Mansard roof truss system: design device

Due to the construction of a mansard roof, possibly significantly increase the usable space of low-rise private houses. However, this is a very laborious process that requires a preliminary calculation, subject to certain rules and techniques. Properly designed mansard roof truss system is the key to creating a comfortable, safe, functional, and durable house.

Mansard roof truss system: Design Features

Before the construction of the attic needs a good project. The appearance of the future of the roof should be in harmony with the general appearance of the building. There are several types of truss frame structure, which depend on the type of the roof, and step trusses embodiment mansard roof. Opt for a particular configuration, it is necessary to know exactly from which structural elements is truss system. It is the supporting skeleton of the roof, and maintains not only its weight, but also the impact of precipitation.

Proper installation of roof system provides the reliability, functionality and durability.

When you create a mansard roof project should be:

• perform a correct calculation of the load on the bearing load-bearing walls and the foundation, avoiding its excess;
• choose quality insulation to avoid uneven heating of premises;
• choose a good sound insulation due to choose the right roofing material;
• pick up a good waterproofing;
• choose a light weight lining materials for finishing the attic.

Schemes mansard roof

Truss system may have an inclined or a hanging structure. In suspension designs rafters rely on mauerlat and ridge pole. To distribute the load on the rafters are set lower and upper tightening. When the ramp length of more than 4 m, to prevent sagging in the lower part of the structure rafters propped up by means of struts and braces. The main advantage of this design is that all of its elements are placed in unused areas of the attic, which creates more space.

Oblique design is used in homes, where the building is located in the middle of carrying the partition on which rest the feet building. The inner support structure is laid sill, which plays a role mauerlat, and it mounted racks that hold the ridge pole. This system is used for large areas of a mansard roof of a private house, which the device can be seen in the photo. There can be used for roofing materials with high weight, such as slate or ceramic tile.

There are projects mansard roofs of private homes, where it is used both variants of roof systems. To free space frame elements can be shifted to one side, where they will be used as the basis for the walls, and the bolt is suitable for lining the ceiling. In some of the architectural styles of the beam and the rack can be used as decorative elements.

For decorating large eaves, roof terrace performed with a focus beyond the load-bearing walls. It does not set mauerlat. The system is mounted with the use of beams. Be sure to set brace, special rack cut into the floor joists and rafters are fixed using a reliable connection and an anchoring wire stranding.

Elements of design mansard roof

Truss system under the mansard roof is composed of such structural elements:

• mauerlat;
• rafters or beams of the racks;
• uprights;
• runs;
• a ridge;
• crates;
• additional beams, purlins and Regel.

The basis of the entire roof construction is mauerlat, which consists of wooden rafters, fixed to the external walls of the building. These boards are attached the other elements of the framework mansard roof. The main purpose is mauerlat perception and even distribution of the entire load of the total roofing system on the bearing wall of the building.

Rafters or beams of the racks constitute the skeleton of the roof structure. should be selected boards that are capable of withstanding a load of roofing cake together with the outer coating for the data elements. To maintain the pillars of the beams or rafters purlins are used, mounted at an angle. Vertical racks hold the center of the roof beams, preventing them from bending. They also provide support for a ridge.

In order to ensure the rigidity of the future of the roof structure on the long roof mounted systems ridge beam. Lathing is an additional wooden structure that is fastened to the rafter system, and is the basis for future roof.

Types mansard roofs

Today, there are several options for mansard roofs, which have a different design rafter frame:

• Shed;
• gable;
• broken lines consist of two or more rays from different angles of inclination;
• hipped have two triangular ramp with short sides and two trapezoidal roof slope with long;
• poluvalmovaya have two short end of the hip part of the front roof;
• characterized domed circular or polygonal shape;
• vaulted have a cross-sectional shape of an arc.

Pent roof is the most simple in execution plan. To him often turn when you need to make the attic in a small country house. The most popular among other types of mansard roofs of private houses, photo clearly confirm this is a gable roof. Its design and construction of their own hands does not cause difficulties. Especially if we are talking about a gable roof.

When choosing a sloping roof, it is possible to get a large, functional and comfortable attic room with no additional work associated with the construction of walls. Today, many owners of private houses zealous prefer a gable roof truss system under the decking, construction which does not require many technological and technical tricks and unnecessarily high flow of funds for construction materials.

