The space under the roof as a living space was first used in France in the 17th century. Popularized houses with an attic roof Francois Mansart, in whose honor they were named. Parisians immediately appreciated the idea, especially the opportunity to circumvent the communal law, according to which the state withdrew fees for each floor, which the attic was not. The fashion for the attic gradually spread throughout the world, especially this type of architecture was liked by the inhabitants of Europe and America.
Until the Soviet era, such superstructures were unclaimed; during the existence of the superpower, SNiPs and GOSTs were developed to equip such structures, but they have been widely used only recently. At the same time, experts argue about their feasibility, some argue for, others refute them, prove that the savings on construction are negligible, if not completely absent, and the concept of beauty is purely individual.
According to external signs, the attic and attic are similar, but it is wrong to apply one name to another. Firstly, it is a heated room, secondly, it is residential, thirdly, it is brought into the project, registered as a functional part of the house, to which all the necessary communications are connected. The main feature is that the roof at the same time serves as a roof, ceiling and walls.
The main difference between the attic floor and the attic space is the minimum wall height of one and a half meters, this follows from the definitions of this design in regulatory documents, for example, SNiP 2.08.02-89 Appendix 2, SP 118.13330.2012 Appendix B, SNiP 31-01-2003, from other sources.
The main advantages of such a structure include:
Aesthetic properties and design. Using a higher, constructive roof, equipped with windows, gives the building a finished look, makes it original.
Savings on building materials. The weight of the structure is much less than a full floor, so there is no need to make a reinforced foundation.
The possibility of completion. If there is a good foundation, you can convert the finished structure, increase its living space due to the attic.
Construction speed. Compared to two-story buildings, attic roof construction takes less time.
Maximum use of the area. Allows you to use empty, non-exploitable space.
Great view. At night, you can observe the sky, during the day for the movement of clouds.
The design is not without its drawbacks, considering which developers sometimes abandon their plans for its equipment:
Sloping ceilings. Reducing the used area, it is difficult to approach a low wall, special furniture will be required to arrange the interior space.
Soundproofing. Even when using the best materials, it will not be possible to completely isolate the sound from falling drops of rain, hail, blowing in the wind.
Heating costs. Compared to the usual floor, heat losses here increase by 30-40%, which will require large heating costs in the winter.
Maintainability. The roofing cake is covered with a coating on top, with a layer of insulation and finish on the bottom. In order to inspect the condition of the roof, you will have to dismantle the lining.
Limited selection of building materials. The tree, which is part of the rafter system, changes its characteristics throughout the entire period of operation, respectively, some shifts transmitted for decoration are not excluded.
Heat and waterproofing. For a comfortable and cozy stay, it is necessary to perform complex work on insulation and protection from moisture.
Sophisticated device. It is problematic to do all the calculations correctly, to make a drawing with your own hands, the help of specialists will be required.
Building requirements
Any construction begins with the preparation of the project, which takes into account all the requirements of existing regulatory documents. The attic is no exception. When planning it, you should adhere to the provisions specified in SNiP 2.08.01-89, SNiP 21-01-97, SNiP 23-05-95, namely:
it is necessary to maintain a minimum ceiling height with different slopes;
take into account the provisions for the distribution of living space, the established minimum values for the area of rooms;
arrangement of the flight of stairs;
strict observance of fire safety norms and rules;
providing natural light in the room;
safe wiring of all communications connecting the attic with the rest of the house;
compliance with safety regulations during work.
When designing a new house, all the norms are easy to take into account, but when re-equipping an existing residential building, it is not always possible to make a roof space. This cannot be done if the foundation is not strong enough, which is not able to withstand additional loads, and also if for some reason it is not possible to make the ceiling height at the highest point not less than 2.5 m.
Rafter system: features, varieties and design
The rafter system can be called the skeleton of any pitched roof, it is a frame for laying and holding the building materials used in arranging the roofing pie. For the attic floor, it still acts as a wall and floor. Strength, reliability, aesthetics and stylistic direction, the life of the entire device depends on it. Based on structural features, among all the structures, two main types can be distinguished:
Hanging.
The hairy.
Each individual type is characterized by its own distinctive features that are unique to it. The choice of a particular model depends on many factors, which include:
dimensions of the building;
weight of roofing, insulation, finishing material;
the presence of internal capital partitions;
geometric shapes of the roof;
option of the selected building material for the rafters themselves;
climatic zone, atmospheric loads in the form of snow, rain, winds;
financial opportunities of the developer.
Hanging
The definition of a variety of a system is carried out at the design stage of a building. However, it is not difficult to make a choice, the hanging structure will become an uncontested option for structures in which internal capital walls-partitions are not provided. Their main feature is that they rely solely on two opposing external load-bearing partitions.
It is better to install the structures in a house whose distance between the side walls does not exceed 6 m. In this case, the simplest truss is constructed, consisting of two rafters connected from above at a certain angle. Bottom horizontally, it is strengthened by puffs consisting of wooden beams. For these purposes, you can also use metal profile bars, which are called heavy. Such a device allows to reduce the spacer load on the reference points.
