How to make a four-pitched hip roof. How to make a hipped roof and calculate the design How to make a hipped roof yourself

The roof on a private house can be any, this is the business of the property owner. The type of roof structure is selected based on general style and the size of the house, weather conditions and the financial capacity of the builder.

All hipped roofs are divided according to the form of execution into several types:

• Tent. Such structures are erected on rectangular or square buildings. The slopes of such a roof are isosceles triangles converging at one point;
• Hip. 2 slopes of this design are represented by trapezoids, 2 by triangles. It is the slopes of a triangular shape on the gables that are called hips. It is worth noting that hip types of roofs are the most common among all hipped types;
• Multi-forceps, or valley. Very difficult to build types of roofs that are not as common as those mentioned above.

Tent and hip structures are devoid of gables, so their device is considered economical. by the most milestone the construction of such a roof is the precise installation of the truss system and competent calculations of the necessary material.

An example of the implementation of a roofing system

For fastening the rafters, one of 2 methods is used: layered or hanging. The layered method of installing rafters is very complicated from a technical point of view and is used where there are no bearing walls inside the roof. The layered method is simpler and cheaper. It is used on all roof structures with 4 slopes and a slope angle not exceeding 40°.

The technology of this roofing system

The truss system of a hipped roof must necessarily have slanting (diagonal) rafters directed towards the corners of the building. These items are made using double board or bar. The load on the rafters is very high, they are often made of 2 parts.

Important: in order to fix both parts of the rafters more securely, they are supported with a special support stand.

next element roof structure hip roofs are sprigs. These short rafters are located at the corners and rest with their tops on the slanting elements. The connection of these two types of rafters in several places provides strength to the erected frame.

Scheme of the truss system for the hip roof

If the length of the diagonal rafters exceeds 7 m, a support stand is additionally mounted. One end of the rack rests under the rafters, the other - on the sprengel (a beam laid in the corner of the roof on two adjacent walls).

Installation of the stand-support is carried out on a waterproofing layer laid on the ceiling. If the truss is reinforced with struts, it is customary to talk about the construction of a truss truss.

Hipped 4-pitched roofs are no less popular than hip roofs. They are characterized by simplicity and a high margin of safety. This design has its own characteristics that distinguish its installation from the hip system:

• There is no ridge run on hipped roof structures, the diagonal rafters are connected at the top point. To strengthen the tent truss system, many builders install a central rack. Otherwise, the entire structure is assembled from suspended elements, secured with puffs and other fasteners.
• The rafters in the center are mounted in the direction from above to the walls, the angle of inclination is 90 °. In a parallel plane, the sprigs and the cranial beam are installed, reinforcing the slanting elements;
• In the absence of a beam as part of the structure, it is possible to cut the sprockets into the rafters or nail them;
• Strengthening of long diagonal rafters is carried out according to a similar principle with hip structures (sprengels).

The described technology describes the general rules by which the installation of the truss system of a hipped roof of a private house is carried out. In industrial or large-scale residential construction, other methods of erecting roof structures are used that can withstand heavy coverage.

To prevent the wood from starting to rot, under reinforced concrete floors a bed is laid, located on 2 layers of waterproofing.

Set of rules for installation

To correctly install the rafters on the roof with four slopes, you must follow a few rules:

• The project of the truss system, expressed in the choice of the type of roof structure and the most complete drawing of the future roof;
• The slope of the slopes is determined;
• The choice of the type of truss structure (layered or hanging);
• Calculation of the need for material, determination of the required thickness of the timber, boards on the rafters. Important: saving on material for the manufacture of rafters is stupid, the strength of the entire roof frame depends on this moment.
• Purchase of consumables: screws, nails, etc.;
• Assembling the base of the truss structure below, on the ground. After that, it will only be necessary to lift it up and begin to strengthen it;
• All elements of the rafter system must be firmly fixed in their places, constantly monitoring the strength and reliability of the fasteners;
• Construction work at height should always be accompanied by additional safety measures (strong belt, cable, etc.).

By following these simple rules, it will be much easier to cope with the installation of rafters on a hipped roof.

Necessary calculations

The truss system of a hipped roof is a very important operation, on which the reliability of the structure and its service life directly depend. Errors in drawings and calculations at this stage should be completely excluded.

To perform a competent calculation of the roof on a 4-pitched structure, you need to know the following parameters:

• The angle of inclination of the slopes of the future roof;
• End length;
• Width of cornice overhangs;
• The presence or absence of a support column under the ridge. If there is a support post under the ridge, a layered truss system is designed, in the absence of such, a hanging one.
• The need for additional support posts.

Online calculators consider only the length of the rafters, not taking into account the diameter of the timber or boards. Knowing the cross section of these elements allows for more accurate material calculations. The choice of material is made based on the total loads on truss system during operation (mass of lathing, roofing materials, etc.).

To calculate the consumption of roofing materials, the following calculations are performed: The area of ​​​​a 4-pitched roof, consisting of the sum of the areas of its triangle slopes; The area of ​​each triangle is determined based on the length of the wall and the height of the slope.

Important: the area of ​​\u200b\u200beach slope can be determined based on the known angle of inclination and the height of the ridge node.

When calculating the truss system, it is worth taking into account additional points that complicate the calculation of consumables. This is a roof over small dormer windows, visors over bay windows, etc. details external design roofs. Any of these elements is calculated separately, after which all the resulting areas are added to the total roof area.

When self-calculating roofing materials, it is necessary to lay down a certain percentage of the error, usually from 10 to 15%.

