To install a gable roof yourself, you only need average carpentry skills and an understanding of its manufacturing technology. It's not hard to figure all this out. It is also necessary to involve an intelligent assistant in the process, because many operations cannot be performed by one person. Therefore, many undoubtedly take on this work and cope with it successfully.
Do-it-yourself gable roof installation
Building a country house involves considerable expenses. Therefore, many people are looking for options to reduce the cost of this process by using modern materials and technology. Currently, frame buildings with gable roofs have become very popular. This happens largely for the reason that even a person with minimal knowledge of construction can carry out such a design with appropriate preliminary preparation.
A gable roof is formed by triangular trusses connected to each other by a longitudinal top beam(ridge run) and lathing
However, constructing a roof is a crucial moment that requires serious consideration. You need to calculate:
- correct angle tilt;
- rafter length;
- the distance between them;
- methods of connecting various parts to each other.
Without experience in performing such work, you should not take on complex structures, but you can easily build a small house with a simple gable roof with your own hands.
Design features of gable roofs
Such a roof consists of two inclined planes located at a certain angle. Along the end walls there are pediments, which are a vertical continuation of the walls. In shape they are isosceles or arbitrary triangles, if the slopes are arranged under different angles to the horizontal. In the case of a gable sloping roof, the gables are shaped like trapezoids.
When building a roof, a rafter system is created, which is a supporting element roofing pie. Rafter system can be made in the form of hanging rafters if there are no permanent partitions inside the building box. If they are available, a deck frame is installed when the span is supported by three or more points.
Depending on the configuration of the building, a gable roof can be erected according to different schemes How to make a gable roof yourself
Depending on the design of the rafter system, its main elements may be different, but the main details are present in all options:
- Rafters - main load-bearing element structures onto which roofing material is mounted through the sheathing.
- The ridge girder, also called the center beam, combines all the rafter legs into a single whole and evenly distributes the load on the mauerlat.
- Rack - used in deck structures as additional support for a permanent internal partition.
- The bench is a horizontal beam on which the racks rest, serving to evenly distribute the loads on the power plate.
- Mauerlat is a support beam between the walls and the upper structure of the building, intended for attaching rafters.
- Lathing - flooring made of boards 25 millimeters thick for fastening finishing coating roofs.
Regardless of the type of rafter system, it always contains several basic elements Roof design
In the process of designing a rafter system, it is necessary to optimally place all frame elements to ensure uniform roof load over its entire area. The main types of load are:
- Snow - occurs under the influence of a layer of snow that lingers on the roof. At high rates for the construction region, the angle of inclination of the roof is increased so that the snow falls off as it accumulates.
- Wind - associated with the force of the wind. In open, windy places it is higher. A means of counteracting wind loads is to reduce the angle of the roof.
Thus, it is necessary to find the optimal combination of these indicators with simultaneous exposure to wind and snow. Data on specific loads for the construction region can be found on the Internet.
Gable roofs with a simple design give the house an elegant and festive look.
Photo gallery: projects of houses with gable roofs
A gable roof allows you to arrange a small attic room on the second floor. The angle of inclination of a gable roof is selected based on the intensity of the winds and the average snow load in the construction area. Despite the simplicity of the design, a gable roof can be the central element general design buildings Roof slope angles do not have to be the same
Calculation of gable roof parameters
Determining the main characteristics of the roof is necessary already at the foundation design stage to calculate the impact total weight buildings on a supporting base.
Area calculation
With a symmetrical gable roof, it is enough to determine the area of one slope and double the result.
The height of the roof depends on the selected slope angle. Usually it is in the range of 30–45 degrees. In the first case, the height will be half the distance from the projection of the ridge to the axis of the Mauerlat. Using the Pythagorean theorem and carrying out calculations, we find that the length of the slope for a building 10x9 m will be equal to 5.05 meters. The area of the slope is defined as 5.05 x 10 = 50.5 square meters. And the total roof area will be 50.5 x 2 = 101 m2.
In cases where a gable roof has an unbalanced roof, i.e. the ridge axis is shifted from the building axis, the area of each slope separately is calculated using the same method and the results are summed up.
However, this calculation does not take into account the area of the roof overhangs. They are usually 0.5–0.6 meters. For one slope, the overhang area will be 0.5 x 5.05 x 2 + 0.5 x 10 = 4.1 + 5 = 9.1 m2.
The total roof area will be 101 + 9.1 x 2 = 119.2 m2.
Most rafter calculations are made using the Pythagorean theorem, reducing the structure to a set of rigid figures - triangles Calculation of rafter cross-section
The cross-sectional size of the rafters depends on several factors:
- the magnitude of the load on them;
- type of materials used for rafters: logs, timber - homogeneous or glued;
- rafter leg lengths;
- wood species;
- distances between the axes of the rafter legs.
All these parameters have been calculated for a long time, and to determine the cross-section of the rafter legs, you can use the data below.
Table: rafter section size
As the installation pitch of the rafters increases, the load on each of them increases, which leads to the need to increase the cross-section.
Common dimensions of the main parts of the rafter system:
Determining the angle of inclination
The angle of inclination of the roof slope is determined by the requirements of its finishing coating:
One of the reasons for reducing the angle of inclination is the desire to make the attic or attic space as large as possible. This intention is also the reason for installing a sloping roof.
Calculation of the distance between rafters
This parameter depends on the type of finishing coating, or rather, its weight. For the heaviest material, the distance should be minimal, from 80 centimeters. In the case of using a soft roof that is light in weight, the distance can be increased to 150 centimeters. The number of rafters and translations is calculated as follows:
- The length of the building (10 meters) must be divided by the distance between the rafters, presumably 120 centimeters: 1000 / 120 = 8.3 (pieces). We add 1 to the result obtained, it turns out 9.3.
