The choice of a specific roof and roofing must be made at the design stage of the building. Modern technologies and building materials allow architects to create a huge variety of solutions, both design features, as well as the coatings and technologies used. When choosing a specific solution, a large number of factors influencing the roof elements are taken into account. Despite such a variety of roof types and designs, they all have several common elements.

Roof element name	Short description
	It can be flat, single-slope, gable, multi-slope hip, complex, domed, etc. The rafters themselves can be layered and hanging, whole or extendable.
	Depending on the type of roofing materials, it can be solid or lattice. Some roofs have a special ventilation counter-lattice.
	Used during the installation of warm roofs, it consists of a vapor barrier layer, insulation and wind protection.
	It can be rolled or pieced, made from natural or artificial materials. Roofing materials have a significant impact on its cost and complexity of roofing work.

The table shows only general names; each type of roof has its own additional elements. Roofs may have windows and gables, gutters and other engineering structures.

Let's look at the most commonly used roof elements using the example of one of the most complex structures - a hip roof with a bay window.

The roof in question does not have gables, the main part is covered with a gable hip, the bay window has a hip roof.

Pediments

Pediment - the front part of the wall various shapes. On the sides it is limited by two slopes, in the lower part by a cornice. Pediments are most often made from the same building materials as facade walls, but there are other options for constructing these elements.

Recently, the geometric appearance of pediments has expanded significantly; now you can find the following forms:

• keel-shaped - reminiscent of an overturned ship;
• onion-shaped - the shape of a bow;
• semicircular - a vertex with a circular end;
• interrupted - there is a horizontal cornice for inserting a window;
• male - made of logs as a continuation of the crown section of the wall;
• stepped - the size of the steps decreases upward;
• trapezoidal - pediment in the form of a regular trapezoid.

On ordinary buildings, gables most often have a traditional triangular shape.

The part of the roof located between the outer rafters. May have the shape of a trapezoid, rectangle, triangle, etc.

IN apartment buildings roofs are most often single-pitched flat, slope - concrete slab ceilings Such roofs have roll coverings, in some cases may be exploitable. They make winter gardens, recreation areas, swimming pools and other elements to improve the comfort of living.

The part of the building protruding beyond the projection of the facade with its own separate roof. The roof of a bay window can be semicircular, rectangular or multi-faceted. In our example, the bay window is symmetrical and located exactly in the middle of the facade wall. Dimensions of the building are 11×13.5 m. Rafter legs and vertical supports rest on the mauerlats and beds.

It is made of boards or timber, fixed along the perimeter of the facade walls or to a specially prepared reinforcing belt. The lower ends rest on the Mauerlat rafter legs. The element must be firmly fixed; if the masonry materials of the facade walls do not have high levels of physical strength, then a reinforcing belt must be installed under the Mauerlat. In cobblestone houses, the upper crown is used as a mauerlat. To prevent the walls from spreading, metal or wooden dowels of large diameter and length are used; they connect several crowns of the house together.

Made from timber or boards, attached to load-bearing interior partitions directly to the masonry materials or armored belt, serves as a support for various stops of the rafter system.

Waterproofing should always be laid between walls and wooden elements; ordinary roofing felt is considered a universal and best option. If you have extra money and a desire to spend it, you can buy modern mastics based on modified bitumen. The construction effect is the same, the financial effect is much different from the option with roofing felt.

Prices for timber

This architectural element can be applied to both the ceiling and the roof. The fact is that many supports of the rafter system rest on these beams; without them, the construction of complex roofs is impossible.

The distance between the beams is selected taking into account the standard sizes of insulation. When installing these elements, the features of the bay window roof should be taken into account; the beams must support all rafter legs. The corner beams of the bay window are located on the bisector of the corner, otherwise the roof and the overhang of the cornice will be asymmetrical. Placed on mauerlats and beds or on walls.

Cornice

The element that separates the vertical plane of the wall from the plane of the roof is called a cornice.

May have several varieties.

1. Order cornice. It comes forward sharply and hangs strongly over parts of the facade, performing the function of protecting them from precipitation.
2. Gezims. The cornice has the form of a strip divided into several longitudinal projections and depressions; it can be located either directly under the roof or between floors as decorative element facade of the building.

If the building has a wooden cornice, then it is recommended to hem it with boards immediately after installing the beams; this greatly simplifies the work on the further construction of the rafter system. In addition, the cornice itself is also much easier to hem immediately after installing the beams. Once the floor beams and cornice are ready, you can begin installing the support frame.

One of the most important load-bearing elements of the roof. Consists of vertical supports nailed to the beams and horizontal ridge girders. The dimensions of the support frame depend on the dimensions of the roof, complex options may have several support frames: one is installed under the ridge, the rest in the weakest places of the rafter legs.

Horse

The joint line of the upper parts of the roof slopes. Simple roofs have only one edge, while complex elements have several.

A special device is installed on the supporting frame of the bay window roof - a centering core.

Prices for different types of roofing ridges

Roofing ridge

All the rafters of the bay window roof converge on it. This is a centering element approximately 50 cm high and about thirty centimeters thick. It is made from solid lumps or laminated boards, serves as a support for the rafters, and is fixed on the vertical support of the bay window frame.

Main roof rafters

The most important and most famous element of the roof. They bear all the forces of the roof and are made from boards of various sizes. The calculation is done at the house design stage. At the top, the rafters are fixed to each other or to the ridge board; they can rest against ridge run or have a separate support frame.

At the bottom, the rafter legs rest against the mauerlat and can be hanging on layers.

1. Hanging rafters. Used on small buildings and structures, they have only two points of support. At the top they rest against each other or against a ridge board located between the rafter legs. Below they rest against the mauerlat. Tightenings can be used to strengthen the structure. These are ordinary boards that fix two rafter legs in the upper part, thus preparing the simplest trusses.
2. Layered rafters. The name of the element means that the rafter legs overlap any additional supports. They can be placed in different places, be vertical or angular.

fillies

They are attached to the rafters, lengthen these elements, reduce the cost of the rafter system and improve its performance characteristics. To make fillies, thin boards can be used; significant forces are not applied to them. The fillies allow you to extend the slope beyond the wall to a considerable distance and additionally protect the gable walls from the negative effects of natural precipitation.

Purpose - to improve the appearance of the overhangs of the roof slopes, to minimize the risk of the roof being undermined by sharp gusts of wind. It is made of boards, then covered with wooden or plastic soffits.

Corner rafters

Used only in complex situations pitched roofs ah, the longest elements of the rafter system. They require special attention during manufacturing and installation.

Special elements to increase the rigidity of fixation of corner rafters. They can rest on floor beams or specially installed elements.

Bay window rafters

The largest elements of a complex roof cover the bay window. One end rests against the centering core, where the upper edge meets, and the other end against the beams.

This is the general initial structure of the roof; in the future, it is necessary to install various vertical, horizontal and inclined connections to increase the rigidity of the structure and increase its load-bearing capacity. The quantity is calculated individually for each roof; each truss option may have significant differences. But there is common types elements of rafter systems.

It is installed at an angle to the vertical, one end rests against the rafter, the other against the vertical support and the floor beam.

Vertical stand

It supports the rafter leg, is installed vertically, the lower end rests against the floor beam.

It is mounted in the upper third of the rafter leg, installed at an angle, the lower end rests against a horizontal tie.

Fixes two rafter legs into the truss structure.