Self-assembly of the structure

Before proceeding to the description of the installation sequence of the rafters, it is necessary to briefly describe the main elements of this design:

• Mauerlat - the lower base-support for the rafters;
• Slanted or diagonal rafters at one end rest against a pair of legs of the following rafters, at the other end against a Mauerlat or a beam built into it;
• Narozhniks are called shortened rafter-legs;
• Run - a beam that plays the role of an additional base. It is located parallel to the Mauerlat and serves as a support for the rafters;
• Struts, racks - are installed to obtain spans;
• Lying - support for racks. Attaches to the inside of the wall or floor posts;
• Sprengel - an element that additionally strengthens the frame of the structure;
• Crossbars - additional components of the truss structure that prevent the appearance of spacers.

Stretching of the truss system can occur due to improper arrangement or leaning of the legs one on top of the other.

Depending on the source material for building a house, the following structural details can act as a supporting element:

• Brick or stone houses - Mauerlat;
• Log cabins from logs or timber - upper crowns;
• Frame structures - top trim.

Before installing the truss system, the geometry of all walls is checked. The skew of the angle of the slope will entail a skew of the future roof. Bringing all the rafters into a ridge knot is a skill that comes to the master over the years. Accurate calculation and constant level control are required.

First, diagonal rafters are mounted at opposite corners. The rafters are supported on the Mauerlat with the help of short trusses. Notches are made at the ends of the sprengels to a depth of 0.5 of the height of the material section. After that, the guards are attached.

Installation of the truss system is a responsible event, which is quite difficult to perform on your own in the absence of experience.

The hipped or hipped roof is one of the most popular roofing options in the construction of individual housing around the world.

Unlike the gable roof of the house, on the sides of which gables are mounted, the hipped one has additional slopes in the shape of a triangle.

A four-pitched roof with your own hands is very difficult to perform, and if you are interested in how to make a four-pitched roof, you should definitely familiarize yourself with the theoretical part first.

Before starting work, you should carefully calculate everything, draw up drawings and a project in which you need to indicate the placement of various elements and other design features.

The calculation of the hipped roof and the project must take into account all the loads that will affect the building.

The design must be very strong, withstand strong winds, snowfall and other weather conditions. The service life of the roof depends on how correctly the roof material is selected.

That is why, when creating a project and drawings, it is very important to calculate everything correctly. Project of a hipped roof in the photo:

Before creating a project and a drawing of a hipped roof of a house, you must first find out the angle of inclination of the slopes, which depends on many factors, such as the purpose of the attic, the choice of roof material, and the features of atmospheric influences.

Most often, the angle of inclination of the roof of individual houses is from 5 to 60 degrees.

If in your region precipitation and winds are not very strong, then the angle of inclination of the structure may be insignificant.

If in your area it often rains heavily, and in winter it snows, then the angle of inclination of the hipped roof of houses should be from 40-45 to 60 degrees.

The finishing material, as well as installation features, also depend on the option, what angle of inclination the structure will have:

• if the angle of inclination is less than 18 degrees, wavy and flat slate, as well as roll materials for roofing;
• when the angle of inclination is up to 30 degrees, varieties of tiles are usually used;
• for a roof whose slope angle is at least 30 degrees, piece material is usually used.

Calculation of the slope of the roof in the photo.

The design and calculation of the structure must take into account where all the elements of the roofing system will be located. When you have determined the slope of the hipped roof, you must also calculate the height of the ridge.

Roof truss system

Roof device of this type private houses involves the calculation of the desired section of the rafters. The calculation is made based on the loads that your hipped roof will receive.

Calculations, as well as the design of the structure, should include wind load, the maximum possible mass of snow in winter, the angle of inclination of the roof.

When calculating the distance between the rafters, it is necessary to evaluate their ability to withstand loads, as well as their safety margin, which should be 1.4 or more.

The type of device of the truss system depends on the features of the building, and therefore may be different.

If the house has a load-bearing wall or supports from pillars, then layered rafters are usually used, but if the support device is not possible, then hanging rafters are made.

In some buildings, both types of rafters are used simultaneously.

When carrying out a drawing and a project for a future building, it is important not only to decide on the type of truss system, but also to take into account additional elements fasteners, which will give the structure strength and reduce the load on the beams.

Calculation of roof loads

When developing a drawing and a roof project for individual houses, it is important to correctly calculate the loads.

Loads are of the following types:

• constants - the weight of the insulating material, various materials finishes and insulation, weight of materials
• for roofing and lathing weight;
• temporary - the weight of snow in winter, the negative impact of the wind;
• additional - various designs that are attached to the roof.

When creating a project and a drawing of the roof of your house, you should adhere to the average snow load, which is 180 kg per square meter.

But if the angle of inclination is 60 degrees or more, then the snow load is not taken into account.

As for wind loads, their average value is usually 35 kg per square meter, but if the roof slope is less than 30 degrees, this amendment is not taken into account.

After making all the calculations, you can proceed to the choice of material for the roofing device.

The photo below shows a diagram of the structure of a hipped roof and the name of all structural elements.

The choice of materials for the construction of the roof

When the hipped roof area is covered with roofing material, a lot of waste remains.

Therefore, in order to cover the area of ​​\u200b\u200ba hipped roof, roofing materials are usually chosen, the elements of which are small.

The most common materials for covering the roof area are flexible or ordinary tiles, slate sheets, ondulin, metal tiles.

To build a roof that will last for several decades, you need Special attention pay attention to the selection of materials for the construction of the truss system.