- Since the number of rafters cannot be fractional, the result is rounded to the nearest whole number - 9.
- The distance between the rafters is finally set: 1000 / 9 = 111 centimeters.
With this distance, all rafters will be equidistant, and the load from the roof will be distributed evenly.
The length of the rafters is calculated using the Pythagorean theorem, as already shown above.
Do-it-yourself gable roof installation
Work on the installation of the rafter system begins with the installation of the Mauerlat.
Mounting the load-bearing device on the wall
Mauerlat is made from high-strength wood - oak, larch, etc. If such materials are not available, pine can be used.
Timber happens standard length- 4 or 6 meters. Therefore, connecting several parts along the length is inevitable. It is made with cutting of the connected ends “half-tree”, for example, for a beam with a cross-section of 150x150 millimeters, a sample of size 75x150 with a length of 300 mm is made. The ends are overlapped. Fastening is carried out with two or four M12 or M14 screws with the installation of large diameter washers. Using the same principle, the beams are connected at the corners. Finished design is a regular rectangle that is installed on the upper plane of the wall along the perimeter.
Two beams are spliced using a sample of wood on each of them. They are then bolted together The technology for installing the Mauerlat provides for its placement strictly along the axis of the wall or offset in any direction. In this case, you cannot place the support beam closer than 5 centimeters from the edge. To increase the service life of the Mauerlat, it should be installed with waterproofing along the wall surface. Most often, roofing felt is used for this.
Methods for attaching the Mauerlat to the wall
- Installation on anchor bolts. Perfect option with monolithic walls. Threaded rods are embedded in the wall when it is cast.
- Wood dowels. They are nailed into a drilled hole. With this fixation, an additional metal fastener.
- Forged staples. They are used with pre-installed wood embedded parts.
- Stud or fittings. The pins are walled up during the laying of the wall and are removed through the support beam along drilled holes. The diameter of the fasteners should be 12–14 millimeters, the protrusion above the surface of the beam should be 10–14 centimeters.
- Steel wire. A bundle of two or four wire strands is installed when laying the wall 2-3 rows before its end. The Mauerlat is tightened using a crowbar. Often used as additional fastening support beam.
- When installing a reinforcing belt, fastening with studs or anchor bolts is also used.
The mounting locations should be approximately halfway between the rafter legs.
Video: installing a Mauerlat on an armored belt
Photo gallery: methods of mounting the Mauerlat on the wall
The studs are embedded in the wall while it is being poured, then the Mauerlat is put on them and secured with bolts. The wire is also installed at the stage of laying the wall. The Mauerlat can be secured using wire ties passed through holes in the beam. In the spaces between wall blocks wooden plugs are inserted into which the staples are then secured
Types of rafter systems and their installation
The choice of roof truss design is determined by the configuration of the building. If there are no internal capital partitions, a hanging rafter system is constructed.
If there are permanent partitions, it is necessary to use a floor installation scheme.
Manufacturing of rafter pairs
This is the name of a pair of rafter legs connected into an arch with the installation of a spacer element in the form of a tie for a hanging system or a crossbar for a decking system.
Installation of rafter pairs is carried out in three ways:
- Assembly is done at the top after installing the translations. They are covered with plank flooring nailed down.
- The formation of rafter pairs is carried out on the ground in the immediate vicinity of the house. Only blanks that represent a rigid triangular structure are assembled. Lifting of products is carried out when the rafter pairs are ready for the entire system. For this purpose, it is possible to use lifting devices in the form of a manual or drive winch, which represents certain inconveniences and additional costs. On the other hand, assembly on the ground is much easier and more accurate.
- The roof is assembled directly at the installation site in detail.
In any option, the rafter legs are mounted according to the template, which is the first truss. For higher assembly accuracy, it is advisable to fix the parts of the next pair to the previous pair with clamps.
When assembling rafter systems on the ground, all structures are made according to a template, which is the first manufactured truss. This makes the installation more accurate Procedure for installing the rafter system
Prefabricated roofing elements are installed in the following sequence:
Fastening rafter system parts
For reliable connection roof frame elements use various auxiliary elements made of galvanized steel up to 1.5 millimeters thick.
The use of additional fasteners ensures a strong assembly of the rafter system When assembling using additional connectors, labor productivity increases and the strength characteristics of the structure increase.
For connecting roof elements wooden buildings special fastening devices are used. Thus, the upper joint of the rafters is often connected using a hinge. This is due to frequent movements of the building, including seasonal ones.
The hinged connection allows you to avoid large stresses at the junction of the rafters during seasonal movements of the log house For the same purpose, sliding fastenings are used on houses made of this material.
A reliable sliding connection of the rafters with the Mauerlat relieves this unit from stress during deformations of the structure Video: quick production of rafters
Before installing the sheathing, the roof is insulated. For this:
- The internal sheathing is filled from the attic or attic side.
- The vapor barrier film is stretched.
- Insulation is being installed.
- A moisture-proof film or membrane with one-sided permeability is laid.
Thus, in addition to insulation, it creates ventilation system under-roof space. It starts working after installing the coating.
It is more convenient to lay the insulation layer on the outside on the internal sheathing with a vapor barrier coating IN certain conditions Roof insulation can be done from the inside; it is not so convenient, but you can safely work in any weather conditions. The formation of the roofing pie is done in the reverse order. Each layer of insulation as it is laid must be strengthened in the openings between the rafters.
Creating a frame pediment
Before you begin decorating the gable, you need to arrange the sheathing and lay the finishing roof covering.
When forming the sheathing, the type of future roofing is taken into account. It is made from edged boards 25 millimeters thick. Lathing happens:
- Solid - boards are packed at a distance of 2–4 centimeters from one another. Used when using tiles or soft roofing.
