The pitch of the rafter system for metal tiles. Do-it-yourself rafter system for a gable roof - installation instructions. Construction of a gable roof rafter system for metal tiles

The pitch of the rafter system for metal tiles. Do-it-yourself rafter system for a gable roof - installation instructions. Construction of a gable roof rafter system for metal tiles

Each of the individual developers knows that the roof of any house is one of its most important structural elements. The roof protects the building from the effects of various adverse atmospheric phenomena, such as snow, rain, scorching sun rays, and also helps to retain heat in the home. Therefore, in order for the roof to effectively cope with the functions assigned to it, it must have adequate reliability and high strength.
As you know, the basis of any durable roof is its frame or rafter system. The reliability and strength of the roof, as well as the service life of the entire building, depend on how competently the rafter system of the building is designed and subsequently correctly assembled.
It is worth recalling once again that the reliability of the roofing structure depends on the thoroughness of the preliminary calculations, or more precisely, on the correct choice of the pitch between the rafters of the roof, which will subsequently be covered with metal tiles.
If, during preliminary calculations, the loads acting on the roof are incorrectly determined, or the parameters of the rafters are incorrectly assessed, during subsequent operation the roof may become deformed or even completely destroyed.
When calculating the design of the rafter system, it is necessary to correctly calculate the distance between the rafters. This part of the calculation does not present any particular difficulty if standard calculation methods used by specialists are used for this purpose.
The design features of the rafter system depend on the type of roofing (in our case, metal tiles), as well as on the loads acting on the roof. These loads can be either temporary or permanent.

The category of temporary loads includes the following impacts:

  • pressure created by wind flows;
  • the mass of snow lying on the roof;
  • the mass of moisture falling in the form of rain;
  • loads arising during the performance of certain repair work.

The category of permanent loads includes the following factors:

  • weight of the roof covering;
  • a lot of materials intended for roof insulation;
  • mass of finishing and facing materials (if there is an attic);
  • weight of the sheathing and rafter structure.

When designing a frame structure, first of all, you need to decide on its type, which directly depends on the method of installing the rafters. Rafters can be inclined, hanging or combined. The number of designed rafters, their cross-section and the distance between them are chosen depending on the type of attic. The attic can be either attic or non-residential.
To manufacture the structure of the rafter system, coniferous wood with a moisture content of no more than 20% is used. The wood chosen for rafters should not have blue stains or rot. The lumber selected for manufacturing is carefully treated with fire retardants and antiseptics.

Preparatory stage

Creating a roof for any building begins with choosing the type and material used as a roofing covering. Currently, most individual developers choose metal tiles as roofing for their homes. A roof created using this material is strong, durable, highly attractive in appearance, the material itself is not expensive and is easy to install. At the same time, metal tiles are much lighter than their counterparts - ceramic tiles.
Externally, a roof created using metal tiles has the same attractive appearance as a roof using clay tiles. However, if we compare metal and clay tiles, it is necessary to note the advantages that metal tiles have in comparison with their clay counterpart:

  • metal sheet tiles are a more technologically advanced material, as a result of which the creation of a roofing covering does not take much time and other resources;
  • metal tiles have less weight than their clay counterparts, the numerical value of which can be determined from the ratio: (weight of 1 m² of clay tiles) – (weight of 1 m² of metal tiles) = 35 kg.

Calculation of the number of rafters and the step of their installation

Table depending on the length of the rafters on the pitch between them and the cross-section of the timber used

Rafter length, m

Distance between rafters, cm

Rafter beam cross-section size, cm

until 3

120

8 x 10

until 3

180

9 x 10

up to 4

100

8 x 16

up to 4

140

8 x 18

up to 4

180

9 x 18

until 6

100

8 x 20

until 6

140

10 x 20

To calculate the required number of rafters, you need to perform the following operations sequentially:

  1. Measure the length of the roof slope. Then divide the resulting value by the step length between adjacent rafters.
  2. Add one to the value obtained during the calculations under point No. 1. Round the resulting value to the nearest whole number. Using a similar method, calculate the number of rafter legs for the roof slope.
  3. Next, the length of the slope should be divided by the numerical value of the number of rafters, and then the axes of their installation should be determined.
  4. The pitch of the rafters is directly dependent on the type of roofing, as well as on the angle of inclination of the roof slope.

For example. The length of the slope is 18 meters. The step size between the rafters is 0.8 m. Therefore, 18/0.8+1=23.5≈24. So, to create a roof frame you will need 24 rafters.

Installation of rafters

It should be noted that rafter systems created for various types of roofing have minor differences. The difference depends on the size of the sheets of material used, as well as their own weight. To create the design of the rafter system, you will need to prepare the following materials and tools:

  • hacksaw for working with wood;
  • chainsaw;
  • chisel;
  • carpenter's axe;
  • construction stapler;
  • plumb line and building level;
  • screwdriver;
  • electric drill;
  • hammer;
  • self-tapping screws;
  • nails;
  • metal elements intended for fastening rafters;
  • board 50x150 mm, intended for rafters;
  • timber 150x150 mm, used to create a Mauerlat;
  • board 25x100 mm, intended for the construction of sheathing;
  • timber 30x50 mm, used during the construction of the counter-lattice.

After all the required calculations have been completed and the appropriate tools and materials have been prepared, you can begin assembling the structure of the rafter system, on which the metal tiles will subsequently be laid.

