wooden elements must be treated with antiseptic and fire-retardant compounds.

After this, you can begin work, which takes place in the following sequence:

On walls with walled studs, a mauerlat is mounted around the perimeter. If there is a load-bearing wall inside the building, we lay a beam or purlin on it that is the same height as the mauerlat.
If the house is being built from building blocks, then the Mauerlat is most conveniently laid on threaded rods, walled into the wall during its laying.
Cable ties with cornice extensions are attached to the Mauerlat parallel to the short wall.
Vertical posts are placed on the tie rods, delimiting the attic space.
The racks are connected to a tie that serves as the ceiling of the attic space. The trusses installed in this way are connected to each other by horizontal girders.
Vertical posts, top ties and horizontal purlins form the frame of the attic space
The lower and then the upper rafters are installed, which are attached to the ridge part.
To strengthen the lower and upper rafters, struts, headstocks and ribs are used.
The sheathing and front board are installed on the eaves overhang.
After installing all the rafter joists, all that remains is to lay the sheathing and nail the front board

We looked at the assembly of the rafter system using the example of a broken mansard roof. The construction of other structures consists of similar operations and mainly consists of performing work according to the design installation diagram, which reflects the methods of connecting the elements of the rafter system. With carefully calculated drawings, a team of four people is able to install a roof with a rafter system of any complexity.

Video: installation of an attic roof

We examined the rafter group of the attic roof, its design, calculations, as well as a diagram and description of the main components. They offered an option for step-by-step installation of load-bearing structures of the attic, attached illustrations and videos that explain the procedure for assembling the structural elements of the attic roof. Now its successful construction depends only on the careful fulfillment of the requirements of instructions and technologies and the availability of certain skills for the performers to carry out construction work. We wish you success.

The attic is both another floor where you can live and a beautiful external appearance of the entire private house. Even if the attic will be used only in the summer season and will not be heated, nevertheless, this space under the roof in any case forms a strong “cushion of air” that traps heat inside the entire building.

Building an attic roof with your own hands is possible, but only if you are a specialist with extensive experience or you need help from such a person, because this part of the house has a complex structure.

A do-it-yourself mansard roof can be erected under various roofing structures, but the most popular ones are broken and gable. To choose the required design, you need to analyze these two types in detail.

Also, the person who carries out the construction needs to decide on the type of rafter system for the attic roof. It is necessary to create a mansard roof pie. Let's take a closer look at them.

Types of rafter system

The construction of an attic floor or a house with an attic begins with the construction of a rafter system. Different types of roofing refer to one of two types of rafter systems. In total, there are two types of rafter system for mansard roofs:

Hanging;
Layered.

Do-it-yourself mansard roof, its construction begins with the choice of rafter system. These two types have their own distinctive nuances. The choice of one type or another depends on the location of the (main) walls of the building. Let's look at each variety separately in more detail.

Hanging system

The rafter system of the attic roof is called hanging because its support (hanging rafters) is located on the outermost walls with load-bearing capacity. This happens if the building does not have load-bearing partitions, but only walls from the outside.

This type of construction can only be used in a situation where the distance between the external walls does not exceed eight meters. Because this design creates a huge load on the base of the main walls.

To make the load on the base much less, construction elements such as vertical bars (headstocks), tie rods, support beams, and struts are used.

So, struts are structural elements that pull up floor beams and are intended to connect and transfer loads. The construction head hangs the tie to the ridge part of the roof.

In this truss structure, bars that are quite thick are used to create floor beams. The cross-section of such bars is 100×200 millimeters. In order not to make a mistake in calculations, you need to trust a professional, because the reliability of the floor depends on this.

Layered system

A distinctive feature of this design is that it rests not only on the walls, but also on the partitions built on the base of the building. Therefore, at the design stage of the attic space, it is necessary to carefully consider all the elements of the foundation structure if you are planning to install a strip foundation. Load-bearing partitions will be built on it. A layered rafter structure is a more suitable option for building an attic, because it can withstand much greater pressure than the previous system. The layered variety guarantees reliability for floor beams.

If your roof has a broken structure, then the attic rafter system should be combined. This means that a hanging system is suitable for ridge rafters, and a layered system is suitable for side rafters.

Installation of a roof with an attic

During the construction of a brick building, the front side of the attic is also made of brick. This simplifies the process, since you do not have to calculate the parameters of all roof elements. However, it must be remembered that the walls must be on a reliable foundation. They must also have the required thickness, because the pediment creates enormous pressure on the foundation of the building.

