Project documentation

1. We are adding an attic to an already finished house
2. What's included rafter system?
3. Thermal engineering
4. Construction process in detail
5. Advantages of the frame system

Many owners private houses want to make their home more functional. You can achieve the goal by increasing the free space that can be used for personal purposes. Experts suggest using the area under the roof itself for this, namely building an attic. This process cannot be called easy, but if the technology is followed, it is possible to make an addition, both at the stage of building a house and after putting it into operation. Both options will be discussed below. DIY mansard roof.

We are developing a project

Anyone interested in how to build mansard roof with your own hands, first of all you need to understand that this part of the building is quite complex. If there is such an opportunity, then it is better to design an additional floor at the construction stage, because not all already built houses can be equipped with additional floors. square meters. The main obstacle is the increase in load on the foundation part, which requires its strengthening.

In general terms, the whole process can be divided into stages:

• The construction of the attic roof begins with drawing up drawings;
• then the walls of the under-roof room are erected;
• the next stage is the arrangement of the roof itself, performing insulation and waterproofing work;
• window installation;
• interior decoration of the room.

Only strict adherence to technology makes it possible to obtain a durable and, most importantly, reliable building.

Each stage of work is important in its own way, one of them is design. Here it is important to take into account the dimensions of the room, the material that will be used as the main one, the features of the roof, the degree of its slope, the number of slopes, etc. There are several ways to design a superstructure. The least expensive is to compile the necessary documentation manually; for this you will need at least minimal experience and knowledge. You can go the other way - use ready-made drawings, but no one can guarantee that they will be perfect; adjustments may need to be made.

The most expensive, but win-win option is to contact specialists. There are many companies offering to create a project that matches the parameters of your home in a short time. A team of specialists will also help you choose the right building materials. The main requirements for consumables are: ensuring durability in operation, reducing the overall load on the base. We must not forget that new project must be agreed upon by government agencies; if it is drawn up correctly, then there will be no problems with this.

What if the house has already been built?

IN in this case The construction process begins with dismantling work. Having disassembled old roof, you can not only expand the usable space later, but also ensure the safety of the new add-on. You don’t have to hire someone for these purposes; you can do everything on your own. First you shoot roofing material from the outside, then the sheathing, and at the end you dismantle the rafter system.

When the dismantling work is safely completed, proceed to strengthening the walls on the lower floor. This stage cannot be neglected, because the additional load is not only on the foundation, but also on the vertical structures. To do everything right, you will need to carry out calculations to determine the strength level of the old walls.

Mansard roof components of the structure

Understand how to build a roof mansard type, information about the main load-bearing parts and connections will help.

1. Rafter legs - they transfer the load exerted by the weight of the roofing material on the walls of the building. Section wooden beams is selected taking into account such indicators as angle of inclination, span width, pitch, design load. If you do not know how such calculations are carried out correctly, it makes sense to contact a specialist. In private construction, it is permissible to use approximate values, but we must not forget about a small margin.
2. Narozhniki - this is the name of the rafter legs, supported on one or both sides by sloping elements. Their cross-section is determined in the same way as in the case of the main rafters.
3. Sloping legs - this type of structure is used in the construction of a hip roof. It is used as a base for sprigs. The cross-sectional indicator is determined taking into account the load and span. Remember, this figure should be greater than that of the rafter legs.
4. The crossbar is a support beam for the rafters, located in the upper part of the structure, namely in the ridge or at the break of the slope (if a sloping roof is planned).
5. Mauerlat is one of the main elements, it is a support for all rafters, through it the load on the walls is transmitted and evenly distributed. The optimal cross-section is 100x100 or 150x150mm, it all depends on the complexity of the object.

Just so you know, the construction of a Mauerlat is not required if we are talking about the construction of a frame or wooden house. This is because the support for the rafters is the crown of the walls or frame. mansard roof

Construction cannot be done without additional elements, such as struts, racks, and contractions. They are necessary to reduce the cross-section of load-bearing structures. Their size is selected taking into account the convenience of making connections. Arguing on the topic: “How to build an attic roof for a house,” — One cannot fail to mention the material. Experts emphasize that the wood should only be used from coniferous species, for example, pine, larch, spruce. The grade should be first, maximum second, and humidity no more than 15%. Before use, do not forget that all boards and bars must be treated with an antiseptic.