Usually for the construction of a hipped roof, lumber is used from wood. conifers.

Do not neglect the quality of wood, choose a material without defects, which can further reduce the quality and durability of the structure.

An important criterion for choosing lumber is its moisture content, which should be no more than 15 - 20%.

If this indicator is exceeded, the beam should be dried before use, so that during the service the hipped roof does not distort or deform.

The construction of rafters for the roof of a house is usually carried out using a rectangular beam, the cross section of which should be calculated for each individual case.

To build such a structure, boards with a rectangular section measuring 50 by 100, 50 by 200, 100 by 150 and others are usually used.

If necessary, then in the process of work, you can double the boards to obtain the desired diameter.

To build a hipped roof, special steel elements are often used that hold the rafters firmly in one position for many years.

In addition, supports for ridge runs are also often made of metal.

Construction of a pitched roof

All wooden parts for the roof frame are treated with a special compound that will protect the tree from fire. In places where the beam will be adjacent to brick or stone, it must be wrapped in waterproofing.

The construction of a hipped roof begins with laying the Mauerlat building around the perimeter of the roof area.

Fasten it with wire loops or studs, which are embedded in the wall or in the floor slabs. Next, install the central beam, which is located on the central axis of the house.

It should rest on a floor slab or internal wall.

In order for the structure to be absolutely symmetrical, it is important to correctly calculate and mark the location of the diagonal rafters, as well as the ridge support.

The height of the ridge must also be marked with maximum accuracy.

A clear symmetrical marking of the structure will make the load distribution uniform and prevent the roof from distorting in the future.

After the Mauerlat has been installed along the perimeter of the roof area, the beams are placed under the ridge run. The height of the ridge must strictly comply with the design drawings.

Diagonal beams withstand high load during service, so they must be installed very well.

If the length of the beam or board is not enough, diagonal supports are made of two parts. In order for the junction not to experience the maximum load, a support bar is installed under it.

The structure can be made the most rigid if the joint with the support is located at such a distance that is equal to a quarter of the length of the rafter beam from its upper edge, which is attached to the ridge.

It is best to implement diagonal rafters with the help of prefabricated rafter legs, which are convenient to mount. You can see the process of installing diagonal rafters in the video.

The device of this roof involves the installation of not only full-length rafters that are connected to the ridge, but also those that are attached to diagonal beams - sprigs.

The closer to the corner of the house, the shorter the jumpers.

The distance between the rafters is determined during the development of the roof project, but it should be borne in mind that each slope must have at least three central rafters.

To give the structure maximum rigidity, supports, braces and puffs are attached in the necessary places. The scheme for attaching the rafters can be seen in the photo.

The final stage of the roof device is the installation of the rafter sheathing. Usually, a beam measuring 50 by 50 mm is used for the crate. The step of the crate depends on what roofing material you have chosen.

If the attic area will be used as a living room, then ventilation should also be installed.

To date, all manufacturers of roofing materials also offer ridge parts of the same textures and colors.

The main ridge is installed on the hipped roof, and skates that cover the gaps between the main slopes and hips.

Complete the installation of a hipped roof by installing cornices and gutters. The whole process is shown in the video.

A hipped roof, otherwise called a hip roof, has long been widely used in European countries. Currently, an increasing number of owners country houses in Russia, this durable and reliable roofing system is preferred.

The most important difference between the hip roof is that its design does not involve gables. Instead, there are 2 additional ramps.

• classic hipped roof (all overhangs are at the same height, all four slopes with straight rafters, and corner ribs originate from the central ridge);
• hipped roof (the corner ribs of the slopes diverge from one point in the center of the roof, there is no ridge run in its design);
• Danish roof (involves short slopes with gables in the upper part of the roof, which are used for lighting and ventilation);
• half-hipped roof (with a stretch it can be attributed to four-slope roofs, because its design is more like a gable roof - the rafter legs run parallel to each other and are installed on the long side, based on the Mauerlat);
• sloping roof (mansard) corresponds to its name, and has many broken lines, which allows you to build a higher ceiling on an additional floor and maximize the use of living space;
• multi-pitched hip roof (despite the fact that the number of slopes is more than 4, the principle of assembling the truss systems of this one of the most complex varieties is no different from the construction of a simple four-pitched roof).

Advantages and disadvantages of a hipped roof

Any roof has strong and weak sides in its design. And the hipped roof configuration is no exception, and its advantages and disadvantages are usually considered in comparison with the gable roof - the most common and simple option roofs.

The benefits include:

• a properly designed roof resists even hurricane-force winds well;
• little susceptible to destruction of the roof in those places where there are cornice overhangs;
• due to the rigid structure (due to the angular ribs that converge to the support beam of the ridge), it does not undergo serious deformation;
• large overhangs on all sides protect the facade of the building from precipitation;
• the possibility of arranging an additional attic or attic space;
• attic space thanks to this design, the roof warms up evenly and retains heat well;
• attic windows can be mounted directly in the roof slopes - there is no need for gables;
• external attractiveness, which can be further emphasized by a well-chosen roofing material.

The disadvantages are:

• the complexity of engineering calculations and construction;
• impressive weight of the structure;
• large financial expenses than when building a gable roof, however, it should be noted that you do not need to spend money on brickwork of gables;
• through ajar skylights during rain, water penetrates, while with windows located in the gables of a gable roof, this problem does not arise.

