The roof is an important structure of the house. She completes the construction of the building frame, after which only the finishing remains. The most common execution scheme with two slopes. The gable roof is made by hand without much difficulty, you just need to understand the technology.
Roof structure
Before you start installing a gable roof, you need to figure out what it is. The design differs from all other gables. You can bring the following varieties of them, depending on the method of assembly truss system:
- shed - gables have the shape of a trapezoid or a right triangle;
- gable is characterized by triangular gables;
- four-slope (hip) has no vertical edges.
The main elements of the gable roof system are:
- rafters;
- Mauerlat;
- crossbar;
- struts;
- racks;
- contractions (screeds);
- crate;
- thrust bars and pads.
Rafters are the main supporting structures. When building with your own hands, it is important to choose their cross section correctly, otherwise an emergency situation may arise.
Preparing to start work
Before you make a gable roof, you will need to select materials. Installation begins with the choice of wood. To build with your own hands robust design, resistant to external factors you will need to follow these guidelines:
For construction, it is better to choose conifers of the first or second grade - it will be right to choose coniferous wood materials (spruce, pine, larch are more resistant to decay);
- the assembly of the structure is carried out from wood of the first or second grade, the use of the third for critical elements is unacceptable;
- it is better to choose those lumber that is produced in the northern regions, the more difficult the growing conditions of the tree, the denser its structure;
- they try to choose the material that is cut down at the end of the cold period of the year (February-March).
- load from snow cover (snow area);
- weight of roofing;
- rafter step;
- span (distance between reference points);
- insulation thickness.
A heat-insulating layer is required when designing a living space in the under-roof space of a house - an attic. Most often, do-it-yourself installation of mineral wool material is performed to improve thermal insulation characteristics. At the same time, it is important to provide a ventilation gap between the heat insulator and the roofing. The height of the rafter leg should not be less than the thickness of the insulation. To increase the clearance, such an element of the system as a counter-lattice is introduced - a bar that is nailed parallel to the rafter leg and increases its height.
The most convenient rafter pitch for a private house is the one that provides a clear distance of 0.58 m between them.
This allows you to correctly install the plates mineral wool without undercuts and additional elements. For such a step, the following recommendations for the cross section can be given, depending on the span:
- span 3 m - rafter size 40x150 mm;
- 4 m - 50x150 mm;
- 5 m - 50x175 mm;
- 6 m - 50x200 mm.
It is important to know the following: load-bearing capacity and bending resistance are more affected by height than width. If necessary, increase the bearing capacity more effectively increase the height.
Another element whose cross section will need to be selected is the crate. The most optimal value will be a thickness of 32 mm. With increased load, the value is increased to 40 mm.
The remaining components of the truss system of the house are assigned constructively, based on what lumber is available. But at the same time, strength requirements should still be taken into account.
Immediately after purchasing the material, before the assembly of the system begins, you will need to process all the elements with special compounds with your own hands.
Gable, like any other roof of the house, needs the following types of protection:
- antiseptic, produced in without fail, allows you to prevent the processes of decay and the occurrence of mold and fungus (even if installation is not planned some time after the purchase of wood, processing is carried out immediately);
- flame retardant, optional, but very important, increases the ability of the tree to resist fire, which increases the safety of the building.
Installation of the truss system at home
To build a roof at home with your own hands, you need to do all the work in a certain order. Installation of elements does not cause difficulties, but the quality of nodes and connections must be controlled. The most important areas are:
- fastening the Mauerlat to the wall;
- fastening rafters to the Mauerlat;
- fastening the rafters to each other.
To properly build a roof with your own hands, the work should be done in the following order:
- Mauerlat installation;
- installation of rafters at a design angle;
- fastening of the legs in the upper part;
- unfastening of load-bearing structures with the help of racks, struts and contractions;
- installation of counter-lattices, battens, waterproofing;
- do-it-yourself insulation of the roofing system;
- installation of the lower lathing, installation of roofing.
Mauerlat fastening to the wall
When installing with your own hands, it is important to understand where to put the Mauerlat. A bar with a section of 150x150 mm or 200x200 mm is installed on the inner edge of the outer walls. At the same time, it is important to ensure sufficient thermal insulation of such a site. The outer part of the fence in this area can be made of the same material as the walls.
In this case, laying is performed at an angle equal to the slope of the slopes. The second option is to fill the space with expanded clay concrete. These methods are relevant for stone houses(brick, foam concrete, expanded clay concrete, etc.). If you plan to build a frame or wooden house the upper trim or the crown of the wall will act as a Mauerlat.
There are several ways to get the job done:
- Staple fastening. To do this, wooden blocks are installed in the penultimate row of masonry, to which the lower part of the brackets will be attached, and the upper part is wound into the Mauerlat. Wooden corks must be impregnated with an antiseptic.
- Wire attachment. To perform this option, you will need to lay a wire 3-4 mm thick in the masonry walls or a monolithic belt, its length should be such as to wrap the beam and twist the wire rod.
- Fastening with bolts or studs. The options are similar, but the first one provides more reliability. Fasteners are laid in a monolithic belt. After that, the beam is laid on studs or bolts. To make holes for them in the right places, lightly tap on the Mauerlat. The resulting recesses will be places for drilling holes. After their preparation, the beam is finally installed in the design position and tightened with nuts.
When building a house, it is also important to know how to build up the Mauerlat. Standard sizes lumber - 6 m, and the walls can be longer. To connect two elements along the length, you will need to perform a direct lock. To do this, cut out the lower part of one element, and the upper part of the other. Fastening is done with bolts. It is not recommended to cut at an angle in this case. With the help of a direct gash, corner joints are also made.
The choice of mounting method for the Mauerlat largely depends on the material of the walls, more precisely on its strength. For lightweight concrete, a mandatory event will be the pouring of a monolithic belt around the perimeter.