- Sparse - the distance between the boards is 15–25 centimeters. This sheathing is installed under metal tiles, corrugated sheets, slate and other similar materials.
- Rare - the distance between the boards is from 0.6 to 1.2 meters. Used when the length of the covering sheets is equal to the length of the slope with an overhang. This coating is made only to order.
The sheathing should be brought out beyond the gable rafters to create an overhang.
A frame is mounted on the front trusses for fastening the front finishing material Roofing installation
Before laying the sheathing, the roof is insulated and a moisture-proof layer is laid. Further:
- The roof covering is being laid. The installation sequence is from bottom to top in rows. The straightness of the first row is controlled by a stretched cord.
- Roofing sheets are fastened with self-tapping screws using shock-absorbing gaskets.
When installing the final roof covering, you cannot skimp on fasteners, the protective layer must be durable, able to withstand wind and snow loads.
Sheets of metal tiles are laid from bottom to top, starting from the corner of the roof Installation of gables
The sheathing of frame gables is done based on the characteristics of the material intended for the front finishing. The following products can be used for this:
After installing the sheathing, it is necessary to lay moisture protection from polyethylene film 200 microns thick. It can be secured with construction staples. This work is done outside. Using the film, you can cover the outer surface with the selected finishing material.
The gables must be insulated with roll or tile insulation. The thickness of the protective layer must be at least 10 cm, and for areas with cold climates - at least 15 cm. An internal moisture-proof layer of film is stretched over the insulation.
A lathing for the front finishing is placed on top of it, for which bars measuring 50x50 millimeters are used. The entire building is finished at the same time, after the roof is insulated.
During the process of facing the pediment, windows are installed, if they are provided for in the project, and in some cases, doors.
The pediment of a wooden house with a gable roof is most often finished with clapboard Decoration of overhangs
Roof overhangs, both gable and eaves, except for pure decorative function designed to protect walls and foundations from water or snow. Their sizes are usually 50–60 centimeters. The design of overhangs is carried out various materials:
- planed board, installed end-to-end or overlapped;
- tongue and groove lining;
- block house lining;
- sheet plastic;
- sheet profiled or smooth metal;
- finished goods made of metal or plastic - soffits.
There are several ways to install overhangs:
Ventilation holes must be made along the hem. They can be of any size, but large ones must be covered with a fine-mesh mesh made of any material. This allows you to avoid birds and harmful insects from entering the under-roof space. Soffits are sold ready-made ventilation grilles.
Ventilation is installed only on eaves overhangs; it is not needed for gable overhangs.
When finishing with soffits, there is no need to drill ventilation holes - they are already made at the factory Video: do-it-yourself gable roof installation
With the modern abundance of building materials and their quality, you can install a gable roof yourself. The cost savings will be quite significant. But it can also result in losses if you do not carefully think through every step during construction. I wish you success!
A gable roof is the best do-it-yourself option for an inexperienced builder. It is simple to implement, but at the same time reliable and can withstand significant loads from both wind and precipitation. She, of course, is not very beautiful, but she looks quite organic in the baths.
To do everything consciously, you need to understand the structure of a gable roof and the purpose of all its elements. Let's start in order.
Mauerlat
This is a large block attached to load-bearing walls ah along the perimeter of the building. It is this element that accounts for most of the load from the roof. And it is the Mauerlat that transfers it to the load-bearing walls.
For this element, square bars measuring 100*100 mm or 150*150 mm are used. They are connected to the walls using embedded studs. If the bathhouse is wooden, then the upper crown usually serves as the Mauerlat. For all other types of walls, a belt is made of reinforced concrete into which studs are embedded. Then the beam of the selected section is “put on” the studs and tightened with nuts. Sometimes it is additionally secured with long pins.
Since the thickness of the walls is often greater than the width of the mauerlat, its outer side can be covered with bricks. This will make the system more reliable. Only the wood needs to be wrapped in two layers of roofing felt to protect it from moisture and rot.
Rafter legs and ridge
The ridge is horizontal wooden block, located at the top point of the roof and connecting two slopes. The rafters or rafters rest on it and on the mauerlat. Since the ridge bears quite a large load, it needs to be made of a large cross-section and choose durable wood.
The height of the roof ridge is determined based on the roof slope and the width of the building. The slope angle of the roof is a value that depends on climatic factors: if there is a lot of snow in winter, then you need to make the slopes steeper. The snow will come off well from them. If in the region strong winds, a high roof will experience heavy loads and may be damaged.
For average conditions optimal angle The roof slope is about 35°-45°. They will not be heavily loaded by the wind, and the snow will not accumulate heavily. In addition, with this angle, you can choose any type of roofing: any of the tiles, soft roofing, slate, metal tiles.
Also remember, the higher the ridge is raised (steeper the slopes), the larger the roof area will be. And this will lead to the fact that the purchase costs roofing materials and the volume of work will be large.
Knowing the slope angle and width of your bathhouse, you can calculate the height of the roof ridge. To do this, the width of the building must be divided by two (if the ridge is in the middle and not shifted to one side or the other) and multiplied by the tangent of the slope angle (the first formula in the figure). In order not to look for the required coefficient in mathematical tables, it is written out and summarized in a simple table.
| Roof pitch angle | 5 | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 |
| Tg A (ridge height calculation) | 0,08 | 0,17 | 0,26 | 0,36 | 0,47 | 0,59 | 0,76 | 0,86 | 1 | 1,22 | 1,45 | 1,78 |
| Sin A (rafter length calculation) | 0,09 | 0,17 | 0,26 | 0,34 | 0,42 | 0,5 | 0,57 | 0,64 | 0,71 | 0,77 | 0,82 | 0,87 |
Multiply half the width of the house by this coefficient. Get the height of the ridge for your bathhouse. For example, the width of the bathhouse is 4 meters, the angle chosen is 35°. We calculate: 4 m / 2 * 0.76 = 1.52 m - the height of the ridge from the ceiling.