Puffs located at the base of the rafters serve as the ceiling of the lower floor, the attic floor. With an increase in the width between the partitions to 9 m, a headstock and a collar are added to the farm, up to 14 m - an additional device of struts and a headstock. When choosing this system, do not forget that the entire load falls on only two fulcrum, so you should reduce the weight of the roof due to roofing building materials.
Pop
This type of structure is mounted in buildings with internal load-bearing walls. Compared with the previous version, the device and installation of this type is much simpler. In this case, the load distribution occurs evenly on all supports. The system consists of a Mauerlat (bars located on the upper end part of the external load-bearing walls), a horizontal lay, a ridge run fixed to vertical struts, struts, rafters and lathing.
The overhead system is most often used in the construction of residential buildings. It can have different designs, among which there are:
Rampless rafters without backwater. They are characterized by the presence of strict and free fastening. They are divided into three subspecies:
the lower part of the rafters is attached strictly, the top is free;
the bottom of the rafter leg is fixed on the sliding elements, the top is tight;
bottom - sliding, top - firmly pressed against the ridge with bars.
Spacer rafters without backwater. This is the middle option between the roof and hanging device, where the ridge does not fully perform its functions.
Rafters with struts. These are both of the species discussed above, with retaining elements supporting the rafter legs.
With rafters. In this scheme, the skate is completely absent. This option is suitable for buildings with two load-bearing partitions located inside.
Materials for the manufacture of rafter systems
For the construction of the rafter system, the number of materials used in the work is limited. You can choose between metal and wood, combine both types of raw materials. Reinforced concrete structures are also found, but they are not used in the construction of suburban buildings. Most developers prefer natural wood. It is easier to work with, it is an environmentally friendly product.
Wooden rafters can be safely called a classic look. For their manufacture, solid logs, boards, glued beams are used. When choosing, it is advisable to pay attention to the quality of the wood, as well as to the fact that coniferous species were cut down in winter, deciduous in summer. Experts recommend purchasing the following species: larch, oak, pine, spruce. The first two types are the most durable, but difficult to process.
A very important point is the grade of the tree. For Mauerlat, bedding, skating, it is best to use oak or larch of the highest quality.Rafter legs, racks can be made from coniferous options, both first and second grade, and even the third is suitable for struts. When calculating the building materials of a standard system, 75% is usually assigned to wood of the first grade, 25% to the second.
All wooden blanks are divided into three main types: raw, semi-dry, dry. Experts recommend choosing only the last option for installation work, which will help to avoid subsequently deformation of the components.
Also, for the construction of a private structure, metal is used. Most often they resort to it if necessary to organize an overlap of a length of 10 meters or more. In this case, the wooden beam is replaced by a profile pipe. The connection of the elements is carried out by welding. There are combined options when the bed, Mauerlat, ridge run, racks are made of metal, all other parts are made of wood.
Mansard roof structural elements
The structure of each roof is different, it all depends on the purpose of the roof space. First of all, the seasonality of the attic is taken into account. The most complete roofing cake is constructed when the room will be used constantly. It includes the following components:
Roofing building material: metal tile, corrugated board, flexible bitumen, composite, natural, ceramic, cement-sand tile.
Ventilation system: natural, forced, forced and exhaust, combined.
Waterproofing: perforated film, film-membranes made of polymers, polymer-bitumen coating.
Each of these layers is very important, without them it is impossible to equip a room comfortable for living, to decorate the interior, to make a beautiful exterior cladding. All these elements are mounted on the rafter system, which consists of: Mauerlat, ridge run, support racks, battens, counter battens, bed rest, rafters, struts.
Mounting technology
It is quite difficult for an inexperienced developer who does not know all the nuances to prepare a project, draw a drawing, indicating all necessary. Even experienced architects and builders who are familiar with such a construct can make a mistake. Violation of the technology, the slightest inaccuracy in the organization of the ventilation system, hydro-, thermal insulation, will lead to irreparable consequences, will lead to expensive repairs.
Having made a firm decision to build a house with a mansard roof, you should initially familiarize yourself with regulatory documents, study the design features of such structures, plan correctly, make a rafter system calculation, choose the most suitable materials used for work, and also look at ready-made examples. If you are not completely sure of your own knowledge and skills, it is better to seek help from specialists who will either do the work themselves or help the owner with advice.
Project preparation
Any serious construction activities begin with design. This issue should be taken responsibly, the strength, functionality, aesthetics, and durability of the structure depend on it. When drawing up the plan, it is necessary to rely on the current norms and rules, namely: SNiP 2.08.02-89, SP 20.13330.2016 (SNiP 2.01.07-85), SNiP 23-05-95, SNiP 21-01-97, SP 70.13330 .2012. Given these documents, make up the project, which includes:
The scheme of the rafter system with the display of all elements.
Layout of hydro-, steam-, thermal insulation.
Drawing showing the placement of roofing materials.
Type of interior decoration.
A general drawing of a roofing cake with an indication of the slope of the slope, the height of the roof.
Sketch with the arrangement of windows to provide natural light.