Racks, ties and struts are made of boards, long vertical supports and purlins are made of timber. Designers often suggest making these elements from paired boards, which is cheaper and more reliable. Paired boards always have higher bending resistance than timber of the same thickness.

Endovy

The joints of the slopes are at an obtuse angle. The most dangerous element of the roof, this is where leaks most often occur. A special beam or board is installed in the valleys, which is called a valley. During the construction of valleys, you need to use only high-quality lumber, and be sure to take measures to protect them from rotting and damage by pests.

They are used to strengthen the structure on large roofs, made from bars or boards.

All elements of the rafter system must be rigidly fixed to each other. This can be done either with the help of modern metal perforated plates and corners, or with ordinary nails or metal staples. After all the work is completed, you can begin making the sheathing.

Holds roofing material; technical parameters depend on the physical characteristics of roofing coverings. The sheathing can be solid or lattice. A very important element from the point of view of the longevity of the roof. The sheathing must ensure that the roofing will not sag under the weight of the snow cover, the sheets of metal tiles are firmly fixed and will not come off due to sudden gusts of wind.

Sheathing can be made from either new or used lumber. The main requirement for them is the absence of putrefactive damage. Appearance does not matter; the sheathing is always hidden by roofing coverings.

Counter-lattice

Mounted on warm roofs, it provides proper conditions for natural ventilation to remove moisture. Increases the service life of the roof and prevents premature failure of loaded elements of the rafter system. The linear parameters of the counter-lattice have strict standardized values. Failure to follow the recommendations of professionals causes a violation of the effectiveness of natural ventilation; the consequences of such a situation are very unpleasant.

Wind boards

They are fixed on the sheathing from the side of the gables. They perform two functions: they prevent roof undermining and improve appearance Houses. Can be wooden, metal or plastic.

Cornice boards

They improve the design appearance of the roof and prevent the rafter system from getting wet. Made from metal or lumber.

Prices for construction boards

Construction boards

The main task is to create an airtight roof covering and protect the interior from wind, rain and snow. Currently, there are many types of roofing, each roof element has its own technical characteristics. When choosing, you need to look not so much at the cost, but at the operating time. A cheap roof lasts for about ten years; economically, it is very expensive to completely replace the roof after such a short service life.

The element is present only in warm roofs and consists of several layers.

Elements warm roof may have different names for the materials used, but this does not change their structural function.

Gutters

Purpose - to drain melt and rain water from the roof slopes, to prevent excessive soil moisture under the foundation of the building, to protect the base from waterlogging. These roof elements can be made of plastic or metal and have different prices and shapes. But they always consist of the same elements.

1. The gutter receives water from the slopes and directs it to the vertical drainage elements. The gutter has end caps and is equipped with connecting and rotating elements.

   

2. Funnel. Can be installed on gutters, through which water flows from the gutter into vertical pipes. There are funnels that are attached at valleys in places where installation of ordinary gutters is impossible for some reason. Such funnels for collecting water from valleys are immediately connected to individual pipes.

   

3. Fastening elements. Fix the pipes to façade walls and gutters to the rafter system. They allow you to adjust the angles of inclination and distances; they can be metal or plastic.

   

4. Round pipes. They drain water away from the house and are equipped with end switches, connectors, and tees.

   

   This roofing element performs two functions: it protects gutters from excessive forces during the spring melting of snow from the roof slopes and prevents injury to pedestrians. Snow guards are made of metal pipes or sheet steel. They must be fixed to the rafters or sheathing; screwing only to the roof in places where it sag is prohibited. The choice of a specific type of snow guards and their installation locations depends on the climatic zone of the building.

   

   

   Attic spaces

   Roof elements can be residential or non-residential. Recently residential attic spaces are called attics, but they were used for such purposes before. Unfortunately, not as often as many home owners would like. The problem was the extreme backwardness of the Soviet construction technologies and materials. As soon as imported goods appeared on the domestic market, attics became very popular in our country.

   

   

   Non-residential attic spaces are most often used in various extensions and utility buildings. They are used only for storing various things, in rural areas converted for crop storage.

   Conclusion

   The article provides the names of elements according to terminology building codes and rules, in practice, builders can call certain structures with different words, but their purpose does not change. It is recommended to always use the correct terminology to prevent inevitable confusion and annoying errors.

   Video - Knots of the rafter system

Roof structure of a private house

Many people mistakenly believe that roofing and roofing are the same thing. The roof is the topmost part of the roof. In general, the roof structure is a system consisting of:

Floors. This is the base of the roof (on the upper side it is the floor of the attic or attic, on the side of the living space it is the ceiling).

Attic or attic. Both premises are under the roof, the first is non-residential, the second is residential.

Load-bearing structure. Designed to absorb the load from the roofing “pie” and protect the building from precipitation. In fact, it is a rafter system.

Roofing or roofing “pie”. It is a sequence of layers, each of which is responsible for a specific function. The roof covering protects the roof from all types of precipitation and wind, waterproofing prevents the slightest leaks, and thermal insulation eliminates heat loss through the roof. The types of roofing elements are listed below.

Auxiliary equipment. Can be installed both on the roof and in it. This includes lightning protection, drainage system and snow protection.

Roof structural elements

Names of pitched roof elements:

The ramps are the main elements. They are called inclined planes, which provide the function of uninterrupted drainage of water from the roof area. We can say that the slopes located at an angle ensure the entire roof is waterproof.

Ribs are the angles that form at the joints of the slopes.

The valley - or also called the valley, is formed internal corner. This angle is obtained at the intersection of two roof slopes. It is also one of the main structural elements of the roof.

The descent is the lowest part of the slope.

The dropper is what is located even lower than the descent. Designed to protect the wall of the house and the cornice from rainwater falling on them.

The eaves overhang is the horizontal part of the slope that protrudes beyond the area of ​​the horizontal walls.

Front overhangs are elements of the roof of a building, representing the front part of the slope, located at an angle.

A gutter is a place where melt or rainwater is collected.

Additional elements of the roof roof - ridges, end strips, corners, ebbs, etc.

Drain. It can be external - this is when drainpipes are installed near the external wall of the house and through them water from the gutter is discharged to a special designated place outside the house.

Internal drainage involves installing drainpipes inside the walls of the house.

Important: internal drainage is more expensive to implement. Its installation is justified for flat roofs.

These elements of the roof of a house for a pitched roof are not presented in full list. It can be called typical. Some roofs may have more elements, or, conversely, some of them may be missing.

Geometric roof shapes

Today there are a large number of types of roofs. All structures are divided into two main groups - flat and pitched. The first group is roofs with a slope of less than 30 degrees. Their device is standard. It is much more difficult with pitched structures. Today there are pitched roofs:

Single-pitch. A roof that has one slope in its design, located under different angles(more than 30 degrees).

Gable. It consists of 2 slopes and a pediment (a triangle at the end of the roof).

Attic. It is a broken structure.

Important: not always attic system assumes that there is a living space under the roof. But most often this is exactly the case.

Hip roof is a type of hip roof structure. All slopes of this design are identical triangles.

A hip roof is a structure in which the end slopes are triangular in shape, and the rest are in the shape of a trapezoid.

Half-hip - the main feature of the design is that the gables do not reach the border of the side overhangs. Also often in such projects, roof windows are located under the end overhang.

Roof with sloping surfaces. Implemented on buildings whose roofs have different levels.

