How to make a sloping roof frame. How to build a sloping roof: taking into account the correct technology. Video - Do-it-yourself sloping roof
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broken roof differs from gable construction installation of rafter legs in two levels. The following collection of videos about a sloping roof will help you understand the technology for creating such rafter system of two levels.
Broken roof on the bathhouse
Here you will see the construction of a sloping roof on a bathhouse made of timber. Workers first installed the interior supports and rafters for the lower tier. This was followed by the covering of the rafter system and gables. Only after this the team began installing the rafters of the upper part.
Sloping roof rafters for a timber house
IN next video presented step-by-step instruction for assembling the rafter system. First of all, you need to install a support beam of the required length, taking into account the overhangs. Look carefully at how to connect the two parts of the support beam. Pay attention to the location of the docking bar. It must be inside the house.
In the second part of the video you can watch the installation of a rafter system on a house. The sheathed front gable is installed first. Then the remaining elements of the system and the rear sheathed gable are raised.
Making roof overhangs correctly
In the following video you will see instructions for installing a roof overhang.
Do you want to learn how to design an attic sloping roof yourself? Many questions are answered in the following video. Using the recommended program, you can independently develop a sloping roof project for your home.
Many owners of private houses, experiencing a completely understandable desire without special costs to get an extra living floor, they turn the attic into an attic. In this case, it is advisable to build a broken roof instead of a conventional roof with straight slopes. We will tell you in this article how and from what such structures are built.
Types of sloping roofs
A sloping roof differs from a regular one in that its slope consists of two planes:
- the top is flat;
- the lower one has a slope of more than 45 o.
It looks as if an ordinary gable roof was taken by the middle of the slopes and stretched to the sides and upwards, thereby significantly increasing the volume of the attic space. But increasing the volume is only one of the advantages of such a solution. The second is the ability to make the roof higher. After all, its upper part, at the level of which the wind pressure is maximum, due to its slight slope, experiences less wind loads than a conventional roof with straight slopes.
The slope of a sloping roof consists of two planes with different angles tilt
Distinguish the following types broken roofs:
- Single-pitch. It consists of only one broken slope, while the walls have different heights. This type of roof is the simplest, but it is rare and mainly found on extensions.
- Gable. Classic version, including two falling into different sides broken slopes. The ends of the roof - the gables - are vertical and represent a continuation of the walls.
- Three-slope. In this version, a third broken slope appears at one end instead of a pediment. This type of roofing looks more interesting and creates less load on the foundation. end wall. The gable roof is asymmetrical, so it is used mainly on attached buildings.
- Four-slope (hip). There are no pediments, there are broken slopes on all sides. It is being erected on a separate building. Disadvantage - the volume of the attic is reduced compared to the classic gable version. Advantages: spectacular architecture and minimal load on the foundation under the end walls.
The slopes of a sloping roof can rest on:
- Walls.
- Floor beams placed outside the walls. This option is more difficult to implement, but it allows you to make the attic more spacious.
Along with the usual ones, there are sloping roofs that have additional structural elements:
When installing a sloping roof, a combined rafter system is used. The upper flat rafters - they are called ridge rafters - are hanging, that is, they are supported only by the lower ends, and the upper ends are joined to each other. To prevent these rafters from moving apart under the influence of their own weight and snow load, they are connected by a horizontal element - a tie.
The side rafters are layered. They lean and bottom- on the walls using a Mauerlat, and on the top - on vertical racks.
In the sloping roof rafter system, both layered and hanging rafters are used simultaneously
Due to the simultaneous presence of both layered and hanging rafters This system is called combined. In some cases, the side rafter has to be supported in the middle by a strut that rests on the base of the post.
The racks, in turn, rest on the floor beams. If the attic floor is made of concrete slabs, then to support the racks a wooden beam is laid on it - a bench. The racks form the frame of the attic walls, and the ties form its ceiling.
The frame of a sloping roof consists of rafters - hanging and layered - and additional elements that ensure structural rigidity
Rafter attachment points
The reliability of the rafter system depends on the correctly chosen method of fastening its elements.
Under the influence of load, the hanging rafters will move apart, sliding along the surface of the beam or tie. To prevent slipping, the following types of connections are used:
- If the roof slope exceeds 35 o, a single-tooth lock is sufficient for fastening.
The tenon rests on the reciprocal groove of the tightening and does not allow the rafters to move apart
- For flatter slopes, a double tooth is used. To enhance the strength of the connection, two stops are cut out in the tightening. One of them - the outer one - is supplemented with a spike. An eyelet is cut out to fit its size in the mating part of the rafter.
For flat slopes, fastening the rafter leg to the tie is usually done using a double-tooth lock
- The most complex node of a sloping roof is located at the intersection of the hanging rafters, the tie and the layered rafters. Therefore, it is reinforced with bolted connections.
A pair of bolts effectively counteracts the torque at the connection point between the rafters and the tightening
- The rafter leg is attached to the mauerlat using corners and staples. To facilitate installation and limit the movement of the rafter, a stop block must be nailed to its lower surface.
A support board or block placed on the bottom edge of the rafter leg prevents it from sliding down
Broken roofs with “cuckoo”, balcony, window
If the roof has a “cuckoo” roof, then its rafter system is connected to the main one. The “cuckoo” roof can be:
The presence of a “cuckoo” weakens the main rafter system; in addition, careful sealing of the junction is required different parts roofs. Because of this, it is better to entrust the design and construction of roofs with such elements to specialists.
A balcony in the attic can be organized in three ways:
To install a roof window, bars are secured between the rafters to outline the opening. They will play the role of a supporting contour for the window structure.
There are known cases when construction companies In order to expand the attic space, they decided to modify the classic truss scheme of a sloping roof, abandoning the usual arrangement of racks.
The technical solution is as follows:
As a result of strengthening the break point of the slope with overlays, a pair of rafters works as one rafter leg of a curved shape.
Is it possible to make a sloping roof with a raised puff?
The location of the tightening is higher than usual - a technique that is sometimes resorted to when erecting a gable roof with straight slopes. But in the case of a sloping roof, a raised tightening device is not practiced, since this requires moving the racks, as a result of which the attic space becomes less wide.
Calculation of the sloping roof truss system
To determine the dimensions of the rafters, you must:
To calculate the strength, you need to measure the angles of inclination of the rafters with a protractor.
Strength calculation
Today calculation of the rafter system mansard roof can be done using specialized software systems. But you need to be able to do it manually, because in the field a computer is not always available, and it will be useful to check the results before starting work.
To carry out calculations, you need to know the standard snow and wind loads characteristic of the construction region. This data should be found in SNiP 01/23/99* “Construction Climatology”. According to this document in Russian Federation There are 8 zones with standard snow loads from 80 to 560 kg/m2.
The map shows the standard values of snow load for each climatic region of our country
The value of the standard snow load can be taken from the reference table.
Table: standard snow load values by region
| Region No. | I | II | III | IV | V | VI | VII | VII | 80 | 120 | 180 | 240 | 320 | 400 | 480 | 560 |
Actual snow load will depend on the angle of inclination of the slope. It is calculated using the formula S = S n * k, where S n is the standard snow load in kgf/m 2, k is the correction factor.
The value of k depends on the angle of inclination of the slope:
- at angles up to 25 o k = 1;
- for slopes from 25 to 60 o k = 0.7;
- for more steep roofs k=0 (snow load is not taken into account).
Parts of the slope of a sloping roof have different slopes, and accordingly, the actual snow load for them will be different.