Placement of drainpipes, ventilation, chimney.
Laying artificial lighting.
Heating system.
Sewer communications, pipe and drain connections.
The internal layout of the space.
Calculation of the rafter system
When designing the attic floor, it is very important not to make mistakes. It is necessary to correctly calculate the rafter system, which depends on the type of structure used in the work of materials, including finishing. The easiest way is to make the necessary calculations using special programs by downloading them online, using online projects. Such actions can be done with your own hands, for this you need to consider the following points:
determine the type of structure: hanging, layered;
know the length and width of the building;
to estimate the level of seasonal precipitation, for this it is enough to drive in a query in any search engine: precipitation map “specific region”, the angle of the roof will depend on this parameter;
determine the wind load (by analogy with the previous option);
distance between parts.
Online calculators posted on the Internet do not completely solve the issue. The results obtained are difficult to verify on their own, to verify their reliability. Only experienced engineers can do the calculations. You can try it yourself, but to calculate the parameters you should familiarize yourself with the exact methods, for example, SNiP II-25-80, TKP 45-5.05-146-2009.
Frame manufacturing
For clarity, consider a small workshop on installing a sloping roof. The whole process step by step is as follows:
A ruberoid is rolled onto the end part of the bearing walls.
A timber is installed over the entire perimeter of the structure, which is a Mauerlat, with the help of anchors it is fixed to the partition.
Overlapping beams consisting of three boards are knocked down, two of which are equal in width to the same parameter of the building, and one of them is 1 meter wider, protrudes 0.5 m on each side of the walls.
Downed logs are laid along the span with an interval of 0.5 m, on both sides they are attached to the Mauerlat using self-tapping screws and metal corners.
At the Mauerlat level, the support beams along both partitions are installed and fixed on the floor beams in a level strictly perpendicularly. Elements located on parallel partitions, with the upper ends connected by a board.
The protruding boards from the floor beams using jibs are connected to the upper ends of the support beams at a certain angle, metal plates are used for fixing.
A waterproofing is laid on top of the jibs, on top of which there is a counter battens and a battens.
From the top in the center of the structure, the skate is placed at the desired height to ensure an appropriate angle of inclination.
The rafters are installed, which are joined together over the ridge run.
Next, perform the steps described in paragraph 7.
Proceed to the formation of the frontal part. To do this, set outs fixed on one side to the nearest floor beam, in the middle to the front Mauerlat. The distance between them and the ledge outside the wall is 0.5 m.
The outriggers are equipped with front struts taking into account the planned middle of the window.
The next step will be covering the frame with roofing materials.
Warming and vapor barrier
After installing the rafter system, the outer crate and the counter-crate, they proceed to the insulation of the structure. Experts recommend using mineral wool, which goes well with wood, leaks moisture, and allows wood to breathe. Also, polystyrene plates, polyurethane foam, ecowool are used for these purposes. The layer thickness is usually in the range of 20-25 cm, but sometimes reaches 30 cm.The installation process of the insulation is as follows:
Corresponding to the size parts are cut out of the material selected for work.
Insulation is installed between the rafters.
If the width of the rafter legs is not enough, a counter-lattice is stuffed on top, the second level of heat-insulating materials is laid.
Mineral wool is covered with vapor barrier on top. For this, single-layer, multi-layer, reflective films are used.
On top of the resulting structure, the crate is nailed.
Perform the interior decoration of drywall, MDF, PVC, other building materials.
Installation of the crate
Roofing pie has a rather complex system. The counter and crate are very important components of the overall design. The first element is a fairly thin counter-rails, which are responsible for providing the roof with ventilation, the second is the basis for fixing the roofing and finishing material.
External installation work begins after laying a layer of waterproofing on the rafters. The installation of counter-racks does not cause difficulties, they are attached with the same step as the rafters. The lattice is fixed on top. Depending on the building material used to cover it, it is available in two ways:
Solid. Boards are laid close to each other. This option is used for bituminous tiles, corrugated board.
Sparse. The distance between the boards is 50 - 60 cm. Suitable for slate and tile.
Finish Options
When choosing a suitable roofing material, several points are taken into account: aesthetic, functional. On the one hand, it is necessary to emphasize the design of the building, its style, on the other hand, to provide reliable protection of the roofing cake from atmospheric precipitation. It also takes into account the weight of the coating, its durability. Manufacturers of building materials produce many different options that satisfy different customer requirements, among which are:
Metal and corrugated board.In fact, it is a steel sheet with a different texture, covered with several additional layers: zinc, anti-corrosion, primer, polymer, protective. This material is in demand in the decoration of private houses with an attic.
Soft roof. For work, use flexible tiles (shingles), roll coatings, membranes. These building materials easily take the desired shape, are not subject to corrosion. The service life reaches 50 years.
Copper roof. This is the most expensive option of all. Its service life is 150-200 years. She does not need repair and maintenance.
Natural (ceramic, cement-sand) tiles. This material heats up rather slowly and cools, which ensures the preservation of heat in the winter, and in the summer - cool. It is characterized by good sound insulation.