The most difficult to install are hipped, arched dome and roof terraces. Their device requires a professional approach. These mansard roof, photo private houses clearly reflect this, have an unusual and highly aesthetic design. They are characterized by a large number of fractures pitched for which the device valleys. Scheme truss system feature and demonstrate the uniqueness of the design. The unsatisfactory state of each of the valleys (interior angles) can be a potential danger to the integrity of the roof.

Pent roof terrace. Photo of successful Projects summary

The most simple, reliable and cheap option is the pent roof mansard. The result is a custom layout building. This type of roof is used for industrial and commercial buildings. It is also often used for small single-storey private houses. Here, all the roofing materials can be used.

The design involves the creation in the high part of a mansard roof window. In this design, there is no strong point, which simplifies its installation. Mauerlat fixed to the walls with different levels, due to which the bevel is formed. It supported beams.

The angle of the ramp should be in the range of 35-45 degrees. The smaller the deviation, the greater the snow would accumulate on the roof surface, which require the creation of additional supports and strengthening supporting beams. In addition, it will significantly reduce the attic. The design is able to withstand strong winds when the correct orientation of the roof slope, the need to increase structural stability.

Useful advice!If the opposed bearing walls a distance of not more than 4.5 m, you can not mount holding up the elements, but just put on the walls of the long wooden beams. This further reduces the cost of construction of the roof.

This type of roof requires the use of simple elements to create the ventilation of roof space. Enough to sew two perforated soffit overhangs, or mount the ventilation grille.

But do not choose a shed roof for the rather narrow buildings, which is inexpedient to arrange the attic floor in this way.

Gable mansard roof: Features Construction

Gable roof is the most common and reasonable solution that allows you to get comfortable attic. Photos of houses with mansard roof this configuration, confirm the demand structure.

Design and construction of the gable mansard roof with his hands does not cause any difficulties. It is formed by two inclined planes (ramps) which intersect in the area of ​​the ridge at a predetermined angle. With the right choice of the optimal angle can create a reliable protection of the building by heavy rainfall, strong winds, extreme snow pressure during heavy snowfall.

There are varieties of roof system configuration of the bi-mansard roofs:

• symmetrical gable roof is a classical one, making it possible to evenly distribute the load on the bearing wall and support the roof. The disadvantage of this design is the presence of sharp corners which take the attic space;
• asymmetrical roof is a custom design, wherein the skate can be displaced to one side. If one of the angles is greater than 45 degrees., Got quite a spacious attic room. However, in the calculation should take into account uneven load distribution on mauerlat and load-bearing walls.
• polygonal surface has a mansard roof rays, bendable middle forming faces resembling two rectangles.

Mansard roof truss system. Drawings classic version

When the question arises, how to make a mansard roof of the house with his own hands, you should choose the most simple in execution and practical option for a further operation. Therefore, for private houses preference sloping ceilings.

This design allows you to not only create a significant of attic space, but also because overhangs that fall low enough to protect the upper part of the walls of the building and the foundation of the weather precipitation. In addition, it is a good solution for the creation of the original exterior of a private house.

Related article:

Warming of the attic from inside if the roof is already covered: materials and technologies

How to choose the right material. How to avoid common mistakes in their work. Phased execution of works with his hands.

The angle of inclination sloping roof depends on the region, climatic conditions and the roofing material. Classical polygonal mansard roof drawing which graphically displays it, has a ratio of inclination of the upper plane of the floor ramps to 30 degrees, and the lower -. 60 degrees. The angle of inclination of the lateral surfaces may vary from 45 to 80 degrees.

Useful advice!For regions where characterized by strong winds, better to arrange a flat roof. Because, the more the ramp, the more wind resistance it creates.

Taking into consideration these data, the parameters of the house, and that the ceiling height in the attic should not be less than 2 m, it is possible to perform the calculation of all the parameters. Conventionally, the load can be ignored on the side surface from rainfall, since they will be held in the upper roof part.

Calculation of the mansard roof

On specialized sites can be found drawing sloping mansard roof with his hands for a small house. It can be taken as a basis for the implementation of the future settlement, which includes the calculation of the attic space, loads, elements of roof construction and the amount of building materials.

You can use many years of experience of experts for the calculation of a mansard roof, which repeatedly erected classical sloping ceilings and can tell what kind of material you need use. It is from this depends on many parameters of the rafter frame. Calculating the amount of lumber to create a roof system is reduced to the definition of the height and width of the span and, accordingly, the number of wooden bars, which is multiplied by their height.