Thermal calculations

The construction of an attic is not complete without the use of insulation; most often mineral wool is used for this purpose; it is supplied in slabs or mats. It is also possible to use polyurethane foam, ecowool, polystyrene foam, and extruded polystyrene foam. Having decided on the material, you need to choose the right thickness; here it is important to take into account the height of the rafters, it should be equal to or slightly greater than the thickness of the heat-insulating layer. Subject to use mineral wool it is necessary to ensure the presence of a ventilation gap; it is a space of 50 mm between the heat insulator (its upper surface) and the roof. mansard roof

Step-by-step description of the process

Let's move on to the main thing - how to build an attic roof for a house with your own hands. To cope with this task, it is important to follow a certain sequence of work. It all starts with attaching the Mauerlat to the wall (if the house is not frame or wooden), then the rafter system is installed along with struts and racks. It cannot be done without installing waterproofing and wind protection. Before laying the outer roof, sheathing is done. Finally, insulation is carried out from the inside, covering protruding structural elements.

And now a little more about some of the stages.

1. If laying a mauerlat is required, this is done on the inside of the outer wall. There are several ways to fasten elements; to a large extent it depends on what the house is built from. The work may use anchors, studs or staples. In relation to buildings made of foam or aerated concrete, a monolithic belt is made, due to this it is possible to prevent destruction. After the construction of the mauerlat, the crossbars are mounted (if necessary), the supporting structures are laid out, and the rafter legs are laid out at a certain interval. Fastenings can be made rigid or hinged.
2. Before you start laying insulation, try to protect it from negative impacts from outside. We are talking about laying a membrane sheet that protects from wind and moisture, and securing the sheathing. After this, you can begin laying the finishing coating; alternatively, you can use bitumen shingles.
3. In order to ensure effective thermal insulation of the house, the material must be laid without gaps or cracks. If you plan to use polystyrene foam, the resulting spaces must be filled with sealant/foam. Upon completion of the work, a vapor barrier is fixed from below, then the internal lathing, after which you can begin covering the ceiling. Ideal option in this case it is plasterboard 12.5 mm thick.

To ensure access to natural light into the room, as well as airtightness, you need to install special roof windows. Their feature is the ability to withstand the effects of external precipitation, which are negative. The possibility of high-quality ventilation of the living space is also important. When it comes to installing windows, it is better to contact specialists, because they have all the necessary skills.

Positive features of the add-on

Information on how to properly build an attic roof will not hurt anyone, because it is an excellent solution for a building for any purpose. If you give preference frame version, you will be able to appreciate its main advantages. For example:

• the design is lightweight, which means it does not heavily load the main building. It follows from this that there is no need for additional strengthening;
• compared to stone options, construction of this type is much cheaper;
• it is possible to provide high level thermal and sound insulation;
• The attic can be made of any shape or configuration. mansard roof

And lastly, the consumables used are quite light, so there are no difficulties in lifting them up.

In an effort to effectively use all available space country house Many owners equip the attic. When doing this, you need to be prepared to arrange the roof in a certain way. At its core, the attic is a converted attic and requires certain constructive solutions and some alterations in thermal insulation and roofing. In general, the construction of an attic roof for a country house is not much different from the construction of other types of roofs. But due to operational features Attic roofs and the requirements for them must have knowledge and understanding of the specifics of the arrangement of this type of roof.

Types of mansard roofs

Like any construction works, the construction of an attic roof begins with the design stage and selection of the most suitable attic roof for the structure, its type and type. For the attic, shed roofs or regular and sloping gable roofs are used. On top of everything else, on appearance roofs are influenced by the materials used and the design features of the roof itself.

Depending on the structural features of the building itself, several standard roof solutions are used during the construction of the attic. Mansard roofs: photos and description

• Gable roof for a single-level attic. This option is a regular gable roof, under which an attic is located. During design and construction, no major difficulties arise due to the simplicity of calculations and the ease of construction of the truss structure. The main disadvantage of this roof design is the small interior of the attic with rather low ceilings.

• Broken gable roof for a single-level attic. Unlike a conventional gable roof for an attic, a broken structure uses 4 pitched planes located at different angles. This type of roof structure is somewhat more complex to design and construct, but its undeniable advantage is the full-size interior space.

• Single-level mansard roof with remote consoles. The design of this type of roof is more complex compared to the previous ones. But the spacious room and full-fledged vertical windows compensate for the shortcomings in the complexity of design and construction. The design feature of an attic with such a roof is its displacement and extension beyond one of the sides of the house, and the roof is more like a pitched one.