Varieties of attic roofs
The main types of attic structures differ from each other in design features. They can be divided into two large groups - single-level and two-level. The former are combined with a roof of any type (broken, gable), the latter are mounted on mixed supports, designed for rooms at different levels.
Single slope
A simple roof device due to the lack of a ridge and the difficulties with its arrangement. Such designs have a non-standard look. Mauerlat is mounted on opposite walls of different heights and the beams are fixed, a bevel is formed with an inclination angle of 30-45 ° С. It is impossible to make it smaller, since there may be difficulties with the outflow of snow and rain water, which will lead to additional load on the supports.
The sloping roof allows for the installation of large windows on the high wall of the attic floor. The simple and low-cost design has several significant drawbacks. The room on the narrowing side will be inconvenient to use, there will be restrictions in the choice of its purpose. Before choosing this option for construction, it is necessary to consider the efficiency of using the room.
For the construction of a shed roof, several rafters will be required. They are laid on the walls in increments of 1 meter.Between them lay insulation and waterproofing material. Correct installation is a guarantee of reducing heat costs to a minimum.
Gable
The most common, economical roof option. It is easy to install and maintain. The traditional form is flat gable, suitable for single-story construction, looks like a classic triangle.
Due to the design features - the presence of slopes on both sides, there are difficulties with the design of the interior in the living room (it is impossible to arrange high furniture, a feeling of tightness). The rational use of corners will help to solve the problem, for example, for a bed or changing the plan at the initial stage of construction - raising the rafter system to the desired height.
Broken line
Each slope is made of two parts fastened together at a certain angle. Such a break allows you to make the attic room comfortable. The identical size of the base of the house and the sloping roof can increase the living space of the attic floor by 50%, in contrast to a simple gable structure.
Useful area increase the lower parts, the steep top reduces the cost of roofing materials. High ceilings in rooms under such a roof give a feeling of freedom and space.
The structure of the sloping roof is complex, since it requires the creation of a massive rafter frame. It is more suitable for square houses. Particular attention must be paid to drawing up the drawing. The durability and reliability of a sloping roof will depend on the accuracy of the calculations made. The following factors must be considered:
Weight of roofing material;
Load of insulation components;
Crate step, rafters;
The weight of the lattice structure and counter-lattice;
Slope angle;
The length of the slopes from the ridge to the eaves;
Probable loads (seasonal, temporary and others).
With remote consoles
A popular option for a mansard roof, despite the complexity of the design.The main advantage is the ability to expand the space by shifting to the edge of one of the sides of the room. The design allows you to push the external vertical wall outside the facade and make large windows in it.
In addition to the advantages, roofs with remote consoles have significant drawbacks - the complexity of installation, the high cost of building materials. On one side is a large pitched plane, and on the other, there are already two of them. Under a wide ledge, you can make a carport or porch, a covered terrace.
Two-level
In houses with a high roof, more than 5 meters, it is possible to equip a multi-level platform on the attic floor. It can be two separate rooms connected by a staircase, a large studio with steps, a dressing room from several compartments.
Separately, such an add-in is not made. Two-level rooms must be planned in advance, at the design stage, always taking into account the features of the foundation. The scheme of the rafter system is complex, it is developed taking into account the asymmetric arrangement of the slopes.
It is especially necessary to make calculations for the second level of the attic, since it will be based on columns. Using the advantage of panoramic lighting of such structures, you can create greenhouses, conservatories in the attic.
Multi-gable roof
It differs from standard options by the presence of several pediments (3 or more). The roof looks presentable and massive, thanks to several departments, especially if the finish matches the architectural style.
The multi-pliers system consists of separate slopes connected in one structure. The part of the wall between the slopes is called the forceps. Conventional mansard roofs have only two of them. Products from several pediments can be of varying complexity and are made in different variations. The place for an extension can be allocated, the part of a wall for a panoramic window is increased.
Installation of such a roof is complicated and costly.Building materials will require much more than the construction of a standard system. Due to the great mercy and complex configuration, a large number of scraps and residues of roofing materials remain. But such negative aspects more than compensate for the following advantages of multi-forceps systems:
High bearing capacity;
High resistance to external influences (gust of wind, snowfall, bright sun);
Ease of maintenance. Due to the large slope of the slopes, rain water and garbage do not linger on them;
High skate. An opportunity to equip living rooms under it.
Four-Slope
The roof system has four slopes. They can be the same as the tent roof, pairwise identical. In the first case, it will not be possible to provide daylight access through standard window structures; installation of attic openings and anti-aircraft lamps will be required.
The design of any type of gable roof must be approached responsibly. Designs have many junctions, require reliable walls, a solid foundation. Depending on the design of the cottage, the design features of the site, choose the type of roof of the main building.
Hip
Such a roof consists of two pairs of slopes trapezoidal and triangular. The ridge in the upper part is 2 times shorter or 3/4 shorter than the house itself. The design will be durable and outwardly attractive with proper design and compliance with certain requirements for membranes and beams.