In a similar way, the country’s territory is zoned according to the magnitude of the wind load.
The territory of our country is divided into eight regions, in each of which the wind load has its own standard value
There is a reference table to determine the standard wind load.
Table: standard values of wind load by region
| Region No. | I a | I | II | III | IV | V | VI | VII | 24 | 32 | 42 | 53 | 67 | 84 | 100 | 120 |
The actual wind load depends on the height of the building, its surroundings and the angle of the slope. The calculation is made using the formula:
W = W n * k * C, where W n is the standard wind load, k is a tabular coefficient depending on the height of the building and the environment, C is the aerodynamic coefficient.
Table: correction factor taking into account the height of the building and type of terrain when calculating the actual wind load
| Height buildings, m | Terrain type | ||
| A | B | IN | |
| Less than 5 | 0,75 | 0,5 | 0,4 |
| 5–10 | 1 | 0,65 | 0,4 |
| 10–20 | 1,25 | 0,85 | 0,55 |
Terrain types differ according to the following characteristics:
- Zone A - open areas where the wind does not encounter obstacles (coast, steppe/forest-steppe, tundra).
- Zone B - areas where there are wind obstacles with a height of at least 10 m: urban development, forest, terrain folds.
- Zone B - densely built-up urban areas with buildings within 25 m in height.
Aerodynamic coefficient C takes into account the angle of inclination of the slopes and the prevailing wind direction. It should be understood that the wind can exert not only pressure: at small angles of inclination of the slope, a lifting force arises, tending to tear the roof away from the mauerlat. To determine the C coefficient, you need to use reference tables.
Table: aerodynamic coefficient values - the air flow vector is directed towards the slope
| Slope slope, hail | F | G | H | I | J |
| 15 | -0,9 | -0,8 | -0,3 | -0,4 | -1,0 |
| 0,2 | 0,2 | 0,2 | |||
| 30 | -0,5 | -0,5 | -0,2 | -0,4 | -0,5 |
| 0,7 | 0,7 | 0,4 | |||
| 45 | 0,7 | 0,7 | 0,6 | -0,2 | -0,3 |
| 60 | 0,7 | 0,7 | 0,7 | -0,2 | -0,3 |
| 75 | 0,8 | 0,8 | 0,8 | -0,2 | -0,3 |
Table: aerodynamic coefficient values - the air flow vector is directed towards the pediment
For those areas of the roof where lifting force occurs, the value of coefficient C is negative.
The actual snow and wind loads are summed up and, based on the result obtained, the cross-section of the rafters is selected (taking into account their pitch and maximum length). Below is a table for rafters made of premium grade softwood (for other grades the values will be different). Its cells indicate the maximum permissible rafter length for the corresponding cross-section, pitch and load.
Table: maximum permissible length of rafters in accordance with the pitch of their installation and the magnitude of the snow load
| Section, mm | ||||||
| 100 kg/m2 | 150 kg/m2 | |||||
| Distance between rafters, mm | ||||||
| 300 | 400 | 600 | 300 | 400 | 600 | |
| 38 x 80 | 3,22 | 2,92 | 2,55 | 2,61 | 2,55 | 2,23 |
| 38 x 140 | 5,06 | 4,6 | 4,02 | 4,42 | 4,02 | 3,54 |
| 38 x 184 | 6,65 | 6,05 | 5,26 | 5,81 | 5,28 | 4,61 |
| 38 x 235 | 8,5 | 7,72 | 6,74 | 7,42 | 6,74 | 5,89 |
| 38 x 286 | 10,34 | 9,4 | 8,21 | 9,03 | 8,21 | 7,17 |
Installation of rafters in increments of 600 mm should be considered the best solution: with such an inter-rafter distance, the rigidity and stability of the structure will be maximum, and for insulation it will be possible to use slabs of mineral wool or foam plastic of standard width.
Video: attic calculation
DIY construction of a sloping roof
Broken roof refers to building structures medium difficulty. If you have certain skills and several smart assistants, it is quite possible to build it with your own hands.
Selection of necessary materials
To build a sloping roof you will need:
- Vapor barrier film - polymer or anti-condensation film with an internal non-woven textile layer.
- Waterproofing. You can use a special plastic film or the so-called superdiffusion membrane, which retains moisture but allows steam to pass through.
- Annealed wire with a diameter of 3–4 mm, which is used as fasteners when constructing a rafter system.
- Other types of fasteners - bolts, nails, staples, special fastening plates with stamped teeth.
- Steel sheet with a thickness of 1 mm - linings will be cut from it for fastening the elements of the rafter system.
- Roofing material and screws (nails) for fastening it.
- Lumber.
- Insulation - mineral wool, URSA (fiberglass), expanded polystyrene.
Rafters and other elements are usually made from the cheapest type of wood - coniferous. It should not contain rotten areas or signs of damage by bugs. All wood must be treated with antiseptics before installing the rafter system.
When constructing a sloping roof rafter system, pine beams and edged boards without defects or damage are used
The following lumber will be required:
- for floor beams - timber with a section of 150x100 mm, if the beams are supported by external and internal load-bearing walls, or with a section of 200x150 mm when supported only on the external frame of the building;
- for the manufacture of Mauerlat - timber with a section of 150x100 mm or 150x150 mm;
- for racks - usually a beam of the same cross-section is used as for floor beams;
- for rafters - a board or beam, the cross-section of which is determined by the above calculations;
- for some fastening elements and subfloor - unedged board various thicknesses;
- for sheathing - edged board with a cross-section from 25x100 to 40x150 mm, depending on the pitch between the rafters and the type of roofing material;
- for counter-lattice - a board 50–70 mm thick and 100–150 mm wide.
The procedure for performing work on the construction of a sloping roof
The process of constructing a sloping roof is as follows:
- Mauerlat is laid on the walls. You must first lay a waterproofing layer of roofing felt under the timber.
- The Mauerlat is attached to the wall using studs or anchor bolts embedded in it (in this case you will have to drill holes in the wall) with a diameter of 12 mm. The fastener must extend into the body of the wall at least 150–170 mm. The Mauerlat can also be tied to the wall with annealed wire embedded in it.
For buildings made of concrete or building blocks, it is most convenient to attach the Mauerlat to studs embedded in the armored belt when it is poured
- Install floor beams. If the floors are expected to extend beyond the walls, they must be laid on a mauerlat. Otherwise, the beams are laid on the walls through a roofing material pad and attached with corners or staples to the Mauerlat.
- Determine the middle of the floor beam and step back to the left and right exactly half the width of the attic room - this is where the racks will be installed.
- The timber is nailed and then set strictly vertically, using a plumb line and building level, and are finally attached to the floor beam using corners and wooden overlays.
Vertical posts are installed strictly vertically, and then connected with longitudinal girders and transverse ties
- Having installed both racks on the floor beam, they are connected at the top with a horizontal beam - a tie. Again, corners should be used for fastening.
- Side rafters are installed on the sides of the resulting U-shaped structure. At the bottom, each rafter rests on a mauerlat, for which it is necessary to cut a groove in it (the rafters). Fastening to the Mauerlat is carried out with brackets or corners.
The rafter leg is attached to the mauerlat using brackets, angles and other special fasteners
- If the length of the rafter exceeds the maximum allowable, it is supported by a strut resting against the base of the rack. Additional stands and so-called contractions are also used.
To further strengthen the rafter legs, you can use struts, grips and additional racks
- Determine the middle point on the tightening: it will be installed here vertical beam- grandma. Its function is to support ridge knot, that is, the junction of the upper rafters.