From the width of the insulation depends on the pitch between the rafters, which should be less than 3 cm width thermal insulation material to minimize waste and simplify its installation. Boards for rafters also selected taking into account the thickness of the insulation material. In the case of basalt wool, 200-250 mm thick and create the required ventilation gap of 20-30 mm, the minimum width of the board is 230 mm. Thickness trusses must be more than 50 mm.

For beams and pillars to be selected with beam parameters of 100 × 100 mm, which will create a durable and reliable construction even for areas in difficult weather conditions.

To calculate the number of insulating and roofing materials used mathematical formulas for determining the area of ​​geometric shapes, which are formed of a certain type of a mansard roof.

Today, the Internet can be done on-line calculation of the mansard roof. To start the type indicated mansard roof truss system diagram, insulation and roofing material and geometric parameters are requested. For more accurate results you should use the services of a specialist, who not only perform the calculation of loads and dimensions of the building elements, but also tells what kind of material is best choose.

Windows for mansard roof

Garret differs from conventional Improvement in that its walls is rafter frame, which consists of certain roofing surfaces, which is clearly shown in the drawings mansard roofs. This affects the window design for the room, which is okay to skip the natural light, and at the same time to hold the load in the form of strong winds or heavy weather precipitation. This is due to the fact that the impact of weather conditions on the sloping part of the roof is much stronger than on the massive bearing elements of the building.

Important!According to the SNP, the window area should be at least 10% of the total floor area.

Window in a mansard roof is graphically displayed photo may be located in the roof plane, obliquely or vertically, or be the end of the attic. Vertical windows in the roof of the plane may be protruding above it (Dormer), or recessed into the room.

The most popular and easiest to install a slanted window in the roof plane. It is able to skip the maximum amount of natural daylight. After installation of the roof surface does not change, but remains smooth. However, this option requires the establishment of proper sealing abutment. Here you should use a special model with reinforced glass and reinforced-plastic frame.

The area of ​​the window opening is selected in proportion to the angle of the roof. The width of the window should be selected so as to fit into the distance element between the rafters without violating the integrity of the structure. If the window is much wider, then we need to establish a reinforced beam, which will connect the rafters cut for window installation. In this case, if a narrow window is not enough, it is better to install two adjacent rather narrow element that will ensure the integrity of the rafter frame.

To set-Dormer window requires complication roof geometries, namely requires installation of lateral and upper valleys with subsequent thorough waterproofing. Also complicated laying of roofing.

Vertical box, recessed into the room, it is advisable to arrange only when it will be implemented through a balcony. In other cases, it is unnecessary significant financial costs (complication roof geometry) to obtain minimal effect (insufficient natural light).

A simple, practical and cheaper option is to install a window in the end of the roof. This is especially true for country houses with mansard roof.

Mounting methods mansard roof

Apparatus mansard roof truss system can be implemented in two ways. The first option involves the collection of the rafter frame on the ground and then lift it off the shelf upstairs at home and thoroughly secured. The method is efficient for small structures.

How to make a roof terrace with the collection of the roof system on earth? Pre top of the building are set vertically and fix extreme designs, which will be subsequently gables. Temporarily fix them, you can use the long boards, nailed to the wall. In mauerlat created depressions with a predetermined pitch, which will be mounted on the assembled structure. To ensure proper geometry and create a structure stiffening elements can be attached to its struts. When it is finished the installation of the side beams and the whole system will acquire the necessary rigidity, spacers can be removed. Video installation of roof system gable mansard roof clearly show all the features of this embodiment.

The second option is more traditional. He suggests the device mansard roof in place in compliance with the strict sequence of actions. This method is the most convenient and efficient in the construction of large roof system. Because for lifting the assembled structure upstairs necessary to involve specialized equipment.

How to build a mansard roof in the traditional way?

Some subtleties of technology in the construction of mansard roofs of private houses depend directly on its type. However, the sequence of operations is similar for all types of mansard roofs.

Before you make a mansard roof, must be laid in the longitudinal direction of the load-bearing walls mauerlat, and secure it to the masonry or Laying nets by means of pins or rods. Mansard truss roof of a wooden house can be mounted on the upper crown, which will play the role of mauerlat.

Building a mansard roof starts with installing beams to overlap. They attach to the mauerlat. Then the beams are fastened foot building. In the center of the beams should be noted the place of installation of poles and skating element.

should mount the rack of boards, fixing them by means of corners Subject to the same distance. The first pair of struts sealed puffs of wooden bars. On the formed U-shaped structure to be mounted rafters. They can be mounted on mauerlat or use the slot blanking the beam overlap.