If the roof of your attic house will be used as an additional floor, then the pediment should be made of brick or foam blocks. This will create a room under the roof.

In order for the under-roof space to have an acceptable height with a gable roof and spaciousness, the angle of each slope should be 45 degrees. The size of the angle depends on the width of the side of the building (end). If the angle is made smaller, the space of the room under the roof will also decrease. If the angle is large, then the height will be enormous; the attic and its rafter system will put a huge load on the foundation. Also, the expenditure of funds will be unjustified.

Installation of a gable roof is much easier than for an attic with a sloping roof. Since, to build the first one, straight rafters for the attic roof are used, kinks and other connections, which are additional, are eliminated. But the broken roof of the attic allows you to build a more spacious room, and thanks to this design the ceilings will have the desired height. The design of the sloping mansard roof not only creates space, but also makes the structure solid. The complexity of this design lies in the fact that it has a huge number of connecting nodes. All these connections must be made according to the rules, then you can guarantee high quality.

Before purchasing material for a certain type of attic roof truss system, you need to carry out a design with the required dimensions.

Attic room project

When you draw a diagram of your attic space, draw it in a variety of views to better study how the assembled components are placed. It is necessary to correctly calculate the height of the roof ridge - this is the most important, because the area of the room under the roof depends on this element. It is impossible to collect unnecessary things in a project; all calculations must be accurate.

In addition to the height of the ridge, it is necessary to make calculations of the height of the ceiling, as well as the size of the under-roof space.

The distance from the attic floor to the roof ridge should be two and a half meters. If this distance is less, then it is not an attic room, but just an attic.

In order for the elements to have accurate values and be positioned correctly, it is necessary to rely on a figure that has right angles (rectangle or square). The rectangular figure is a section of the attic. Starting from the sides of the section, you can determine the required angles (45-50 degrees). You can also determine the location of the roof ridge, rafters and other structural elements.

At the very beginning, it is necessary to determine the middle of the width of the front wall. The midpoint of the width of the front wall will help determine the height of the roof ridge and ceiling, the location of the stud walls, and the dimensions of the eaves overhang.

Due to the fact that any structure has a certain number of connecting nodes that have different locations. It is better to draw each connecting element separately in order to find out all the features of the connection with each other.

A diagram of the rafter system for the attic roof must also be prepared. Each rafter system design and its variety has primary and secondary elements. Main components:

The first main element is the floor beams. They are mounted to form the basis of other parts of the rafter structure. Floor beams are laid on the load-bearing walls of the house.
The structure also consists of a rafter leg. It is straight in a gable roof or consists of two parts in a sloping roof. In the latter version, the rafter that is located at the top is called the ridge rafter because it creates the highest point, which is the ridge of the roof. Other attic rafters form walls and are called side rafters.
The next element is timber. This is the most important part in a gable roof structure. However, most often timber is not used when constructing a sloping roof.
Mauerlat. This is also a powerful beam, which is laid on top along the perimeter of the outer wall. The rafter legs are installed on the Mauerlat.
Another component is the racks. This is a support for strengthening a particular roof structure. Two types of rafters are attached to the broken roof: side and ridge. In another type of roof, a support for long rafters acts as a post.
Bevels. They are the connecting element for the racks. Also, bevels are longitudinal beams that give the structure additional strength.
The next part is the attic floor beams. These are connecting nodes for racks, as well as a base for arranging the ceiling.
Inter-rafter purlins. Their installation is carried out in a sloping roof to provide rigidity.

If you compiled the project yourself, then it needs to be checked by a professional. If so, he may make some adjustments.

Characteristics of materials used

If the drawing is made, then it is necessary to carry out calculations based on it: how much material is needed to build the attic. Products must meet the required properties. They must also be environmentally friendly and fireproof. For wood, you need to carry out specially designed treatment using antiperines. Thanks to this treatment, you can increase the level of fire resistance of wood.

Therefore, the following materials will be useful for construction:

The first material is boards. They will be intended for rafter legs. The section is selected according to the calculation results.
A beam whose cross-section is 150×200 millimeters (may be different). It is intended for floor beams. The choice of section depends on the type of rafter system and the distance between the load-bearing walls of the building. The timber is also used for purlins and valleys. If these elements are in the project at all.
Another beam, the cross-section of which is 150×150 (maybe different), to lay another beam - the mauerlat.
The next material is unedged board. It is necessary to lay the subfloor.
The wire is made of steel, which should have a diameter of four millimeters. It will be needed to hold some parts together.
It is necessary to collect products for fastening: nails, bolts, staples, corners.
Another material is a sheet of metal, the thickness of which should be one millimeter.
Timber intended for lathing covering and antiseptic-treated timber (counter-lattice). The choice of polymaterials depends on the type of roof.
Products used for roof insulation.
Films designed for waterproofing and vapor barrier of the space under the roof.
Roofing material and components for its fastening.