The hip, half-hip roof has an interesting structure, which positively affects the perception of the ceiling inside the room. He seems taller. The advantage of a hip roof is as follows:
Visually increases the interior space, leaving the view from the facade unchanged;
The ability to create panoramic lighting;
Resistance to winds due to the special shape of the ramps;
High rigidity design is durable and safe.
Hipped
It is being built over a building with equilateral bearing walls, with a square type of foundation. All ramps are the same size. The main difference between such a roof is the complete absence of a ridge. Its function is performed by the central support, at the top of which the rafters are closed. The hipped roof is performed in various versions, but for all types, there must be sprigs, Mauerlat, lying, vertical rack, sloping rafters.
The absence of gables reduces the design cost of the structure, there is no need to load the foundation. There is a uniform heating of the roof and the departure of melt water. Among the shortcomings, one can distinguish a complex rafter system. Any node from a large number of elements can lose stability.
Asymmetric
An original, non-traditional solution has a lot of advantages associated not only with external characteristics. Correctly located slopes solve the problems of energy saving, compactness, saving building materials. Such roofs are erected over incomplete upper floors and attics, the area of which is less than the first level.
Stylish, original design is convenient and easy to design. Such a house can be linked with any relief and landscape design. On the attic floor under an asymmetric roof, it is convenient to install technological equipment - ventilation, heating systems, solar panels. The following types of roofs are popular:
Plain asymmetric;
Partially broken;
With a skate in the center;
With the displacement of the skate.
With the cuckoo
A small ledge on the attic - “cuckoo”, has its own architectural system. The element is paired with the main roof, covered with the same roof. Before you include it in the project, you should make sure of such a need, since it will reduce the strength of the rafter system, it can cause water to enter the attic.
"Cuckoo" on the roof performs not only decorative functions.The design makes it possible to add one or more windows, increases the practicality of the room. Additional area can be used for any domestic purposes. Such an extension can be done with your own hands in the following variations:
Arched;
Hip
With one or two slopes.
L-shaped
The sequence of construction of the L-shaped roof will differ depending on the width of the gables and their correspondence to each other. The construction system consists of two gable roofs that crash into each other. They are connected at an angle of 90 ° C in the most complex unit.
The roof of the L-shaped building can be of varying complexity. The end walls of a simple design have the same width, complex pediments have different dimensions. The docking process in this case is complicated by the different heights of the skates. Often such roofs are made broken, with different heights of gable halves.
The use of SIP panels for the attic roof
The formation of the roof over the attic from SIP panels is the most convenient way. According to the project created taking into account such a technique, the roof does not need to be additionally insulated. For exterior decoration, you can use any material. The roof will in any case be solid and even.
If you have the right tool and certain skills, you can easily build a simple roof or a complex configuration with your own hands, with several windows and skates of different sizes. A warm roof made of SIP panels can dramatically improve living conditions in an existing building.
When drawing up the project, it is necessary to take into account possible difficulties in the construction of the structure. The roof will have many joints, which can adversely affect its strength. Due to the large number of construct residues, financial costs will increase. To create supporting frames, more timber and other auxiliary material will be required.
Design: Attic interior decoration
You can create a budget, functional interior on the attic with various materials. More often, the walls are sheathed with drywall, lining, plywood. Modern design allows you to make a room above the main house in any architectural directions.
The interior design of the attic will depend on the purpose of the room. If the house is built of wood, the interior should be made of the same material. Eco style is the most winning option. Convert a simple attic to any room. From the top floor you will get a well-lit study, a spacious dressing room, a relaxation room, a playroom for children.
The usual high furniture for the attic will not work. It should be only the most necessary items. Bulky sofas will look ridiculous in a room with low ceilings. Modular designs, low poufs will look good.
Conclusion
The mansard roof has both advantages and disadvantages. During the preparation of the project, it is necessary to take into account all the nuances in order to finally make sure of its necessity. Just remodeling the attic will not be enough, it needs to be re-planned, to make a reliable roof and thermal insulation.
The space under the roof as a living space was first used in France in the 17th century. Popularized houses with an attic roof Francois Mansart, in whose honor they were named. Parisians immediately appreciated the idea, especially the opportunity to circumvent the communal law, according to which the state withdrew fees for each floor, which the attic was not. The fashion for the attic gradually spread throughout the world, especially this type of architecture was liked by the inhabitants of Europe and America.
Until the Soviet era, such superstructures were unclaimed; during the existence of the superpower, SNiPs and GOSTs were developed to equip such structures, but they have been widely used only recently. At the same time, experts argue about their feasibility, some argue for, others refute them, prove that the savings on construction are negligible, if not completely absent, and the concept of beauty is purely individual.
Content
Advantages and disadvantages of attic roofs
According to external signs, the attic and attic are similar, but it is wrong to apply one name to another. Firstly, it is a heated room, secondly, it is residential, thirdly, it is brought into the project, registered as a functional part of the house, to which all the necessary communications are connected. The main feature is that the roof at the same time serves as a roof, ceiling and walls.