It is important to provide waterproofing between wood and stone material. For this, roofing material, linokrom or hydroisol are most often used.
There are two most common options for doing do-it-yourself work when building a house:
- with a gash;
- without drinking.
In both cases, the rafters are additionally fixed with metal corners on both sides. When using a system with a gash, you will need to process the timber at an angle corresponding to the slope of the roof of the house. When installing without a gash, it is necessary to prepare a support beam with your own hands, which will not allow the system element to move across the Mauerlat. As an additional fixation, nails are hammered and a wire is twisted from the leg to the wall (you can perform such an attachment through one leg).
2 types of fastening rafters to Mauerlat How do-it-yourself gable rafters at home will be installed for detailed and visual information, it is recommended that you familiarize yourself with the series “knots wooden roofs residential rural buildings. This album contains a large number of options for fixing all the elements that will help you complete the installation without errors.
The arrangement of a gable roof is considered a very practical and right decision in the construction of a residential or commercial building. This option combines the relative simplicity of execution and reliability, ease of maintenance and long service life. In this material, we will talk about how to install a gable roof truss system with your own hands, what are its varieties, and how to calculate the dimensions of its individual elements. Our step-by-step instructions will allow you to deal with any complications that may arise in the process.
A roof with two slopes has a whole list of advantages:
- ease of calculation;
- various versions;
- saving materials;
- the possibility of natural outflow of water;
- low probability of water leakage due to the integrity of the structure;
- the possibility of arranging an attic or attic;
- reliability and long service life;
- ease of preventive maintenance.
Varieties of gable roofs
Consider the main types of roofs with two slopes, the truss system in which will differ slightly in execution.
Symmetrical gable roof
This is the simplest gable roof, however, the most reliable and in demand. Symmetrical slopes allow you to distribute the load on the Mauerlat and load-bearing walls evenly. In this case, the type and thickness of the insulation layer do not affect the choice roofing material. Thick beams of rafters have a sufficient margin of safety, so they will not sag. In addition, spacers can be installed at your discretion.
Among the disadvantages of this option, one can only note a too sharp angle of the slopes, which makes it difficult to use the attic floor and creates "deaf" zones that have no use.
Roof with two asymmetrical slopes
If the angle of inclination of the slopes is made more than 45º, some unused areas of space can be used. It will even be possible to equip a living space in the attic. However, some additional calculations will be required, as the load on the walls will become uneven.
Broken roof with external or internal break
This configuration makes it possible to place a spacious attic or attic under the roof. However, in this case, more complex engineering calculations will be required.
The design of rafters for arranging a roof with two slopes
The design of the gable roof truss system assumes the presence of such components:
- Mauerlat. It is a durable bar made of oak, pine, larch or other strong wood species, which is laid around the perimeter on the load-bearing walls of the building. The purpose of the Mauerlat is to evenly distribute the load. The cross section of the bars is chosen based on their structure - solid or glued, as well as on the age of the building. The most commonly used beams are 100 × 100 or 150 × 150 mm.
- rafters. The whole structure is created from such elements (read also: ""). Connecting at the top point, two rafters form a farm. They are made from logs or durable bars.
- puff. This part serves to grip the rafters and ensure their rigidity.
- Runs. In those places where the rafter legs are joined, a ridge run is attached, on which the skate will subsequently be mounted. And with the help of side runs, the frame of the rafters is given additional strength. The expected load determines the size and number of such elements.
- Rafter rack. This is a vertical beam that partially takes over the weight of the roof. If the gable roof scheme is simple, then one such beam is placed in the center. For a long span, three bars may be required - one in the center and two on the sides. If an asymmetrical roof is being erected, then the location of such a beam is determined by the length of the rafter legs. Under the rafters for a sloping roof, racks are placed on the sides to make room for movement. Beams are placed in the center and sides if there are two rooms.
- Struts. These are rack supports. If significant winds and precipitation are expected in winter period, install longitudinal, as well as diagonal racks.
- Sill. A rack for rafters rests on it, and struts are also attached.
- crate. The selected roofing material is attached to it, and you can also move along it during work. Fix the crate perpendicular to the rafters. Please note that the crate allows you to evenly distribute the mass of roofing material over the rafter system.
The installation scheme of the gable roof truss system will greatly facilitate all construction work. How such a roof scheme will look depends on the type of roof.
Please note that the material for the truss system must be of the highest quality, treated with flame retardant and antiseptic agents. There should be no knots or cracks on the beams for rafters, Mauerlat and racks. Only a small number of knots are allowed on the crate, firmly seated in the wood.
Calculation of frame elements for a gable roof
Laying Mauerlat on the walls
This element is mounted on a load-bearing wall along its entire length. If it's about log house, then the upper crown can serve as a Mauerlat. For buildings made of aerated concrete or brick, a Mauerlat equal to the length of the wall will be required. Sometimes this detail can be laid between the rafters.
With a lack of material length for the Mauerlat, several pieces can be spliced. At the same time, the edges are sawn at 90º and joined with bolts - wire, dowels or nails are not suitable.
There are two ways to lay a Mauerlat on top of a load-bearing wall:
- symmetrically in the center;
- offset in the desired direction.
Mounting of the Mauerlat is carried out on a pre-laid waterproofing layer of roofing material. This will protect the wood from rotting.
It is worth taking a responsible attitude to the process of attaching the Mauerlat, since in strong winds it must withstand a particularly heavy load.
As fasteners for Mauerlat, you can use the following consumables:
- Anchors, which are indispensable for monolithic materials.
- Wooden dowels. These parts are used in houses made of timber and logs, although they require additional fastenings.
- Staples.
- Reinforcement or special studs. This option is preferable for buildings made of foam or aerated concrete.
- knitting or steel wire- This is an auxiliary fastener, used almost always.