Required rafter section

Rafters are roof parts that bear the main pressure, so their cross-section must meet certain requirements.

The size of the required timber depends on different standards:

The first parameter is the step between the rafter legs.
Length of rafter legs between support points.
The last parameter is snow and wind load.

Almost all of these parameters can also be calculated from the drawing.

Step-by-step installation instructions

A do-it-yourself roof with an attic does not end at the design stage. Do-it-yourself installation of an attic roof must be carried out step by step, according to a specific algorithm of actions. Then you will get high quality. Installation is practically no different, regardless of whether you have a sloping roof or a gable roof. How to build a roof with an attic and how to do it correctly? Let's consider each stage of installation separately.

Fastening the Mauerlat

It is necessary to make a frame for the attic roof. The first stage is securing a powerful beam (mauerlat) to the side of the walls. The rafter legs will be installed on it. Its installation is carried out on a waterproofing layer of roofing felt.

Thanks to this element, the pressure will be distributed evenly across the base of the building.

Fastening is carried out using metal pins. The depth of insertion of metal pins should be 150 millimeters. If the beam is fastened to the wall of a wooden house, then it is done using wooden edges.

How to make a rafter system? Installation of the rafter system begins with the installation of wooden beams to create the ceiling. These components are attached to a powerful log at the top. The rafter legs are attached to these components.

In another situation, their installation can be carried out on walls insulated from moisture. Fastening is carried out thanks to the corners to the inside of the powerful beam. Next you need to find the middle of these elements in order to understand where the support and ridge posts are located.

The racks will help determine the width of the walls of the attic space.

The cross-section of the bars intended for the constructed racks must be similar to the cross-section of the wooden floor beams. They are attached to each other thanks to specially designed corners. They are secured with nails, and then everything is leveled using a building level.

Then the layered rafters are installed. Then a narrow notch is cut out. Thanks to the narrow recess, the rafters are installed on a powerful beam. Installation is carried out using brackets.

Then the ridge rafters are installed. They are fastened together thanks to a metal plate. The grandmother joins the skate. This was the completion of one part of the rafter structure. The rest are built in the same way.

After the attic is built, it is waterproofed. After this, you can get a full-fledged roofing pie on the roof, and the construction of the house with your own hands is completed.

Do-it-yourself attic roof is a complex and responsible process. To build a roof for a house, you must also follow safety precautions while working. If you do not have any experience in this work, then it is better to entrust the roofing to professionals who will do everything efficiently and at a high level.

The attic floor is a more spacious and well-prepared attic for living. The characteristics of the premises dictate their conditions regarding the roof. The installation of an attic roof does not require the contractor to have any special knowledge and skills. It is enough to prepare the necessary tools, read the instructions in detail and follow its recommendations in everything.

There are several types of mansard roofs. Check out the features of each of these roofs and choose the most suitable option. The main points of construction technology are common to all types of construction.

The simplest option is a pitched mansard roof. This design is made with some bias. It is used quite rarely, because due to the slope, the usable area of the attic space is reduced.

The most popular option is a gable mansard roof. The interior of the roof space will be comfortable and spacious. A gable roof is simple and advantageous to install.

It is a type of gable structure. In this case, the slopes will not be smooth, but broken. Typically, sloping roofs are used in cases with small houses.

Hip roof consists of four slopes. The rafter system of a hip roof is somewhat more complicated.

Half hip roof is a type of hipped roof. In this case, the half-hip is usually understood as that slope that, as it were, cuts off part of the end side of the gable roof. The cut can pass from the bottom and form a trapezoid, or from the top and create a triangle.

Interesting varieties of hipped mansard roofs are pyramidal and conical roofs. Such designs look best on polygonal houses and round buildings. Perfectly combined with other types of roofs.

They are used quite rarely. This design has a smooth parabolic or circular shape. Previously, such roofs were widely used in rectangular houses.

What does the attic roof structure consist of?

A mansard roof in cross-section represents a “pie” consisting of several layers.

Guide to calculating a mansard roof

The attic roof is calculated according to an extremely simple scheme. It is important to take into account not only the useful, but also the blind area of the attic space. In this case, a zone in which the distance between the ceiling and floor is more than 90-100 cm will be considered useful. The remaining places are traditionally considered a blind zone. It is impossible to live in such areas, but in their place you can install a variety of shelves and other household supplies.