Now about the rafter legs. They are made from pine or spruce bars, or better yet, larch. Section 50*150 mm or 50*100 mm. The choice of thickness of the bars depends on:
The length of the rafter leg is also calculated using a mathematical formula: the height of the ridge is divided by the sine of the angle of inclination (second formula in the figure). The sines of the angles of inclination are also in the table. Find desired value and you think. For example, for the 1.52 m ridge we found and the rafter angle of 35°, 1.52 m / 0.57 = 2.67 m will be needed.
Roof overhang and filly
But the roof does not end exactly above load-bearing wall. It continues beyond the walls for about 40 cm. This protrusion is called the roof overhang. This is done so that the water flows further from the foundation and does not wash it away. That’s why the rafter legs are longer. If their length is not enough, they are extended with boards called “fillies”.
To organize the roof overhang, boards are added to the rafters - fillies Types of rafter systems
Rafter systems come with hanging or layered rafter legs. Those hanging rest only on the outer walls of the building (on the mauerlat or upper crown). In order to increase the reliability of the system, so as not to collapse the walls, they are connected with ties (also called a lintel or crossbar). This type of rafter system is suitable for buildings of small width (less than 10 m) and in cases where there is no load-bearing wall running in the middle.
Two types of rafter systems - with hanging and layered rafters The second type of system is with layered rafters. They rest on a ridge beam and a mauerlat, but the load from the roof is also distributed onto the middle load-bearing wall, through vertical bars - purlins, which are installed at the same pitch as the rafters and rest on the bottom tie.
Do-it-yourself installation of gable roof rafters
For most baths, the system is made with hanging rafter legs - the dimensions allow this to be done. In this case, there is less consumption of lumber and less time is required for its arrangement. Most the work can be moved to the ground.
They make one triangle from the rafters according to all the rules and dimensions. They try it on and then make it required quantity its exact copies. The finished rafters with ties and crossbars, fastened and measured, are lifted onto the roof. There they are placed strictly vertically in designated places and secured to the Mauerlat and the ridge.
For an example of how you can make a gable roof with hanging rafters, see the video.
When the length of the roof slope is more than 4.5 meters, to increase the reliability of the system, install vertical racks, which support at one end rafter leg, and the second rests against the floor beam. This is done regardless of the type of rafter installation: both hanging and layered. They also install slopes that make the structure even more rigid.
In any case, the rafters will need to be attached to the ridge beam, as well as to the mauerlat. The figure below shows options for attaching to the ridge.
It will also be necessary to attach the rafters to the mauerlat. How this can be done - see the photo below.
Sheathing device
Making a gable roof with your own hands ends with the installation of sheathing for the roofing material. For this purpose outside rafters, a waterproofing film or membrane is rolled out. Lay it in a horizontal direction. Start from the bottom and work your way up. The second and all subsequent rows are laid with an overlap of at least 15-20 cm. They are secured with small nails or staples from a staple gun.
After installing the rafter system, a waterproofing film or membrane is attached to it, and a sheathing is placed on top There are two ways - with or without counter-latching. The counter-lattice is stuffed along the rafters, and on top there are sheathing bars. Thus, between the waterproofing and the roofing material, a air gap. This option is better from the point of view that such a roof will dry out better and faster. And this is very important for baths.
Without a counter-lattice, the bars are packed directly on top of the waterproofing. There is a gap here too, but it is smaller, therefore, the ventilation will be worse. But this option is also acceptable: less consumption of materials and work.
After making the sheathing, all that remains is to secure the selected roofing material.
Results
Now you know how to make a gable roof with your own hands. Of all the types, this is the simplest option that can be made by a non-specialist.
Are you already at the finish line in building your dream home, and it’s time to understand the intricacies of the rafter system? Let's just say: pleasant worries await you: calculating the angle, weight and safety factor of the rafters, an agreement with a familiar craftsman or company, or preparing everything necessary tools for independent carpentry work.
And so that tomorrow all these worries do not become a headache and you do not worry about whether this or that knot is being done correctly, we have prepared this article for you. So, let's figure out how to make high-quality rafters for a gable roof with your own hands so that it is no worse than purchased ones.
- Short production times.
- Technological precision of all details.
- Identical, already adjusted dimensions of all structural elements.
But then be prepared for the following disadvantages:
- High cost (at least twice as much as if you planed the rafters yourself).
- Delay in delivery (especially during the season).
- Using low-quality or under-dried wood (and then the roof will “sink”).
So convenience or quality? If this is not your first time carving or planing something out of wood, feel free to take on making rafters! Here's what it all looks like in real life:
Rafters in construction world in simple language it is customary to divide and the main ones, i.e. load-bearing ones, on which the roof is supported, and auxiliary ones, which are located inside the roof and serve as support for hemming the ceiling and walls of the attic (if one is planned). Strength and reliability depend on how accurately and correctly you calculate the rafter system in advance. future roof.
The rafter system of any gable roof itself consists of the following basic elements that you need to make:
- Mauerlat.
- Vertical racks.
- Crossbars.
- Rafter legs.
- Spacers.
- Ridge run.
Complex roofing structures with multiple elements it is better to entrust the calculation to a professional, but with a small roof of a private house you can handle it. To do this, you will need these simple formulas that will help you find out how thick the rafters should be, with what slope and what span:
How to draw up a project for a future roof?
The golden rule in roof construction is to measure seven times and cut only once. And first of all, it is important for you to understand that each rafter leg has its own individual location. Therefore, first be sure to draw up a detailed project, and it is better to special program. Only after this, using your 3D model of the future roof, mark exactly where and what kind of connections the rafters will have with the Mauerlat and with each other.