- Install the upper (ridge) rafters. In the ridge assembly they must be firmly attached to each other, for which it is necessary to use powerful bolts with washers or plates or a steel plate.
The connection of rafter joists in the ridge part of the roof can be done end-to-end, overlapping or half-timbered
- Place the headstock in its place.
- Everything is collected in this way roof trusses. First, you should assemble the outer trusses - then between their key points it will be possible to stretch pieces of cord, which act as a guide when assembling the intermediate trusses.
- The trusses are fastened to each other with horizontal purlins, which should connect the upper parts of the racks. The purlins can be installed at an earlier stage, immediately after the installation of the racks.
- The finished rafter system is covered with a waterproofing film on top. As already mentioned, along with conventional polymer films, membranes are produced today that act as a barrier to water but allow steam to pass through. IN different directions this membrane acts differently, so it needs to be laid right side(there are marks on the canvas). The film roll is unwound in horizontal rows, moving from bottom to top, and the next row should lie on the previous one with an overlap of 150 mm.
The waterproofing coating is laid parallel to the eaves overhang with an overlap of 150 mm
- The overlapping areas are taped with double-sided tape. The film should not be stretched - it should sag by 2–4 cm. To prevent the material from slipping, it is fixed with a stapler (construction stapler).
- Along the rafters, a counter-lattice is placed on top - boards 50–70 mm thick and 100–150 mm wide. This structural element is necessary to create a ventilated gap between the waterproofing and the roofing material - this will remove condensation formed due to steam penetrating under the coating.
- On top of the counter-lattice, in a direction perpendicular to it, a sheathing is stuffed - boards, slats or solid flooring, the parameters of which depend on the type of roofing material and the design load.
Counter-lattice bars form ventilation gap, and the longitudinal rows of the sheathing serve to fasten the roofing material
- The roof covering is attached to the sheathing.
Video: installing a sloping roof
Insulation of the roof is carried out after completion of the installation of the rafter system and laying of the waterproofing layer. A special feature of a sloping roof is that the insulation is laid along the lower rafters and the ceiling of the attic space formed by the ties. The upper triangle of the roof is left cold to ensure ventilation of the under-roof space.
Insulation boards must fit into the gaps between the rafter joists with a noticeable tension, so as not to create conditions for the formation of cold bridges
If a regular film was laid over the rafters as waterproofing, there should also be a ventilated gap of at least 10 mm between it and the thermal insulation. If a superdiffusion membrane was installed, there is no need to create a gap.
Insulation boards are laid in several layers with offset joints in each row. A vapor barrier membrane is mounted on top of the insulation.
The roof is a multi-layer structure consisting of protective films, insulation, roofing and ventilated gaps
Video: insulation of a broken attic roof
https://youtube.com/watch?v=UqWyrNQ4eq0Selection of roofing materials
It remains to decide what to cover the roof with. There are quite a lot of roofing materials today; we present a comparative description of the most popular of them.
Ondulin
In appearance, ondulin resembles slate, only it is multi-colored. In terms of internal composition, it is structured completely differently: it is bitumen material, like roofing felt, only the base is not cardboard, but a rigid sheet of pressed cellulose. Ondulin costs a little more than slate, but still remains in the category of budget materials.
Disadvantages of ondulin:
- burns;
- has low strength;
- short-lived;
- in hot weather it can emit a characteristic bitumen smell;
- on the shaded side, like slate, it can become overgrown with moss, although manufacturers claim that this is impossible.
In addition to low cost and extensive color range The material also has quite tangible advantages:
- does not make “drumming” sounds during rain or hail;
- unlike slate, it is plastic, which makes it more durable impact and can be used to cover roofs with complex contours (“unbendable” slate would largely go to waste);
- has low thermal conductivity compared to metal coatings, so it does not heat up so much in the sun.
Corrugated sheeting
Today, corrugated sheeting is one of the most popular roofing materials. “Profiled” translated into everyday language means “wavy”, only the waves of corrugated sheeting are not sinusoidal, like those of slate and ondulin, but trapezoidal.
Corrugated sheeting is available in the form metal sheets with trapezoidal waves
Corrugated sheets are made from steel sheets, which are coated with a double protective layer: first with zinc, then with polymer. The material is very durable: its service life can reach 40 years. But you need to take into account that much depends on the type of protective polymer used:
- Acrylic. The least resistant type of coating. It is easily damaged during installation, it fades quickly and can peel off after only 3 years of operation.
- Polyester. Most often used. In terms of cost and durability, it is the best option for normal conditions, when there is not a large amount of pollution in the atmosphere and the roof is not subject to intense mechanical stress. Polyester is applied in a layer 20–35 microns thick, so during installation, special care must be taken to avoid damaging the coating.
- Plastisol (PVC-based polymer). It is applied in a layer 175–200 microns thick, therefore it has increased resistance to mechanical stress and withstands the chemical aggression of a heavily polluted atmosphere. But it is not designed for high temperatures and intense ultraviolet radiation, therefore for southern regions doesn't fit. Another drawback is that it burns out quickly (in 4–5 years).
- Pural. This polyurethane-based coating appeared relatively recently. Applied in a layer 50 microns thick, it is also resistant to solar radiation, and to chemical exposure, and to temperature changes. It also gives the material wear resistance.
- Polydifluorionad. Corrugated sheeting with such a coating is the most expensive, but it is also the most durable. Designed for extreme climatic conditions or chemically active environments. For example, it is advisable to use such corrugated sheeting to cover buildings located on the seashore, or the buildings of a chemical plant that produces emissions into the environment.
Metal tiles
Metal tiles, like corrugated sheets, are made from steel sheets with a polymer coating, only they are given a more complex shape that imitates the surface of ceramic tiles. Looks more impressive, but to give the desired shape It is necessary to use thinner steel, so metal tiles are inferior in strength to corrugated sheets.
Metal tiles are superior in aesthetic qualities to corrugated sheets, but inferior in strength and durability
Metal tiles have the following advantages:
- Light weight.
- Economical.
- Aesthetics.
- Resistant to fading and abrasion.
But this material has disadvantages that can upset the homeowner:
- High level of sound transmission: during rain and hail, the house will be noisy.
- Large amount of waste when covering roofs complex shape.
Monolithic polycarbonate
A transparent roof made of monolithic polycarbonate is a rather exotic option. Insulation in this case, of course, is not provided, so such a solution would be appropriate only in a region with a warm climate.
Polycarbonate as a roofing covering is mainly used on non-residential buildings, agricultural structures and buildings located in the southern regions
For fixation plastic panels a frame made of aluminum or steel profiles is attached to the rafters. When fixing polycarbonate, you need to take into account that this material changes greatly in size with temperature changes, therefore:
- the diameter of the mounting holes should be 2–3 mm larger than the diameter of the screws;
- It is impossible to screw the screws tightly.
Monolithic polycarbonate is different:
- impact resistance;
- low specific gravity;
- resistance to fire and fading;
- inertness towards aggressive chemical elements;
- ease of handling and cleaning.
At the same time, this material is unstable to small sharp objects and has a high coefficient of linear expansion when heated.
Soft roll roofing
Traditionally, the following types of soft roll coverings are distinguished:
All these materials are produced on the basis of bitumen or a bitumen-polymer mixture. They can only be used on roofs with a slope of up to 25 o - such a coating can slide off steeper slopes in the heat. Not long ago, new varieties of soft roofing coverings, the raw materials for which are rubber and petroleum-polymer resins. They can be laid on slopes of any steepness and, unlike bitumen ones, they withstand the effects of negative environmental factors well (service life is 25 years) and are laid in one layer (bitumen-containing materials are laid in 3–5 layers).