Assembly of trusses or trusses
Farm assembly can be done using one of the following methods:
- Beams for rafters are assembled and mounted directly on the roof of the building. This process is quite laborious, since all measurements, trimming and coupling of the bars will have to be done at a height. However, you can do it on your own, without the involvement of technology.
- Trusses or truss pairs can be fixed to the ground, and then the finished elements can be raised to the roof of the building. On the one hand, this simplifies the process of installing the rafters, and on the other hand, due to the large weight of the structure, lifting it up will require special equipment.
Please note that it is worth starting the assembly of truss pairs only after marking. And if you make a template in advance, for which you take two boards equal to the length of the rafters, and connect them together, then all pairs will turn out to be exactly the same.
Installation of rafters
After assembly and lifting to a height, the installation of gable roof rafters is carried out wooden house. To fix them on the Mauerlat, cuts are made at the bottom of the rafters. The first to install two trusses from opposite ends of the roof.
After that, a rope is pulled between the starting pairs, along which all the other truss trusses will be aligned and the ridge will be installed.
Now you can mount the remaining pairs in compliance with the calculated step between them. In cases where pairs are assembled directly on the roof, a ridge run is attached between the two end trusses. Subsequently, rafters are installed on it.
The order of installation of halves of rafters according to the opinions of professionals may differ. Some prefer to lay the bars in a checkerboard pattern so as not to overload the foundation and walls during work. Others tend to install pairs of rafters in series. Be that as it may, rafter legs may need props and racks - it all depends on the size of the roof and the shape of the trusses.
Skate mount
A ridge is an element that is formed by attaching rafters at the top point. As soon as all the details of the truss system for gable roof will be installed, it is necessary to perform a capital fixing of all structural elements.
Lathing installation
The presence of lathing is mandatory in the construction of any roof. It not only supports the roofing material and allows it to be securely fastened, but also makes it possible to move along the roof during work.
The distance between the individual boards is chosen based on the type of roofing material:
- soft roofing is laid on a continuous crate without gaps;
- for a metal tile, a crate is needed with a step of 35 cm (between the two lower rows - 30 cm);
- slate and corrugated board can be laid on the crate in increments of 44 cm.
Results
Thus, in order to assemble a truss system for a roof with two slopes, many nuances should be taken into account and any possible complications should be foreseen. We hope that our advice will help you cope with this difficult task and create a high-quality and durable roof for your home.
The truss system of any object is equivalent to the value of the load-bearing structural elements of the house. The roof plays the role of a node under which the stiffening ribs of the building are assembled. Accordingly, when installing the roof with your own hands, it is required to give the maximum value to all structural units, even when using a simple option - gable.
Advantages of gable roofs
There are a lot of options for pitched truss systems. Among them, simple symmetrical is especially popular. Why? Here are her virtues:
- On the basis of a gable roof, variations are created to reflect the special architecture of the building.
- Simple calculations, easy to understand.
- One-piece construction keeps you dry inner space and unhindered flow of water, snow, ice.
- The maintainability, strength and durability of a gable roof are much higher than other options.
Depending on the size, homeowners always have the opportunity to equip the under-roof space, make it a full-fledged floor or attic. In a word, a gable roof is the right and profitable solution for any object, whether it is a residential building, a summer residence or a bathhouse.
Elements of the truss system
Depending on the type of roof structural elements differ. Without knowledge of the appointments of each, it is impossible to arrange a reliable coverage at home. Let's analyze in detail:
Mauerlat
The basis of the truss system. It is a beam with a section of at least 150 mm, or an I-beam channel, if the roof structure is metal. Located on bearing walls ah object. Its purpose is to distribute the load of the system evenly throughout the structure of the house.
Rafter leg
Structural basic unit of the system. Together with others, it forms a truss system - strengthening the strength of the entire roof. It is made of a wooden beam, which is not inferior in cross section to Mauerlat or profile pipes.
Rafter rack
Vertical bar or pipes. Depending on the variant of the gable roof, the pillars can be located in the center and / or on the sides. They take part of the weight of the entire truss system, which is why the cross section is 150 mm.
Rafter girders
Horizontal beams laid on racks and under the ridge to support the rafter legs. They provide structural rigidity and relieve stress on trusses.
Puffs and braces
Connecting beam for rafters. The action is similar - relieving the stress of a beam or metal and making the structure rigid.
lying down
Mounting support for racks and struts. To securely connect these two elements, you need a large cross-section beam - 150 mm or a thick-walled pipe of impressive diameter.
Lathing beam
Elements laid perpendicular to the rafters. Serve to install the selected roofing and create a multilayer protective cake. The cross section is small - 40–50 mm.
If the planned roof structure is made of wooden beams, you should carefully consider the quality of the wood upon purchase - the beam should not have knots interspersed, be made of soft wood.
Also, wood must have natural moisture, otherwise it will begin to dry right in the system structure, cracking, deforming the roof model, depriving it of reliability and safety.
Calculation of the truss system
double roof - complex structure. The project takes into account many factors - natural nuances, wind, constant and variable loads. It is extremely difficult to make calculations on your own, without special knowledge about the climate of the area, the features of the material for the manufacture of the system, the nuances of pressure distribution.
Ideally, the calculations are at the mercy of professionals, you can independently choose only the material for coating - the following parameter depends on its type:
Tilt angle
The minimum angle of inclination of the roof relative to the parallel of the earth is 5 degrees. However, its dependence comes from the chosen roofing material. In this capacity, traditional slate, profiled sheet, flexible and metal tiles are used.
They are guided by the following rule: the steeper the slope, the more textured the roof can be.
From 5 degrees for laying rolled protective insulation of the roof. The number of layers matters - up to 15 degrees three-layer coatings, above - two- and single-layer coatings.
- From 6 - ondulin.
- From 11 - slate.
- From 12 - corrugated board.