Calculation of the slope of a hipped roof

When it comes to the slope of a hipped roof, we mean the slope of the longitudinal (trapezoidal) slopes. To correctly determine this parameter, it is necessary to take into account certain factors individually and in combination:

• the slope depends on the design of the roof and facade of the building;
• the greater the slope angle, the greater the consumption of building materials and the complexity of the work performed;
• the slope of a hipped roof can be in a wide range from 5 ° to 60 °;
• in regions with frequent and heavy rainfall (winter snowfalls are especially worth considering), preference is given to a large roof slope - from 45 ° to 60 °;

• in areas where strong winds prevail, it is better to choose a small slope angle (from 9 ° to 20 °), which will significantly reduce the windage of roofing materials;
• if roofing materials are collected from piece units, then the slope of the roof slope must be at least 25 °, otherwise moisture will seep through the seams;
• most often, a universal angle of inclination of 20-45 ° is chosen.

Materials for the construction of a hipped roof

Before approaching the issue of choosing a material, it should be noted that due to the specific design of a hipped roof, during its construction, a considerable part of the building materials will turn into waste. Therefore, the choice should be based on the financial capabilities of the customer. The most economical will be the material that consists of individual elements of a small size.

• coniferous wood (pine, larch) is usually used for rafters;
• you need to pay attention to the quality of lumber (there should be no defects that can affect the strength and durability of the roof);
• in order to avoid deformation of the roof, the moisture content of the wood should not exceed 18-22% (for measurement, you can use the device - an electric moisture meter);
• if the moisture content of lumber exceeds the permissible values, they must be dried (drying is done in the shade, under a canopy and in a draft);
• for rafters, a rectangular beam will be optimal (its cross section is determined during design);
• an alternative to a rectangular beam can be a board with a section of 50 x 100 or 50 x 200 mm (if necessary, use double boards);
• to increase the strength of a multi-pitched roof, steel fasteners are used (they allow you to keep the relative position of the rafters unchanged);
• supports for the most loaded skates can be made of metal elements;
• most high strength different combined designs.

Common types of hip roof coverings:

• Flexible tiles. It has several more names: shingle, roofing tiles, shinglas. This is not only the most economical coating option, but also the lightest (1 m 2 weighs about 8 kg). For the production of the basis of such tiles, fiberglass impregnated with bitumen is most often used. It is the base that gives the coating flexibility and elasticity. Outside flexible tile sprinkled with slate, basalt granulator or mineral chips, which not only provides protection from environmental influences, but also gives the roof a variety of shades.

• Metal tile. One of the most popular materials used for roofing. It consists of sheets of galvanized or aluzinc steel. Special layers in the composition of the metal tile prevent corrosion. Its weight is only 4-7 kg per 1 m 2, and the color palette includes up to 45 shades. In addition, metal roofing is eco-friendly material. Among the disadvantages of such a coating, it can be noted that it makes a lot of noise when it hits raindrops or hail, and when cutting, a lot of trimmings are formed.

• Ordinary tile. This is a natural material, which is a tile (flat or curly) made of baked clay. This is a durable, but rather heavy material (30-75 kg per 1 m 2). Usually clay tiles are laid on a powerful crate. To create the desired shade, you can cover with colored glaze.
• Slate sheet. This type of material is used to cover the roof with a slope of more than 12 °. If the slope angle is less, moisture may enter through the joints of the slate sheets. The use of slate allows you to significantly speed up the construction time due to the ease of installation. In addition, it is a very economical material. Of the minuses, one can note insufficient strength under mechanical stress, as well as the ability to accumulate moisture, which, with sudden changes in temperature, can lead to cracking.
• Ondulin. For the production of this roofing building material, bitumen, cellulose fibers, mineral additives (as a filler), fiberglass and resins (for strength) are used. Thanks to mineral pigments, ondulin retains its color for a long time. The cost of this material is low, it can withstand significant temperature changes, has impact resistance and moisture resistance.

How to create a pitched roof project

• choose the type of construction;
• analyze the likely loads on the rafters (taking into account the winds in a particular region, the maximum mass of snow, the degree of slope angle of the slopes);
• experienced builders recommend choosing rafters with a margin of safety of 1.4;
• calculate the pitch of the rafters;

• evaluate the bearing capacity of the truss system;
• find out if additional elements are needed when erecting rafters (for example, braces or puffs), because it is they who give the structure the necessary rigidity and strength;
• determine the coating material;
• taking into account the slope angle, calculate the height of the roof ridge.

How to calculate the load on the truss system

There are two types of loads:

• constant (which consists of the mass of the roof, lathing, rafters, insulation and girders);
• temporary (wind strength, abundance of snowfalls, payloads).

According to building codes and regulations (SNiP) in middle lane our country snow load equal to 180 kg / m 2. In case of accumulation of snow mass, this value can increase up to 400-450 kg/m 2 . With a roof slope angle of 60 ° or more, the snow load is not taken into account.

The wind load in the same region according to SNiP is 35 kg / m 2, and if the slope angle is less than 30 °, then this value is not taken into account in the calculations of the roof.

There are additional correction factors for different regions of the country.

The payload is taken into account when ceilings are suspended from trusses or it is planned to install water heating tanks, ventilation devices and other suspended objects.

When designing the truss system of the future roof, special attention should be paid to two main points:

• calculation of the strength of the rafters themselves (you need to make sure that they do not break under the influence of loads);
• calculation of the degree of possible deformation of the rafter system with the selected parameters (for example, the deflection of the rafters used for mansard roofs should not exceed 1/250 of their length).

Do-it-yourself installation of a hipped roof

Before proceeding directly to the installation of the hip roof, it is necessary to process all the wooden parts of the future structure with special fire-fighting agents. And at the places of contact of wood with concrete or brickwork lay the rolled insulating material.