We also produce such materials - these are Rukril and Cromel membranes. The roll width can reach 15 m, so there will be very few seams in the coating.
Membranes are attached either to special glue, or using self-tapping screws.
As can be seen from the drawings and diagrams, a sloping roof allows you to use with maximum benefit attic space. But at the same time, it surpasses the complexity of a conventional pitched roof, both in calculations and in implementation. Therefore, in the absence of sufficient experience, it is advisable to entrust its design and construction to a specialized organization.
After lofts came into fashion, that is, essentially, attics converted into housing, sloping roofs became extremely popular. This is a kind of variation on the theme of a gable roof, but with a slightly more complex geometry. Thanks to the arrangement of a sloping roof in your home, it becomes possible to increase the useful living volume of the attic - significantly raise the ceiling in extreme points stingray In addition, as many believe, such a roof looks more unusual and much more impressive than a simple gable roof.
The construction of a sloping roof is somewhat more complicated than a gable roof, but easier than any four-slope roof - hip, half-hip, hipped, as well as others with more exotic geometry. However, before you begin to study this topic, it is recommended that you familiarize yourself with the basic terms and concepts and learn how to build more simple options roofs - single-pitched and gable.
Broken roof: where to start
In construction, even a doghouse cannot be built without planning, so the zero step in constructing a sloping roof will be drawing a drawing. It can be done on a computer or manually. First, we build a frontal projection of the foot (the foot, in short, is the base of a house without a roof) of our house. Now, also observing the proportions, we build on the drawing the roof we like. Don’t forget that there will be an attic underneath it, so you need to think about the height of the ceilings in it. This way we will get the approximate roof height, slope degree and other parameters.
On the proposed plan the break is located at a height of 3.1 meters, which, in fact, will be (conditionally, without taking into account the under-roofing pie) the final height of the ceiling in the attic. If the finishing is done with plasterboard, then in the end the ceiling in the attic floor will be about 2.5 meters - quite good. The outer angles of the slopes with the horizon are: ridge - 30°, side - 60°. By the way, if the angle of the slope is 60° or more, then the snow load may not be taken into account in the calculations - the snow will not be retained on it. Your own drawing may have other options.
Calculation of the components of the rafter system
To prevent our roof from collapsing under its own weight and the weight of the “roofing pie,” we need to accurately select the cross-sections of the beams and boards of the rafter system, and also calculate their maximum strength. To do this you need to use a special program “ Calculation of rafters and floor beams».
To calculate the cross-section of the beams of the side slopes, you need to open the tab (they are at the bottom of the window) “Sling.1”. Next, we establish a suitable section and introduce from plan of our house is an indicator of the vertical reaction force (in the picture in the program it is a red arrow pointing upward) at the highest point of the rafters. Let's call this indicator Q1 kg.
When installing tie boards, under each one, somewhere in the middle of the length, we install a temporary support. This allows you to reduce the degree of sagging. You can use supports 2.5x15 cm (in the illustration you can see a support for only one puff). They are necessary so that during the installation of the rafters there is no fear that one of the beams will break, and also to prevent sagging.
We put a 2.5×15 board on top of the ties, which will tighten them and make the entire structure more stable. Important: this board cannot be installed exactly in the center - it will interfere with further installation. It will be enough to retreat from central axis about 20 cm to the right or left.
Now we install the side rafters as shown in the illustration. We do not forget that, despite all our efforts, the geometry of the roof base may not have been ideal. Therefore, first we make a template along the end beam. Then on all subsequent rafters we make only the top cut. After this, we place the rafter in the place we need and only then we finally file it down. Only after this we fasten the rafters.
If the length of the beam is not enough, it can be extended, but an additional stand must be placed under the joint.
Now you can install the plugs for insulation material as shown in the illustration.
Next, you can install the rafters of the upper ridge slope. We make a temporary stand: take a 2.5×15 board and place it exactly perpendicular to the extreme tightening, as done in the illustration. The right (or left) edge of the board should be aligned exactly with the center axis. Now we take a board of the same cross-section, apply it to our central post and make marks with a pencil where the upper and lower cuts will be - we have a template.
When building a roof for an attic room, it is sometimes impossible to ensure its normal height at the same angle of inclination along the entire slope. In this case, the sloping roof of the house comes to the rescue, the rafter system of which is a little more complex than that of a conventional gable roof. Before building such a structure, it is necessary to understand its main elements and components.
What is a sloping roof
It is typical for houses with an attic. It has two slopes on both sides. The slope that is located closer to the eaves has a greater angle of inclination than the one that is closer to the ridge.
A device of this design is technologically more complex than a conventional one. gable roof, but it allows you to win at the height of the room. Instead of an attic with a sloping ceiling, the owner gets full rooms. This is achieved by the fact that slopes with a large angle of inclination act as a continuation of the vertical walls, and with a smaller angle - the ceiling.
The broken roof has two slopes on both sides
Main elements of the system
Before you make a sloping roof, you need to understand its basic elements. The structure consists of:
Basic elements of a sloping roof
- layered rafter legs, which form a steeper slope (layered rafters - inclined beams resting on two sides, from below - on the mauerlat, and from above - on the crossbar);
- hanging rafter legs that form a gentle slope (spacer structure, support occurs only from below, the expansion is perceived by the contraction);
- mauerlat - timber, which fits along the inner edge outer wall and allows you to evenly distribute the load from the rafters.
- purlins (crossbars), in a sloping roof there can be 2 or 3 of them (two are always present, they serve as the upper support for layered rafters, in some cases they provide a third run in the ridge, in this case all inclined beams of the system become layered, there are no hanging rafter legs);
- racks for purlins which will serve as a frame for the longitudinal walls of the attic (can be installed in increments under the insulation, which will facilitate its installation);
- strut systems, the design allows you to relieve the rafters;
- ties (contracts, tightening), the device of which is provided at the level of the break of the slope (serves to absorb the thrust from the hanging rafters and as a frame for the attic ceiling);
- pendants (headstocks), which is provided for long scrum lengths and prevents sagging.
Selection of materials
To build reliable roof attic, it is necessary to carefully control the quality of the materials used. For structural elements It is worth choosing wood of the first or second grade. The quality is also affected by the time and place of procurement. The best option We will become a material with the following characteristics:
Thanks to resin coniferous trees are more resistant to rotting
- Origin - conifers trees. Due to the resin content, they are more resistant to rotting and destruction. One of the best building materials is larch, followed by pine and spruce.
- Place of growth - northern regions. The harsher the tree's growing conditions, the slower it grows. At the same time, the growth rings are located as close to each other as possible, increasing strength.
- Felling time is the end of winter, the beginning of spring. Again, the completion of growth in winter conditions creates a stronger material for construction.
Besides quality wood, roofing is impossible without antiseptic treatment of all elements.
If necessary, the structure is also treated with fire retardants, which increase fire resistance.
Work production technology
Frame construction process
- Installation of Mauerlat on the walls. The method of fastening depends on the material of the walls. On brick or concrete beams, they are laid on a previously prepared layer of waterproofing. You can use roofing felt (an outdated version), roofing felt, linochrome, waterproofing or other bitumen roll materials. Fastening is carried out using anchors pre-installed in the wall. For wooden houses, you can consider the option of fixing them to brackets. On average, the cross-section of the Mauerlat is taken to be 100x100 or 150x150 mm.