- From 14 to 20 - metal tiles.
- From 15 to 45 - soft roof.
Thus, the resulting precipitation - snow, water - will not linger on the surface, although complete cleaning requires one's own efforts or the involvement of specialists for the installation of the Anti-Ice system.
Determining the parameters of the rafters - step, length, section
The rarer the step, the more impressive the cross-section of the beam or the diameter of the pipes should be. As a rule, for load-bearing structures, this parameter is at least 150 mm, 100 mm for country houses and related construction - gazebos, baths, outbuildings.
Next, you need to set the number of rafters per slope: its length is divided by the installation step, which is from 60 to 100 cm + 1 extreme leg. Multiplying the result by 2 gives the total. Depending on the section of the beam, the amount of rafter legs and the installation step vary.
The length of the rafters is calculated simply if school knowledge about right triangle left in the luggage. The rafter leg is equal to the hypotenuse of the resulting figure. The calculation is as follows: A² + B² = C², where - A is the height of the roof, B is half the length of the pediment, C is the length of the rafter leg. To the resulting value is always added from 30 to 70 cm for cornice overhangs.
Types of truss systems
Before getting down to work, it is important to choose a truss system option for a gable roof. There are few of them, each has its own advantages and disadvantages:
hanging
Suitable only for a standard roof width of 6 m, respectively, this is the length of the rafter leg. Fastening occurs by fixing the ends to the ridge run and the bearing wall. Be sure to install a puff that levels the stress and pressure of the structure.
In addition, they will play the role of load-bearing beams. Without them, the structure will disperse under weight. The advantages of the option are in the absolute dryness of the roof surface during the off-season, and in less deformation at the time of shrinkage.
Layered
The option is suitable for any roof width. Reliability and stability is ensured by fixing the bed to the Mauerlat. Thus, the pressure is leveled by the rack, which reduces the tension in the rafter legs. The advantage of the system is simplicity, but the design requires large investments - additional lumber is required to equip the beds.
hybrid
These systems are typical for multi-pitched roofs, where transitions are accompanied by numerous reinforcements, beams, posts, beds, slopes and other elements for the stability of the entire structure. The device is expensive and complicated, so only a professional should deal with the project and construction. At least curate it.
Do-it-yourself installation of a gable roof
So, when the option of the truss system is selected, lumber is purchased, a roof project is drawn up, you can get to work. You cannot deviate from the sequence of steps. This threatens to delay installation and loss of structural reliability.
Mauerlat mount
If the length of the beam for installing the Mauerlat is insufficient, an extension is made. Using the half-tree cutting method, the ends are connected. Additional fasteners are anchor bolts. Do not use self-tapping screws, dowels or nails - they are unreliable. Mounting to the wall is as follows:
- There must be a margin of at least 5 cm from the edge.
- Holes are drilled along the wall for inserting fasteners. Similar actions are carried out with a bar.
- Mauerlat is attached to the edge with steel studs. The fastening step is more often 2 times than the distance between the rafter legs. Subsequently, before installing the main units, they are guided by metal marks.
Important - before laying the Mauerlat, the edge of the wall is protected with waterproofing. Spread one layer even if the house is made of wood.
Making and fixing rafters
Roof trusses are convenient in that they can be assembled on the ground in finished structure and move to the roof. This will reduce installation time, however, the model is heavy and lifting equipment will be required, which, of course, will increase the cost of the project.
For budget construction another way is good:
- At the bottom and top of the rafter legs, a gash is made to attach to the Mauerlat and the ridge run. This must be done separately with each unit, after lifting the wood up.
- Places for fixing are marked on the Mauerlat and a ridge run is installed: racks are installed along the gables, on which a beam is placed. If the length is not enough, it is increased, but in a different way, unlike the Mauerlat - a board is screwed to the junction from both sides.
- Depending on the chosen model of the truss system - layered, hanging - they make cuts in the ridge beam, Mauerlat or drill holes in them for fasteners.
- Next, begin the installation of rafter legs from opposite ends of the roof, gradually moving towards the middle. Between the corners of the extreme trusses, it is not bad to stretch the cord to exactly match the entire horizontal part.
- Between themselves, the rafter legs are connected by puffs and struts. Under the ridge part, at the angle formed by the rafters, wooden linings are stuffed, and the ends themselves are tightened with bolts.
More recently, professional builders have begun to use sliding fasteners for roof installation. Metal plates securely hold the bearing elements and at the same time move due to shrinkage. This cancels out its effects.
The work of fixing the rafters is hard and long. You should calculate the time in advance - you can not leave the roof unfinished during the rainy season, otherwise the rigidity of the structure will be lost in the future due to absorbed moisture.
Gables and framing
The side parts of the roof - gables, are made in the form of ready-made shields from boards and are completely installed at the top. Difficulties should not arise - it is only important to carefully file them at the required angle. It is necessary to fasten the crate only after it is known final view roofing. For instance:
- Under the corrugated board, the step of the crate beam will be 440 mm.
- The metal tile is fastened to the crate in increments of 350 mm.
- A soft roof needs a solid plywood coating.
It is important to note the places for the passage of the chimney - the crate should not come into contact with a brick or metal surface. The distance to the hot unit is at least 15 cm. Before installing the lathing, the finished roof is covered with waterproofing with allowances extending beyond the edges of the walls. Then the beam is mounted.
If it is decided to make a warming cake from above, then first strengthen the vapor barrier with inside, then put the selected material into the boxes formed by the rafter legs. Next, waterproofing and wind protection.
Then it is required to re-mark the contours of the rafter legs with a beam 20 * 20 and then fill a new layer of the crate, along which the roofing material will be laid - the formation ventilation ducts. This method will save the capacity of the under-roof space if the owners are going to use it for a specific purpose.
Roofing material flooring
Regardless of the type of roofing raw material, installation starts from the edges of the roof and leads it up, laying one unit on top of the other. Thus, rain moisture will not get under the material.