Installation is carried out in the following order:

• laying a Mauerlat along the perimeter of the building, which is a support for the entire future system (consists of a bar with a section of 100 x 150 mm or 150 x 150 mm);
• the mauerlat is fastened with studs (threaded from M12 or more) or loops made of durable wire built into the wall;

• installation of a bed (the central beam of the truss system) as a support for struts and racks;
• the central beam is laid on the inner wall of the building or on special brick columns, which are located on the floor (in some cases, on the floor slabs);
• strictly vertical installation of special racks to support the ridge (the strength of the entire future roof depends on this);
• fixing the ridge beam with the help of a mowing system (be sure to use a plumb line and a rail);
• installation of diagonal rafters (the height and angle of inclination of the roof depend on them and on the ridge run). In some cases, they have to be assembled from 2 parts, and then - to unload the joint - an additional support is installed under it;

• installation of ordinary rafters is carried out based on a Mauerlat and a ridge beam (like diagonal ones, they can be reinforced with racks or struts) in increments of 600 mm;
• strictly parallel to the ordinary rafters, angular (spreaders) are installed so as to exclude their convergence in one place. The length of the sprigs will decrease as you approach the corners of the slopes;
• the installation of the crate takes place in direct proportion to the selected roof covering (it can be solid or with gaps). Under the crate, bars with a section of 50 x 50 mm or boards with a thickness of 200-250 mm are used;

• laying heat and sound insulation;
• installation of roofing material to the crate using self-tapping screws;
• installation of ridge parts (a long narrow sheet of material that is bent longitudinally at an angle); The main roofing ridge is laid along the upper edge of the roof, secondary between triangular slopes and trapezoidal;
• filing cornices and installing gutters (it is more practical to use an industrial drain system).

Based on the foregoing, it is safe to say that it is quite difficult to make a hipped roof with your own hands, but this reliable design is worth the effort and financial investment spent on it.

Four-pitched roof: video

Four-pitched roof: photo

Roofing of four slopes - what is it good for? The numerous operational advantages of this type certainly outweigh the disadvantages. Is the rafter system of a hipped roof as simple as many beginners in the construction business think? You will definitely find out soon! We will describe the important nuances and features of the stages of the construction of a hip roof in this article.

What you need to know about four-pitched truss systems?

There are two variants of four-slope roofs: hip and tent. The first type has the shape of a rectangular envelope, consisting of two main trapezoidal slopes and a ridge, and two gable (side) slopes - triangles:

A hipped roof is four identical isosceles triangles connected at one upper point (reminiscent of a tent):

Both options provide for the installation of both layered and hanging rafters which are installed using standard technologies.

How to choose the type of truss system for a 4-pitched roof?

In the absence of a central roof support, the choice is made in favor of a hanging truss system. If for each rafter you can find the upper and lower supports, then you should choose a layered structure. This option is easier and more affordable for non-professional craftsmen. It is only necessary to remember two main conditions: with a rigid fastening of the bottom and top of the stop, a reinforced Mauerlat is needed, since the thrust is transferred to it; when hinged or semi-rigid (for example, the top is hinged and the bottom is rigid or vice versa), the Mauerlat does not need to be reinforced:

The choice of one of the types of hipped roof should be determined by the shape of the house itself. For square houses tent rafters are erected, for rectangular ones - hip rafters. Also, you can find complex multi-pitched roofs of a combined type, which contain both hip and tent elements.

And hip and tent structures retain the main functions of a gable roof (for example, the possibility of arranging an attic) and look very aesthetically pleasing:

Why is a four-pitched roof more popular than a two-pitched one?

“Why the extra headache and complexity?” You ask: “After all, you can build a simple gable roof much faster and cheaper.” Here, the masters emphasize some important points in favor of choosing exactly four slopes for the roof:

1. High wind resistance. The four-pitched roof has no gables, all its planes are inclined towards the ridge. This design minimizes the impact strong wind and reduces to "0" possible destructive consequences.
2. The most successful load distribution. A multi-pitched roof withstands the maximum amount of precipitation, since gentle slopes take part of the main load. Therefore, sagging, deformation and destruction of the truss system, in this case, have a minimal probability.
3. The availability of a choice of any method of roof insulation. Straight gables require a special approach when choosing the type of roof insulation, as they are located vertically and are subject to wind blowing. The gentle slopes of hip and tent systems allow you to evenly insulate the roof with any available material.

In addition to the listed "pluses", a roof with four slopes saves heat well, can be lined with any roofing material and always has a neat appearance.

The device of the four-slope truss system

The four-pitched truss structure consists of the following elements: Mauerlat, ridge beam, central and hip rafters, slanted legs, as well as beds, racks, crossbars, struts and other reinforcing parts. Let's look at the most basic elements.

I. Mauerlat

Mauerlat is the most important detail construction, since the entire truss system rests on it. He represents a powerful wooden beam 100x200, 100x250, 100x100, 150x250, 200x200 cm. Mauerlat is made from solid high-quality wood, mainly conifers. The rafter system of a hip roof, like any multi-pitched roof, requires a solid fastening of the base bar. The order of installation of the Mauerlat in this case: the formation monolithic foundation at the end of load-bearing walls with the installation of spiers; laying waterproofing; processing and installation of Mauerlat around the perimeter of the whole house; reinforcement with anchors and other fasteners for maximum reliability of the base.