- Installation of purlins and racks under them. Depending on the design of the building, drains should rest either on floor beams or on load-bearing walls. Installation of reinforced concrete floors on the span is not allowed. The device depends on the insulation used: for mineral wool it is better to install studs with a pitch of 0.58 m, for polystyrene foam - 0.6 m, for polyurethane foam the stud spacing has no strong meaning. For the crossbar, the same cross-section is most often used as for the mauerlat; the stand can be of the same cross-section as the crossbar (100x100, 150x150 mm).
- Lay the layered rafters. Attaching to the mauerlat and crossbar is done by notching. For fixation, nails or steel corners with self-tapping screws are used. Additionally, on each or through one rafter leg, fastening to the external walls is performed. To do this, a ruff is placed in the wall. A twist of double wire with a diameter of 3-4 mm is pulled from the inclined beam to the ruff. IN wooden house Instead of twisting and ruff, you can use staples. The cross-section of the rafters is taken depending on their pitch and roofing material.
- Install struts. To attach the strut to the leg, nails and a thrust beam are used.
- Truss installation. The truss consists of hanging rafters, scrum and suspension. The structure can be assembled directly on the roof or on the ground. The legs are attached to each other at the top point using pads on both sides. The fight can also be double (one board on each side). All fastenings are made with nails, bolts or studs. Studs or bolts are accepted with an average diameter of 10 to 14 mm.
- Laying a layer of waterproofing.
- Top sheathing.
- Installation of insulation.
- Vapor barrier and bottom sheathing.
- Laying roofing material.
- Sheathing the gable frame.
- Ceiling lining and attic finishing.
Installation of lower and upper rafters
Wood treatment with antiseptics and fire retardants can be carried out both before and after assembling the roof structure. It is best to complete this activity immediately after purchasing the material.
The process of preparing the system for laying roofing
Space lighting
The attic design involves two methods of lighting:
Do-it-yourself broken roof complicates installation skylights, since most often the role of the walls of the room is performed by racks.
In this case, the space is limited by the cladding along the racks and scrums. There is no space left to install skylights. In this case, windows are provided in the gables and dormer windows. A dormer window of the simplest design is a “birdhouse”. It has walls and slopes resting on them.
If you do not plan to sheathe the space along the studs, then you can install skylights. They will give the room a special coziness.
Proper installation of elements will allow you to get reliable protection interior spaces for a long time.
Sloping roof: rafter system and installation diagram
The design of a sloping roof is not as complicated as it might seem at first glance. We will tell you how to build a sloping roof with your own hands.
Construction of houses
Particular importance has recently been attached to increasing the functionality of buildings while maintaining an attractive appearance. These goals are precisely served by a do-it-yourself sloping roof, which allows you to additionally create living space by organizing an attic space with maximum comfort. A sloping roof is a type of roof that is one of the most difficult to design and build. However, it doesn't this type roofing is less popular.
Sloping roof concept
Roofs are called broken because of their shape and large number broken lines. At its core, a sloping roof is a type of gable roof, which allows you to get a large area of living space on the attic floor. But for many developers, organizing additional space is not very important; they simply like this roof shape better than the traditional gable roof.
Another advantage of building a sloping roof lies in the possibility of obtaining on the attic floor high ceiling. That is, such a structure can be made higher than an ordinary gable structure, which often cannot withstand wind loads due to too steep angles of inclination. Similar opportunities are provided by a fracture on the slope: the upper part, which is more vulnerable due to the perception of wind load, has a slight slope, but Bottom part drops sharply down.
Sloping roof device
The hipped sloping roof is the most popular, because it is this design that ideally combines the low complexity of constructing rafter systems and the maximum efficient use living space. With such an approach minimal investment You can additionally get full-fledged rooms that are completely suitable for living at any time.
The installation of a sloping roof implies the presence of fairly large rafter structures, but since it is customary to use a modular installation method during its construction, the entire system can be assembled without the use of complex lifting equipment. The posts and rafters are cut at a certain angle where the slopes break. To fasten the components of the entire system, plywood “kerchiefs” are used, which have a thickness of no more than 2 centimeters.
This design of a hipped roof is excellent for houses with relatively small dimensions, where it is not possible to create a sloping roof of complex shape. And for large buildings They usually create a slightly different rafter system.
Types of sloping roofs
There are several types of sloping roofs depending on the number of slopes: single-pitch, double-pitch, three- and four-pitch. As a rule, the comfort of living in a house, as well as the reliability of the building, depend on this parameter.
The sloping roof includes 2 broken slopes. A pitched roof is a kind of inclined plane fixed to walls of varying heights. This solution is the most common, because it involves the creation of a fairly simple rafter system.
A gable roof consists of 2 slopes directed in diametrically opposite directions. This type of attic organization is also very popular. And all because this type of roofing is of very high quality in use. Vaulted roofs Typically typical for rectangular residential buildings.
A three-slope sloping roof has one vertical wall at the end, and the second end is made with the same profile breaks as the side slopes of the roof. This design is lighter due to the absence of one main wall. In addition, a gable roof is installed when the attic roof is connected to the roof of another part of the residential building.
The hipped roof has broken profiles along all 4 slopes of the wall. This is the most difficult option for sloping roofs from a technical point of view. But they are the lightest in weight.
However, if it is important for the developer, then you can make a heptagon. But sloping roof projects with such a profile break are used extremely rarely in practice due to the difficulties that arise in the installation of rafters and installation of the roof covering.
Not only houses, but also balconies (loggias) in an apartment can have a roof, including a panoramic one. It is better to entrust the installation to specialists. Unique glazing of balconies with roofs of any complexity.
Sloping roof shape
The shapes of a sloping roof can be completely different. Such roofs in most cases have the shape of a parabola and are most often found in private rectangular houses. The slopes have a trapezoidal shape along the long sides and triangular shape in short Often, drawings of a sloping roof and its rafter system are much more complex, and diagonal rafters appear in them.
Semi-hip structures are considered a type of hipped sloping roof. The half-hip is a kind of end slope; the end of a gable roof does not cut it off entirely, but only its lower and upper parts.
The roof at the lower location has the shape of a trapezoid, and at the top – a triangle. TO hip roofs include such varieties as conical, domed and pyramidal structures. Such sloping roofs are often installed for buildings of round and polygonal shape.
Construction of a sloping roof
Despite all the complexity of a sloping roof, the structure can be built with your own hands. Having decided on the dimensions of the product and the layout of the sloping roof, you can begin its construction. Attic structures have many features that distinguish them from other roofs. If installed incorrectly, the roof may leak, have poor ventilation, and may accumulate on top. rainwater, ice and snow.
Material selection
It is recommended to make the rafter structure for a sloping roof from wooden materials, which helps to significantly lighten the supporting structure. In this case, use reinforced concrete structures And metal profiles not advisable.
To form a rafter structure, a wooden beam is required, which has optimal humidity. Coniferous wood is mainly used for construction, as it is inexpensive and the most soft material. To form the sheathing you need an edged board.
The lighter the weight of the roof, the more reliable the entire broken roof will ultimately be. Such materials include metal tiles, soft roofs, galvanized iron and reed fabrics. The connection of rafter structures is made using metal brackets and brackets secured with self-tapping screws.
Size calculation
Before building a sloping roof, a fairly accurate calculation should be made. The slightest errors in the distribution of loads can provoke poor-quality creation load-bearing structure, which will not support the entire weight of the roof and rafters. To make the calculation correctly, you need to have on hand: a roof design project, a calculator and a tape measure.