• Two-level mansard roof with mixed type of support. Roofs of this type are the most difficult to design and construct. Such roofs are designed in conjunction with the house, as one whole, due to the multi-level placement of rooms.

Various mansard roof designs are not much different in design from conventional pitched roofs. Of course, there are certain design features, but in general they are the same as gable or single-pitch, and consist of the following main elements:

. Roof. The outer part of the roof, which serves as protection against various atmospheric phenomena.

. Lathing. Most often, wooden boards to which the roof is attached, as well as insulating materials.

. Ridge run. The upper part of the entire truss structure.

. Rafters. These are the stiffening ribs of the entire roof structure; they can be layered or hanging. Layered rafters are used for the attic roof.

. Mauerlat. This structural element consists of beams laid around the perimeter external walls and connected to the walls using special fasteners. Everything is attached to the Mauerlat truss structure.

.Diagonal connections. To ensure the reliability and strength of the entire rafter structure, the rafters are connected to longitudinal beams and vertical posts using diagonal connections or bevels.

. Internal supports. To give the roof stability, the rafters and/or ridge girder are supported by vertical beams.

. Insulation layer. Due to the fact that the attic roof and the interior premises are practically one whole, to maintain temperature and humidity conditions, a multi-layer insulation cake is laid between the roof and the walls of the room. The insulation consists of hydro- and vapor barriers, sound and noise insulation, as well as a thick layer of thermal insulation. In addition, proper insulation of the attic roof is important for the safety of the roof itself.

Mansard roof construction technology

When designing and constructing an attic roof, many builders and designers, either out of ignorance or doing their work poorly, make serious mistakes in insulation, ventilation and truss structure. The result is an attic roof, which literally after a couple of seasons becomes unusable, fungus and mold appear, and the roof begins to leak or completely collapse. This happens due to a violation of the mansard roof construction technology.

Due to the fact that the attic roof is maximally drawn to the walls of the interior, and in this case it is quite difficult to obtain excellent heat transfer performance, the entire attic roof structure must have excellent thermal insulation, ventilation and a properly constructed rafter structure using wood treated with fire-bioprotectants.

To make your attic roof reliable and durable, you need to know the following:

• The thickness of the rafters must be more than 250 mm. For such rafters you can use laminated veneer lumber;
• Use materials as thermal insulation that will not lose their properties in the event of increased humidity. For example, extruded polystyrene foam or foam glass;
• between the roof and the thermal insulation layer we make full ventilation with vents and hoods, through which air will circulate under the entire surface of the roof;
• on the inside, along the entire surface of the thermal insulation, it is necessary to install a vapor barrier layer;
• With outside rafters, a layer of waterproofing and, if necessary, a layer of sound insulation are laid under the roof.

Such requirements are determined by certain natural and physical phenomena. But first things first:

A large thickness of the rafters is required to be able to lay a 20 cm thick layer of thermal insulation between them, and this in turn entails an increase in the mass of the entire roof structure, which is supported by the rafters.

The wood for the entire structure is processed by special means for protection against fire and microorganisms, which is a strict requirement of SNiP. This will protect it from damage by fungi and increase its service life.

If you use such popular materials as mineral and glass wool for thermal insulation, you can only gain in ease of installation and lightening of the entire structure as a whole. But cotton wool, no matter what it is, is cotton wool that absorbs water like a sponge, cakes and loses its insulating qualities. If you choose a material other than polystyrene and foam glass, you should focus on complete resistance to moisture, low heat transfer coefficient and relatively low weight.

A thermal insulation thickness of 20 cm is necessary because in our latitudes it is very cold in winter and very hot in summer. A feature of the attic design is large heat losses in winter and rapid heating of the room in summer. Large layer thermal insulation will prevent heat loss and penetration inside. But this is only one of the reasons, the second is the safety of the roof. The fact is that the heat that escapes from their premises in winter warms up the roof, on which there is a layer of snow and partially causes it to thaw, and snow is a natural insulation. Melted snow at sub-zero temperature turns into ice, which has no thermal insulation properties, it makes the roof heavier and ultimately destroys the roof itself. And since up to 100 cycles of thawing and freezing can occur in one day, the roofing material will fail in just one season. In summer, the room becomes incredibly hot and stuffy, and you need to install an air conditioner, or even two. But these inconveniences can be avoided by installing a thick layer of proper thermal insulation.