Design with skylights. A difficult project to implement. It is a two-level roof, each level has a different shape. The walls of the upper level are most often made of transparent materials. The upper level slopes rest on the supporting planes of the lower level.

Vaulted type. Represents two or more arcuate surfaces.

Folded type. A system of gable or multi-slope roofs - each section is combined with another.

Domed roof. Externally, such a roof looks like a hemisphere.

Roof with multiple gables. There are many varieties. For example, several slopes are connected to each other at different angles, resulting in a polyhedron.

Video

The roof occupies a priority place in the functional purpose of the building. It’s not for nothing that people say: “if only there was a roof over your head.” After all, without it, even the strongest walls will not last long - they will be destroyed by water, wind and sun. What structural elements the roof consists of, what role the roof plays in its composition and how to properly maintain this structure will be discussed below.

What is a roof and what does it consist of?

The words roof and roofing are often used interchangeably. Meanwhile, in strict terminology, these are different, although interrelated concepts.

The roof is the structure crowning the building, which serves as protection from adverse atmospheric exposure. The main purpose of the roof is to protect the building from precipitation: rain, snow, melt water. In addition, it performs heat-insulating functions, preventing the leakage of warm air from the room and overheating of the internal space under the influence of solar radiation.

The roof is an integral part of the roof and is an external waterproofing coating that prevents moisture from penetrating inside. The main purpose of the roof is to drain water from the roof surface. In order for water to flow in the desired direction, the roof is located at an angle to the horizontal axis. Even flat roofs have a certain angle of inclination (up to 12 o), due to which atmospheric moisture enters the drainage gutters.

The roof is the outer part of the roof that is in direct contact with the atmosphere

Roofing device

Structurally, the roof is divided into several elements.

1. Bearing layer. Consists of sheathing, screed or solid flooring. The type of support lining is determined by the type of roof covering and roof installation technology.

   For light sheet coverings on pitched roofs, the base is usually a sparse sheathing made of wooden slats or metal profile

2. Insulation layer. There are:
   
3. Roofing covering. The topmost layer that is in direct contact with the external environment. The main characteristics of the coating are durability, strength and weight.

Different designs can combine one or more layers of insulating materials.

When choosing roofing coverings, the following properties are taken into account:

• resistance to solar radiation;
• waterproof;
• elasticity;
• resistance to temperature changes.

Types of roofing

There are many materials from which roofing coverings are made. They can be divided into two large groups. One category includes roofs made from natural components - metal, stone, sand, asbestos, as well as straw, reeds, reeds and even moss. Another group, which arose not so long ago, includes polymer and synthetic types of roofing - bitumen, ceramic tiles, roofing felt, etc. The raw materials for production are petroleum products combined with paper, fiberglass, ceramic chips and other components. Recently, it has become widespread polymer additives, which are introduced into the composition of the roofing material. Plasticizers prevent cracking and corrosion of the outer covering and significantly increase the service life of the roof.

Below is a list of the most commonly used roofing materials.

1. Slate. A group of roofing coverings made of cement and asbestos, which have undergone molding and heat treatment under pressure, use in great demand, their production is growing every year. This is due to the low price and high quality products.

   Slate is one of the most popular roofing materials

2. Ruberoid. Roofing roll material with high waterproofing properties. It is made by impregnating construction cardboard with bitumen, followed by coating with a refractory compound and anti-stick coating (sand, talc or asbestos).

   Roofing felt is usually laid in several layers, changing direction so that the last row is vertical

3. Profiled sheeting. Profiled steel sheet treated with zinc, polymer powder paint or other water-repellent composition.

   To cover the roof, you can use only special types of roofing sheeting, which are distinguished by increased bearing capacity and high wave height

4. Roofing made of zinc-titanium alloy (or D-zinc). It looks like tinned copper and has a service life of up to 140 years. Modern metallurgical technologies have reached a level where an alloy of titanium and zinc is cheaper for the manufacturer than pure copper roofing. Therefore, D-zinc has good prospects as a roofing coating.
5. Corrugated bitumen sheets (ondulin). They consist of construction cardboard 1.5–3 mm thick, impregnated with a light fraction of bitumen.

   In appearance, ondulin is very similar to slate, but in composition these roofing materials differ considerably

6. . Another name is slate shingles. It is made from certain rocks by splitting into flat plates. It has an almost unlimited service life.

   Slate tolerates weather anomalies well and is slightly sensitive to mechanical damage

7. . The starting material is wood. The dried blanks are used to cover the roof in the manner of tiles.

   Wooden shingles are an environmentally friendly coating that lasts 50 years or more

8. Sheet steel coated with zinc. Used in standing seam roofing. The connection of sheets and plates (rebates) is made by folding the edges into a single surface.

   Steel sheets are connected using a seam lock, which ensures high tightness of the connection

9. Roofing made of copper sheets. One of the traditional types of coating in the Middle Ages to the present day. It is resistant to mechanical damage and adverse atmospheric factors. A layer of copper oxide forms on the surface, which prevents corrosion. Layer thickness - from 0.5 to 1 mm.

   Copper roofing is one of the most durable roofing coverings, lasting up to 150 years

10. Aluminum roofing material. A very promising type of coating. Unlike copper, which has a high cost and considerable weight, aluminum does not increase the load on the building structure. Minimum service life of 100 years. Coating with special polymer dyes ensures the desired color scheme and durability of the roof.

    Installation of aluminum sheets is carried out according to the principle of seam roofing

11. Tol. A product of impregnation of construction cardboard with tar made from coal or shale. The surface is sprinkled with mineral powders that protect the rolls from sticking.

    Roofing felt has a short service life, so it is usually used to cover the roofs of outbuildings

12. Glassine. It is used as an auxiliary material for the installation of lining layers and is cardboard impregnated with a soft fraction of bitumen.
13. Ceramic plastic roofing. It is made from clay mixed with polyaffins (synthetic plasticizers), which are characterized by high reinforcing properties. During the production process, a permanent dye is added to the composition.

    The shape of the ceramic plastic roof imitates slate shingles

14. Roof tiles. One of the most archaic building materials, known since the times of Ancient Rome. Originally made from baked clay. Differs in a variety of forms and durability. This material has a large number of modern modifications:
    • ceramic tiles- the closest analogue of ancient roofing material. Despite the large mass and labor-intensive installation, it is popular because it is a natural product;

      Ceramic tiles are assembled using sheathing laid in increments equal to the size of the tiles

    • metal tiles - an imitation of ceramic coating, made from sheet steel by stamping. It has the advantage of being lightweight, but inferior in terms of thermal conductivity and noise absorption. Requires mandatory grounding;

      A generally recognized disadvantage of metal tiles is high sound conductivity

    • bitumen tiles. Other names - soft or flexible tiles. It is produced by applying a layer of petroleum bitumen to fiberglass canvas. Due to its ease of manufacture, it comes in a variety of colors, shapes and sizes. Ease of assembly, good dielectric characteristics and sound insulation characteristics - all this contributes to the growth of popularity among consumers;

      With help soft tiles you can create complex patterns on the roof surface

    • . A copy of a ceramic tile made from cement and sand. Its properties are comparable to the original, but it costs much less;

      The relatively low price contributes to the popularity of sand and cement tiles

    • . Consists of sand bound polymer composition with a dye. Lasting, flexible material, not subject to cracking under temperature and mechanical loads;

      The distinctive features of polymer-sand tiles are strength and lightness

    • composite tiles. Piece products that are made from steel sheet coated on both sides with an anti-corrosion alloy. The outer layer is sprinkled with small stone granules and covered with a matte glass-like glaze. Despite its low weight, it has a very impressive appearance and a long service life.