Further, should proceed to install ridge rafters, which are connected by means of metal pads or bolts with washers. To produce the necessary rigidity to the central part of the side straps and the rack, attach braces, and tightening the center mount beams. Similarly installs other farms with a distance of 60-100 cm. They are fixed together by means runs.

Since fixing is performed using staples mansard all nodes structure and give it the final strength. This is followed by lathing mount, which may be solid or sparse, depending on the embodiment of the roofing.

If you are using shingles, slate or asbestos cement flat web material, perform continuous crate. It is set in two layers. The lower deck is composed of bars 20 cm thick, stacked in increments of 30 cm. The upper deck consisting of planks size 20 × 50 cm, is beaten with respect to the lower layer at an angle of 30-45 degrees.

For clay tiles, slate azbestotsementnogo, metal, Steel, metal coating type is used sparse lathing. To do this, it performed the installation bars, section 5 × 5 cm and a step in the 20-30 cm from the eaves up perpendicular to the rafters. On overhang must install flooring wooden planks width of about 70 cm. Followed fasten the bars along the ridge and edges which are joined end to end. Intuitively, this process can be seen on a photo frame of roof gable roof under the metal.

Technology insulation mansard roof

Thermal insulation of mansard roof of a private home not only to insulate the attic, but also to create proper insulation throughout the roof system that lasts for many years.

As part of the circuit insulation mansard roof is a complex of measures, which include the establishment of thermal, hydro, and vapor barriers. On top of the cake roofing laid roofing material, which protects the entire structure from adverse environmental factors. To protect the insulation from the adverse effects of the condensate, which reduces its insulating properties, it is necessary to protect it from the roof material. This may be used one of the proposed sheet materials:

• waterproofing film, which is attached to the outside of the rafters. She should not touch the insulation material, so cut off from his crate or counter-;
• ̶ diffusion membrane is attached to the insulation and protects it from any moisture.

Useful advice!Waterproofing material should be laid with light sag, eliminating the possibility to pull it.

The waterproofing layer is necessary to expand across the rafters. We must start from the bottom. The first row of drops in the gutter. Each subsequent roll must overlap of 10-12 cm. Thus it should reach the ridge. There, the material is cut along the top edge and is secured on both sides. Along the ridge of the roof should be to roll out a strip which runs down both sides of the roof to the gutter, which ensures a uniform water abstraction.

Vapor barrier layer as a membrane is a reliable insulation protection from penetration into its thickness of a pair of spaces. The material is also laid overlapped and fastened to the joists by means of staples of a stapler. All joints and places of contiguity should be carefully glue using a special double-sided adhesive tape a vapor.

Useful advice! On the insulation film deposited bold line from which the next layer should start. Following in her canvases are held together with duct tape.

Important rules for insulation of mansard roof

When the question arises what is best for insulation mansard roof, there is no single answer here. However, due to the fact that for a typical high mansard roof inclination angle should not use soft materials which will cake and the sliding surface.

Roll insulation to be installed from the bottom up. To do this, use a staple gun and lace. Rolling roll, the material is pressed against the slats. With the help of lace and staples drawn the letter Z. By this technique, each layer of insulation is attached.

It is better to give preference to the plates, the density of 30-50 kg per cubic meters. m. In this case, step trusses have to adjust for the size of a heater which is 10-15 mm should be less than the width of thermal insulating plates. This is required to ensure that the material could become vraspor without formation of cracks and well-maintained between the beams. If the width is smaller or larger, it will be necessary to cut the material. Create a clean cut is not always successful, and also remains a large amount of debris. Positioning plate should be such that the stitches of the previous row overlap followed.

Insulation is placed so as to provide a minimum amount of cold bridges. In addition, the remnants of the material can be laid on stuffed by the required width of the strips of the room. On top of the layer of insulation is laid, steam, and lathing is performed for future finishes. Such an embodiment, wherein even overlap the rafters, almost completely eliminates the formation of cold bridges. Despite the fact that it will take a little more insulation material, loft eventually get warmer, which will give the opportunity to reduce space heating costs.

Important!promote the formation of cold bridges in the roofing cake moisture. This may lead to rot trusses, swelling insulation material, corrosion of metallic structural elements, the appearance of unpleasant odors indoors.