Equally important is proper roof ventilation. It will help cool the roof, both in summer and winter, and also remove excess moisture from under the roof. All this will ensure comfortable living in the attic, protect against the appearance of mold, fungi and rot, and in addition will protect the roof from destruction in winter.

Regarding steam, hydro and sound insulation, everything is simple. Vapor barrier allows excess moisture from the premises to pass through and prevents its penetration from the outside; waterproofing protects thermal insulation materials and the room from accidental moisture ingress. And sound insulation reduces the noise level from impacts of rain, hail and wind on the roof surface.

Phased construction of an attic roof

Carrying out all the work to create a roof for an attic requires builders to have some experience in this area. Unlike ordinary pitched roofs, building an attic roof with your own hands is somewhat more difficult due to the installation of angled windows in the roof itself and the broken structure of the slopes. To build an attic roof with your own hands, you must adhere to the following stages of work:

Design

The first thing you have to do is develop a roof project. To do this, you can turn to specialists or, if you are good with a computer, do everything yourself in an architectural program. Also at this stage, all the necessary calculations of loads, the angle of inclination of roof slopes, etc. are carried out. To do everything right, you should contact necessary information to a document such as SNiP “Loads and Impacts”.

Construction of the rafter frame

This stage of work is the most labor-intensive, and for a do-it-yourself attic roof to be made with high quality, the combined efforts of 3 to 4 people will be required. We begin the construction of the attic roof by laying and securing the mauerlats along the entire perimeter of the house, using timber with a section of 100x100 mm.

Construction of an attic roof photo:

After this, we install a frame for the attic space, the racks of which will also serve as supports for the rafter structure. To do this, we use a beam with a cross-section no smaller than the cross-section of the longitudinal beams on which the racks will rest. First of all we install vertical racks at the beginning and at the end of the building. We fix them to the longitudinal beams using special stamped metal corners and self-tapping screws. To facilitate all fastening work, we use a screwdriver. Now we lay the jumper over the racks and secure it.

We stretch the cord between the two resulting arches, and if everything was done correctly, it will be strictly horizontal, if not, you will have to disassemble one of the arches, trim it a little and reinstall it. Now, using a stretched cord, we install similar arches with the step provided for the rafters. We connect the resulting arches with jumpers, which we secure with stamped corners or nail plates.

Having assembled the frame of the future interior space, we proceed to install the rafters. We start with those that have the greatest angle of inclination and are on the same level with the frame of the attic room. There are no particular difficulties here. The beam for the rafters is cut to the required design length, a groove is cut at the base of the beam for installation on the Mauerlat, and the top is cut at a certain angle. After which each rafter is installed in place and fixed to the main structure.

The next step is a little more difficult, since you will have to install the upper rafters. The difficulty lies in maintaining a certain angle and centering of the entire structure. To make the task easier, you can first make a template from two long boards that will exactly repeat the future connected rafters. Using this template, we cut the rafters on the ground and then install them in place. The rafter installation algorithm is the same as for the interior frame arches.

To complete the installation of the rafter structure, we nail the sheathing. For lathing, both ordinary boards and sheets of plywood or chipboards can be used. This will depend on the type of roofing materials.

Creating an Insulation Pie

Having installed the rafters and sheathing, we begin to create the insulating layer. To do this, first of all, we lay a vapor barrier on the inside of the rafters and fix it to the rafters with brackets. Next we lay thermal insulation material and we carefully ensure that it lies close to the rafters and does not leave any gaps. On top of the thermal insulation, in increments of 50 cm, we fill the lathing, which will hold all the thermal insulation.

On the outside of the rafters we lay a layer of waterproofing, which will protect against accidental penetration of moisture. Finally, we lay the roof on top of the waterproofing.

Construction of an attic roof: video tutorial

Diversity finished projects The attic roofs are very extensive. They can be with or without windows, rounded or strictly straight, with one slope or several. But no matter what the attic roof is, its construction will require the knowledge and skills of a construction master.

A sloping attic roof is very convenient in a dacha as an additional room. You can build it yourself, using a minimum of money and time. You can build an attic roof with your own hands in relatively little time and you don’t need any special construction knowledge for this. There will also be big savings in staff costs, and you can call a few people you know to help.

In order for the attic to be spacious enough, its roof must be broken, that is, refracted at different angles. A broken mansard roof should be planned in advance; you can even draw approximate drawings of mansard roofs, how you would like to see it in the end.