It is important to determine as accurately as possible the angle of inclination of the rafters and at what angle they need to be cut. And don’t worry about how to make all these rafters for a gable roof yourself: all you need is a regular machine.
Determining the angle of inclination of the roof: calculating the loads
The angle of inclination of a gable roof is made from 5° to 90°. But the most proven and standard option– 35°-40°, where loads are most rationally distributed and building materials are consumed.
Straight slopes are built when in the future there will be only a non-residential attic under the roof, the main function of which is ventilation and regulation of heat exchange. But when the under-roof space is planned to be residential, attic, they initially plan a so-called sloping gable roof. Its difference is that the slopes in the middle have a kind of kink, which changes their angle to a steeper one. This design is quite suitable both for arranging an attic and for protecting the entire house from bad weather.
Please note that most roofing materials are only suitable for pitches greater than 45°.
Constant and variable roof loads
The same loads determine what rafter pitch you need for your gable roof. This table will help you choose the right section of rafter legs:
Indicators of rafters for deflection
Even strong-looking rafters may not be suitable for constructing the roof of a residential building due to the fact that they have insufficient deflection properties. There are separate paragraphs in the SNiP section called “Loads and Impacts”.
And the easiest way to increase the deflection strength of rafters is to make the cross-section larger. It’s a little more difficult to strengthen it with a special beam, bringing its edge to the strut.
Reinforcing elements for rafters
The more racks, struts and contractions, the more durability and stability the entire rafter system has.
If you have any suspicions or even an exact estimate that simple design roof will not withstand future loads, make additional reinforcements for it. Such prevention will never hurt, but it will save you from many problems. Note that it is especially offensive when the garage roof falls in - right on top of the car. And such problems are not a joy for a residential building.
The rigidity of the rafter structure is enhanced by struts, additional purlins and support posts. The braces are designed to reduce the span of the rafter legs. Their angle of inclination to the horizontal is usually at least 45°.
A purlin is a horizontal beam that is parallel to the ridge and secured to vertical posts. More details in the video:
Determining the type of roof: cold or warm?
And now about the concept of the attic. If you are building a roof for a bathhouse or a small utility room, it can be done using the most simplified technology - install rafters, connect them at the ridge and cover them with sheets of roofing felt. But for the roof of a residential building, where ventilation is important, this principle cannot be used. There will already be at least three levels:
- The upper or first level of the rafters is about 200 mm.
- The average one is always equal in height to the auxiliary rafters.
- The third one is already on the edge of the wall.
This makes it convenient to install insulation, because the roof of a residential building is characterized by the fact that heat rises upward and, in the absence of thermal insulation, the roof covering is constantly heated.
The result: in winter, the snow melts and slides down, freezing and accumulating even more at the cold cornice. This causes a lot of problems: long dangerous icicles, and clogged drainage system, and the gradual destruction of the entire roof. Decide for yourself!
Determine the type of rafter system: layered or hanging?
So, now is the time to think about the support bases for future rafters, which also need to be prepared in advance and on which many parameters of the roof itself will depend. Thus, rafters are divided into layered, hanging and hybrid.
Hanging rafters usually the lot of small and light roofs, the distance between the supports does not exceed 6 meters. But in buildings with a load-bearing middle wall or additional supports, layered rafters are installed to strengthen the roof. Or this combined option:
Another difference is that the hanging rafter system forces the Mauerlat to work in compression, while the layered rafter system works for shear. But the main task of both layered and hanging rafters is to transfer the loads of the entire roof to the walls and foundation as evenly as possible.
Selecting material for rafters
So, if you have decided on future loads, it’s time to choose suitable material. The following are usually used for making rafters:
- Wood. Solid wood, boards or laminated veneer lumber.
- Lightweight metallic profile. We are talking about galvanized steel profiles.
- Black metal. These are I-beams and steel channels.
- Heavy reinforced concrete structures for industrial construction.
Dry board: economical option
If large loads are not expected on the rafter system, then make the rafters from dry planed boards with a small cross-section. But if knee-deep snow is not uncommon in your area and the roofing material is not light, then you will have to make some of the component elements glued. That's the whole difference.
It is most convenient to make elongated side rafters and diagonal rafter legs from the board. So, a 40 mm thick board, which is often used for outbuildings, is not suitable for a roof. At least 50 mm! Moreover, the longer the rafter leg is planned, the wider the board itself should be. So, rafters 6 meters long will have to be made from boards 150 mm wide, and even longer ones - from boards 180 mm wide.
For the roof frame house this is truly one of the best options!
And also rafters made from boards are the most economical, and at the same time they are almost as strong as lumber. It is only important to choose the right section and use quality material. Therefore, when purchasing material, be sure to take with you special device to measure wood moisture content and use it. There is nothing worse than damp rafters. And it’s not just a matter of future mold: such a roof will begin to warp and warp, because this material changes its shape when it dries. The fastenings at the rafters will fly off and even the covering of your gable roof will bounce off in places. In a word, there will be no problems!
But from regular board It is most convenient to splice rafters along the length:
Durable metal: resists moisture
And, you will be interested to know that rafters can be made not only from wood! Thus, iron rafter systems, which were once used exclusively for industrial construction, are regaining their former popularity today. And, note, this roofing material has many advantages, the most valuable of which is complete absence fungus from dampness. After all, the space under the roof most often “pleases” with random leaks.
And the work itself with such rafters during installation is no more difficult than with wooden ones - see for yourself:
Beams: the benefits of high-quality wood
The beam is more durable, but the disadvantage is that it has a lot of weight and you have to make cuts in the fastening areas. For a log this is not only a problem, but also some loss of the load-bearing capacity of such a rafter leg. But so far this material is the most popular for making rafters.