The procedure for constructing the rafter system structure:

  1. First of all, it is necessary to install a mauerlat from timber of the appropriate cross-section. The Mauerlat is the base of the roof structure, which takes on the load from the rafter legs. The timber selected for this purpose must be laid along the perimeter of the walls, within the pre-prepared reinforcement belt, and then secured with anchor bolts. A layer of waterproofing in the form of a strip of roofing material of the required size must be laid under the timber.
  2. On a horizontal, flat surface, in accordance with the data from previously prepared sketches, it is necessary to create a template using flat boards. The template is used for the subsequent production of roof trusses. In the ridge they must be secured with nails or metal plates.
  3. In the timber from which the Mauerlat was previously made, at pre-calculated distances, notches of the appropriate size are made, intended for the subsequent installation of rafter legs.
  4. The previously made trusses are lifted onto the roof and installed on the timber. In this case, it is necessary to attach the outer blocks first. The verticality of their installation must be checked using a plumb line.
  5. Next, a cord should be pulled between the two outer trusses, along which the remaining elements will be installed. The rafter legs must be attached to the Mauerlat beam using self-tapping screws and metal corners.
  6. Horizontal wooden lintels should be installed at the top of the trusses.
  7. In the lower area of ​​the rafter legs, it is necessary to install a cornice overhang, the projection of which from the vertical plane of the house wall must be at least 50 cm. For this purpose, a board or beam of the appropriate size should be installed in the appropriate place on the wall, at the level of the ends of the lower part of the rafters. The end of the rafter leg must be secured on one side with a short board, which is called a “filly,” and on the other side it must be attached to the wall.

Processing of structural elements of the rafter system

During its subsequent operation, the roof truss system will be exposed to a number of unfavorable factors, therefore, during its construction, it is necessary to ensure that the wooden parts of the structure are impregnated, thus creating the following types of protection:

Preparing the frame for laying the roof

For subsequent installation of metal tiles, the rafter structure must be prepared. To this end, the following activities should be performed in the specified order:

  1. On the surface of the wooden rafters, on which metal tiles will subsequently be laid, it is necessary to unroll a special film designed to protect against moisture and secure it to the bars of the structure using a stapler. During installation of the film, it is necessary to ensure an overlap between adjacent strips of at least 150 mm; the joints between adjacent strips must be taped with adhesive tape. The sag of the film should be about 20 mm.
  2. It is necessary to install a counter-lattice on top of the installed waterproofing film. For this purpose, wooden blocks with a cross section of 30x50 mm are used. The counter-lattice will provide the roof with the necessary ventilation gap.
  3. Next, boards with a section of 100x25 mm must be secured to the mounted counter-lattice. At the same time, they must be laid so that the first board from the bottom is twice as thick as the next boards. The pitch of the sheathing should be in the range of 350 - 450 mm.
  4. The roof drainage system fittings should be installed on the frame prepared in this way.
  5. Upon completion of the work described above, the roof rafter system can be considered fully prepared for the subsequent installation of metal tiles.

Metal tiles are a lightweight, durable, effective roofing material that ideally solves the problems of low-rise construction. Its steel endurance is perfectly combined with undeniable technological advantages. Laying large-sized sheets is done tens of times faster compared to piece-meal competitors. It lasts a long time and does not require a powerful base.

You can install the roof and build a simple frame for installation with your own hands. There will be no difficulties in your work if you know how a gable roof is structured - the rafter system for metal tiles and the installation process must take into account the technical and technological features of the coating.

Metal tiles belong to the class of rolled products. In essence, it is the old familiar sheet steel, profiled in two mutually perpendicular directions. The longitudinal and transverse waves formed as a result of profiling give the sheets a similarity to the ceramic roofing prototype. The outer side is equipped with a colored polymer film that performs protective and decorative functions.

Disadvantages of the material and ways to eliminate them

The ability to imitate roofing ceramics did not rid the material of the standard disadvantages of metal. Thin sheets quickly heat up under the sun's rays and quickly say goodbye to the heat at the slightest drop in ambient temperature. There is no insulation: heat and sound waves easily penetrate inside the steel roof and go outside unhindered. The list of disadvantages is significantly supplemented by the ability to collect condensate due to the difference in the thermal properties of the coating itself and the rafter frame elements in contact with it.

Low insulation performance and condensation are two “scourges” of a metal roof. You can get rid of them by arming yourself with information about the proper construction of a frame with a correctly laid roofing pie. If the installation of the rafter system for metal tiles is carried out in accordance with all technological requirements, complications with laying the material and operating the structure will not arise.

To ensure that the traditional behavior of a steel roof does not bother owners and does not cause premature wear, it is necessary to correctly distribute the layers of the roofing cake. Responsibility for distribution lies with the rafter system, the list of responsibilities of which includes:

  • Retention of the components of the roofing pie, which are laid on top, below and between the rafters.
  • Formation of air channels that eliminate condensation, and often the possibility of its occurrence.
  • Preparation of a number of supports aligned in one plane for the installation of future slopes by laying profiled sheets.

If we figuratively compare the roofing system with a living organism, then let’s say this: the “patient” will live and function normally only with a healthy supporting apparatus. In our case with a rafter frame. The method of dealing with the shortcomings of a steel coating lies precisely in choosing and strictly following an impeccably suitable installation scheme for the rafter system for the subsequent installation of metal tiles.