Also, the design of the attic on the second floor should comply with the general parameters of the structure, since the foundation and walls must be calculated in advance to fit the dimensions of the attic. That is why it is better to first draw up a drawing of the future structure.

How to build a mansard roof with your own hands: useful tips

Please note that the size of the attic directly depends on the angle of the roof. The larger it is, the less usable space in the attic will be, since the corner can steal the height of the room in the attic, keep this in mind. But it’s also not worth experimenting with angles of inclination, since it plays an important role in discharging precipitation from the roof of the room.

And if you are building a house where windy weather prevails, then the angle of inclination can be reduced. So, do it yourself sloping roof it will be much better quality, if you take into account during construction following tips and make sure everything is perfect:

Do-it-yourself attics: what you need when working

To build an attic roof on slate with your own hands, we will need:

1. slate;
2. timber beams and boards;
3. slate and simple nails;
4. insulation;
5. annealed wire and for stretch marks.

You will also need set of tools:

1. axe;
2. construction stapler;
3. hammer;
4. plumb line;
5. hacksaw;
6. roulette.

How to make a mansard roof from metal tiles: a brief description

A mansard roof based on metal tiles is distinguished by a broken slope line, two of them diverge downward at a slight angle from the central ridge and pass to the two lower ones. Thanks to this design, the volume under the roof can be maximized.

A do-it-yourself sloping roof can be created under a completely furnished living space in the attic, also the room on the second floor of a country house can be used as a creative studio, playroom or guest room.

Construction of a gable sloping roof it won't be easy, but hip roof It is much more difficult to build with your own hands. Even the external bulkiness of a sloping roof will become its advantage if you imagine it as an element of the design of the building.

And if you choose the right roofing material, you can even visually reduce its dimensions. In addition, it should be taken into account that the sloping roof will organically fit into the design of the house in the form of a square. And if the building is long and narrow, then the attic under the sloping roof cannot be fully used for additional residential space.

To build a broken mansard roof, you should carry out such calculations:

1. roof weight;
2. weight of sheathing and counter-lattice;
3. weight of steam and waterproofing materials;
4. insulation weight;
5. total span length;
6. slope corners;
7. step of sheathing and rafters;
8. possible periodic loads.

Stages of building a do-it-yourself attic roof

Construction begins with laying wooden beams on top of the waterproofing, on top of which rafter beams will be laid. As a waterproofing use roofing felt. When using a wooden covering, a bottom beam is not needed.

Next, wooden racks are placed on the beams at a distance of about 2 meters from each other. They must be positioned strictly perpendicularly in one plane, since they will support the walls of the attic. From the inside, if desired, they are covered with plywood or plasterboard, insulation is added and sewn up. The drains are secured with metal brackets or spikes.

We lay the top beam of wood and secure it. Then we install a beam for support under rafter leg from a wooden board or timber. This will allow the roof to be attached more firmly to the building. It is advisable to cover the beam layer with roofing felt to prevent rotting. Also desirable reinforce the structure with annealed wire.

We install the rafter legs: we make markings at the locations of the rafters, it is desirable that the step is about 100 cm. We install the outer rafters to the front first, but it is necessary that their upper part coincides with the outer line of the pediment. The rafters must be made from boards that have no knots. When the outer rafters are installed, twine is pulled between them to make the rest easier to install. Then they all connect to each other.

A ridge beam is installed on top of the structure to support the rafter legs. It is needed if the roof is very large and heavy. If the rafter is less than 8 meters, it is not needed, but it is necessary do stretches under your skate. They are needed as insurance when there is a heavy load of snow cover or as ceiling beams attics.

Then we install the fillies. This is done according to the same principle as installing rafters. First, the outermost ones are installed, then all the others are pulled onto the twine. They are absolutely necessary, because if the covering rots, replacing them is much easier than dismantling the entire roof.

A hem board is nailed onto the fillies, which is needed to protect against wind blowing and precipitation getting under the roof.

In the places where you want to place windows, the rafters should be attached with transverse bars, which will also be parts of the opening for attaching the window frame.

Laths for sheathing are nailed on top of the rafters; the pitch of the sheathing depends on the roofing material. On top of the sheathing we attach plastic film with staples as waterproofing, overlapping layers from bottom to top. We put mineral wool insulation on top.

You can line the roof from bottom to top. At break points, the roof of the upper row should be protruded under the flooring of the lower row.