      Composite tiles are available in a wide variety of colors; you can choose the desired shade from a special catalog

15. Straw, reed, turf. The material for knitting roofing mats is natural plant components, harvested in natural conditions. Despite the simplicity and availability of raw materials, these technologies have not been developed on an industrial scale. To this day, like thousands of years ago, harvesting is painstaking manual labor. The exception is turf, which is grown on specialized farms in pre-spread canvases. After reaching a layer thickness of more than 3 cm, the mats are rolled up and transported to the installation site. The disadvantage of reed, reed and thatch roofing is their flammability. With the arrival of electricity in every home, the risk of fire from a minor short circuit in the network pushed traditional methods into the background. Safer materials have replaced them.

    A thatched roof has very high thermal insulation properties, but requires painstaking manual labor and is highly flammable

16. Liquid types of roofing. These include solutions that harden in open air. Most often, such materials are used in industrial construction, since spraying them onto the surface of slopes requires serious equipment. An example is polyurea, which forms a waterproof layer within 10–15 minutes of application to the substrate. In private construction, various types of mastics are better known, mainly bitumen-based. They are rarely used as an independent coating; mastic more often serves as an auxiliary agent for roof repairs.

    Spraying polyurea requires special equipment and certain operator qualifications

17. Polycarbonate roofing. Appeared in the arsenal of roofers not so long ago. Polycarbonate is transparent and is not affected by ultraviolet rays. It is used for greenhouses, greenhouses, winter gardens and indoor swimming pools. You can often find polycarbonate roofs at bus stops in large cities. Popular visors over entrance doors from this material.

    Polycarbonate is usually used to cover greenhouses, gazebos and canopies over building entrances

Roof installation

Depending on the installation technology, roofing materials are divided into:

• typesetting (all types of tiles);
• sheet (slate, metal sheet materials);
• (roofing felt, roofing felt);
• mastic (“ liquid rubber", polyurea);
• membrane (polyethylene films and membranes).

To avoid confusion and misconceptions, the consumer needs to remember that profiled metal materials, such as copper, corrugated sheets, aluminum, etc., are produced not only in the form of sheets, but also in the form of rolls. Flexible roofing also has different packaging - piece, roll, large membrane-type sheets and mastic. The choice of size and shape depends on the transportation conditions and type of installation.

Laying piece roofing is a more labor-intensive process. Nevertheless, this material is preferred for construction in the private sector. Large-sized membrane panels are used exclusively for the construction of large objects with large roof areas. This is explained by the fact that during installation the piece material is less prone to deformation and does not create longitudinal stresses along the sheathing.

Stacked laying of tiles is labor-intensive, but the result is a beautiful coating with a minimum amount of waste, which does not exert longitudinal loads on the sheathing

The support on which the roof is installed is the rafter system for pitched roofs, and the ceiling (or attic) floors for flat roofs. Before installing the outer covering on the roof, a sheathing is assembled, which can be sparse or solid.

Depending on the type of roofing material used, solid or sparse lathing is used to secure it.

The thickness of the sheathing depends mainly on the type and weight of the roofing:

• To lay roofing felt, it is enough to lay a sheathing of boards up to 20–25 mm thick. At the same time, slate sheets, which weigh from 23 to 35 kg, require boards with a transverse size of 32 mm. The overlap between rolls of roofing felt should be 10–15 cm, between sheets of slate - one wave;
• Installation of ceramic tiles is carried out on a sheathing made of timber with a thickness of 40 mm. In this case, first the top row at the ridge is completely laid out, then the row along the cornice, and after that the remaining rows are installed from the bottom up. The covering elements are attached to the sheathing with nails, and to each other using special grooves along the edges of each shingle;
• soft tiles require a continuous covering underneath, but the thickness is not of great importance, since the total mass of the petals is small. Therefore, sometimes moisture-resistant plywood from 8 mm in diameter is sufficient. The bitumen sheets must overlap each other so that the upper element covers the place where the lower element is attached to the sheathing (this is done with galvanized nails with a wide head);
• polycarbonate is mounted on a wooden or metal frame in increments of 40–60 cm, depending on the roof structure. Since the material is predominantly produced in large sheets (6 m x 2.1 m) and has exceptional flexibility, it is used to create extraordinary architectural forms. Fastening to the frame is done using self-tapping screws with large flat heads;
• Seam roofing is assembled from panels by rolling the edges of adjacent sheets. To do this, each of them has sides that are bent using a special tool. The lathing is a metal or wooden frame. Due to the high thermal conductivity of the material, the roofing cake necessarily includes insulation and vapor barrier, which prevents the formation of condensation on the inner surface.

When installing a seam roof, a special tool is required to connect the sheets

The corrugated sheets are arranged with an overlap of at least 20–25 cm and a gradual horizontal displacement. The most critical roof elements, such as the ridge and valley, are additionally waterproofed with rolled or mastic material.

The lateral overlap of profiled steel sheets must be at least one wave

As can be seen from the examples given, the design of each type of roof has its own characteristics. However, the general principle remains. The roofing material is fixed to the roof using the sheathing, which serves as a connecting link between the rafter system and the roof.

The strength and durability of the entire structure depends on the quality of the lathing.

Video: DIY metal profile installation

Removal and replacement of the roof

When asked when a roof replacement is needed, the most convincing answer is a wet spot on the ceiling of the home. Especially when water drips from it with stubborn persistence.

It is not worth taking it to such extremes; it is better to regularly carry out an annual inspection of the roof and carry out preventive work in a timely manner. However, if the leak comes as an unfortunate surprise, you need to make a strategic decision. This requires an inspection of the roof and supporting structure.

Roof restoration work involves three possible solutions.

1. When the damage affected only the roof, cracks, chips, pockets of corrosion, violation of the tightness of joints, etc. formed on the roof surface; repairs are only needed for the roofing itself. The volume is determined by the area of ​​the lesion. If 40% of the area or more is out of order, it is not advisable to patch such a roof. It is better and cheaper to replace the entire coating. For example, replace slate roofing with metal tiles.

   Over time, cracks and through holes form on the slate, which require replacement of damaged sheets or the entire covering

2. If the wooden elements of the sheathing are damaged, fungus or mold is found on the surface of the boards or panels, blackening or salt protrusion, you will have to replace the sheathing frame along with the roof. Otherwise, the renewed roof will not last long, and the money will be wasted.
3. And the last, worst-case scenario - violations affected the rafter system, the geometry of the attic or attic space was changed. The rafter legs have rotted, and the load-bearing or auxiliary structural elements (crossbars, tie-rods) have sagged. In this case, rafter repairs are necessary, which means complete dismantling of the roof cannot be avoided.

   If, as a result of leaks, the load-bearing elements of the roof have become wet and rotted, it is necessary to completely dismantle the roofing pie and repair the rafter system

Dismantling is carried out in the order reverse installation. For example, dismantling slate is carried out using a hammer and a nail puller. It is more convenient to disassemble such a roof with two people - one knocks the nails from the attic side, and the other pulls them out from outside. Next, the released sheet is lowered from a height to the ground and stored.

To remove the slate covering, it is necessary to remove all fasteners and carefully lower the released sheets to the ground.