The method of fastening depends on the type of material - soft tiles or tiles with a bitumen or polymer base are fused. Solid profiled sheets - ondulin, metal tiles - are fixed in pre-drilled holes to the crate, using rubber pads to seal and preserve the anti-corrosion layer.
As a result: the description of the installation of the truss system and the roof is easy only on the screen or paper. In reality, the process is complex and multifaceted. Therefore, if knowledge is not enough, it is better to invite professionals to work - their work is always guaranteed.
In building your dream home, are you already at the finish line, and it's time to deal with the intricacies of the truss system? Let's just say: pleasant worries await you: calculating the angle, weight and safety factor of rafters, an agreement with a familiar craftsman or company, or preparing all the 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 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 time.
- Technological precision of all details.
- The same, already fitted dimensions of all structural elements.
But then be prepared for such cons:
- High cost (at least twice as high as if you planed the rafters yourself).
- Delay in delivery (especially in season).
- The use of low-quality or under-dried wood (and then the roof will “lead”).
So convenience or quality? If this is not the first time for you to cut or plan something out of wood, feel free to take on the manufacture of rafters! Here's what it all looks like in real life:
Rafters in the construction world on plain language it is customary to divide the main ones, i.e. carriers, on which the roof rests, and on auxiliary ones, which are located inside the roof and serve as a support for hemming the ceiling and walls of the attic (if one is planned). The strength and reliability of the future roof depends on how accurately and correctly you calculate the truss system in advance.
The truss system of any gable roof itself consists of the following basic elements that you need to make:
- Mauerlat.
- Vertical racks.
- Crossbars.
- Rafter legs.
- Struts.
- Skate ride.
Complex roof structures with multiple elements are best left to a professional, but you can handle a small roof of a private house. 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 draft a future roof?
The golden rule applies in the construction of roofs - measure seven times, and cut off 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 better in special program. Only after that, according to your 3D model of the future roof, mark exactly where and what exactly the connections of the rafters with the Mauerlat and among themselves will be.
It is important to determine the angle of inclination of the rafters as accurately as possible and at what angle they need to make cuts. And don’t worry about how to make all these rafters for a gable roof yourself: you just need a regular machine.
Determine the angle of the roof: calculate the load
The angle of inclination of a gable roof is made from 5 ° to 90 °. But the most proven and standard option is 35 ° -40 °, where loads are most rationally distributed and building materials are consumed.
Straight slopes are built when only a non-residential attic will be under the roof in the future, the main function of which is ventilation and heat exchange regulation. But when the under-roof space is planned to be residential, attic, they initially plan the so-called broken line gable roof. Its difference is that the slopes in the middle have, as it were, a kink that changes their angle to a steeper one. And for arranging the attic, and for protecting the whole house from the weather, this design is quite suitable.
Please note that most roofing materials are suitable only for slopes greater than 45°.
Fixed and variable roof loads
From the same loads depends on what step the rafters need to do for your gable roof. This table will help you choose the desired section of the rafter legs:
Indicators of rafters for deflection
Even strong-looking rafters may not be suitable for building the roof of a residential building due to the fact that they do not have enough deflection indicators. There are separate items in the section of SNiPs, which are called "Loads and Impacts".
And the easiest way to increase the strength of the rafters for deflection is to make the section larger. A little more difficult - to strengthen it with a beam, bringing its edge to the strut.
Reinforcing elements for rafters
The more racks, struts and fights - the more stability and stability the entire truss system has.
If you have suspicions or even an accurate count that simple design the roof will not withstand future loads, make additional reinforcement elements for it. Such prevention will never hurt, but it will save you from many problems. Note that it is especially disappointing when the roof of the garage falls through - right on the car. And for a residential building, such problems are not a joy.
Enhance rigidity roof structure struts, additional runs and support posts. Struts are designed to reduce the span of the rafter legs. The angle of their inclination to the horizontal is usually at least 45°.
A run is a horizontal beam, which is parallel to the ridge and is fixed on vertical posts. More on video:
Determine the type of roof: cold or warm?
And now about the concept of the attic. If you are building the roof of a bathhouse or a small master's room, it can be done using the most simplified technology - they put rafters, connected them in a ridge and covered them with sheets of roofing material. But for the roof of a residential building, where ventilation is important, this principle is indispensable. There will already be at least three levels:
- The upper or first level of the rafters is about 200 mm.
- The average is always equal to the height of the auxiliary rafters.
- The third is already on the edge of the wall.
It is so convenient to lay insulation, because the roof of a residential building is distinguished by the fact that heat rises up and, in the absence of thermal insulation, the roofing is constantly heated.
Bottom line: in winter, the snow melts and slides down, freezing and accumulating even more near the cold eaves. There are a lot of problems from this: both long dangerous icicles and clogged drainage system, and the gradual destruction of the entire roof. Decide for yourself!
We determine the type of truss system: layered or hanging?
So, now is the time to think over the supporting bases for future rafters, which also need to be prepared in advance and on which many parameters of the roof itself will depend. So, the rafters are divided into layered, hanging and hybrid.
Hanging rafters are usually the lot of small and light roofs, the distance between the supports of which does not exceed 6 meters. But in buildings with a load-bearing middle wall or additional supports for the roof fortress, layered rafters are arranged. Or a combination like this:
Another difference is that the hanging truss system makes the Mauerlat work in compression, and the layered one in shear. But the main task both layered and hanging rafters - to transfer the loads of the entire roof to the walls and foundation as evenly as possible.
We select material for rafters
So, if you have decided on future loads, it's time to choose the right material. As it is usually used for the manufacture of rafters:
- Wood. Solid wood, boards or glued beams.
- Lightweight metal profile. These are galvanized steel profiles.
- Black metal. These are I-beams and steel channels.