And at the end of the work ridge is installed, and it should be such that precipitation under the roof is reduced to zero.

Also, do not forget about ventilation windows and window openings.

Advantages and disadvantages of a mansard roof

Having an attic in a country private house has a number of both advantages and disadvantages.

The main advantage of the attic - the second floor is the increase in living or usable space small house. Also, such a solution makes the house more attractive from an architectural point of view.

And here it is disadvantages of such a solution:

But, despite this, there are no fewer people wanting to install an attic roof. With the right approach, this solution is very stylish and reasonable, especially if your country house itself is small.

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

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

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

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

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

Hanging structure

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

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

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

Layered system

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

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

Do-it-yourself mansard roof: video, photo

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

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

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

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

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

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

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

Video: rafter system for a sloping attic roof

Attic project

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Video: calculating a mansard roof using software

Material parameters for the construction of an attic roof

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

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

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

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

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

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

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

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

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

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

• Vapor barrier and waterproofing membranes.

• Insulation materials intended for roof thermal insulation.

• Roofing material and special fasteners.

Rafter section

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

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

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

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

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

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

μ - correction factor, which depends on the steepness of the roof slope.

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

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

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

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

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

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

Wp = W × k × c

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

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

The letters in the table indicate the following zones:

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

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

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

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

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

Once the snow and wind loads have been calculated, they can be summed and taken into account design features system, identify the cross-section of the rafter boards.

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

The total load value is indicated in Kilopascals (kPa). Converting this value into the usual kilograms per m 2 will not be special labor. 1 kPa ≈ 100 kg/m².

As for the dimensions of the board along its cross-section, it is rounded up standard sizes lumber.

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

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

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

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

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

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

1. Mauerlat fastening.

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

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

1. Installation of the rafter system.

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

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

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

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

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

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

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

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

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

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

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

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

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

Waterproofing attic roof

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

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

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

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

If you use soft roof, then plywood sheets are usually fixed to the counter-lattice.

How the roof covering is installed

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

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

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

The attic is attic space, intended for housing or storing household utensils. Unlike flat roof in multi-storey residential buildings, the attic roof can be gable or multi-slope. For the construction of cottages, in the price-quality ratio, the best option is a gable roof.

general description

Mansard roofing is wooden structure in the shape of a triangle or polygon. It consists of rafters and rafter beams. From above it is closed with a “pie” of insulation, vapor and waterproofing. The rafter legs support the entire mass of the roof. The rafter beam acts as an additional connection and support.

The outermost pairs of rafters form a pediment. It comes in triangular and trapezoidal shapes, which depends on the type attic structure. Inside there is a living space with straight or broken walls.

Main advantages and disadvantages

Any building structure has characteristic positive and negative properties. Knowing these features will help when choosing roofing system.

Advantages

• Manufacturing and installation times. The gable system has been studied for a long time, and detailed step-by-step instructions for its design and construction have been compiled. Therefore, the work can be done with your own hands in a short period of time.
• High level of protection of interiors from snow and rain. All roof elements are located at a certain angle. This makes it impossible for snow caps and small puddles of water to form on the roof surface.
• High level of protection of the joints between the wall and the roof from the wind. ends gable roof hang over the walls, thereby protecting the joints from wind blowing.
• Increase in common living space. Attic spaces are suitable for creating additional bedrooms, wardrobes or playrooms for children.

• Price. Materials for constructing a gable roof can be found at any hardware store at reasonable prices.
• Aesthetic beauty. The gable mansard roof looks attractive. It will decorate any residential building.

Flaws

• In some cases, construction may require a significant amount of materials.
• If it is necessary to convert the attic space into a living space, then additional Construction Materials to strengthen the existing structure.

Types of mansard roofs

There are a few structural types attic gable roofs, which can vary in the shape of the slopes, be symmetrical or asymmetrical, and located at different levels relative to the ground.

The shape of the slopes differs:

• A gable, flat mansard roof is a traditional form for low-rise construction. It is a classic triangle. This design is easy to install and maintain. It's inexpensive.

A flat attic roof is not always suitable for the construction of residential premises. This is due to its design features.

Important! The optimal slope of the slopes is 35°-40°. This angle gives an even distribution of loads. With this angle of inclination it is impossible to create a full-fledged attic space. This is why broken-shaped slopes are often used

• Gable sloping mansard roof. Each slope consists of two parts, fastened together at an angle. Thanks to this break, it becomes possible to create a full-fledged attic space. At same size At the base of the house, a sloping roof allows you to get 40-50% more useful living space than when using a traditional gable roof.