The main advantages of such a structure include:
The design is not without its drawbacks, considering which developers sometimes abandon their plans for its equipment:
Building requirements
Any construction begins with the preparation of the project, which takes into account all the requirements of existing regulatory documents. The attic is no exception. When planning it, you should adhere to the provisions specified in SNiP 2.08.01-89, SNiP 21-01-97, SNiP 23-05-95, namely:
When designing a new house, all the norms are easy to take into account, but when re-equipping an existing residential building, it is not always possible to make a roof space. This cannot be done if the foundation is not strong enough, which is not able to withstand additional loads, and also if for some reason it is not possible to make the ceiling height at the highest point not less than 2.5 m.
Rafter system: features, varieties and design
The rafter system can be called the skeleton of any pitched roof, it is a frame for laying and holding the building materials used in arranging the roofing pie. For the attic floor, it still acts as a wall and floor. Strength, reliability, aesthetics and stylistic direction, the life of the entire device depends on it. Based on structural features, among all the structures, two main types can be distinguished:
Each individual type is characterized by its own distinctive features that are unique to it. The choice of a particular model depends on many factors, which include:
Hanging
The definition of a variety of a system is carried out at the design stage of a building. However, it is not difficult to make a choice, the hanging structure will become an uncontested option for structures in which internal capital walls-partitions are not provided. Their main feature is that they rely solely on two opposing external load-bearing partitions.
It is better to install the structures in a house whose distance between the side walls does not exceed 6 m. In this case, the simplest truss is constructed, consisting of two rafters connected from above at a certain angle. Bottom horizontally, it is strengthened by puffs consisting of wooden beams. For these purposes, you can also use metal profile bars, which are called heavy. Such a device allows to reduce the spacer load on the reference points.
Puffs located at the base of the rafters serve as the ceiling of the lower floor, the attic floor. With an increase in the width between the partitions to 9 m, a headstock and a collar are added to the farm, up to 14 m - an additional device of struts and a headstock. When choosing this system, do not forget that the entire load falls on only two fulcrum, so you should reduce the weight of the roof due to roofing building materials.
Pop
This type of structure is mounted in buildings with internal load-bearing walls. Compared with the previous version, the device and installation of this type is much simpler. In this case, the load distribution occurs evenly on all supports. The system consists of a Mauerlat (bars located on the upper end part of the external load-bearing walls), a horizontal lay, a ridge run fixed to vertical struts, struts, rafters and lathing.
The overhead system is most often used in the construction of residential buildings. It can have different designs, among which there are:
Materials for the manufacture of rafter systems
For the construction of the rafter system, the number of materials used in the work is limited. You can choose between metal and wood, combine both types of raw materials. Reinforced concrete structures are also found, but they are not used in the construction of suburban buildings. Most developers prefer natural wood. It is easier to work with, it is an environmentally friendly product.
Wooden rafters can be safely called a classic look. For their manufacture, solid logs, boards, glued beams are used. When choosing, it is advisable to pay attention to the quality of the wood, as well as to the fact that coniferous species were cut down in winter, deciduous in summer. Experts recommend purchasing the following species: larch, oak, pine, spruce. The first two types are the most durable, but difficult to process.
A very important point is the grade of the tree. For Mauerlat, bedding, skating, it is best to use oak or larch of the highest quality.Rafter legs, racks can be made from coniferous options, both first and second grade, and even the third is suitable for struts. When calculating the building materials of a standard system, 75% is usually assigned to wood of the first grade, 25% to the second.
Also, for the construction of a private structure, metal is used. Most often they resort to it if necessary to organize an overlap of a length of 10 meters or more. In this case, the wooden beam is replaced by a profile pipe. The connection of the elements is carried out by welding. There are combined options when the bed, Mauerlat, ridge run, racks are made of metal, all other parts are made of wood.
Mansard roof structural elements
The structure of each roof is different, it all depends on the purpose of the roof space. First of all, the seasonality of the attic is taken into account. The most complete roofing cake is constructed when the room will be used constantly. It includes the following components:
Each of these layers is very important, without them it is impossible to equip a room comfortable for living, to decorate the interior, to make a beautiful exterior cladding. All these elements are mounted on the rafter system, which consists of: Mauerlat, ridge run, support racks, battens, counter battens, bed rest, rafters, struts.
Mounting technology
It is quite difficult for an inexperienced developer who does not know all the nuances to prepare a project, draw a drawing, indicating all necessary. Even experienced architects and builders who are familiar with such a construct can make a mistake. Violation of the technology, the slightest inaccuracy in the organization of the ventilation system, hydro-, thermal insulation, will lead to irreparable consequences, will lead to expensive repairs.
Having made a firm decision to build a house with a mansard roof, you should initially familiarize yourself with regulatory documents, study the design features of such structures, plan correctly, make a rafter system calculation, choose the most suitable materials used for work, and also look at ready-made examples. If you are not completely sure of your own knowledge and skills, it is better to seek help from specialists who will either do the work themselves or help the owner with advice.