Accurately measure all the dimensions of the sloping roof and transfer them to the sketch. It is better to split a roof of this type into several different geometric shapes– trapezoids, rectangles and triangles. Next, measure the area of each figure, and by summing them up you can find out the total area of the attic roof.
In order not to encounter a shortage of roofing material during the construction process, you need to produce it detailed calculations. This will also help you save money without overpaying for extra material. You already know the total area of the roof, so you can easily calculate how much sheets of roofing material will be needed to construct it. When calculating, you need to take into account all the subtleties roof frame and the presence of cornices with skates.
Wood protection
Before making a sloping roof and forming rafters, it is recommended to protect the wood from excessive dampness and take care to prevent processes that support combustion. To do this, it is necessary to treat all structures with antiseptics and fire-fighting compounds before installation.
In the arsenal of protective equipment today there are many compounds that prevent rotting wooden structures. Apply the compounds in several layers using a wide brush so that they penetrate as deeply as possible into the wood. When working with similar active substances It is worth protecting your hands and respiratory organs with a mask and special gloves.
Location of floor beams
Before you start placing floor beams, you should definitely watch a video about a do-it-yourself sloping roof. Then install the wall plate and floor beams. Select the cross-section of the floor beams as 100 by 200 millimeters. Along the two lines of the rack, align the outer beams of the timber strictly vertically, then tighten the laces and install the intermediate ones.
A distance of no more than 3 meters is allowed between them. All racks are usually secured with temporary spacers. The height of the racks is selected 10 centimeters more than the planned height of the ceilings in the rooms.
I would like to note that when a new roof is being made on an old house, often when looking from above at the laid out floor beams, a strict rectangle does not appear. In order to facilitate the work, it is necessary to place the racks in such a way that they necessarily form a rectangle.
Side wall frame
Place the purlins from the board on top of the posts and install the remaining posts. The resulting structures will serve as the future frame of the side walls of the attic. Install and attach tie rods to the purlins. It is customary to place a temporary support under each of them in the middle of the span, so that when installing the rafters of the upper slopes, you can safely walk on the strings and not be afraid that they will break.
After installing all the ties, fasten them on top with a board, and the structure will become more rigid as a result. Following the instructions on how to properly build a sloping roof, you should install the side rafters and plugs for the insulation, after which you can begin installing the rafters of the upper slopes.
Installation of the upper slopes
First you need to make a rafter template. Take required trim boards and secure it temporarily on the outer crossbar in vertical position. One of the upper corners of the board must exactly coincide with the geometric center of the sloping roof. Make 2 rafters according to the template and install them, securing them with a brace.
Next you need to install all the other rafters. If you are interested in how to build a sloping roof according to traditional version, then remember that it is enough to install 4 struts on the roof - 2 in different directions. Temporarily fasten the remaining pairs until the sheathing is created with an inch board. According to the drawing, hangers are sewn on, which prevent the ties from sagging when you remove the temporary supports.
After this, you need to install the pediment frame and sheathe it, make cornices, sheathing, gable ebbs and overhangs. Next comes the line roofing works. After connecting all structural elements, they need to be further processed to prevent the harmful effects of moisture.
Waterproofing and roof insulation
To create a comfortable atmosphere in the attic space and reduce energy costs for heating the room, it is worth taking care of waterproofing the roof. It is preferable to use a special “ roofing pie", which allows you to create optimal humidity. You can find out what it looks like by watching a video about a sloping roof.
First install a special roofing or waterproofing film on the sheathing. Place any insulation on top of it - bulk, rolled or in mats. Place a layer of roofing felt on it, which must be attached to the sheathing using dowels. Then the second row of sheathing is placed.
Roofing
After the sloping roof is made, and the construction work on insulation and waterproofing of the roof is completed, it is time to select the roofing material. Regardless of the fact that the roof of a sloping roof has several angles of inclination in its design, it is customary to install the roofing material using conventional technology.
The sheathing system is applied to special counter-battens, which allow for natural ventilation of the roof. When organizing the lathing, you need to ensure strict adherence to geometric dimensions in order to facilitate the installation of roofing material, which should be carried out in accordance with the requirements of SNiP and the technology recommended by the manufacturers.
It is not advisable to cover such roofs with copper tiles or iron, because the room becomes very stuffy and hot in summer, despite the presence of a large number of windows. After installing the roof, you can begin installing gutters.
Roof drains
When installing a sloping roof, drainage is absolutely necessary. Their purpose lies in draining water that flows from the roof from the foundation and walls of the building. The lifespan of a house without drainage will be extremely short. Drains for a sloping roof can be made of plastic, non-ferrous metals or galvanized steel. Some manufacturers coat such drainage systems with special polymer coatings that increase the material’s resistance to corrosion.
Today you can also find plastic drainage systems on sale, which are characterized by low cost, low weight, low noise level under wind load, various options colors and design. Modern plastic water drainage systems are resistant to temperature changes.
Of course, in the photo of broken roofs, drainage systems made of non-ferrous metals - copper, aluminum or titanium - look more attractive. In addition, they are characterized by a high level of corrosion resistance. But their cost is too high for the average developer.
Installation of roof windows
Without natural light the attic will not become a full-fledged living room. It is necessary to install skylights that have special frames that are subject to fairly stringent requirements. Since such structures are usually installed in the roof, their design must imply excellent waterproofing, because they are subject to heavy loads from precipitation.
Dormer windows are usually made of PVC or wood. Double-glazed windows for such structures must be energy-saving; they are covered with a special film that can protect them from damage and dirt. The window opening mechanism should also be convenient, because they are quite difficult to clean.
Attic glazing is characterized by its own characteristics. The window area with vertical lighting should be 1/8 of the roof area. This ratio with built-in windows reaches 1/10. Windows can be installed in one or several rows, they can be combined.
An important point when installing roof windows is the sealing of the slopes - they protrude slightly above the surface of the sloping roof. It is advisable to install special spacer bars that should be located between the vapor barrier film and the drywall. This will prevent condensation and create the required air flow. Samu vapor barrier film should be installed along the entire contour of the attic and windows; there should be no extra holes or cracks in it.
Thus, the construction sloping roof– quite complex technological operation, and if you do not have the appropriate skills, you should entrust this work to specialists. But if you are determined, our recommendations and instructions, which cover the question of how to properly make a sloping roof, will help you independently implement the project and allow you to build a beautiful sloping roof with minimal investment.
How to make a sloping roof with your own hands, Construction portal
Construction of houses Particular importance has recently been attached to increasing the functionality of buildings while maintaining an attractive appearance. These goals are precisely served by the done
How to build a sloping roof yourself?
Using an attic instead full second floor allows you to rationally use the available space and significantly expand living space. There are many options for attics; the most popular of them is the sloping roof, which is not only aesthetically attractive, but also financially profitable. If you wish, you can build such an attic with your own hands.
What parts does a broken attic consist of?
The first stage of roof construction is design and calculation; Regardless of whether the project is ordered from a special organization or you plan to make a design drawing yourself, first of all you need to understand what main parts the broken attic consists of.
In essence, a sloping roof is a residential attic, sufficiently well insulated and protected from moisture and noise to make it comfortable to live in. Therefore, in design it differs slightly from an ordinary gable roof.
- vertical racks;
- ties - horizontal beams;
- rafters - stiffening ribs, which are the skeleton of the entire structure;
- struts - diagonal beams supporting rafters;
- Mauerlat - wooden beams with special fasteners connecting the structure to the walls of the house;
- ridge girder - a set of upper elements of the rafter system;
- headstocks - fastenings that provide rigidity to hanging rafters;
- contractions - horizontal struts that remove part of the load from the rafters;
- sheathing - frame for fastening roofing material and insulation;
- roofing - can be made of ceramic tiles, different types slate, corrugated sheets and many other materials;
- heat, hydro and sound insulation.