For clarity, a broken gable system can be divided into three triangles. Two right triangles make up the side slopes. The outer line of the slopes will be their hypotenuse. The upper part of the roof consists of one isosceles triangle, which lies on two rectangular ones.

Important! In the side triangles there is a broken line attic system Only layered rafters are used. In the upper triangle, you can use both layered and hanging ones.

By location they are distinguished:

• Symmetrical slopes are a classic option, where the two halves of the roof of the house are a mirror image of each other. In such gable system The maximum area of ​​the under-roof space is used. The symmetrical roof looks organic. Such houses are recommended for fans of tried and true classics.

• Asymmetrical slopes are a bolder option. The ridge line does not coincide with the center line of the entire house. The lengths of the slopes can vary greatly. With this roofing arrangement, the area of ​​the attic space is reduced. Houses with such a roof are recommended for fans of modern asymmetrical architecture.

Slopes located at different levels

They are missing a skate. The slopes in the attic are not connected to each other, but seem to hang over each other. Houses with this type of roofing look unusual and are not widespread in our country.

Hip and half-hip roofs

These mansard roofs They form a separate species due to the fact that their slopes are located not only on the sides, but completely or partially replace the pediments.

• Hip. The classic version of four slopes. The two main side ones are trapezoidal in shape. Instead of pediments there are “hips”. All four slopes encircle the walls at the same level from the ground.

• Half-hip. Their design is specially designed for areas with high wind loads. This type has the most complex shape of all gables. The side slopes have the shape of a polygon. The hips end approximately in the middle of the side slopes. This type of roof is suitable for creating a full-fledged residential second floor.

Important! In some reference books, hip and half-hip roof structures are called hipped roofing structures. The essence and principle of operation of the system does not change.

General principles of the device

Any building construction consists of a skeleton and a shell. Roofing or rafter systems are no exception. From their strength and performance characteristics The comfortable and safe accommodation of homeowners, as well as the terms of trouble-free operation, depend.

The skeleton of a gable mansard roof is a wooden rafter structure. It must meet several basic requirements:

• Strength. Withstand the weight of snow and water, as well as wind and other types of dynamic loads.
• Ease. The lighter the frame, the lower the cost of the entire house.
• Functionality. The rafters should evenly distribute the load on the load-bearing elements without overloading individual areas.

The covering of a gable roof is a shell that protects the interior from heat, cold, moisture, snow and wind. It must meet several basic requirements:

• Ease. How less weight roofing, the lower the load on the rafter system. The final cost of the entire structure depends on this.
• Reliability. Roofing is the first and main line in the path of an aggressive external environment.
• Aesthetic beauty. The roof is one of the most prominent elements of a building. They pay attention to him first.

The main structural elements of a gable attic roof

• Mauerlat is a rectangular or square wooden beam. It connects load-bearing walls and rafters together, distributing the load along the entire perimeter of the building. The Mauerlat is laid along the walls and secured with anchors or fittings. Rafters are installed on top of it.
• Rafter legs are the basis of the roofing system. The entire burden falls on them. The rafters are made from wooden beam square or rectangular section. At one end they rest on the Mauerlat, and at the other they are connected to each other. According to the method of fastening, rafter legs can be layered or hanging.
• Ridge beam is a structural element with a square or round cross-section. It is located on top and the upper part of the rafter legs rests on it.

These three elements form the basis of any attic gable roof. From these you can build a simple rafter system. For more complex structures there are a number of additional elements:

• A strut is a beam that supports the rafters and is installed at an angle to them. At the bottom, the strut rests on the floor beam.
• A stand is a beam that serves to support the rafter leg. It is installed at right angles to the ceiling.
• A scrum is a beam that connects two vertical load-bearing elements. Its main function is to absorb tensile forces in large rafter systems.
• A crossbar is a beam that additionally connects the rafters together. He doesn't let them leave.
• The sheathing is a beam that serves as the basis for installing the roofing. It is made from boards and fastened with a certain step across the rafters.

The number and frequency of installation of these elements depend on the design load on the attic gable roof. We must remember - the more elements, the more expensive and heavier the entire structure. The less space will be left for the attic living space. Therefore, before building, you need to carefully calculate everything, and it is better to make a full-fledged one with all the calculations.