How to insulate a roof terrace: the progress of work

There are two ways roof insulation: the inside or outside. When using the first option, you can push the performance of interior trim for a certain period. The second option involves the full range of activities, which allows for rapid completion.

How to insulate a roof terrace outside? For this it is necessary to prepare the surface trusses, purging it of protruding elements that can damage the hydraulic and vapor barrier layer. From inside the room across the rafters need to fill the crate, which is located a heater. Instead crates, can be attached to galvanized wire or cord.

On the part of the roof on the crate insulating layer is mounted in compliance with the above rules. Mansard roof insulation thickness should be more than 100 mm. Above the insulation material is laid superdiffuzionnaya membrane. Next, fill a crate, which will lay a roofing.

Now, with the inner side of the room must be secured and glue vapor barrier. Then you can proceed to the interior decoration. This variant of the roof insulation is considered to be the easiest to implement. Insulating panels easily fit on a previously created crate.

Technology insulation mansard roof with his hands inside is done in two stages. The first mandatory step is as follows:

1. Is unrolled and secured to the rafters waterproofing layer.
2. Stuffed crate.
3. Mounted roofing material.

After performing the obligatory list of works, it is possible to postpone the mansard roof insulation for an indefinite period, which may be due to the lack of financial means at the moment.

The second stage less easy to implement. Insulation will be executed mansard roof inside. It is necessary to create an enclosing structure that will hold the insulation, and prevent its expulsion of more than possible. To this end, between joists stuffed trims in increments of 40-50 cm. They will not only keep the insulation, but also create the necessary ventilation gap.

Further carried out the installation of thermal insulation layer with all the rules. It stuffed crate. Further it is necessary to position and affix vapor barrier membrane. You can then begin the finishing. To do this, you can mount the crate, and you can do without it.

Varieties of insulation for the attic roof. What is the best insulation?

Today, there are several options for the mansard roof insulation:

• mineral wool;
• polystyrene;
• polyurethane;
• Styrofoam;
• glass wool;
• izovert;
• ecowool.

The most popular material is mineral wool, namely basalt. This relatively inexpensive material discharged convenient thickness and sufficient rigidity. It retains heat well, is not flammable and does not rot. However, she is afraid of water. Therefore, to ensure the preservation of all the technical and operational characteristics, it must be carefully protected from all sides.

The foam has good performance characteristics that give it the ability to create good thermal insulation. Price of the material is relatively low. It is easily installed between the rafters vraspor due to its flexibility and because the plates can be purchased the required size. All joints should be sealed with foam.

Useful advice!During combustion it is able to give off noxious substances, so better to give preference to self-extinguishing marks where special additives are used.

The material is not afraid of water. He does not make steam, which is the main drawback of the foam. In this connection it is necessary to create a good ventilation system in the attic, leading to additional financial costs.

It has better characteristics extruded polystyrene, whose thickness is two times less than that of mineral wool, and a half than that of the foam. Material system equipped with locks that eliminates the formation of cracks. Epps is not formed on the fungus and mildew, its not like rodents and insects. However, he does not let couples that requires the creation of a good ventilation system. Another drawback is the high cost of the material.

Recently, a new type of insulation - foamed polystyrene. It is applied to the surface in liquid form, filling the gap. In this case, to react with oxygen, increases several times in size, forming a monolithic coating.

Useful advice!Application of foam polystyrene will enable correct position in case of lack of waterproofing layer when installing roofing.

Another new generation of thermal insulation material is ecowool, which has good performance. However, its application requires special technology. Loosened wool is fed under pressure into a closed cavity, filling all the voids and form a coherent solid layer of insulation. To organize the enclosed cavity to the rafters below and above the sheeting is nailed in the form of plywood, fiberboard or gypsum fiber.

A distinctive advantage of this material is its ability to carry out steam. Here, the humidity is regulated in a natural way that does not require the vapor barrier. However, between the insulation and the roof must be created ventilating gap, where the movement of air masses.

Today, among the possible projects of houses with mansard roof, you can choose the most appropriate and attractive option, and make it a reality for your own private home. To make the house a visually beautiful and aesthetic, you need to get serious about the choice of type of a mansard roof, which should be in harmony with the building's design. Properly arranged truss roof system can perfectly perform all of its operational and safety functions, which will create a warm, cozy and comfortable room.

Creating a mansard roof with his hands in steps. video instructions