Thus, the entire structure consists of a set of right triangles; They are connected to each other by wooden beams. All the described elements can be easily found in the drawing of a broken attic.
Technical requirements for a sloping roof
The following requirements apply to sloping roofs:
- the height of the attic walls must exceed 2.2 m;
- must be ensured good ventilation so that moisture does not condense under the roof;
- the roofing material should have a small mass;
- the design must provide measures against the impact of additional load on the rafter system - that is, the roof elements must withstand not only their own weight, but also, for example, snow;
- the attic loses heat faster than the lower floors, so special attention should be paid to thermal insulation;
- To ensure fire safety, all wooden beams and sheathing elements should be treated with fire retardants.
Types of rafter systems
The structure of a sloping roof is very simple - its slope seems to break into lower and upper parts, each of which is installed at its own angle. Most often they are mounted at an angle of 60–70° and 15–30°, respectively.
Based design features attic, we can distinguish these types of attic sloping roofs.
- Two types of rafters are used: hanging and layered. The attic floor beams are installed slightly short of the edges of the walls of the lower floor. The lower slope is made of layered rafters, which are attached to the walls of the house using a Mauerlat. The frame of the attic walls is made from the racks. Such triangles are installed along the walls and connected with contractions. At the top they are joined by triangles of hanging rafters resting on a tie.
- To increase the area of the room, the lower edges of the rafters can be extended outside the house. In this case, they will not be attached to the Mauerlat, but to the ceiling, which, in turn, is supported by external walls oh at home with the help of a Mauerlat. The rafters must be supported by struts. The racks go deep into the floor beams by no more than a third of their thickness.
- This sloping roof rafter system is distinguished by the fact that the upper triangles are made from layered rather than hanging rafters. The ties serve as supports for the struts of the upper triangles.
Calculation of a sloping roof
Before starting work, two calculations must be made:
- determining the amount of required building materials;
- calculation of the bearing capacity of the structure.
Determining how much material is needed is very simple due to the simple geometry of the sloping roof. Load-bearing capacity is not so easy to figure out. To calculate it, you need to take into account:
- roof mass;
- approximate mass of snow;
- the mass of the sheathing;
- mass of steam, hydro and heat insulating materials;
- roof dimensions;
- angles of installation of slopes;
- step of installation of elements of the rafter system and roofing sheathing;
- additional load: mass of people and equipment, windows, ventilation, etc.
Based on these data and with the help special programs the load-bearing capacity is calculated. Depending on what load-bearing capacity is required, the cross-sectional area used in construction is selected wooden beam. If something doesn’t suit you, the project can be corrected by changing the rafter system, choosing a different roofing material, or placing the rafters less frequently.
In most programs, the structure of a sloping roof can be visualized - the 3D model will immediately show how changes will affect appearance attics.
What materials need to be prepared?
After developing the project, it will be clear what cross-section of timber should be used, what roofing material is best to choose, and what the roof sheathing should be like. You will have to purchase a wide variety of lumber: timber for forming the mauerlat, edged boards for the rafter system, boards for sheathing. They need to be selected correctly to ensure a durable and reliable design.
Tips for choosing lumber:
- Coniferous wood species - pine, spruce - are best suited for attic construction - they are strong and rigid enough to withstand the entire load;
- the wood must be well dried - its humidity should not exceed 20%;
- the material must be free of knots, cracks, traces of biological damage and other defects.
Everything before installation wooden elements sloping roofs are treated with fire retardants and antiseptics, as well as impregnations against rotting. This treatment should be repeated periodically so that the load-bearing elements of the structure do not have to be replaced.
In addition to the main material, you need to stock up on metal fasteners to connect the rafters to the Mauerlat and to each other, insulating and roofing materials.
Roof installation
Mauerlat installation
The construction of a sloping roof begins with the installation of a mauerlat to which the ends of the rafters will be attached. The nuances of this stage vary depending on the material from which it is built. ground floor- if its walls are stone, you need to punch holes for anchors in them in advance and install fasteners. The spacing between anchors should not exceed 2 m.
Waterproofing material is laid on the wall surface. Then the beam is marked, and holes are drilled at the fastener installation points. The Mauerlat is put on the anchors and tightened tightly with nuts.
Installation of floor beams
- first, the outer beams are installed at the ends of the building;
- strings are stretched between them to indicate the plane;
- intermediate beams are installed.
Installation of racks
The racks must be positioned strictly vertically. The principle of operation is the same as in the case of floor beams - first the outer racks are mounted, then the intermediate ones in the same plane. The step between structural elements should not exceed 2 m. The racks are fixed with temporary spacers. The height of the beams is 10 cm more than the planned ceiling height.
Between the racks purlins are installed from edged boards. In the end it should be finished frame For interior walls attics.
Installation of puffs
The cross beams are connected not to the posts, but to the purlins, using metal roofing corners. If the width of the room is large, it is worth installing temporary spacers under each tie so that when walking on them during the construction of the upper slopes, the beams do not break or bend.
Installation of rafters
First, the lower rafters are installed. They are placed in the following order:
- mounting points on the Mauerlat are outlined - the step between them should be 1–1.2 m;
- on rafter legs fastening points are cut out according to the template;
- First, the outer rafters are attached, then, as before, the intermediate rafters are attached along the twine;
- The struts are installed in accordance with the drawing.
The upper rafters are installed in the same way - according to the template. They are attached to puffs and connected to each other; a longitudinal connection with a ridge beam is required only if the length of the attic exceeds 10 m. Otherwise, you can get by with struts, with which the structure of the sloping attic roof will be quite rigid.
The last stages of work are covering the gables and attaching the sheathing for the roof. Window openings should be left in the gables (at least 1/8 total area external walls of the attic).
Structural insulation
All that remains is to lay the roofing pie on the finished frame. Its first layer is a vapor barrier, which prevents moisture from penetrating the insulation. Placed on a vapor barrier membrane thermal insulation material- it is recommended to use stone basalt slabs. They are laid in several layers with the joints shifted, which will protect against the occurrence of cold bridges. The size of the slabs should be several cm larger than the pitch between the counter-lattice beams. So that the insulation does not sag and lose its performance characteristics, its density must be at least 35 kg/m 3.
The insulation is covered on top with a waterproof membrane, which allows steam to pass through but does not allow liquid moisture to penetrate into the room. The roof is laid on top of the waterproofing layer - the features of its installation depend on the selected material.
After installation of the roof, only finishing touches- installation of drainage systems, decorative finishing. Inside finishing material also attached to the sheathing over the insulation. The broken roof has been built. As you can see, it is quite possible to do this with your own hands - only the design and calculations will probably have to be entrusted to professionals.
Do-it-yourself sloping roof: rafter system, photo
The first stage of building a sloping roof is design and calculation... In essence, a sloping roof is a residential attic, well insulated and protected from...
Using an attic instead of a full second floor allows you to rationally use the available space and significantly expand the living area. There are many options for attics; the most popular of them is the sloping roof, which is not only aesthetically attractive, but also financially profitable. If you wish, you can build such an attic with your own hands.
Users often search:
What parts does a broken attic consist of?
The first stage of roof construction is design and calculation; Regardless of whether the project is ordered from a special organization or you plan to make a design drawing yourself, first of all you need to understand what main parts the broken attic consists of.