Most suitable for the manufacture of rafters is lumber that meets the requirements of GOST 8486-86 or 2695-83. And this:
- Humidity no more than 18%, measured with a moisture meter.
- Cracks that are not through and do not exceed half the length of the board.
- For each linear meter - no more than three knots, and each of them - no more than 30 mm in diameter.
Therefore, when purchasing wood for rafters, be sure to check the documents from the seller, which indicate the quality of the product.
The type of wood is also important. The fewer knots and cracks there are on the beams, the better. Some varieties also boast good moisture resistance and resistance to rot and pests. For the roof this is what you need. Therefore, we recommend making rafters from wood coniferous species, which is rich in resin, and resin is a natural barrier against rotting. But special processing is still needed.
And also take into account this fact: when manufacturing a rafter system, you need to purchase 5-7% more material than necessary, because it will not always be possible to make an ideal rafter cut or notch of the required depth. There will still be overspending, so stock up on it in advance so that you have wood of the same moisture content and properties for the entire rafter system.
Otherwise, if any individual elements you had to purchase roofs separately; they may take longer to dry (wood always dries), or vice versa. The distortions can be considerable, i.e. the entire roof frame will be constantly exposed to different physical forces of tension and pressure. Any experienced roofer will tell you how bad this is and what it entails. Therefore, take more material for making rafters than you plan. If everything goes smoothly, there will be something to use to make the first bench in front of the new house.
Treatment with antiseptics and propylents
And at this stage it is already important to protect the future rafter system from biological destruction. You don’t want your roof to collapse after a couple of years of use, do you? Therefore, be sure to treat the wood for the rafters with fire and bioprotection.
The rafters are usually impregnated with an antiseptic and then treated with a fire retardant on top. You can also alternate this processing several times. If you use universal impregnation, know that it usually contains products with for different periods services. For example, fire protection will end before bio.
But the choice of means for processing today is huge. These are also universal protective equipment, and a variety of fire retardants and antiseptics. It’s easy to decide: if you are building in a fairly hot and dry area, first of all use fireproofing impregnations, which deprive the wood of its natural flammability. And if your house is located where the air humidity is almost high all year round– protect from rotting.
You can, of course, use both drugs - but just do not mix, otherwise the whole material will deteriorate. You just need to choose one product as an impregnation, and the second as a protective surface layer. Just try to dilute everything in the concentration indicated by the manufacturer. But do not treat frozen or damp wood with anything: its fibers simply will not absorb anything.
Video tip on the topic of processing rafters:
Note that a brush or spray when processing rafters gives little result - complete immersion and subsequent drying are much better. Just use a regular container, cover it with film from the inside and make a “bathtub” for future rafters. Moreover, it is advisable to do all this on the ground, as soon as you bring the material to the site, because in the finished rafter system it will be difficult to reach the internal elements of the connections. And they are the most defenseless in terms of moisture penetration. After processing, dry the parts so that all sides are ventilated for at least 24 hours.
Do not forget also that wood, like any natural material, is subject to biological destruction. Therefore, in addition to fire-bio-protection, it is important to consider waterproofing in all places where the rafter system adjoins the brick walls of the house, if any.
Making the correct cuts on the rafters
Now let's move on to practice. First of all, you definitely need to make a convenient template according to which you will make even, identical rafters:
And follow these instructions:
You will have to tinker with the rigid mount:
If we are talking about moving units, then follow this principle:
In practice, everything is actually simple:
As you can see, the eyes are afraid, but the hands do!
How to assemble a rafter system?
Finally, the rafters are ready, and you can start installing them.
Build on the ground or on the roof?
So, in reality everything is quite simple and somewhat similar to the children's designer. The easiest and most convenient way is to make trusses directly on the ground, and only then raise them. It is a little more difficult to assemble the rafters directly on the roof, but it is easier to lift them there. This is where you start: if you have the opportunity (a crane, for example) to drag 200 kg of one truss onto the roof - drag it, if not - lift each individual rafter 50 kg using improvised means and do the assembly on the spot.
So, first of all, for convenience, make a template according to which you will assemble the roof trusses, and another template for mounting cuts on the rafters (use plywood). All you have to do is cut out mounting cuts on the rafters, attaching a template, and connect them together at a certain angle. This triangle is called a roof truss.
Attention to strength - rules for increasing length
If the thickness or length of the board is not enough to make a normal rafter leg, extend the rafters. And there are several ways:
- Connect the boards together by folding them with their wide sides and stitching them with nails.
- Lay the boards half the length, resulting in a particularly strong rafter leg that can withstand considerable loads.
- Make an oblique cut at the ends to create a vertical anti-slip stop, and connect with a bolt.
- Lay two overlapping boards a meter long, connecting the rafters with pins or nails.
Also keep in mind when calculating that the roof ridge accounts for about 50% of the load of the entire rafter system. Therefore, always make a ridge beam so that its safety margin is at least 25% greater than originally calculated.
And the most vulnerable parts of the rafter structures are the lower ones, those that rest on the Mauerlat.
Preparing roof trusses
You need to secure the rafters using:
- External straight bracket.
- Metal corner plate.
- Internal metal rod.
You can also connect such rafters with studs - this will even be stronger. To do this, instead of making a cut, we now make a cut into half the tree and connect the rafters with a ledge. Next, drill a hole for a 12-14 mm stud and secure it with nuts and wide washers.
Let's start with a review of proven old-fashioned methods:
If you decide to make roof trusses more reliable new technology you will need a tool like this:
Here's how they work:
In details:
When assembling a roof truss hanging type you need to connect the upper ends of the rafter legs. To do this, cut the end of each at exactly the same angle at which you are making the roof, connect the beams with cut planes and secure with two nails. Cover the joint with a wooden cover or metal plate.