Types of rafter systems for metal roofing

Roofs with metal tile covering are erected over permanent and temporary residences. Gazebos, verandas, and bathhouses covered with metal “scales” look interesting. Depending on the purpose of the structure and the conditions of its operation, roofs with metal tiles are installed with or without insulation. The presence of thermal insulation is closely related to the structure of the rafter frame:

  • For insulated roofs, a system is constructed that includes three insulating layers and one or two ventilation circuits.
  • For cold roofs, a system with one insulating layer and one ventilation circuit is installed.

Insulated roof structures are erected if you plan to actively use the attic all year round. The rafter frames of warm roofs are designed so that they are located in the space between the rafters. Analogs without insulation are installed on small dachas and buildings intended for temporary residence.

A roof without thermal insulation is also constructed in the case of insulation of the attic floor. For example, above a bathhouse or a residential building with a low attic space that is clearly not intended for use, it is more reasonable to lay insulation between the ceiling beams or above them.

In the construction of rafter frames, rolled metal and lumber are used for laying profiled sheets. Metal products are closer in properties to coatings, but wood is more suitable for the tasks of private construction. It is easier to work with it for an independent owner who has decided to build and cover the roof with his own hands.

It’s easy to make all the frame elements yourself from lumber, assemble and connect them into a rafter system. Wood is warmer and more attractive in terms of environmental aspects.

Advantages of a gable design

The simplest option for constructing a rafter system for laying metal tiles is rightfully recognized as a design with two slopes. Its rectangular planes are ideal for laying sheets of similar shape. The hip or one will require much more effort with diligence. Many owners are depressed by the increased consumption of large-sheet material for roofing structures with full-length and shortened hips, and are not happy with the complexity of cutting.

Manufacturers claim that the optimal design for laying metal tiles will be a design with a slope angle of 12 to 15º. Structures of lesser steepness must be equipped with a reinforced waterproofing carpet. On steeper roofs, the number of fasteners increases and the installation step decreases. In both situations, the budget for the arrangement will be increased due to the purchase of additional insulating materials and hardware products.

Depending on the size of the metal tile and the dimensions of the structure being installed, the sheets are laid in one, two or more rows. Laying in one row is a priority, because transverse seams reduce insulation parameters and are potentially dangerous for leaks. Manufacturers consider 4-4.5 m to be the best sheet length for arranging the roofs of private houses. Among the offers of most metal tile suppliers there is a very popular service for cutting sheets to size, which is incredibly convenient for laying on slopes with individual sizes. The length of the sheet is equal to the sum of the length of the slope and the length of the overhang, which is 0.4-0.6 m, depending on the architectural solution.

The metal tiles are mounted on the sheathing, which in turn is attached to the rafter system. The lines of all structural parts of a gable roof are strictly vertical and horizontal, which significantly facilitates the process of laying profiled sheets with similar edges. If the rafter system is built without flaws, then there will be no problems with installing the sheathing and roofing.

Construction of the rafter system

We found out that the rafter system works in tandem with the roofing pie. The layout of the rafter frame is directly related to the number of “cake” layers. Let's analyze the most complex insulated design option and find out which components we do not need to build a cold roof.

The rafter structure of a gable roof is a series of alternately installed pairs of rafter legs, the design features of which depend on the architectural data of the box being equipped. Manufactured and produced in accordance with the rules regulated by:

  • Layered technology, requiring two specific supports for the top and bottom of each rafter leg. It is used if the building has an internal load-bearing wall or rather powerful columns are installed instead. The use of the layered method is allowed if the ridge girder racks can be installed on floor beams with high load-bearing capacity or if the floor is made of reinforced concrete slabs.
  • Hanging technology, requiring support only for the bottom of the rafter legs. The top of the elements of the hanging rafter system rests against each other in pairs. It is used if the box does not have an internal load-bearing wall and the ability to install supports under the ridge girder.

Option #1 – rafter frame for a warm roof

The use of insulation forces one to resort to technological tricks, thanks to which the layer important for the structure can retain its insulating qualities. And they will inevitably shrink when wet, because... The water that appears in the body of the material will facilitate the passage of heat waves.

Water appears in thermal insulation in three situations:

  • Penetration of household fumes attacking thermal insulation from inside the structure being used.
  • Formation of condensation due to the difference in temperature outside the building and in the attic.
  • Leaks observed during snowmelt and heavy precipitation, resulting from non-compliance with technology and operational errors.

A properly laid roofing pie, correctly distributed and securely fixed by the rafter system, is simply required to eliminate the listed misfortunes. In addition, the responsibilities of the rafter structure include the formation of ventilation channels through which air flows wash the thermal insulation and the inner surface of the metal tiles.

Ventilation channels created by installing lathing and counter-lattice create conditions for regular ventilation and removal of condensation from the space under the roof, thereby extending the life cycle of the roof itself and the wooden parts of the rafter system.