In essence, a sloping roof is a residential attic, sufficiently well insulated and protected from moisture and noise to make it comfortable to live in. Therefore, in design it differs slightly from an ordinary gable roof.
The following main elements of a sloping roof are distinguished:
- vertical racks;
- ties - horizontal beams;
- rafters - stiffening ribs, which are the skeleton of the entire structure;
- struts - diagonal beams supporting rafters;
- Mauerlat - wooden beams with special fasteners connecting the structure to the walls of the house;
- ridge run- a set of upper elements of the rafter system;
- headstocks - fastenings that provide rigidity to hanging rafters;
- contractions - horizontal struts that remove part of the load from the rafters;
- sheathing - frame for fastening roofing material and insulation;
- roofing - can be made of ceramic tiles, different types of slate, corrugated sheets and many other materials;
- heat, hydro and sound insulation.
Thus, the entire structure consists of a set of right triangles. They are connected to each other by wooden beams. All the described elements can be easily found in the drawing of a broken attic.
Technical requirements for a sloping roof
The following requirements apply to sloping roofs:
- the height of the attic walls must exceed 2.2 m;
- good ventilation must be ensured so that moisture does not condense under the roof;
- the roofing material should have a small mass;
- the design must provide measures against the impact of additional load on the rafter system - that is, the roof elements must withstand not only their own weight, but also, for example, snow;
- the attic loses heat faster than the lower floors, so special attention should be paid to thermal insulation;
- To ensure fire safety, all wooden beams and sheathing elements should be treated with fire retardants.
Types of rafter systems
The structure of a sloping roof is very simple - its slope seems to break into lower and upper parts, each of which is installed at its own angle. Most often they are mounted at an angle of 60–70° and 15–30°, respectively.
Based on the design features of the attic, these types of attic sloping roofs can be distinguished.
- Two types of rafters are used: hanging and layered. The attic floor beams are installed slightly short of the edges of the walls of the lower floor. The lower slope is made of layered rafters, which are attached to the walls of the house using a Mauerlat. The frame of the attic walls is made from the racks. Such triangles are installed along the walls and connected with contractions. At the top they are joined by triangles of hanging rafters resting on a tie.
- To increase the area of the room, the lower edges of the rafters can be extended outside the house. In this case, they will not be attached to the Mauerlat, but to the ceiling, which, in turn, is supported on the external walls of the house using the Mauerlat. The rafters must be supported by struts. The racks go deep into the floor beams by no more than a third of their thickness.
- This sloping roof rafter system is distinguished by the fact that the upper triangles are made from layered rather than hanging rafters. The ties serve as supports for the struts of the upper triangles.
Calculation of a sloping roof
Before starting work, two calculations must be made:
- determining the amount of required building materials;
- calculation of the bearing capacity of the structure.
Determining how much material is needed is very simple due to the simple geometry of the sloping roof. Load-bearing capacity is not so easy to figure out. To calculate it, you need to take into account:
- roof mass;
- approximate mass of snow;
- the mass of the sheathing;
- mass of steam, hydro and heat insulating materials;
- roof dimensions;
- angles of installation of slopes;
- step of installation of elements of the rafter system and roofing sheathing;
- additional load: mass of people and equipment, windows, ventilation, etc.
Based on these data and using special programs, the load-bearing capacity is calculated. Depending on the load-bearing capacity required, the cross-sectional area of the wooden beam used in construction is selected. If something doesn’t suit you, the project can be corrected by changing the rafter system, choosing a different roofing material, or placing the rafters less frequently.
In most programs, the structure of a sloping roof can be visualized - the 3D model will immediately show how changes will affect the appearance of the attic.
What materials need to be prepared?
After developing the project, it will be clear what cross-section of timber should be used, what roofing material is best to choose, and what the roof sheathing should be like. You will have to purchase a wide variety of lumber: timber for forming the mauerlat, edged boards for the rafter system, boards for sheathing. They need to be selected correctly to ensure a durable and reliable design.
Tips for choosing lumber:
- Coniferous wood species - pine, spruce - are best suited for attic construction - they are strong and rigid enough to withstand the entire load;
- the wood must be well dried - its humidity should not exceed 20%;
- the material must be free of knots, cracks, traces of biological damage and other defects.
Before installation, all wooden structures are treated with fire retardants and antiseptics, as well as impregnations against rotting. This treatment should be repeated periodically so that the load-bearing elements of the structure do not have to be replaced.
In addition to the main material, you need to stock up on metal fasteners to connect the rafters to the Mauerlat and to each other, insulating and roofing materials.
Roof installation
Mauerlat installation
The construction of a sloping roof begins with the installation of a mauerlat to which the ends of the rafters will be attached. The nuances of this stage vary depending on the material from which the lower floor is built - if its walls are stone, holes for anchors must be punched in them in advance and fasteners installed. The spacing between anchors should not exceed 2 m.
Waterproofing material is laid on the wall surface. Then the beam is marked, and holes are drilled at the fastener installation points. The Mauerlat is put on the anchors and tightened tightly with nuts.
Installation of floor beams
Installation sequence:
- first, the outer beams are installed at the ends of the building;
- strings are stretched between them to indicate the plane;
- intermediate beams are installed.
Installation of racks
The racks must be positioned strictly vertically. The principle of operation is the same as in the case of floor beams - first the outer racks are mounted, then the intermediate ones in the same plane. The step between structural elements should not exceed 2 m. The racks are fixed with temporary spacers. The height of the beams is 10 cm more than the planned ceiling height.
Purlins made of edged boards are installed between the racks. The result should be a finished frame for the interior walls of the attic.
Installation of puffs
The cross beams are connected not to the posts, but to the purlins, using metal roofing corners. If the width of the room is large, it is worth installing temporary spacers under each tie so that when walking on them during the construction of the upper slopes, the beams do not break or bend.
Installation of rafters
First, the lower rafters are installed. They are placed in the following order:
- mounting points on the Mauerlat are outlined - the step between them should be 1–1.2 m;
- fastening points are cut out on the rafter legs according to the template;
- First, the outer rafters are attached, then, as before, the intermediate rafters are attached along the twine;
- The struts are installed in accordance with the drawing.
The upper rafters are installed in the same way - according to the template. They are attached to puffs and connected to each other; a longitudinal connection with a ridge beam is required only if the length of the attic exceeds 10 m. Otherwise, you can get by with struts, with which the structure of the sloping attic roof will be quite rigid.
The last stages of work are covering the gables and attaching the sheathing for the roof. Window openings should be left in the gables (at least 1/8 of the total area of the external walls of the attic).
Structural insulation
All that remains is to lay the roofing pie on the finished frame. Its first layer is a vapor barrier, which prevents moisture from penetrating the insulation. Thermal insulation material is laid on the vapor barrier membrane - it is recommended to use stone basalt slabs. They are laid in several layers with the joints shifted, which will protect against the occurrence of cold bridges. The size of the slabs should be several cm larger than the pitch between the counter-lattice beams. To prevent the insulation from sagging and losing its performance characteristics, its density must be at least 35 kg/m3.
The insulation is covered on top with a waterproof membrane, which allows steam to pass through but does not allow liquid moisture to penetrate into the room. The roof is laid on top of the waterproofing layer - the features of its installation depend on the selected material.
After installing the roof, only the finishing touches will remain - installation of drainage systems, decorative finishing. Inside, the finishing material is also attached to the sheathing over the thermal insulation. The broken roof has been built. As you can see, it is quite possible to do this with your own hands - only the design and calculations will probably have to be entrusted to professionals.