- Heavy reinforced concrete structures for industrial construction.
Dry board: an economical option
If heavy loads are not expected on the rafter system, then make the rafters from a dry planed board with a small section. But if knee-deep snow is not uncommon in your area and the roofing material will not be easy, then you will have to make some of the constituent 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 board 40 mm thick, which is often used for outbuildings, is not suitable for a roof. Not less than 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 a board 150 mm wide, and even longer - from a board 180 mm.
for the roof frame house it really is one of the most the best options!
And also the rafters from the board are the most economical, and at the same time they are almost not inferior in strength to the timber ones. It is only important to choose the right section and use quality material. Therefore, when buying material, be sure to take a special device for measuring wood moisture and use it. There is nothing worse than damp rafters. And it's not just about future mold: such a roof will lead and warp, because this material changes its shape when it dries. At the rafters, fasteners will fly and even the cover of your gable roof will bounce in places. In short, no problems!
But from an ordinary board it is most convenient to splice the rafters along the length:
Durable metal: resistance to dampness
And, you will be interested to know that rafters can be made not only from wood! So, iron truss systems, which were once used exclusively for industrial construction, are returning to their former popularity today. And, note, this material for the roof has many advantages, the most valuable of which is complete absence damp fungus. The under-roof space, after all, most often “pleases” with accidental 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 quality wood
The beam is more durable, but it is bad because it has a lot of weight and cuts have to be made at the attachment points. For a log, this is not only a problem, but also some loss in the bearing capacity of such a rafter leg. But so far this material is the most popular for the manufacture of rafters.
Most of all, lumber is suitable for the manufacture of rafters, which meets the requirements of GOST 8486-86 or 2695-83. And this:
- Humidity is not 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 running meter- no more than three knots, and each of them - no more than 30 mm in diameter.
Therefore, when buying wood for rafters, be sure to check the documents from the seller that speak of product quality.
The type of wood is also important. The fewer knots and cracks on the beams, the better. Some varieties also please with good moisture resistance and resistance to decay and pests. For the roof, this is what you need. Therefore, we recommend making rafters from coniferous wood, which is rich in resin, and resin is a natural barrier against decay. But special processing is still needed.
And take into account also this fact: in the manufacture of the rafter system, the material needs to be purchased 5-7% more than necessary, because it will not always be possible to make an ideal cut of the rafter or cut of the required depth. There will still be an overrun, and therefore stock up on it in advance so that you have a tree of the same moisture content and properties for the entire rafter system.
Otherwise, if any individual elements roofs you had to purchase separately, they may take longer to dry (wood always dries), or vice versa. Distortions can turn out to be considerable, i.e. the entire roof frame will be constantly affected by different physical forces stretching and pressure. Any experienced roofer will tell you how bad it is and what it is fraught with. And therefore - take more material for the manufacture of rafters than you plan. If everything goes smoothly, there will be plenty to make the first bench in front of the new house.
Treatment with antiseptics and propylene
And at this stage it is already important to protect the future truss system from biological destruction. You do not want the roof to collapse after a couple of years of operation, 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 treated with a flame retardant on top. It is also possible to alternate such processing several times. If you use universal impregnation, be aware that it usually includes products with different periods services. For example, fire protection will end earlier than bio.
But the choice of means for processing today is huge. These are universal protective equipment, and a variety of flame retardants, and antiseptics. It's easy to decide: if you are building in a fairly hot and dry area, first of all use fire-retardant impregnations that deprive the wood of natural flammability. And if your house will stand where the humidity is high, almost all year round- protect from decay.
You can, of course, use both drugs - but only without mixing, otherwise the whole material will deteriorate. You just need to choose one agent 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 hint on the topic of rafter processing:
Note that a brush or a spray when processing rafters give little result - complete immersion and subsequent drying are much better. Just use a regular container, cover it with a film from the inside and make a “bathroom” for future rafters. Moreover, it is desirable to turn all this on the ground, as soon as you bring the material to the place, because. in the finished rafter system it will be difficult to get to the internal elements of the joints. And they are the most defenseless in terms of moisture. Dry after processing the part so that all sides are ventilated, and for at least 24 hours.
Do not forget also that wood, like any natural material subject to biological degradation. Therefore, in addition to fire-bio-protection, it is important to consider waterproofing in all places where the rafter system adjoins brick walls home, if any.
We make the right 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 a rigid mount:
If we are talking about moving nodes, then follow this principle:
In practice, everything is really simple:
As you can see, the eyes are afraid, but the hands are doing!
How to assemble a truss system?
Finally, the rafters are ready, and you can proceed with their installation.
Build on the ground or on the roof?
So, in fact, everything is quite simple and somewhat similar to a children's designer. The easiest and most convenient way is to make farms right 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. So start from this: 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 by 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 trusses, and another template for mounting cuts on the rafters (use plywood). You just have to cut the mounting cuts on the rafters, attaching a template, and connect them together at a certain angle. This triangle is called the truss truss.
Attention to strength - rules for increasing the length
If the thickness or length of the board is not enough to make a normal rafter leg, build up the rafters. And there are several ways:
- Bring the boards together, folding them with wide sides and stitching them with nails.
- Lay the boards in half the length, resulting in a particularly strong rafter leg that can withstand considerable loads.
- By making an oblique cut at the ends to create a vertical anti-slip stop, and connect with a bolt.
- Lay two boards with an overlap of a meter in length, connecting the rafters with studs or nails.
Also consider when calculating that the roof ridge accounts for about 50% of the load from the entire truss system. Therefore, always make the beam for the ridge so that it has a safety margin of at least 25% more than it was originally calculated.
And the most vulnerable parts of the truss structures are the lower ones, those that rely on the Mauerlat.
Cooking truss trusses
You need to fix the rafter knots with the help of:
- External straight brace.