If we imagine a conventional cut of a warm roofing pie with a rafter system from the inside of an already finished structure, then the sequence of layers and ventilation ducts will be as follows:

  • Clapboard, plasterboard panels, or similar material used for the interior of an attic space.
  • Internal lathing designed to secure the vapor barrier layer to the rafters.
  • Vapor barrier that prevents household fumes from penetrating into the insulation.
  • Rafters between which insulation is laid. The width of the rafter leg should be 3-4 cm greater than the thickness of the thermal insulation. In other words, the specified gap for ventilation must remain between the upper plane formed by adjacent rafters and the outer surface of the insulation. If the thickness of the insulation is equal to the width of the rafters, i.e. The thermal insulation lies flush with the conventional plane of the slope; a lathing made of timber with a side of 30 or 40 mm is nailed to the rafter legs. This will create the required gap.
  • Waterproofing, which is laid either on the rafters, if there was no need to install a counter-lattice, or on a counter-lattice. Classic polyethylene waterproofing film is prohibited from contacting the insulation so that moisture does not appear in its body. Waterproofing materials of the class of polymer diffuse membranes are allowed to lie directly on the insulation, because they are able to let excess moisture out without letting it in. Therefore, when using polymer membranes, there is no need to create a ventilation channel between the hydro- and thermal insulation.
  • External sheathing that simultaneously performs three significant functions. It is used for fastening waterproofing, to form another air gap between the waterproofing and the metal covering and serves as the basis for installing sheets of metal tiles.
  • Finish coating.

Bitumen varieties of rolled materials cannot be used as waterproofing of roofing systems under metal tiles and corrugated sheets. When heated, the insulation and roofing will release substances that destroy each other's structure.

Let's summarize. A standard roofing pie for an insulated roof has three layers and two ventilation circuits, if classic waterproofing was used in construction. There are three layers and one ventilation channel in a cake with polymer diffuse waterproofing. All components are attached to the rafter system, which must withstand the weight of the materials and the snow load. For the domestic middle zone, the total load is approximately 200 kg/m².

Most often, rafter legs for metal roofs are made from boards with a cross-section of 50×100 or 50×150 mm, if the rafter installation step recommended by the material manufacturer has been followed. If the distances between the rafter legs are greater than the recommended value, the cross-section of the outer sheathing should be increased.

The diagram of a roof structure without insulation clearly confirms that it does not contain a heat-insulating layer. This means that there is also no need to install all types of insulation protection from getting wet. However, waterproofing is still needed to protect the wooden rafter system in case of leaks. And ventilation between the water-repellent material and the metal coating should also be built.

A cross-section of a cold roofing cake for metal tiles looks like this:

  • Rafter legs, the cross-section of which is calculated without taking into account the weight of the insulation and related components.
  • A waterproofing layer laid over the rafters.
  • Lathing designed to provide a ventilation gap, fix waterproofing and fasten sheets of metal tiles.

The sheathing for both types of rafter systems is laid in a special way. The step of its installation is determined by the distance between adjacent transverse steps of the metal tile sheet. The distance depends on the brand of roofing, on average it is 300, 350 and 400mm.

The dimensions of the starting lath should be different from the subsequent ordinary bars. For example, if all ordinary laths are made of a block with a cross-section of 30x50mm, then to make the very first element from the eaves line you need to take a block of 50x50mm. The distance between the starting block and the cornice line is always less than the step between the row laths. So it is necessary that the first transverse step of the sheet lies exactly on the base.

Video instructions for installation work

The video will clearly introduce you to the process of constructing a rafter system and installing metal tiles:

The diagrams for the construction of rafter systems with insulated and cold roofing pies, disassembled “on the shelves,” represent a general guide to the actions of an independent roofer. In fact, designs are modernized and adapted to the real conditions of a particular facility. However, they may well serve as the basis for your own development.

In the vast majority of cases, when repairing a roof, the choice falls on metal tiles.

In addition to the long list of economic and operational advantages, this material is also interesting for its suitability for self-installation.

In this case, even the basic skills of a home craftsman will be enough to ensure that the roof is not only durable and practical, but also attractive in appearance.

Advantages of metal tiles

The widespread use of metal tiles is due to the combination of the following advantages in this type of roofing material:

  • Economic expediency.
    Compared to most other roofing coverings, metal tiles have a relatively low cost.
    What makes purchasing such a roof even more profitable is the ability to avoid hiring builders to install it, as well as its long service life.
  • Light weight.
    With an average weight of 1 sq. m of material is about 6 kg, the total mass of the roof is relatively small. This allows you to do without the use of a powerful and expensive rafter system. In addition, a lightweight roof does not require the installation of continuous sheathing, which simplifies the calculation of the roof and reduces the cost of work.
  • Resistance against external factors. Protection is provided by the use of several security words in the design of the roofing sheet. Therefore, the metal base of the canvas is not afraid of prolonged exposure to moisture, direct sunlight, or damage during installation or hail.
  • Aesthetics. The production technology of metal tiles allows you to create absolutely any texture. Accordingly, on the market you can easily choose an option that suits the overall exterior of the building. The range is further expanded by the possibility of painting sheets in all shades of the palette.
  • Fire safety. The basis of the metal tile is a sheet of galvanized steel. This material is completely non-flammable, making it absolutely fireproof.

The indicated advantages of metal roofing make it the most practical, affordable and attractive externally a roofing option.

Materials and tools

To install metal tile sheets, you will need a set of traditional tools for finishing work:

  • electric screwdriver;
  • jigsaw or circular saw;
  • marker;
  • construction stapler with staples;
  • metal scissors;
  • scotch;
  • laser plane builder or construction level;
  • roulette.

Important! To cut sheets of metal tiles, you cannot use grinders with abrasive discs operating at high speeds. Their use will lead to overheating of the steel base, melting and destruction of the polymer protective coating. Such damage greatly reduces the service life of the roof.