Project preparation
Any serious construction activities begin with design. This issue should be taken responsibly, the strength, functionality, aesthetics, and durability of the structure depend on it. When drawing up the plan, it is necessary to rely on the current norms and rules, namely: SNiP 2.08.02-89, SP 20.13330.2016 (SNiP 2.01.07-85), SNiP 23-05-95, SNiP 21-01-97, SP 70.13330 .2012. Given these documents, make up the project, which includes:
Calculation of the rafter system
When designing the attic floor, it is very important not to make mistakes. It is necessary to correctly calculate the rafter system, which depends on the type of structure used in the work of materials, including finishing. The easiest way is to make the necessary calculations using special programs by downloading them online, using online projects. Such actions can be done with your own hands, for this you need to consider the following points:
Frame manufacturing
For clarity, consider a small workshop on installing a sloping roof. The whole process step by step is as follows:
Warming and vapor barrier
After installing the rafter system, the outer crate and the counter-crate, they proceed to the insulation of the structure. Experts recommend using mineral wool, which goes well with wood, leaks moisture, and allows wood to breathe. Also, polystyrene plates, polyurethane foam, ecowool are used for these purposes. The layer thickness is usually in the range of 20-25 cm, but sometimes reaches 30 cm.The installation process of the insulation is as follows:
Installation of the crate
Roofing pie has a rather complex system. The counter and crate are very important components of the overall design. The first element is a fairly thin counter-rails, which are responsible for providing the roof with ventilation, the second is the basis for fixing the roofing and finishing material.
External installation work begins after laying a layer of waterproofing on the rafters. The installation of counter-racks does not cause difficulties, they are attached with the same step as the rafters. The lattice is fixed on top. Depending on the building material used to cover it, it is available in two ways:
Finish Options
When choosing a suitable roofing material, several points are taken into account: aesthetic, functional. On the one hand, it is necessary to emphasize the design of the building, its style, on the other hand, to provide reliable protection of the roofing cake from atmospheric precipitation. It also takes into account the weight of the coating, its durability. Manufacturers of building materials produce many different options that satisfy different customer requirements, among which are:
Varieties of attic roofs
The main types of attic structures differ from each other in design features. They can be divided into two large groups - single-level and two-level. The former are combined with a roof of any type (broken, gable), the latter are mounted on mixed supports, designed for rooms at different levels.
Single slope
A simple roof device due to the lack of a ridge and the difficulties with its arrangement. Such designs have a non-standard look. Mauerlat is mounted on opposite walls of different heights and the beams are fixed, a bevel is formed with an inclination angle of 30-45 ° С. It is impossible to make it smaller, since there may be difficulties with the outflow of snow and rain water, which will lead to additional load on the supports.
The sloping roof allows for the installation of large windows on the high wall of the attic floor. The simple and low-cost design has several significant drawbacks. The room on the narrowing side will be inconvenient to use, there will be restrictions in the choice of its purpose. Before choosing this option for construction, it is necessary to consider the efficiency of using the room.
For the construction of a shed roof, several rafters will be required. They are laid on the walls in increments of 1 meter.Between them lay insulation and waterproofing material. Correct installation is a guarantee of reducing heat costs to a minimum.
Gable
The most common, economical roof option. It is easy to install and maintain. The traditional form is flat gable, suitable for single-story construction, looks like a classic triangle.
Due to the design features - the presence of slopes on both sides, there are difficulties with the design of the interior in the living room (it is impossible to arrange high furniture, a feeling of tightness). The rational use of corners will help to solve the problem, for example, for a bed or changing the plan at the initial stage of construction - raising the rafter system to the desired height.
Broken line
Each slope is made of two parts fastened together at a certain angle. Such a break allows you to make the attic room comfortable. The identical size of the base of the house and the sloping roof can increase the living space of the attic floor by 50%, in contrast to a simple gable structure.
Useful area increase the lower parts, the steep top reduces the cost of roofing materials. High ceilings in rooms under such a roof give a feeling of freedom and space.
The structure of the sloping roof is complex, since it requires the creation of a massive rafter frame. It is more suitable for square houses. Particular attention must be paid to drawing up the drawing. The durability and reliability of a sloping roof will depend on the accuracy of the calculations made. The following factors must be considered:
With remote consoles
A popular option for a mansard roof, despite the complexity of the design.The main advantage is the ability to expand the space by shifting to the edge of one of the sides of the room. The design allows you to push the external vertical wall outside the facade and make large windows in it.
In addition to the advantages, roofs with remote consoles have significant drawbacks - the complexity of installation, the high cost of building materials. On one side is a large pitched plane, and on the other, there are already two of them. Under a wide ledge, you can make a carport or porch, a covered terrace.
Two-level
In houses with a high roof, more than 5 meters, it is possible to equip a multi-level platform on the attic floor. It can be two separate rooms connected by a staircase, a large studio with steps, a dressing room from several compartments.
Separately, such an add-in is not made. Two-level rooms must be planned in advance, at the design stage, always taking into account the features of the foundation. The scheme of the rafter system is complex, it is developed taking into account the asymmetric arrangement of the slopes.
It is especially necessary to make calculations for the second level of the attic, since it will be based on columns. Using the advantage of panoramic lighting of such structures, you can create greenhouses, conservatories in the attic.