Calculate the total roof area. At this point, a roof plan will come in handy. Divide the space into several simple shapes, calculate the area of each of them, and then sum the resulting values to determine the total roof area.

Before you start building an attic roof, pay attention to a number of important details, including features of thermal insulation of the structure, the order of placement of window openings etc.

Deserves special attention permissible angle of inclination of the roof slope If the slope exceeds the permissible value, the area of the attic space will be significantly reduced. This point is individual and is selected taking into account the area of the attic and other important parameters.

Select the appropriate type of rafter system. Rafters, as noted, help to evenly distribute the load on the walls. Additionally, thanks to the rafter system, reliable protection of the house from various types of adverse atmospheric influences is provided.

The simplest version of an attic roof is a triangular design. The most difficult thing to do is to make a mansard roof with a break. If you do not have the appropriate skills, it is strongly recommended not to undertake the installation of complex roofs yourself.

Step-by-step instructions for building an attic roof

There are no super-complicated steps in the construction of an attic roof. You just need to carefully read the instructions and follow all the recommendations step by step.

First step. Calculate the strength of the building. The attic increases the load on the walls and foundation of the house. It is better if qualified specialists do the calculations. If you do not plan to carry out work to strengthen the house, you can skip this stage.

Second step. Calculate the attic and prepare a project for the future attic space and roof. It is also recommended to involve specialists in this work. If you wish, you can try to create a project yourself or use some ready-made solution from available sources.

Third step. Do this as carefully as possible, try not to damage other structural elements of the house.

Fourth step. Make a rafter frame. This is the most labor-intensive stage of the instructions in question. It is better if at least 3 people are involved in arranging the frame at the same time.

Fifth step. Place and secure the Mauerlat. To assemble this element, use wooden blocks measuring 10x10 cm.

Sixth step. Install the frame for the under-roof space. The frame elements will simultaneously serve as supports for the rafters. First, secure the vertical posts along the edges of the building. The racks must be attached to long beams. Self-tapping screws and ordinary metal corners will help you with this.

Seventh step. Attach a jumper to the posts.

Eighth step. Make sure the above items are installed correctly. Any cord will help you with this - simply stretch it between the formed arches. If the cord is in a strictly horizontal position, you have done everything right. If the cord deviates from the horizontal, trim the inappropriate arches or completely replace them with new elements.

Ninth step. Fix the arches together. Nail plates or stamping corners will help you with this.

Attach the first rafters where the roof slope will have the maximum slope. To obtain the required slope, you simply need to cut the bars to the required length.

The first step is preparing the rafters. Cut the bars in advance to the desired length and required angle. At the bottom of the rafter legs, select grooves for connecting to the Mauerlat. The grooves can be made using a chisel.

Second step. Secure each block to its designated place.

Third step. Proceed to installing the upper rafters. Be especially careful at this stage. Observe the desired angle of the slope and the overall alignment of the structure.

Fourth step. The sheathing can be made from plywood sheets or ordinary wooden boards. The type of sheathing must match the selected roofing material. As a rule, a continuous deck is made. This is a universal and most reliable option.

Laying protective materials and completing the work

Attic roofing requires the organization of high-quality protection from various unfavorable factors.

The first step is laying vapor barrier material. The vapor barrier must be fixed on the inside of the rafter system. The material is attached to the bars using special construction brackets.

The second step is laying insulation. Mineral wool is traditionally used for insulation. If you wish, you can opt for a more modern and expensive material. The insulation boards must fit tightly together and also fit tightly to the rafters.

The third step is the installation of the sheathing. The laid insulation needs to be covered with sheathing. Use ordinary wooden blocks. Fasten the sheathing elements in increments of about half a meter. Thanks to this system, the insulation will remain in place.

The fourth step is laying moisture-proofing material. Secure the waterproofing to the outside of the rafter system. Polyethylene film is most often used as a moisture-proof layer. Waterproofing will protect roof elements from atmospheric moisture.

The fifth step is laying the finishing coating. Choose the roofing material at your discretion. The best option in terms of the ratio of cost and quality characteristics is metal tiles. For budget materials, we can recommend slate or its more modern analogue, ondulin.

After you have secured the selected roofing material, the construction of the attic roof can be considered complete. Thus, there is nothing complicated in arranging the considered system with your own hands. Understand the instructions and you will successfully complete all the tasks without outside help.