When rebuilding the roof, for example, from slate to metal tile, it is necessary to adjust the shape of the sheathing, because slate is attached to one row, and metal tile to two. The second frame serves to enhance the natural ventilation of the under-roof space. If the covering is changed from soft tiles to corrugated sheets, there is no need to redo the sheathing. If it’s the other way around, you’ll have to cover the slopes with a continuous coating of OSB or plywood.

Under bitumen shingles it is necessary to make a continuous sheathing on which the lining carpet will be mounted

Dismantling must be carried out by a team or with an assistant. You cannot do this alone; safety precautions when performing high-altitude work prohibit being on the roof without a helmet and insurance.

If the roof was fastened with screws (corrugated sheeting, polycarbonate, etc.), then its disassembly is carried out using a screwdriver. The installer sequentially unscrews the fasteners and removes the sheets from the roof slopes.

Sheets of corrugated sheets connected to the sheathing with screws are unscrewed when dismantled with a screwdriver

The most labor-intensive is considered to be the dismantling of a flat roof covered with several layers of roofing felt (up to 5 or more). When heated in the sun, roofing material eventually bakes into a monolithic carpet, which is very difficult to remove. In this case, a roofing ax is used, with which the roofing is cut out into small islands and disposed of. On large areas specialized organizations use curtain cutters - power tool cutting the roof into pieces. There are wall cutters with electric or gasoline drive. They can only be used if the layer depth is at least 30 mm.

The wall chaser is designed for flat roof thickness from 30 mm

Replacing a roof involves carrying out certain calculations. If the weight of the new coating exceeds the weight of the old (removed) one, it is necessary to correctly assess the ability of the rafter system to withstand increased loads. Sometimes it is necessary to strengthen the rafters by adding additional supporting elements. In this case, use old-fashioned methods Not recommended. It is advisable that the calculations be carried out by a competent engineer familiar with the specifics of the industry.

When replacing heavy types of roofing with lightweight ones, it is enough to calculate the weight of the roof per square meter. For example, when replacing slate with corrugated board, this can be done as follows.

1. It is known that a sheet of eight-wave slate weighs about 30 kg and has an area of ​​1.5 m2. Thus, per 1 m2 there are 30/1.5 = 20 kg.
2. The corrugated sheet has dimensions of 1.2x1.2 m. We calculate its area: 1.2 ∙ 1.2 = 1.44 m 2.
3. The weight of the sheet (depending on the thickness of the metal) is from 7 to 9 kg, so the relative load from it can vary from 4.9 (7/1.44) to 6.3 (9/1.44) kg/m2.

This means that replacement can be done without additional extension of the rafters, since the pressure will decrease by almost 4 times.

Video: dismantling and installation of the roof (slate - metal tiles)

Roof maintenance

Checking the condition of the roof covering is an important preventative measure. The more regular maintenance is performed, the more likely it is that your roof will last longer.

Upon completion of assembly, all objects are removed from the surface: cuttings of roofing sheets, screws, connecting elements and other loose objects. A clean roof surface is a prerequisite for the proper functioning of the roof. The same requirements apply to the drainage system. There should be no foreign objects, debris, accumulation of leaves, etc. in the gutters. The drainage system is used to automatically remove moisture from the roof surface, so monitoring its operation is also preventive measure roof maintenance.

Visual inspection of roofing covering

Inspection of roofing sheets is carried out at least once a year. To do this, it is not enough to assess the condition of the roof from the ground. You need to climb onto the roof and inspect the entire surface at close range. Particular attention is paid to the junction of the slopes with vertical walls, chimneys and other objects located on the roof. If problems are detected, they are eliminated as soon as possible.

Checking the serviceability of roof components

The components include structural elements of the roof. This:

The overall performance and durability of the entire roof depends on the normal functioning of these elements, so you need to carefully monitor their safety. If the ridge is ventilated, you need to check the air intake openings for free air passage. It is not advisable to allow accumulation of water or snow in valleys. Drip rails and cornice strips are sometimes torn off by water and wind. It is necessary to ensure a strong fixation and return them to their original place in case of damage to the fastenings.

Monitoring the condition of the coating

Checking the status of colored and polymer coatings roofing is one of the most important tasks. The process of corrosion and destruction begins with small and unnoticeable damage, scratches and chips. If you eliminate them on time, you can count on the roof to last a long time. The most characteristic signs of a damaged coating are bubbles, discoloration and mechanical damage. Their appearance indicates that it is time to repair the roof.

Drainage system

A system of gutters located along the roof slopes prevents atmospheric water from accumulating on it. If drainage systems do not function effectively enough, destructive consequences for the roof as a whole are inevitable. Having lingered at the edge of the slope, the water freezes or gets onto the inner surface of the roof. This leads to wetness of the wood from which the rafters and sheathing are mounted. The consequence is rot, fungus and mold, which will very soon destroy the wood structure and render the roof unusable. Checking the operation of gutters is a prerequisite for a roof inspection. If the channels are clogged with debris, leaves, etc., they need to be cleaned and restored to working order. It is best to carry out such work after the leaves fly off the trees, but before the onset of cold weather and frost.

Before the start of the winter season, gutters and pipes must be completely cleared of all foreign objects.

Roof cleaning

Experts recommend washing the roof with water and a foaming detergent every two years. Remove debris and dirt using a soft brush and long pile. It is possible to use pumps that supply water under pressure. The impact of a powerful jet of liquid allows you to remove stubborn dirt, sand and earth deposits. It is advisable to carry out the work in the warm season, when the roof dries quickly under the influence of the sun and warm air masses.

To wash the roof, you can use special equipment that supplies water under high pressure.

Video: roof cleaning

Coloring

An effective means of combating roof corrosion is the use of dyes with water-repellent properties. Typically, exterior paint is used that matches the existing color of the roofing.

The paint is applied with a brush or roller. If the damage has not affected the primer, one coat of paint is sufficient. If corrosion has penetrated to the metal, you need to carefully paint not only the affected area, but also the roof within a radius of 15–20 cm. The operation is carried out in dry weather, the paint is applied in two layers with a period of time until the first layer has completely dried.

Sometimes the roof is painted completely. This allows you to create additional protection roofs from the adverse effects of the atmosphere. As practice has shown, the most best paint- shipborne - withstands up to 7 climatic cycles (years) per metal roofing. After this time, it is advisable to repeat the procedure. However, much depends on the region. In warm regions where severe frosts are rare, paint can last from 10 to 20 years.

It is more convenient to paint a roof made of stamped and wavy materials with a brush

The above applies to metal and asbestos-cement types of roofing. Roofs made of polycarbonate, roofing felt or soft tiles cannot be painted.

Video: painting a metal roof

Rules for roof operation in winter

In the cold season, when the air temperature drops below the water freezing threshold, seasonal factors must be taken into account.

Snow removal

With a properly planned and installed roof, problems with snow should not arise. This largely depends on the angle of the roof and the condition of the roof. It is necessary to ensure that zones with different textures do not form on the roof surface. For example, a seam roof needs to be painted periodically, since the paint, under the influence of the sun and the cycles of expansion and contraction of the metal, sooner or later cracks and crumbles. At the same time, the sliding of the snow mass slows down, the snow clings to the remaining paint and stays on the roof. Naturally, in this state of affairs, the home owner needs to monitor the condition of the roofing. The sooner you respond to damage, the fewer losses they will cost. But if snow still accumulates in a layer of more than 10–15 cm, you need to clean the roof. The same applies to ice on the eaves and edges of the slopes. If huge icicles hang from the roof, this indicates that the speed of water rolling off the roof is insufficient, so the water, without having time to move down, freezes in the cold and turns into ice. The second possible cause is clogged and icy gutters.