Of the materials, in addition to the metal tile itself and its accessories, you will need the following:

  • bars 50 x 50 mm;
  • boards 100 wide and 25–35 mm thick;
  • sheet waterproofing material;
  • wooden slats;
  • galvanized screws, nails.

You will also need personal protective equipment and auxiliary equipment: a ladder, scaffolding, a brush for sweeping away debris, etc.

Find out more about laying corrugated sheets on a gable roof:

Structure of the roofing “pie”

The basis for creating a roof made of metal tiles is rafter system. In a gable (or gable, as it is more often called in everyday life) roof, the rafter system has the most convenient configuration for installation work, since it forms only two planes.


A layer of waterproofing material (3) is laid on top of the rafter system. Without it, moisture condensing on a metal roofing sheet will be absorbed into the wooden structures under the roof, destroying them. Waterproofing also helps in cases where the roof begins to leak.

Vertical slats - counter-lattice (4) - are attached to the waterproofing material along the rafters. Their purpose is to organize a ventilated space between the waterproofing and the sheathing.

In addition, the roof structure contains frontal boards (8) and eaves strips (10). The first ones are stuffed onto the end part of the rafters (1) and protect from moisture falling with the wind. The latter serve to remove moisture flowing down the waterproofing layer.

Installation procedure

On gable roofs metal tiles are laid first on one slope, and then on the other.

Laying sheets of metal tiles should begin with lower slope angle.

All installation work on roofing is carried out in several stages:

Checking the geometry of load-bearing roof elements

At this stage, the diagonals of the roof slopes are measured and compared using a tape measure. If they coincide, then the roof has a rectangular shape suitable for laying metal tiles.

In addition, you need to use a level or builder to make sure that the ridge and both cornices are strictly horizontal. The flatness of the slopes must also be checked. Emergency sections of the rafter system are being repaired.

Installation of the frontal board and filing of the roof overhang

The place where the front board is attached (8) is the end (bottom) part of the rafters (1). This roofing element is fixed with galvanized nails.

Front boards should not completely isolate the under-roof space from the street. To ensure free passage of air, ventilation gaps must remain between them.

A horizontal sheathing is installed on the reverse side of the front board under the roof overhang. As such, you can use perforated plastic panels. This option is convenient because it allows you to use fastening j-straps for plastic, nailed to the front board from behind. If boards are used, ventilation slots should be left between them.

Installation of gutter hooks

Hooks(9) should be placed in a straight line with a slope towards the planned drainage. Reliable drainage will be ensured by an angle of inclination from 5 mm per meter of gutter.


The most practical and easy to install are hooks of increased length. They are sewn to the bottom of the rafters on top of the front board. To ensure the vertical position of the hook, grooves of the required depth are cut in the board and the bottom of the rafters.

First of all, the upper part of the hook is nailed or screwed to the top of the rafters. Then it is bent to the required position and fixed to the end of the rafters. If the installation of the drain is carried out after laying the metal tiles, then short hooks are used, the upper part of which does not go under the roofing.

Laying waterproofing material

Rolled water-repellent materials (films) are used for the roofing “pie”. As it moves onto the rafters, the roll unfolds horizontally along the eaves. You should start from the bottom of the roof. Each subsequent strip is laid with an overlap on the bottom one. The amount of overlap is 15 cm.

The waterproofing sheets (3) should be fixed with a construction stapler. The material is allowed to sag up to 2 cm. The joints are taped with tape. The top and bottom of the film are determined by the factory markers applied to it.


Along the rafters on top of the waterproofing they are stuffed vertical(4) and horizontal(6) laths made of wooden strips. They are nailed along the central part of the rafter beams.

Attention! Metal roofing and bitumen waterproofing are incompatible materials. When the roof heats up under the sun, the bitumen will melt and the canvas will lose its ability to repel moisture.

Find out how to make a gable roof gable with your own hands:

Installation of sheathing

The bars or boards of the horizontal sheathing begin to be packed from below, from the eaves. The first beam of the sheathing must have a cross-section larger than the cross-section of the remaining beams. When installing it, it is necessary to control strict parallelism to the cornice. Installation of metal tile sheets begins with fixation on the lower beam of the sheathing. Therefore, the appearance of the entire roof will largely depend on the accuracy of its installation.

The pitch of the sheathing beams depends on the distance between the horizontal waves on the metal tile sheet and must coincide with it. Most often the pitch is 300, 350 or 400 mm. The only exception is the step up to the second beam of the sheathing. Here it should be reduced by 70 mm.


The topmost beams of the sheathing are also stuffed with decrease step, right up to nailing the beams tightly. This will make it easier to install ridge elements and add strength the entire structure. Around roof and dormer windows, chimneys, ventilation ducts and other additional elements(bridges, snow guards, etc.) the sheathing should also be strengthened by stuffing a continuous web of beams.

Installation of curtain rods

The planks are attached along the entire cornice using galvanized self-tapping screws. The fastening pitch is 300 mm. If the length of one bar is not enough, then it is increased. In this case, the planks are laid overlapping with overlaps of 50–100 mm.

The eaves strip is attached with a slight tension, then the roofing material will be more resistant to gusts of wind and less noisy.

Installation of the lower valley

Where the roof planes (for example, the slope of the roof of a house and the slope of the roof of a dormer window) form intersections at a slight angle, the installation of a special strip is required - the lower valley (20b).