- Metal corner plate.
- Internal metal rod.
You can also connect such rafters with studs - it will even be stronger. To do this, instead of a cut, we now make a cut in half a tree and connect the rafters with a ledge. Next, we drill a hole for the stud 12-14 mm and fix it with nuts with wide washers.
Let's start with an overview of proven grandfather methods:
Here's how they work: 
When assembling a hanging type truss truss, 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 make the roof, connect the beams with cut planes and fix with two nails. Close the joint with a wooden lining or a metal plate.
Another useful tutorial:
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 extreme gable roof trusses (they are also called gable). To further secure them, put temporary struts. Next, stretch a strong cord between the extreme tops of the trusses, which will become the level for the intermediate rafters.
Now we raise and place all the other roof trusses at a distance of at least 0.6 meters from each other. Again, if some of the structures turned out to be quite bulky, prop them up with the same temporary supports.
The rest is a matter of technique:
The rafter system is the basis of any roof. The complexity or accessibility of the roof structure depends on the type of roof chosen. Today we will talk about the most simple version- a rafter system for a gable roof. Experienced specialists tell about the structure of the roof frame, the features and functions of its elements, and how the truss system of a gable roof is made with their own hands.
Gable roof: types and benefits
Recall that a gable roof is a type of roof consisting of two planes (slopes) connected at an angle of a certain degree. It can be simple (symmetrical or asymmetric) and complex - broken.
The rationality of choosing a roof of two slopes is determined by its following advantages:
- Profitability and simplicity of erection, in comparison with other roof structures.
- Ease and availability of service at any time of the year.
- Reliability and durability against wind, snowfall, hail and other natural influences.
- The possibility of arranging the attic.
- Better hydro and thermal insulation.
The necessary theoretical minimum for the construction of the truss system
The pitched roof structure is made of metal or wooden beams. Metal is a more "problematic" material. It makes the entire roofing system heavier, cools down and heats up quickly, is more difficult to install and requires the use of professional welding equipment. Based on this, in the construction of private houses (especially with their own hands), wood is mainly used.
There are two main options for the implementation of the truss system for a gable roof - a hanging type device (each rafter leg has two points of support) and a layered method (the rafters are connected at the bottom by a puff, forming a triangular truss, a carrier beam is installed in the middle). A layered structure is necessary if there is a distance of more than 10 meters between the bearing walls. Look at the image:
What does the system of truss elements consist of? Imagine a 3D projection. The skeleton of the roof consists of a mauerlat (rafter base), rafter legs, a ridge, racks, girders, lying, puffs, struts and battens. Mauerlat, lying and puffs are the lower parts of the system on which the entire future roof is being built. First, take a look at the illustration below, and then consider each element separately:
Mauerlat - the basis of all foundations
Mauerlat is a bar made of solid wood (mainly coniferous species) with a cross section of 10-15 cm. These are the optimal dimensions for the required strength and durability of the entire roof structure. The beam is laid on the load-bearing walls of the house to redistribute the spacer load on them.
There are two ways to install the bars of the truss base - with the transfer of load to the walls and without the transfer of gravity. The choice of mounting option for the Mauerlat should depend on the severity of the roofing system, the coating, the thickness of the load-bearing walls and the perimeter of the roof.
In the latter version, the Mauerlat is placed in a pocket, closer to the inner edge of the wall, and fastened to wooden corks with staples (each cork corresponds to the size of a brick and is part of the top row of brickwork).
The bars that take the load are mounted on the load-bearing walls from above with the help of anchors. Masters advise laying a rigid frame on a concrete base in the form of a belt in the wall. High-quality waterproofing is necessarily laid under the Mauerlat.
Details can be found in the video:
Lying - Basic Load Distributor
Lezhen performs functions similar to Mauerlat, and has the same dimensions. Beams are laid on internal load-bearing walls to evenly distribute loads from vertical struts and struts.
See the illustrations for the installation master class:
Rafter legs - ribs of the roofing skeleton
Rafters can be called the main component of the roof frame. This element cannot be left unused or replaced by another part. The legs of the rafters are wooden bars, the cross-sectional size of which can vary from 5 to 15 cm. The rafters rest on the Mauerlat and are interconnected by a ridge.
The installation process of the rafters can be seen in this video:
Skate - a small nuance with great meaning
The final element of the junction of two slopes is called the roof ridge. This is a rib located vertically at the highest point of the roof. A ridge run is mounted at the junction of the rafters. After that, the roof ridge is installed on it. This element fastens the rafters, performs a ventilation function and gives the roof aesthetics.
Racks - receivers of the main loads
Racks are powerful beams that take part of the load of the truss structure. They are installed vertically, usually in the center of the truss. If the project provides for an attic, then the racks are placed on both sides, closer to the roof slopes. When the attic is divided into two rooms, the racks are placed both in the center and on the sides.
Runs - rafter support
Ridge and side runs serve as a stiffener for roof trusses. The greater the load on the system (snowy winters, heavy roofing, large roof area, etc.), the more purlins should be installed on the roof slopes.
Tightening - truss element connector
This structural detail performs the function of fixing the rafters at the base. Thus, a rafter triangle is formed - a farm. Puffs may not be installed in layered systems.
Struts - the strength of the structure
The struts serve as a support for the uprights and strengthen all structural elements. Experts recommend installing struts at an angle of 450. This increases the strength of the system and protects it from deformation under the influence of snow masses and wind.
Lathing - the basis for a roofing cake
Lathing - horizontal wooden slats with a section of 40-50 mm, located on the slopes perpendicular to the rafters. The main purpose of the crate is to fix the roofing material. The frequency and thickness of the battens depends on its type. In addition, the crate helps to move materials during the roofing and serves as an additional element of structural strength.