It is not always wise to undertake roof restoration on your own. The roof is a very important and vulnerable part of the building; it should not be taken lightly. Moreover, if not only the roof, but also the roof trusses need repair. By turning to professionals, you will receive qualified advice and guarantees for the work performed.

When designing any residential building, architects Special attention pay attention to the roof, since it performs not one, but several functions at once, depending on its design features. It must be said that not all future homeowners are satisfied with an ordinary gable roof, although it can be called the most reliable, since it has only two pitched planes and one joint between them. Many are attracted to more complex designs, which add special attractiveness and originality to the building. Other, more practical homeowners prefer attic structures, which can simultaneously serve as a roof and a second floor.

The basis of any roof is an individual rafter system, which has its own design features. It will be much easier to choose the right roof frame if you figure out which ones in advance. types and diagrams of rafter systems used in construction practice. After receiving such information, it will become more clear how difficult such structures are to install. This is especially important to know if you plan to build the roof frame yourself.

Main functional tasks of rafter systems

When settling in pitched structures roofs, the rafter system is a frame for covering and holding the materials of the “roofing cake”. With proper installation of the frame structure, the necessary conditions will be created for the correct and non-insulated types of roofs, protecting the walls and interior of the house from various atmospheric influences.

Roof structure It is also always the final architectural element of the exterior design of a building, supporting its stylistic direction with its appearance. However, the design features of rafter systems must first of all meet the strength and reliability requirements that the roof must meet, and only then the aesthetic criteria.

The frame of the rafter system forms the configuration and angle of inclination of the roof. These parameters largely depend on natural factors characteristic of a particular region, as well as on the desires and capabilities of the homeowner:

• Amount of precipitation in different periods of the year.
• Direction and average speed winds in the area where the building will be erected.
• Plans for the use of space under the roof - arranging residential or non-residential premises in it, or using it only as air gap for thermal insulation of rooms below.
• Type of planned roofing material.
• Financial capabilities of the homeowner.

Atmospheric precipitation and the strength of wind currents place a very sensitive load on the roof structure. For example, in regions with heavy snowfall, you should not choose a rafter system with a small slope angle, since snow masses will linger on their surface, which can lead to deformation of the frame or roofing or to leaks.

If the area where the construction will take place is famous for its winds, then it is better to choose a structure with a slight slope of the slope so that sudden gusts that occur do not tear off individual elements of the roof and roofing.

Main elements of roof structure

Parts and components of rafter systems

Depending on the chosen type of rafter system, the structural elements used can vary significantly, however, there are parts that are present in both simple and complex systems roofs

The main elements of a pitched roof rafter system include:

• Rafter legs that form the roof slopes.
• - wooden beam, fixed to the walls of the house and used to fix the lower part of the rafter legs on it.

• A ridge is the junction of the frames of two slopes. It is usually the highest horizontal line roof and serves as a support on which the rafters are fixed. The ridge can be formed by rafters fastened together at a certain angle or fixed on a ridge board (purlin).
• Sheathing is slats or beams mounted on rafters at a certain pitch and serving as the basis for laying the selected roofing material.
• Supporting elements, which include beams, purlins, racks, struts, ties and other parts, serve to increase the rigidity of the rafter legs, support the ridge, and connect individual parts into an overall structure.

In addition to the mentioned design details, it may also include other elements, the functions of which are aimed at strengthening the system and optimally distributing roof loads on the walls of the building.

The rafter system is divided into several categories depending on different features of its design.

Attic space

Before moving on to considering different types of roofs, it is worth understanding what an attic space can be, since many owners successfully use it as utility and full-fledged residential premises.

The design of pitched roofs can be divided into attics and attics. The first option is called this way because the space under the roof has a small height and is used only as an air layer insulating the building on top. Such systems usually include or have several slopes, but located at a very slight angle.

An attic structure that has a sufficiently high ridge height can be used in different ways, be insulated and not insulated. Such options include an attic or gable option. If you choose a roof with a high ridge, then it is imperative to take into account the wind loads in the region where the house is built.

Slope slope

To determine optimal inclination roof slopes of a future residential building, first of all you need to take a closer look at the already built low-rise neighboring houses. If they have been standing for more than one year and can withstand wind loads, then their design can safely be taken as a basis. In the same case, when the owners set a goal to create an exclusive original project, unlike standing nearby buildings, it is necessary to familiarize yourself with the design and operational features of various rafter systems and make the appropriate calculations.

It should be taken into account that the change in the tangent and normal values ​​of the wind force depends on how large the slope of the roof slopes is - the steeper the angle of inclination, the greater the importance of normal forces and the less tangent forces. If the roof is flat, then the structure is more affected by the tangential wind load, since the lifting force increases on the leeward side and decreases on the windward side.

Winter snow load should also be taken into account when designing the roof. Usually this factor is considered in conjunction with the wind load, since on the windward side the snow load will be much lower than on the leeward slope. In addition, there are places on the slopes where snow will certainly accumulate, putting a large load on this area, so it should be reinforced with additional rafters.

The slope of roof slopes can vary from 10 to 60 degrees, and it must be selected not only taking into account the consolidated external load, but also depending on the roofing covering that is planned to be used. This factor is taken into account because roofing materials differ in their mass; to secure them, it is required different quantity elements of the rafter system, which means the load on the walls of the house will vary, and how large it will be also depends on the angle of the roof. Of no small importance are the characteristics of each coating in terms of resistance to moisture penetration - many roofing materials in any case require one or another slope to ensure the free drainage of storm water or melting snow. In addition, when choosing a roof slope, you need to think in advance about how the process of cleaning and repair work on the roof will be carried out.

When planning a particular angle of the roof slopes, you need to know that the fewer joints between the sheets of roofing, and the more airtight they are, the less you can make the slope of the slope, of course, if you are not planning to arrange a residential or utility room in the attic space.

If a material consisting of small elements is used to cover the roof, for example, ceramic tiles, then the slope of the slopes must be made steep enough so that water never lingers on the surface.

Considering the weight of the roofing material, you need to know that the heavier the covering, the larger the angle of the slopes should be, since in this case the load will be correctly distributed over the rafter system and load-bearing walls.

The following materials can be used to cover the roof: or profile sheet, galvanized steel, corrugated asbestos concrete and bitumen-fiber sheets, cement and ceramic tiles, roofing felt, soft roofing and other roofing materials. The illustration below shows the permissible slope angles for various types of roofing coverings.

Basic designs of rafter systems

First of all, it is worth considering the basic types of rafter systems relative to the location of the walls of the house, which are used in all roof structures. Basic options are divided into layered, hanging, and combined, that is, including elements of both the first and second types of systems in its design.

fastenings for rafters

Layered system

In buildings where internal load-bearing walls are provided, a layered rafter system is often installed. It is much easier to install than a hanging one, since the internal load-bearing walls provide reliable support for its elements, and in addition, this structure will require less materials.

For rafters in this system, the defining reference point is the ridge board, on which they are fixed. The non-thrust type of layered system can be arranged in three options:

• In the first option, the upper side of the rafters is fixed on a ridge support, called a sliding one, and their lower side is fixed by cutting to the mauerlat. Additionally, the rafters in the lower part are fixed to the wall using wire or staples.