A continuous plank sheathing (7) is placed under it. Boards with a cross section of 150 x 25 mm are applied as lathing material.

Under the lower valley you will need a continuous strip of sheathing about 300 mm wide.

The position of the lower valley is selected so that its edge in the overhang area passes over the cornice board. The sheet of metal tiles and the lower valley strip are not directly fastened together, but are laid with porous insulation.

Installing a chimney outlet bypass

For a brick pipe, the procedure will be as follows:

  • A layer of waterproofing is applied around the perimeter with an overlap of 50 mm on the pipe. For fixation, you can use heat-resistant tape;
  • bypass strips (28) are installed;
  • A groove about 15 mm deep is cut along the pipe, into which the upper edges of the bypass strip are inserted. You can only tap on solid bricks; it is prohibited to do this on masonry joints;
  • The drainage bar organizes the drainage of water, which either drains into the nearest valley or is directed to the eaves.

The decorative pipe surround is not installed at this stage of the work; metal tiles are laid first. For round chimneys, the lining is made of sealing tape. To ensure a tight fit to the pipe, the tape will need to be cut along the top edge in several places before gluing.

Installation of metal tile sheets

If it is possible to lay sheets along the entire roof slope in one row, the installation order will be as follows:

  • the outermost sheet is applied and its position is verified relative to the eaves and side section of the roof;
  • the first sheet is fixed in the upper part with one self-tapping screw;
  • the next sheet is laid with an overlap in the wave and aligned vertically;
  • the sheets are sewn together with self-tapping screws, but the threads should not be screwed into the beams;
  • the following sheets are mounted in the same way;
  • the resulting assembly is once again verified relative to the ridge and cornice;
  • The screws are screwed into the sheathing.

If the height of the sheet is less than the length of the slope and you have to lay the metal tiles in several rows, the procedure will be as follows:

  • the first two sheets are laid according to the same pattern as for single-row installation;
  • the third sheet is placed on top of the first with a horizontal offset of 150 mm, after which these two sheets are fastened together;
  • the next sheet is placed above the second and attached to it horizontally. With the third sheet, fastening is carried out on the vertical side;
  • four fastened sheets are aligned together and, by tightening the screws, fixed to the sheathing.


At the final stage fixation produced at the bottom of each wave by bottom cut sheets. In places where vertical overlap, screws are screwed into crest waves. Distance between self-tapping screws should be chosen with this calculation: there should be 6–8 pieces per square meter.

For detailed instructions on installing metal roofing, see this video:

Dormer window device (“cuckoo”)

The location of the "cuckoo" is determined early. When laying sheets of metal tiles, areas corresponding to configurations dormer window.

Roofing pie under the window neatly sawed out. By perimeter windows are being installed additional sheathing beams.

Gaps between the timber and the sheet of metal tiles are sealed. To drain water, install valleys the top and bottom of the dormer window.

Installing the end strip

The purpose of this slats(29) – protection from precipitation and sharp gusts of wind penetrating under the metal tiles. In addition, the end strip also performs decorative function: when installed correctly, its upper edge overlaps crest waves of metal tiles. Screw The end strip starts from the side of the cornice. If it is necessary to build up, provide an overlap in 100 mm.

Installation of the upper valley

The purpose of this element is to drain water, in addition, upper valley(20a) makes roof joints more aesthetically pleasing.

For installation, use self-tapping screws, screwing them in so that don't disturb waterproofing layer. Between the upper valley panel and the surface of the metal tile, a self-expanding insulation.

Installation of junction strips

These planks allow you to organize careful And sealed transition from the roof surface to adjacent walls and other structural elements of the building and roof.

The connection to the wall is arranged according to the same principle as the connection to the chimney.

Installation of ridge strips and external corners

Before installation ridge strip you should make sure that the gap between the waterproofing sheets of adjacent roof slopes is not less than 20 cm. On top of the top continuous sheathing you can lay additional a layer of waterproofing material in a strip of 150 mm.

Fastening is carried out with self-tapping screws screwed into sheathing through the covering wave. To increase the ridge strip, organized overlaps, serving as additional ribs rigidity.


End parts of the ridge are closed with external corners fixed with self-tapping screws. Between the metal tile and the ridge strip is laid insulation made of elastic material.

Installation of stairs, walkway, roof railing and snow guard

Roofing accessories made of metal tiles are mounted on top of the roofing.

Their places placement are determined in advance and are intensifying additional beams and sheathing boards.

Particular attention is paid to installation snow guard(21). It is fixed to the rafters complete reinforced screws.

Installation of a drainage system

When installing water drainage systems The following rules should be followed from the roof:

  • to one drain pipe it is forbidden install more than 10 meters of drainage gutter;
  • Part gutters above the funnel should be cut at an angle with sides in 100–110 mm;
  • funnel should be located under the gutter at a distance of 150 mm.


All elements of the drainage system, including plugs, funnels, etc., have a fixation system among themselves. However, after installation work is completed, they should be further processed. silicone sealant.

Attention! Drainpipes are installed with the crimp down, otherwise leaks cannot be avoided.

Roof grounding with a separate bus

Since metal tiles have the ability to conduct electricity, then for safety reasons it should be provided with a system grounding.

Grounding is done by connecting electrical wires large section with one end to the roof (through a self-tapping screw). The second end is securely attached to metal structure buried in the ground depth at least a meter.