Mauerlat can be laid on the edge of the wall, or in the pocket provided for when laying bricks on the inside of the bearing walls.

II. Slanted legs

Slanted legs are called four corner rafters, which rest on the edges of the ridge and the corners of the Mauerlat. They are the longest among all the rafter legs of the system, therefore they must have a section of at least 100x150 mm for maximum rigidity.

III. ridge beam

The ridge run is a horizontal beam that connects all the rafters, the top of the rafter system. The beam must be strengthened with racks and struts. The ridge must be strictly parallel to the plane attic floor and perpendicular to the posts.

IV. rafters

Rafters for a hipped roof are divided into: central (attached to the Mauerlat and ridge); main hip (mounted on the axis of the ridge and Mauerlat); intermediate and shortened (installed on sloping legs and Mauerlat, connect the corners of the slopes).

V. Strengthening elements

Additional reinforcing elements include racks for ridge beams, crossbars or floor beams, struts of rafter legs, wind beams, etc.

Do-it-yourself rafter system for a hipped roof

Consider step by step process erection of a truss structure. For clarity, we have chosen the most popular option - a hip roof. The hip roof truss system, the diagram of which, step by step, is presented to your attention below:

Step I: Create a project

To depict your version of the hip roof in the drawing, it is necessary to calculate the height, length, slopes of the slopes and the roof area. This is necessary for the clear and high-quality implementation of the project and the selection the right amount Supplies:

Calculations should begin with the choice of the angle of the roof slopes. The optimal slope is considered to be an angle of 20-450. The slope value should correspond to the climatic features of the region. So, in particularly windy areas, the slope should be made minimal, and for areas where precipitation is frequent and abundant, the steepest slope angle is necessary. In addition to the weather, you need to consider roofing material that you plan to use. For a soft roof, the degree of inclination should be less, for a hard one - more.

And another small but important nuance on this issue - it is better to make the slope angle the same for all four slopes. So the load will be distributed evenly, and the structure will be as stable as possible, and the aesthetic appeal will remain “on top”.

Now that we know the slope and width of the house, we can use some simple math to calculate the height of the ridge, the length of the rafters, the posts, and other details of the truss system. When calculating the length of the rafters, do not forget to take into account the cornice overhang (as a rule, its length is 40-50 cm).

The roof area for the purchase of the required amount of roofing material is calculated as the sum of the areas of all the slopes of the structure.

How to draw up a roof drawing?

• We select the scale of the drawing and transfer the dimensions of the house on a scale to a sheet of paper;
• Next, we transfer the selected dimensions of our roof to the diagram: the height of the ridge, its length, the number and size of the rafter legs, struts, racks and all the details, in accordance with the calculations made earlier;
• Now you can count all the necessary materials and start looking for them.

Step II: Getting Ready

For the construction of the roof frame you will need standard tools and equipment: drills, screwdriver, jigsaws, hammers, chisels, etc. We already know required amount materials for the truss system, so we can make their purchase. The lumber for the frame must be solid, free of cracks, wormholes, a light shade, no gray or yellow plaque smell like fresh wood. Wet forest should not be laid on the roof immediately, it must be dried, treated with an antiseptic solution and dried again. Wood moisture should not exceed 20%.

Step III: Mounting the Mauerlat

Mauerlat is the basic part of the entire truss system. It transfers spacer loads to the load-bearing walls of the house. Installing a Mauerlat for a hipped roof is no different from similar structures with two or one slope. This process is described in as much detail as possible in our previous articles.

The base beam, the parameters of which are described above, is placed on the armored belt and high-quality waterproofing. If it is necessary to connect the Mauerlat, then the bars are cut into half the section and overlapped using strong fasteners.

Step IV: Laying the decks or floor beams

If there are load-bearing walls inside the house, then it is necessary to install beds on their ends - the basis for the supporting racks of the roofing system. If there are no more load-bearing floors in the house, then the attic floor is covered with reinforced beams, on which the supports for the roof are subsequently installed, and then the attic floor pie is laid.

Beams must have a cross section of at least 100x200 mm. The step between them is 60 cm. You can slightly adjust this figure, depending on the features of your home. The distance between the extreme beams and the Mauerlat should not be less than 90 cm. This distance is used for mounting the semi-beams of the cornice overhang (removal). The extensions are attached to the two extreme beams with the help of strong anchors and reinforced metal corners.

Step V: Installation of support posts, purlins and ridge

Racks are an important detail for maintaining the structure, they redistribute the weight of the truss system to the beds or floor beams. Racks are installed strictly perpendicular to the plane of the beds. AT four-slope systems supports are installed under a ridge beam (hip roof) or under corner rafters (hip roof):

Racks must be securely attached to the base with metal plates and reinforced corners. Runs are installed as an additional support for racks. In a hipped roof, the girders are rectangular in shape, and for the hips, these are ordinary ridge girders.

After we have made sure that the supports are installed correctly (with the help of a meter and a level), we can fix the upper ridge beam. It is mounted on vertical racks and reinforced with reliable metal fasteners (plates, corners, anchors and self-tapping screws). Now we take on the corner offsets:

Step VI: Mounting the rafters

First you need to install the side rafters, which are based on the ridge beam and the Mauerlat (or are fixed with the extension). To do this, you need to make a template rafter with the appropriate cuts. We attach the rafter leg to the ridge, mark the place washed down with a pencil, then mark the place where the rafters washed down for docking with the Mauerlat and make gashes. Attach the rafter to the supports again to make sure that the docking is correct and correct the shortcomings. Now this sample can be used for the manufacture of all side rafters. Installation of the rafter legs of the main slopes is carried out according to general rules described in the device of the gable truss system (see article and video).