• In the second case, the rafters in the upper part are cut at a certain angle and connected to each other using special metal plates.

The lower edge of the rafter legs is attached to the Mauerlat with movable fasteners.

• In the third option, the rafters are rigidly fastened in the upper part with bars or treated boards located horizontally, parallel to each other on both sides of rafters connected at an angle, and a ridge girder is clamped between them.

In the lower part, sliding fasteners are used to secure the rafters, just as in the previous case.

It is necessary to explain why sliding fasteners are often used to secure rafters to the mauerlat. The fact is that they are able to relieve load-bearing walls from excessive stress, since the rafters are not rigidly fixed, and when the structure shrinks, they are able to move without deforming general design roofing system.

This type of fastening is used only in layered systems, which also distinguishes them from the hanging version.

However, in some cases, for layered rafters, a spacer system is used, in which the lower end of the rafters is rigidly fixed to the Mauerlat, and to relieve the load from the walls, tie-downs and struts are built into the structure. This option is called complex, as it includes elements of a layered and hanging system.

Specify the requested values ​​and click the "Calculate excess Lbc" button

Base length (horizontal projection of the slope)

Planned roof slope angle α (degrees)

Rafter length calculator

The calculation is carried out based on the values ​​of the horizontal projection (Lсд) and the height of the rafter triangle determined earlier (Lbc).

If desired, you can include the width of the eaves overhang in the calculation if it is created by protruding rafters.

Enter the requested values ​​and click the "Calculate rafter length" button

Excess value Lbc (meters)

Length of the horizontal projection of the rafter Lсд (meters)

Calculation conditions:

Required width of eaves overhang (meters)

Number of overhangs:

Gable rafter system

Gable rafter systems are the most popular for one-story private houses. They look neat, fit well into any style of construction, are reliable and can be used, depending on the angle of their slope, for arranging an attic under living rooms, utility rooms or simply to create an air gap that retains heat in the building.

wood screws

Rafters perform a number of significant roofing functions. They set the configuration of the future roof, absorb atmospheric loads, and hold the material. Among the rafter's duties are the formation of smooth planes for laying the covering and providing space for the components of the roofing pie.

In order for such a valuable part of the roof to flawlessly cope with the listed tasks, information is needed about the rules and principles of its design. The information is useful both for those who are constructing a gable roof truss system with their own hands, and for those who decide to resort to the services of a hired team of builders.

In device rafter frame For pitched roofs, wooden and metal beams are used. Source material For the first option, use a board, log, timber.

The second is constructed from rolled metal: channel, profile pipe, I-beam, angle. There are combined structures with the most heavily loaded steel parts and wood elements in less critical areas.

In addition to its “iron” strength, metal has many disadvantages. These include thermal qualities that are unsatisfactory to the owners of residential buildings. The need to use welded joints is disappointing. Most often, industrial buildings are equipped with steel rafters, and less often, private cabins assembled from metal modules.

In the matter of independent construction of rafter structures for private houses, wood is a priority. It is not difficult to work with, it is lighter, “warmer”, and more attractive in terms of environmental criteria. In addition, to make nodal connections you will not need a welding machine or welding skills.

Rafters - a fundamental element

The main “player” of the frame for constructing a roof is the rafter, which among roofers is called a rafter leg. Beams, braces, headstocks, purlins, ties, even a Mauerlat may or may not be used depending on the architectural complexity and dimensions of the roof.

Rafters used in the construction of gable roof frames are divided into:

• Layered rafter legs, both heels of which have reliable structural supports under them. The lower edge of the layered rafter rests against the mauerlat or the ceiling crown of the log house. The support for the upper edge can be a mirror analogue of the adjacent rafter or a purlin, which is a beam laid horizontally under the ridge. In the first case, the rafter system is called spacer, in the second, non-spacer.
• Hanging rafters, the top of which rests against each other, and the bottom is based on an additional beam - a tie. The latter connects the two lower heels of adjacent rafter legs, resulting in a triangular module called a rafter truss. Tightening dampens the tensile processes, so that only vertically directed load acts on the walls. Although a structure with hanging rafters is braced, the bracing itself does not transmit to the walls.

In accordance with the technological specifics of rafter legs, the structures constructed from them are divided into layered and hanging. For stability, the structures are equipped with struts and additional racks.

To support the top of the layered rafters, planks and purlins are installed. In reality, the rafter structure is much more complex than the elementary templates described.

Note that the formation of the frame of a gable roof can generally be done without a rafter structure. In such situations, the supposed planes of the slopes are formed by slabs - beams laid directly on the load-bearing gables.

However, we are now interested specifically in the structure of the rafter system gable roof, and it can involve either hanging or layered rafters, or a combination of both types.

Subtleties of fastening rafter legs

Fastening the rafter system to brick, foam concrete, aerated concrete walls is carried out through the Mauerlat, which in turn is fixed with anchors.

Between the Mauerlat, which is wooden frame, and walls made of the specified materials must be laid with a waterproofing layer of roofing material, waterproofing material, etc.

The top of brick walls is sometimes specially laid out so that along the outer perimeter there is something like a low parapet. This is so that the mauerlat placed inside the parapet and the walls do not push apart the rafter legs.

Roof frame rafters wooden houses rest on the upper crown or on the ceiling beams. The connection in all cases is made by notches and is duplicated with nails, bolts, metal or wooden plates.

How to do without mind-boggling calculations?

It is highly desirable that the cross-section and linear dimensions of wooden beams be determined by the project. The designer will provide clear calculation justification for the geometric parameters of the board or beam, taking into account the entire range of loads and weather conditions. If at the disposal of a home handyman design development no, his path lies to the construction site of a house with a similar roofing structure.

You don’t have to pay attention to the number of floors of the building being constructed. It is easier and more correct to find out the required dimensions from the foreman than to find out them from the owners of a shaky self-built building. After all, in the hands of the foreman is documentation with a clear calculation of the loads per 1 m² of roof in a specific region.

The installation pitch of the rafters determines the type and weight of the roofing. The heavier it is, the smaller the distance between the rafter legs should be. For styling clay tiles, for example, the optimal distance between the rafters will be 0.6-0.7 m, and for corrugated sheets 1.5-2.0 m is acceptable.

However, even if the pitch required for proper installation of the roof is exceeded, there is a way out. This is a reinforcing counter-lattice device. True, it will increase both the weight of the roof and the construction budget. Therefore, it is better to understand the pitch of the rafters before constructing the rafter system.

Craftsmen calculate the pitch of the rafters according to the design features of the building, simply dividing the length of the slope into equal distances. For insulated roofs, the pitch between the rafters is selected based on the width of the insulation slabs.

You can find it on our website, which may also help you a lot during construction.

Rafter structures of layered type

Layered rafter structures are much simpler to construct than their hanging counterparts. A reasonable advantage of the layered scheme is to ensure adequate ventilation, which is directly related to long-term service.

Distinctive design features:

• It is mandatory to have support under the ridge heel of the rafter leg. The role of support can be played by a purlin - a wooden beam resting on racks or on interior wall building, or the upper end of the adjacent rafter.
• Using a Mauerlat to erect a truss structure on walls made of brick or artificial stone.
• The use of additional purlins and racks where rafter legs are required due to the large size of the roof additional points supports.

The disadvantage of the scheme is the presence of structural elements that affect the layout of the internal space of the attic being used.

If the attic is cold and it is not intended to organize useful rooms, then the layered structure of the rafter system for installing a gable roof should be given preference.