Post-installation processing

Metal tiles require periodic inspection(semiannually). From the roof and drainage system clean up debris and leaves, and the surface cleanse soft brush.
The canvas in problem areas can be tint, this will increase its corrosion resistance.

Installing counter battens under the rafters

The system of counter-battens under the rafters allows you to insulation roofs. They are used as counter rails wooden beams or planks nailed.
Further into the space between rafters a layer of insulating material is placed behind the counter-trikes, which additionally reduces noise metal roofing.

Laying vapor barrier and fastening with slats

Leave insulation open is unacceptable, since moisture can get on it and negate the entire insulating effect. To prevent this, apply to the insulation vapor barrier film(16). This material does not allow moisture to pass through, but effectively allows water vapor to pass through, leaving the insulation dry

Wooden slats are placed on top of the vapor barrier for fixing whole pie.

Safety precautions

Work on installing the roof of gable roofs refers to work with high level of danger, and the more slope stingrays, the stricter the safety requirements. Don't neglect them, take care of yours health:

  • be sure to wear safety belt, tied with a strong rope to a strong part of the building;
  • work in shoes that have good clutch with surface;
  • stairs And forests securely fasten to the walls of the house;
  • roof protect scaffolding, scaffolding, mesh or sides with a height of at least 1 m.

When working with metal tiles the following rules should be adhered to:

  • always use mittens;
  • to not allow applying excessive force to metal;
  • take into account the strength of the wind and windage sheets of metal tiles.

In addition, it will not be superfluous to use all available devices that make work easier. Eg, inclined guides from long boards will not only increase safety when rise sheets, but will also ensure the safety of the material.


In general, installation of metal tiles on gable roof does not pose a serious problem. It is enough to follow safety rules and follow all recommendations to get reliable And beautiful roofing at the lowest possible cost.

The following describes the safety rules that must be followed when working with metal tiles: video:

The rafter system for metal tiles is one of the most economical designs of modern roofs. This is due to the low weight of the steel profile sheets of the coating and the absence of solid bases such as OSB or plywood. A lot of literature, instructions, and videos are devoted to the process of proper installation of roofing elements. The process of choosing a rafter system for an individual developer is less clear. This article makes an attempt to inform the average reader how to choose the right rafters for metal tiles.

The design of the rafter system depends on the shape of the roof, the shape and size of the building. There are two main structural schemes of rafter systems: Layered rafters - a simple and reliable non-expanding rafter system in which rafter beams rest (lean) at the top and bottom on walls or beam elements. This rafter system is most popular in individual construction. The layered system consists of rafter legs resting on the mauerlat below and on the girder at the top, racks resting on beds and linings, as well as struts, struts and trusses. Hanging rafters are a more complex system, used in the absence of internal walls, as a rule, with large distances between supports. This design is a spacer design, in which the expansion force is damped by tightening. The structural elements of the system are various types of roof trusses. The advantage of this system is that all elements can be manufactured and assembled both on site and in a factory. In the latter case, all that remains is to complete the larger assembly and installation. The use of such a system is justified for projects with short construction periods.
Another advantage is that finished elements, as a rule, are subjected to fire-retardant impregnation in the factory. In addition, enterprises have a large selection of ready-made design solutions for different types of roofs.

Dimensions and sections of rafter system elements

Ideally, all elements of the house, including the roof, are developed in detail by the design organization. If there is no project or we are talking about reconstruction, then the following information will be useful.
For the manufacture of load-bearing roof structures, wood with a moisture content of no more than 25% should be used. The components can be made of logs, timber and edged boards.
The overall massiveness of the truss roof elements depends on the distance between the load-bearing walls of the building, the climatic region of construction and the slope of the roof. The larger the span, the amount of snow and the heavier the roof structure, the more massive the supporting roof frame.

Geometry of layered rafters

Although the cross-section of almost all elements of the rafter system is a calculated value, in the construction literature the minimum cross-section of the rafter legs is defined as 50×100 mm, the Mauerlat is 150×100 mm, and the minimum height of the beams and spacers is 150 mm. It should be noted that the section of rafters 50x100 mm looks like fireplace matches on the roof, and is often increased for visual comfort. Layered rafters work as bending elements and are calculated depending on the span of the building and the current load. So, among the known quantities there is the length of the roof, the span of the building (the distance between the supports C), the height of the roof, and, at a minimum, a general idea of ​​​​the snow load. Among the unknowns there is the pitch of the rafters (B), the section of the rafters (a×b). Getting rid of the unknowns, we will assign the pitch of the rafters for the metal tiles. The rational distance varies between 0.6 and 1.2 m. If the roof has rafters made of logs, then the pitch of the rafters can be increased to 1.8 m. In a situation with metal tiles, this is not necessary, since you will have to make a thicker sheathing. Rafter spacing from 0.6 to 0.9 m is mainly used for roofs with a cold attic and single rafters. It should be noted that the minimum pitch is rarely used, and installation is carried out in steps of at least 0.7 m. If an attic floor is not expected, any rafter pitch can be used for a cold attic. The cross-sections of rafter legs for simple roofs under normal conditions in the climatic zone of central Russia can be preliminarily determined using the following table.