The diagonal (corner) rafters are mounted next. Their upper edge is mounted on a rack and joined with the edge of the ridge beam. Before this, measurements are taken and the corresponding cuts of the rafter legs are made. The lower end of the diagonals is fixed in the corners of the Mauerlat:

Since the diagonal rafters are longer than all the other legs, they require additional support. This function is performed by sprengels - support beams that are installed under each diagonal leg, in its lower quarter (this is where the greatest load occurs). Sprengel, as well as ridge racks, are installed on the supporting corner beams located in the plane of the floor beams.

Between the corner ribs, the space is filled with auxiliary rafter legs - sprigs. Their lower part rests on the Mauerlat, and the upper part rests on the diagonal rafter leg. The step between the sprigs should be equal to the step between the side rafters (50-150 cm).

Step VII: Lathing

It remains to complete the final stage of the formation of the roofing skeleton - the installation of the crate. These are boards or bars 50x50 mm, which are attached to the rafters parallel to the ridge run and the Mauerlat. The step of the boards of the crate is 50-60 cm. This is quite enough for laying the roofing pie. When soft roof, the crate is laid in 2 layers (counter-crate and crate).

Finally, a few videos:

So, we have described the installation of the hipped roof truss system, its basic principles, and even delved a little into some of the nuances. Hip and tent structures - although not the easiest, but quite feasible option for every novice master. Especially if he has good assistants. We wish you success in your work!

A four-pitched hip roof is considered a rather complex and material-intensive structure, which few homeowners undertake to build with their own hands. But if you decide to independent construction, first go through the preparatory path - study the theoretical materials, including those presented in this publication. Then assemble the layout of the truss system large sizes to deal with the nodes, the nuances of their manufacture and the calculation of the amount of timber. So, let’s take the first step and consider…

Design features

This type of roofing, shown in the photo, is a common ridge roof but without vertical gables. Instead, 2 additional slopes are made on the sides of the building - hips with a different slope angle.

Reference. If all 4 planes are tilted at the same angle, then another type of roof will be obtained - hipped roof. Since its slopes converge at one point in the form of a dome, there is no ridge as such.

The hip roof truss system consists of the following elements (shown in the diagram):

• mauerlat, bed - a powerful strapping beam mounted on the upper plane of the walls along the perimeter of the building and internal partitions;
• roofing slopes are formed due to inclined beams installed with a calculated interval - rafter legs;
• together with stiffening elements - puffs, racks and braces - the rafters form roof trusses;
• ridge run - a beam connecting the upper points of the trusses;
• in some designs, the lower part of the rafter legs is lengthened due to an additional detail - a filly.

Along the line of convergence of the planes, hip rafters are installed, resting on the corners of the building. Their slope coincides with the angle of the main slopes. But the end rafter legs, called sprigs, form steeper or gentler slopes on the sides of the house.

In the construction of 4-pitched roofs, 2 types of trusses are used - hanging and layered. In the first, the lower belt (puff) relies only on the external fences of a private house, therefore it is irrational to put them on too long spans due to the increased consumption of materials for stiffeners. Hanging truss device, see the drawing:

The advantage of layered structures is the ability to rely on capital interior partition and overlapping of large spans without increasing material consumption. Roofing beginners should pay attention to these trusses, as they are more reliable and easier to install.

If it is planned to arrange a residential attic on the attic floor, then the slope of the main slopes increases, and the farm receives 2 supports in the form of racks that form the walls of the room. It is customary to put these parts on beds or floor beams. wooden house. The ceilings of the attic room are formed thanks to horizontal puffs connecting the rafters on top, as done in the diagram:

Hip roof device step by step

Like any serious structure, a hip roof is built by hand in several stages:

1. Creation of a project with the calculation of load-bearing structures.
2. Logging and other roofing materials.
3. Installation of the truss system.
4. Laying a coating with insulation (if necessary).

Design advice. So that you do not have to worry about the reliability of the building, it is strongly recommended to entrust the implementation design work engineers, regardless of financial costs. They will calculate all the parameters - the installation step of the rafters, their cross section, the number of struts and puffs in accordance with weather conditions in your area.

Above, as an example, a drawing of a hipped roof with layered trusses covering 2 spans of 4.5 m is shown. The length of the main rafter legs is 6 m, the height of the ridge is 4 m, the angle of inclination is 41 °. This design can be taken as a basis if the width of the building does not exceed that indicated on the drawing (9 meters). Please note important point: the more the hips are tilted, the greater the load experienced by the sprigs and the central ridge knot, where they rest. In this example, the hips are best placed at an angle of 45-50 °.

The most difficult thing in the construction of hip roofs - correct installation knots for splicing corner rafters with Mauerlat and the upper belt of trusses in different designs. This is another reason to consult with designers who design individual junctions. So that you understand what we are talking about, we present drawings of the upper support node, where the hip rafter leg adjoins the ridge.

Some designs do not provide for the manufacture and installation of a ridge run between trusses. Then the hip ribs are attached to the puff and additional struts, as the drawing prescribes:

The lower support node of the leg on the Mauerlat and the splicing of the rafters looks somewhat simpler, although in reality it requires careful sawing of the boards at various angles, which is reflected in the diagram.

For a visual overview of more complex system, where the hip is combined with the bay window, we suggest watching the training video:

Lumber selection

Before you make a hip roof truss system, you should choose high-quality and dried wood. In terms of price-quality ratio, the most suitable option- coniferous tree - spruce, larch or pine. Pronounced knotiness, rot and traces of vital activity of insect pests are unacceptable.