Another useful master class:
Lifting and installation of finished trusses
Already on the roof, first of all, you need to start by installing those rafters that form the two outer trusses of the gable roof (they are also called gable). To further secure them, install temporary struts. Next, stretch a strong cord between the outermost peaks of the trusses, which will become a level for the intermediate rafters.
Now we lift and place all the remaining trusses at a distance of at least 0.6 meters from each other. Again, if some of your structures turn out to be quite cumbersome, support them with the same temporary supports.
The rest is a matter of technique:
For a good roof, it is very important that every step in its creation goes perfectly. The basis of the entire roof structure is the rafter system, the configuration of which determines the type of upper part of the building. There are different types of such systems, among which you need to choose the most suitable one for yourself, because the functionality and quality of the entire roof depends on the correctness of your choice.
Types of rafter system
The construction of the roof during the construction of a building is of significant importance. And for the roof to be strong enough, Special attention is given to load-bearing systems, which are divided into:
- combined;
- hanging;
- layered.
The roof is a rather complex structure consisting of various parts. The main requirement for a roof is - This is the ability to protect a structure from all kinds of weather conditions and withstand different loads.
The main loads of the roof fall on the rafter system, so it is very important to select the right materials, calculate everything correctly and carry out installation in accordance with the technology.
Installation of hanging rafters
Hanging rafters are intended for buildings in which there are no permanent partitions inside, and the distance between the common load-bearing and side walls is no more than 10 meters. The roof structure in this option rests on the main walls of the building, but because of this it is subject to high loads. To make the voltage a little weaker, use additional details(bolts or crossbars) that secure the truss in a horizontal position.
Depending on the span length, various reinforcing elements are used in the construction of hanging rafters
The lower ties are connected at the base of the rafters and can be used as beams for the attic floor, but they must be laid on the mauerlat. To make hanging rafters, a board with a cross-section of 50x200 mm is usually taken, but each individual building needs its own specific calculations.
Sequence of actions for installing hanging rafters:
Installation of layered rafters
Layered rafters are mainly installed in those buildings where there are load-bearing partitions. They are much easier to install than a hanging system, since strong load-bearing walls located inside the house provide reliable support for the rafters. In addition, this system requires minimal amount building materials.
The ridge board in this case serves as a reference point. Such roofing system installed in one of three options:
To secure the rafters at the bottom of the roof, it is necessary to use sliding fasteners, which relieve the load-bearing partitions from additional stress. In this case, the rafters are not fixed very tightly, so that when the building shrinks, they can move without overloading the roof structure.
But in some cases, you can use a spacer system that is tightly attached to the Mauerlat below. Struts and ties are installed in the structure to reduce the load on the walls. This method is called complex because it combines elements of two systems.
This roofing system is used mainly for the construction of private buildings, so it is worth mentioning the installation work, which is carried out in the following sequence:
Installation work to install the layered system should begin with laying the boards on the floor beams. This device will help you carry out work comfortably and safely.
Combined roofing system
Combined rafters have elements from layered and hanging systems in their design. They are used in the manufacture mansard roof. The walls of the rooms on the second floor are made thanks to vertical posts, which rafter beams are the fulcrum.
The horizontal beams that were installed on top of the racks perform two functions: for the upper slopes they are a mauerlat, and for the side slopes they are a ridge beam. Some part of the rafter system, which is connected at the top of the ends of the racks, simultaneously becomes a tightening for the upper elements and a crossbar for the slopes located on the sides.
The combined roof uses fragments of layered and hanging rafter systems To increase the strength of the structure, it is necessary to install struts that secure the rafters and vertical roof posts. Making combined rafters is a little more difficult than other systems, but the labor intensity of the work is offset by an increase in the load-bearing characteristics of the roof and the presence of a full-fledged room under the roof.
Photo gallery: options for rafter systems
In design hip roof layered rafters are used. For an envelope roof, a rafter system is erected, similar to an attic. In the structures of sloping roofs, at the joints there are special rafters that support the valleys. Multi-gable roofs consist of several different rafter systems, combined into one. In the rafter system of an attic roof, the same element can be both a mauerlat and a ridge
Installation of roof truss system
The rafter system is made of coniferous wood. You can use boards or timber that are treated with antiseptic substances before installation. Fasteners can be as follows:
- wooden scarves;
- metal plates;
- various cuts;
- nails.
When starting to install the rafters, the level of the floors and load-bearing walls is raised, after which waterproofing is laid. The rafter structure is necessary to prevent deformation of the rafters. The supporting elements that give the rafter system stability can be:
- sunbeds;
- struts;
- runs;
- racks.
Insulation of the roof is necessary, but for this you should choose a material for hydro-, heat- and vapor barrier. Installation is carried out layer by layer and only in the sequence in which it is necessary: initially steam-, then heat- and finally moisture-proofing material.
Before laying the roofing covering, the necessary protective materials in compliance with the established ventilation gaps To ensure long-term operation of the rafter system, the necessary air circulation is arranged by installing ventilation holes. To prevent leaks, “collars” are made near the holes to prevent water from penetrating under the roof.
Video: DIY rafter system installation
How is the Mauerlat attached?
The Mauerlat is the foundation of the roof, so you should treat it responsibly. Otherwise, roof repairs will be inevitable in the future. Sequence of work:
Methods of fastening roofing Mauerlat and splicing rafters
The Mauerlat is attached to the walls of the building along the entire perimeter, and the fastenings must be located in close proximity to the inside of the wall. Outside the house wooden detail protected by a slight projection of the wall. The mounting location is also initially determined.