Typical sequence of work for the construction of a layered truss structure:

• First of all, we measure the heights of the building, the diagonals and horizontality of the upper cut of the frame. When identifying vertical deviations of brick and concrete walls, we remove them with a cement-sand screed. Exceeding the heights of the log house is cut off. By placing wood chips under the mauerlat, vertical flaws can be combated if their size is insignificant.
• The floor surface for laying the bed must also be leveled. It, the Mauerlat and the girder must be clearly horizontal, but the location of the listed elements in the same plane is not necessary.
• We treat all wooden parts of the structure with fire retardants and antiseptics before installation.
• We lay waterproofing on concrete and brick walls for installation of the Mauerlat.
• We lay the mauerlat beam on the walls and measure its diagonals. If necessary, we slightly move the bars and turn the corners, trying to achieve the ideal geometry. Align the frame horizontally if necessary.
• We mount the Mauerlat frame. The beams are joined into a single frame using oblique notches; the joints are duplicated with bolts.
• We fix the position of the Mauerlat. Fastening is done either with staples to wooden plugs installed in advance in the wall, or with anchor bolts.
• Mark the position of the prone position. Its axis should recede from the mauerlat bars at equal distances on each side. If the run will rest only on posts without supports, we carry out the marking procedure only for these posts.
• We install the bed on a two-layer waterproofing. We attach it to the base with anchor bolts, and connect it to the inner wall with wire twists or staples.
• We mark the installation points of the rafter legs.
• We cut out the racks to uniform sizes, because... Our bed is exposed to the horizon. The height of the racks should take into account the cross-sectional dimensions of the purlin and beam.
• We install racks. If provided by the design, we secure them with spacers.
• We lay the purlin on the racks. We check the geometry again, then install brackets, metal plates, and wooden mounting plates.
• We install a test rafter board and mark the cutting areas on it. If the Mauerlat is set strictly to the horizon, there is no need to adjust the rafters on the roof after the fact. The first board can be used as a template for making the rest.
• We mark the installation points of the rafters. Folk craftsmen for marking, a pair of slats are usually prepared, the length of which is equal to the clearance between the rafters.
• According to the markings, we install the rafter legs and fasten them first at the bottom to the mauerlat, then at the top to the purlin to each other. Every second rafter is screwed to the Mauerlat with a wire bundle. In wooden houses, the rafters are screwed to the second crown from the top row.

If the rafter system is made flawlessly, the layer boards are installed in any order.

If there is no confidence in the ideal structure, then the outer pairs of rafters are installed first. A control string or fishing line is stretched between them, according to which the position of the newly installed rafters is adjusted.

The installation of the rafter structure is completed by installing fillets, if the length of the rafter legs does not allow forming an overhang of the required length. By the way, for wooden buildings the overhang should extend beyond the contour of the building by 50 cm. If you plan to organize a canopy, separate mini-rafters are installed under it.

Another useful video about building a gable rafter base with your own hands:

Hanging rafter systems

The hanging variety of rafter systems is a triangle. The two upper sides of the triangle are folded by a pair of rafters, and the base is the tie connecting the lower heels.

The use of tightening allows you to neutralize the effect of the thrust, therefore, only the weight of the sheathing, roof, plus, depending on the season, the weight of precipitation, acts on walls with hanging rafter structures.

Specifics of hanging rafter systems

Characteristic features of hanging type rafter structures:

• The obligatory presence of a tie, most often made of wood, less often of metal.
• Possibility to refuse to use the Mauerlat. A timber frame can be successfully replaced by a board laid on double-layer waterproofing.
• Installation of ready-made closed triangles – trusses – on the walls.

The advantages of the hanging scheme include the space under the roof free from racks, which allows you to organize an attic without pillars and partitions. There are disadvantages.

The first of them is restrictions on the steepness of the slopes: their slope angle can be at least 1/6 of the span of a triangular truss; steeper roofs are strongly recommended. The second disadvantage is the need for detailed calculations for the proper installation of cornice units.

Among other things, the angle of the truss will have to be installed with pinpoint precision, because the axes of the connected components of the hanging rafter system must intersect at a point, the projection of which must fall on the central axis of the Mauerlat or the backing board replacing it.

Subtleties of long-span hanging systems

The tie is the longest element of a hanging rafter structure. Over time, as is typical for all lumber, it becomes deformed and sags under the influence of its own weight.

Owners of houses with spans of 3-5 meters are not too concerned about this circumstance, but owners of buildings with spans of 6 meters or more should think about installing additional parts that exclude geometric changes in tightening.

To prevent sagging, there is a very significant component in the installation diagram of the rafter system for a long-span gable roof. This is a pendant called a grandmother.

Most often it is a block attached with wooden pegs to the top of the truss. The headstock should not be confused with the racks, because its lower part should not come into contact with the puff at all. And the installation of racks as supports in hanging systems is not used.

The bottom line is that the headstock hangs, as it were, on the ridge assembly, and a tightening is attached to it using bolts or nailed wooden plates. To correct sagging tightening, threaded or collet-type clamps are used.

The tightening position can be adjusted in the area of ​​the ridge assembly, and the headstock can be rigidly connected to it by a notch. Instead of a bar in non-residential attics, reinforcement can be used to make the described tension element. It is also recommended to install a headstock or hanger where the tie is assembled from two beams to support the connection area.

In an improved hanging system of this type, the headstock is complemented by strut beams. The stress forces in the resulting rhombus are extinguished spontaneously due to the proper placement of vector loads acting on the system.

As a result, the rafter system is stable with minor and not too expensive modernization.

Hanging type for attics

In order to increase the usable space, the tightening of the rafter triangles for the attic is moved closer to the ridge. A completely reasonable move has additional advantages: it allows you to use the puffs as a basis for lining the ceiling.

It is connected to the rafters by cutting with a half-pan and duplicating with a bolt. It is protected from sagging by installing a short headstock.

A noticeable disadvantage of the hanging attic structure is the need for accurate calculations. It is too difficult to calculate it yourself; it is better to use a ready-made project.

Which design is more cost effective?

Cost is an important argument for an independent builder. Naturally, the price of construction for both types of rafter systems cannot be the same, because:

• In the construction of a layered structure, a board or beam of small cross-section is used to make rafter legs. Because layered rafters have two reliable supports underneath them; the requirements for their power are lower than in the hanging version.
• In the construction of a hanging structure, the rafters are made of thick timber. To make a tightening, a material with a similar cross-section is required. Even taking into account the abandonment of the Mauerlat, the consumption will be significantly higher.

It will not be possible to save on the grade of material. For the load-bearing elements of both systems: rafters, purlins, beams, mauerlat, headstocks, racks, 2nd grade lumber is needed.

For crossbars and tensile ties, grade 1 will be required. In the manufacture of less critical wooden overlays, grade 3 can be used. Without counting, we can say that in the construction of hanging systems, expensive material is used in greater quantities.

Hanging trusses are assembled in an open area next to the facility, then transported, assembled, upstairs. To lift weighty triangular arches from timber, you will need equipment, the rental of which will have to be paid. And the project for complex nodes of the hanging version is also worth something.

Video instruction on the construction of a hanging category truss structure:

There are actually many more methods for constructing rafter systems for roofs with two slopes.

We have described only the basic varieties, which in reality are applicable for small country houses and buildings without architectural tricks. However, the information presented is enough to cope with the construction of a simple truss structure.