We present the most "running" sizes of lumber used for phased construction hip roofs:

• main rafter - single board 50 x 200 mm or double 40 x 150 mm;
• mauerlat: minimum section - 100 x 150 mm, optimal - 20 x 20 cm;
• narozhniki - board 5 x 15 cm;
• runs - timber 50 x 150 or 50 x 200 mm;
• struts, crossbars - a board with a thickness of 25 to 50 mm;
• racks - a bar 5 x 10 cm.

A set of mounting plates and corners will also not be superfluous

Note. If roofing structures are calculated for you by design engineers, then they will also draw up a specification of all materials with dimensions.

On the crate for laying corrugated board or metal tiles, boards with a thickness of 25-32 mm are traditionally used, and bars 5 x 5 cm are used on the counter-lattice.

Mounting the strapping beam on the walls

Unlike gable roofs, where the Mauerlat is installed on the side walls, under the hips, the strapping is done around the entire perimeter. An exception is frame, log and lumber houses, where the upper wall crossbar or the last tier of logs acts as a Mauerlat. Then grooves are made in it, where the rafter legs are inserted, as shown in the photo.

On the walls of light cellular stone - aerated concrete and foam block - before laying the strapping, a reinforcing reinforced concrete belt is arranged. Mounting studs are embedded in it, on which a strapping beam is subsequently put on. Step by step the order of work looks like this:

1. Installation of panel formwork, knitting of the reinforcing cage with embedded parts and pouring the belt with M200 concrete mix.
2. Waterproofing the concrete surface with roofing felt or bituminous primer.
3. Installation of the beam and its fixation on the studs.

Mauerlat corner connections are made by cutting into half a tree. In the same way, the timber grows in length if standard size 6 m is not enough. Also, horizontal struts are made in the corners or iron brackets are driven in, which do not allow the bars to move apart under the load of the main and hip rafters.

Advice. Be sure to treat all wooden parts with an antiseptic and flame retardant. One protects the wood from decay, and the second increases its fire resistance.

Assembling the truss system

Roof trusses of large sizes are usually mounted on site, because it will take twice as many workers to lift them from the ground. AT wooden houses first of all, all the beams of the ceiling are installed, and temporary flooring is arranged on them. For the installation of a high ridge, scaffolding will also be needed.

The phased assembly of the hip roof structure is carried out in the following order:

1. As with the construction of a gable roof, the first step is to place the central supports, where the ridge run is attached.
2. The installation of the main rafters is carried out, which are cut from above and below at the desired angle. On the ridge, the oncoming rafter legs are brought out into one plane and fastened with steel plates on self-tapping screws (yellow, not black). Beams are fixed to the Mauerlat with corners.
3. After installing the main trusses, tighten them with crossbars and struts according to the drawings, using bolts for fastening.
4. Install the ribs - the extreme hip rafters. Their connection with the ridge and strapping timber is carried out according to one of the schemes proposed above.
5. Saw off and nail the sprigs to the frame. Each of them is cut at different angles, determined by measuring at 4 points (along each edge of the board).
6. If necessary, fix the fillies to provide an overhang of 0.5 m, and hem the eaves with boards.

Advice. Since the hip ribs are very long, they must be increased and additional supports should be placed. Make the joint near the ridge, where the load on the roof is less, and mount the supports closer to the Mauerlat.

How the elements of the hip structure are attached in reality, see the following video:

Laying the finish coat

This final operation is performed by traditional technology, providing for ventilation of the under-roof space and the installation of a waterproofing layer from a diffusion membrane. The latter does not allow moisture to penetrate from the street into the attic, at the same time, the film freely passes water vapor out. There is only one difference from covering ordinary gable roofs: additional flashings are placed along the fracture lines (on the hip ribs).

The coating material is laid in the following order:

1. The truss system is completely covered diffusion membrane. The canvases are rolled out horizontally with an overlap of at least 100 mm, starting from the bottom. Joints must be sealed with adhesive tape.
2. The film is nailed to the outer edges of the rafters through the bars of the counter-lattice with a section of 5 x 5 cm, providing ventilation under the metal tile or other material.
3. Perpendicular to the direction of the rafter legs, the boards of the crate are nailed. The installation interval depends on the selected coating, and for soft tiles, the packing is continuous.
4. Roofing material and all fittings are mounted on the ends of the roof, as well as around ventilation and chimneys.

Note. The bars of the counter-lattice, nailed to the rafters, should not become an obstacle to the ventilation air. Therefore, they are specially shortened to a length of 2-3 m and nailed with a gap of 5-10 cm between adjacent elements.

The insulation of the hip roof is done both during the installation of the coating and after it, the main thing is to assemble the correct “pie” shown in the diagram. In the first case, the mineral wool is laid from above, under the waterproofing, and in the second - from the inside.

Conclusion

It must be understood that the advantages of a hip roof over a gable roof are few. First, she is beautiful architectural solution, and secondly, it reduces the wind load on the side facades of a private house. But for this, the homeowner will have to pay for the increased consumption of timber and the complexity of construction, and hence the time costs. Hence the advice: do not rush into a decision and think carefully about the pros and cons. But if you have already taken it, then do the roofing with high quality, for yourself, without saving money on consultations with civil engineers.

Structural engineer with over 8 years experience in construction.
Graduated from East Ukrainian National University. Vladimir Dal with a degree in Electronic Industry Equipment in 2011.

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