How to fix the Mauerlat to the wall
The Mauerlat can be attached to the wall in the following ways:
How to fasten rafters to the Mauerlat
All options for attaching the roof rafter system to the Mauerlat can be divided into the following types:
How the rafters are attached at the ridge level
The most common option for attaching rafters to the ridge is a butt connection:
Rafter splicing options
They are used everywhere in the construction industry various options rafter splicing, while selecting a certain technology, you need to pay attention to the design characteristics of the rafter system, which are influenced by:
- purchased materials;
- technical data of the construction site;
- rafter installation step.
Rafters can be spliced as follows:
Each type of rafter system has its own characteristics and is only suitable for a certain type of roof structure. Exactly from correct installation rafters depend not only on the reliability, but also on the strength of the roof, so this stage of work must be approached with maximum responsibility.
1.
2.
3.
4.
5.
6.
The roof is of great importance for the integrity of the entire house. Therefore, many are interested in how to properly assemble a rafter system so that it is reliable and does not have to be repaired in the near future. There are many types of roofs, some of them can be seen in the photo, but the most popular are lean-to and gable structures. Let's figure out how to make a rafter system correctly.
Types of roofs
Before moving on to how to make a rafter system, you need to understand what the common types of roofs are.
A pitched roof is the simplest; even a person who does not have much experience in construction can cope with its creation. However, this type of roofing is used mainly in the construction of commercial buildings. For residential buildings, gable or mansard (sloping) roofs are usually made. These structures are more complex, but you can easily handle them on your own if you know how to make gable roof rafters and follow all the recommendations of specialists (read: "").
The most reliable roofs are hip roofs; they can withstand even enormous loads. They are recommended to be done in regions where there is a lot of snow and strong winds often blow. But their design is very complex, so it is better to entrust their construction to professionals.
A hipped (hipped) roof is used in the construction of square buildings; in its design, it is a type of hip roof.
The most complex roof is a cross roof. During its construction, complex structural elements are used - valleys (grooves). These diagonal auxiliary rafters are installed as additional elements. During construction such complex roof rush is unacceptable. The bulk of the snow accumulates in the area of the valleys, and the reliability of the roof depends on how to make rafters in these places.
Each type of roof consists of rafters and roofing. The rafters are the load-bearing part of the roof, and the roof surface is the enclosing part.
Types of rafters
Before you lay the rafters, you need to know about them design features and decide on the installation option.
There are two types of rafters: layered and hanging .
Hanging rafters - These are inclined beams installed on supports with different heights. The support can be the external walls of the house (in the case of a pitched roof) or both internal and external walls (in the case of a gable roof). The rafter legs do not have to be laid in the same plane opposite to the slopes. They can be mounted alternately on the ridge girder. Alternate laying of rafters in the ridge area makes it possible to create roof truss. For this purpose, all parts are connected together into a single rigid structure.
Materials for rafters
As for rafters made from boards, they are not heavy and are easy to install. You can easily work with this material yourself, without resorting to outside help. Many experts do not advise making connections with nails - it is better to use self-tapping screws. If the work will be carried out using nails, do not forget about linings and liners.
As for how to build a rafter system, it is better to use notches to connect the racks to the purlin or beam.
Installation of the rafter system with your own hands, details in the video:
Options for connecting the rafter system
The rafter system can be connected in three ways:
- struts;
- stands;
- simultaneously struts and racks.
How to properly make rafters depends on the span between the outer walls. A beam of 10x10 centimeters is used to create ridge girder. The bench and mauerlat can be made from logs by cutting them into two edges, or by taking a 10x10 centimeter beam.
When designing a ridge assembly, it is necessary to nail special clamps made of steel strip to the mauerlat and purlin with large nails, taking into account. You don’t have to use steel clamps, but then you need twists made of thick wire with a diameter of 6 millimeters.
Regarding how to make a brick or stone house, you need to lay a mauerlat on the masonry. To secure it securely, it is recommended to place a piece of log or timber about 50 centimeters under each rafter leg. Then they are attached using clamps to metal hooks, which were previously installed 30 centimeters below the Mauerlat.
Many people have a question about how to make rafters for the roof wooden houses. Rafters in wooden buildings laid on the upper crown of the wall. A plank roof truss can be created using a crossbar or with spans (6-8 centimeters). Its structural elements are arranged as follows. They make a single tightening using boards, the thickness of which is equal to the thickness of the rafters. For double tightening, thinner boards (from 40 millimeters thick) are used. For the crossbar and linings, 30 mm parts are used.
How to determine the section of rafters
Before laying the rafters correctly, you need to decide on their cross-section.
This parameter depends on:
- span dimensions;
- expected load (wind force, weight of snow cover and roofing material);
- pitch and installation angle of rafters (roof slope).
There is a dependence of the cross-section of the rafters on the length of the rafter leg.
It is expressed as follows:
- with a step of 300 centimeters, beams with a section of 10x12 centimeters or boards with a section of 6x14, 8x14 or 4x18 centimeters are used;
- with a step of 400 centimeters, beams with a section of 10x16 centimeters or boards with a section of 6x20, 8x20 centimeters are used;
- with a step of 500 centimeters, beams with a section of 10x20 centimeters or boards with a section of 8x22 centimeters are used.
The roof covering must be selected taking into account the roof slope. Also, the choice of roofing material depends on financial capabilities. The greater the roof slope, the more funds will be required to create the roof - this is due to the increased consumption of materials. However, steep roofs provide better drainage rainwater and snow, so they are more reliable and will not require repairs longer. But considering huge selection roofing materials on the market, there will be no difficulties with this.Creating a rafter system for a bathhouse
As for how to make rafters for a bathhouse, it is better to choose a gable roof - then the building will have an attic space that can be used to store brooms and other bath accessories (read: " "). Thus, it is advisable to create a rafter system for a gable roof, it is simpler and more practical.