Roof slope, degrees

Rafter leg pitch, m

Board section

Distance between supports, m

20 - 30 3,0 3,5 4,0 4,5
0,7 50×12050×15050×17550×175
0,9 50×15050×17550×17550×200
1,2 50×17550×2002×50×1502×50×200
The cross-section of the sheathing with a rafter pitch of up to 0.7 m is recommended to be 25 × 50 mm; with an inter-rafter distance of 0.7 to 0.9 m, the size of the bars is 35 × 50 mm, and a rafter pitch of 0.9 m to 1.2 m requires sheathing sections 50×80 mm.

Mansard roof

With a mansard roof the situation is different. Since the time of all-Union unification and typification (experienced builders will understand), the modular dimensions of insulation boards have remained the same: sheet 600x1200 mm (TechnoNIKOL additionally produces insulation boards measuring 500x1000 mm). If you plan to place a living space in the attic space by making an attic roof, the option with the maximum rafter pitch is often used. Moreover, with an insulation thickness of 150 mm and above and the need to make an air gap of 50 mm for ventilation of the under-roof space, a cross-sectional height of the rafter board of 200 mm is required. And with a more massive insulation layer (from 200 mm), which is not uncommon in our country, it is necessary to fill in additional slats. Thus, if there is insulation between the rafters, a pitch of 1200 mm is taken from the conditions of ease of installation of insulation without additional trimming, the possibility of installing various types of roof windows and the manufacturability of the ventilation device for the under-roof space. With a distance between the rafters of 1.2 m and a snow load for the 4th snow region and above (everything north of Sergiev Posad, St. Petersburg, the entire Volga region to Syzran, and further through the Ural ridge), the installation of paired rafter legs is required. The cross-sections of the elements can be preliminarily determined from the table below.

table 2

Roof slope, degrees

Rafter leg pitch, m

Section of the rafter leg

Distance between supports, m

3,0 3,5 4,0 4,5 5,0
20 - 25 1,2 2×50×1502×50×1752×50×1752×50×2002×50×200

You need to connect two boards through spacers with a pitch of no more than 1 meter. A rafter system made of paired boards is more reliable than a single system. And in order to sleep completely peacefully under a new roof, you need to contact the designers to calculate the roof elements. I recommend watching the following video:

The design of a gable roof for private houses is most often chosen, since it is the best option for ease of installation and ease of use, strength and reliability, as well as a style solution. A gable roof is also called a gable roof and has two slopes, which can be located in relation to each other at the same or different angles, that is, the front can be an isosceles or scalene triangle. The latter option can increasingly be found among new buildings, as it is becoming a fashionable style solution. And, in addition to originality, such a roof has some positive features that simplify its operation.

This type of rafter system can be used for all types of roofing materials, but the sheathing attached to the rafters has its own parameters for each covering.

Gable roof: the rafter system for metal tiles, which has its own characteristics, must be carefully studied and calculated in advance, before purchasing materials and installing it. Let's try to understand these issues.

Types of gable roof designs

  • 1 Types of gable roof designs
  • 2 The main components of a gable rafter system
  • 3 Types of gable roof rafter systems
    • 3.1 Layered rafter system
    • 3.2 Hanging rafter system
  • 4 How to calculate the parameters of a gable rafter system
    • 4.1 Loads on the rafter system
    • 4.2 Angle of slope of the rafter system and height of the ridge
      • 4.2.1 Ridge height calculator
    • 4.3 Length of rafter legs
      • 4.3.1 Calculator for calculating the length of the rafter leg
    • 4.4 Calculation of the pitch and cross-section of rafters
      • 4.4.1 Calculator for calculating the distributed load on the rafter leg
    • 4.5 Parameters of other lumber
  • 5 Sequence of installation of the rafter system for metal tiles and roofing
    • 5.1 Video: erection of a gable truss structure under a metal tile roof

First, you need to understand what types of gable roof designs there are, since you will have to choose the most suitable one for a particular building.

  • Simple equilateral gable design

This version of the gable design can be called traditional and the most used, since it is easy to install and maintain, and is also durable and reliable.

Symmetry in this system helps to achieve uniform load on the mauerlat and load-bearing walls. With the correct choice of beam cross-section for arranging the rafter system and Mauerlat, these parts will provide the safety margin necessary for long-term operation of the roof. Additional reliability of the structure will be provided by correctly installed racks, struts and tightening.

The disadvantage of this system for arranging rooms inside the attic space is that after installing the walls and ceiling, a large area is occupied by blind areas in the corner areas of the structure, which remain unused.

  • Simple asymmetrical gable design

The asymmetrical gable design differs from the traditional system in that its slopes are located at different angles. So, one of them is usually more than 45 degrees, which allows you to increase the usable area of ​​the attic space, in which it is quite possible to equip a living space, of course, with proper insulation.

Another important advantage of such a design may be a smaller slope, which is recommended to be planned on the leeward side of the building, where a large amount of snow always accumulates on the roof. A slope that is small in size but has a great steepness will not retain large snowdrifts on its surface.

The disadvantage of an asymmetrical structure is its more complex calculation to achieve uniform distribution of the load on the walls of the house.

  • Broken gable structure

This gable rafter system can be called a rarity, although thanks to this arrangement of the slopes in the attic space, a fairly large room is formed that can be used as a residential or utility room.

In addition to such a rafter system, a broken gable structure can also include an attic option for installing rafters.

An attic broken rafter system can provide a building with a full second floor with spacious rooms, and with enhanced insulation they can be used at any time of the year.

The main components of a gable rafter system

Now let's look at the main structural elements of the gable roof rafter system