Multi-gable roof
It differs from standard options by the presence of several pediments (3 or more). The roof looks presentable and massive, thanks to several departments, especially if the finish matches the architectural style.
The multi-pliers system consists of separate slopes connected in one structure. The part of the wall between the slopes is called the forceps. Conventional mansard roofs have only two of them. Products from several pediments can be of varying complexity and are made in different variations. The place for an extension can be allocated, the part of a wall for a panoramic window is increased.
Installation of such a roof is complicated and costly.Building materials will require much more than the construction of a standard system. Due to the great mercy and complex configuration, a large number of scraps and residues of roofing materials remain. But such negative aspects more than compensate for the following advantages of multi-forceps systems:
Four-Slope
The roof system has four slopes. They can be the same as the tent roof, pairwise identical. In the first case, it will not be possible to provide daylight access through standard window structures; installation of attic openings and anti-aircraft lamps will be required.
The design of any type of gable roof must be approached responsibly. Designs have many junctions, require reliable walls, a solid foundation. Depending on the design of the cottage, the design features of the site, choose the type of roof of the main building.
Hip
Such a roof consists of two pairs of slopes trapezoidal and triangular. The ridge in the upper part is 2 times shorter or 3/4 shorter than the house itself. The design will be durable and outwardly attractive with proper design and compliance with certain requirements for membranes and beams.
The hip, half-hip roof has an interesting structure, which positively affects the perception of the ceiling inside the room. He seems taller. The advantage of a hip roof is as follows:
Hipped
It is being built over a building with equilateral bearing walls, with a square type of foundation. All ramps are the same size. The main difference between such a roof is the complete absence of a ridge. Its function is performed by the central support, at the top of which the rafters are closed. The hipped roof is performed in various versions, but for all types, there must be sprigs, Mauerlat, lying, vertical rack, sloping rafters.
The absence of gables reduces the design cost of the structure, there is no need to load the foundation. There is a uniform heating of the roof and the departure of melt water. Among the shortcomings, one can distinguish a complex rafter system. Any node from a large number of elements can lose stability.
Asymmetric
An original, non-traditional solution has a lot of advantages associated not only with external characteristics. Correctly located slopes solve the problems of energy saving, compactness, saving building materials. Such roofs are erected over incomplete upper floors and attics, the area of which is less than the first level.
Stylish, original design is convenient and easy to design. Such a house can be linked with any relief and landscape design. On the attic floor under an asymmetric roof, it is convenient to install technological equipment - ventilation, heating systems, solar panels. The following types of roofs are popular:
With the cuckoo
A small ledge on the attic - “cuckoo”, has its own architectural system. The element is paired with the main roof, covered with the same roof. Before you include it in the project, you should make sure of such a need, since it will reduce the strength of the rafter system, it can cause water to enter the attic.
"Cuckoo" on the roof performs not only decorative functions.The design makes it possible to add one or more windows, increases the practicality of the room. Additional area can be used for any domestic purposes. Such an extension can be done with your own hands in the following variations:
L-shaped
The sequence of construction of the L-shaped roof will differ depending on the width of the gables and their correspondence to each other. The construction system consists of two gable roofs that crash into each other. They are connected at an angle of 90 ° C in the most complex unit.
The roof of the L-shaped building can be of varying complexity. The end walls of a simple design have the same width, complex pediments have different dimensions. The docking process in this case is complicated by the different heights of the skates. Often such roofs are made broken, with different heights of gable halves.
The use of SIP panels for the attic roof
The formation of the roof over the attic from SIP panels is the most convenient way. According to the project created taking into account such a technique, the roof does not need to be additionally insulated. For exterior decoration, you can use any material. The roof will in any case be solid and even.
If you have the right tool and certain skills, you can easily build a simple roof or a complex configuration with your own hands, with several windows and skates of different sizes. A warm roof made of SIP panels can dramatically improve living conditions in an existing building.
When drawing up the project, it is necessary to take into account possible difficulties in the construction of the structure. The roof will have many joints, which can adversely affect its strength. Due to the large number of construct residues, financial costs will increase. To create supporting frames, more timber and other auxiliary material will be required.
Design: Attic interior decoration
You can create a budget, functional interior on the attic with various materials. More often, the walls are sheathed with drywall, lining, plywood. Modern design allows you to make a room above the main house in any architectural directions.
The interior design of the attic will depend on the purpose of the room. If the house is built of wood, the interior should be made of the same material. Eco style is the most winning option. Convert a simple attic to any room. From the top floor you will get a well-lit study, a spacious dressing room, a relaxation room, a playroom for children.
The usual high furniture for the attic will not work. It should be only the most necessary items. Bulky sofas will look ridiculous in a room with low ceilings. Modular designs, low poufs will look good.
Conclusion
The mansard roof has both advantages and disadvantages. During the preparation of the project, it is necessary to take into account all the nuances in order to finally make sure of its necessity. Just remodeling the attic will not be enough, it needs to be re-planned, to make a reliable roof and thermal insulation.