Overhang elements - final moments
The edge of a roofing system is called an overhang. This is a protrusion of the rafter system above the wall by about 40 cm. The overhang box consists of the following elements: filly (slats connecting with rafters), frontal and cornice boards. The purpose of the overhang is to protect the walls from getting wet during rains and melting snow.
A step-by-step guide to installing a gable roof truss system
To get started, we suggest that you familiarize yourself with the illustration that we have prepared for you:
And now consider the three main stages of the process of installing a simple gable roof truss system:
Stage 1: Calculations and drafting
Work should begin with the preparation of the roof project. It will contain all sizes, shapes and types of fasteners of structural elements. To create a quality project, you need to make the following calculations:
- Calculation of constant and variable loads on the truss system. Permanent loads include the weight of the roof and finishing materials(the attic is also taken into account additionally). Variable loads are the force of wind, rain, snow, etc. The maximum can be considered the main load of up to 50 kg per square meter roofs, and variable - up to 300 kg (taking into account possible snow blockages).
- Accounting for seismic activity, storm winds and features of the location of the house. For example, if the house is surrounded by other buildings, then the load on the roof is significantly reduced.
- The choice of the angle of inclination of the gable roof. When calculating the angle of inclination, the following factors are taken into account: the higher the angle, the more materials will go to the roof (and money, respectively); the slope depends on the roofing material - than softer roofing, the smaller the angle of inclination (for example, for soft tiles an angle of 5-200 is selected, and if you use slate or ondulin, you must select a slope of 20-450).
- Calculation of the pitch and length of the rafters. The step length between the trusses varies from 60 to 100 cm. The heavier the roofing, the more often the rafters need to be distributed. To calculate the length of the rafter, we use the Pythagorean theorem, taking the rafter leg as the hypotenuse of the triangle. The first side will be considered half the width of the house, and the second - the selected roof height. Then we add another 60-70 cm of margin to the hypotenuse we found.
When all calculations are made, you need to make a drawing of parts, connections and the entire project as a whole.
Stage 2: Acquisition and preparation of the necessary materials and tools
For work, it is necessary to purchase lumber, according to calculations, bolts, corners, anchors and other connecting parts, and prepare the appropriate tools (drills, levels, meters, jigsaw, etc.). Wood for load-bearing beams and rafters must be solid and of high quality - knots and wormholes are unacceptable.
Antiseptic, anticorrosive and fireproof wood treatment is a must at this stage. You can start working with the material one day after processing.
Stage 3: Installation of the roof truss structure
It is better to mount the roof frame in dry, non-windy weather, so as not to encounter additional difficulties during operation. At this point, we will take a closer look and look at step by step instructions installation of the truss system.
Installing the truss system: a step by step guide
Step 1. Laying the Mauerlat and the bed. There may not be a bed if there are no more load-bearing walls inside the house. Before laying the Mauerlat on the walls, it is necessary to lay a waterproofing material, for example, roofing material. We measure the tape of the desired width, cut it off and lay the waterproofing on the edge of the wall (where the frame will be installed).
We mark the beams of the desired section and length, trim and begin to form the base frame. Mauerlat should be located on the outer edge of the wall (if a hanging structure is planned) or in a special niche on the wall in front of the threshold (if the roof system is layered). The beds under the racks are laid on the internal load-bearing partitions. The Mauerlat is attached to the wall and wooden plugs with brackets, studs and anchors.
And we invite you to familiarize yourself with the illustration that we have prepared for you:
When laying the frame along the entire length of the wall, we may encounter the need to connect the base beam. They should be performed by cutting the bars at an angle of strictly 90 degrees. Fastening is carried out with high-quality bolts.
How not to damage bricks or blocks when lifting roof boards?
Choose the edge of the wall through which it is most convenient to feed the beams for the roof frame. This edge must be protected with a wooden square. Two trimmings of a rough board about a meter long will do, which need to be knocked together at a right angle. Put the square on the outer edge of the work wall. Now you can lift the boards without fear of damaging walls or window sills with them.
Step 2 Installation of rafters. The first step is to install the extreme rafters. In order for the rafters to be held evenly, we install the racks in the center. We attach the racks to the Mauerlat using an iron corner and self-tapping screws. This temporary part is removed after the installation of all rafters. We fasten the extreme rafters with crossbars and install a ridge run. Attachment type - metal corner, self-tapping screws and studs.
The illustration shows the process of mounting the rafter legs and attaching the rafters to the run:
But how to attach the rafters to the Mauerlat:
Between the extreme farms, it is imperative to stretch the construction thread along which we will level all the slope rafters.
Now we mount all the truss elements according to a pre-marked scheme. We join the rafters over the ridge run.
For more information about the process of installing rafters, see this video:
A system of special racks will help strengthen the rafter legs. On the Mauerlat, wooden bars are fastened from boards of the same thickness as the rafters. The bars must be fixed in increments equal to the selected distance between the rafter legs according to the markup. The length of each board is approximately 40 cm. These racks will transfer the load to the power plate and load-bearing floors. The bars must be fixed to the base with steel corners. Now the rafter legs need to be installed so that one side of each is adjacent to the rack. Then, on the other side of each rafter, we fasten the same rack and grab all three parts with 12 mm studs.
After mounting all the legs of the rack, they are cut flush with the bevel of the rafters from the side of the street. From the inside, an empty corner is formed between the racks, which must be closed wooden triangle(you can use trimming from bevels).
All rafter legs should be additionally strengthened with crossbars, racks, struts and the joints should be reinforced with metal plates. The full process of strengthening the rafters can be viewed on the video:
Step 3. Waterproofing and crate. On the finished rafter ribs, you need to lay a high-quality waterproofing vapor-permeable material under the crate. The entry of the insulating sheet (sheet to sheet) is 15 cm. A counter crate is stuffed onto the waterproofing wooden slats along the edges of the rafters. From above, a crate of the same rails is installed perpendicular to the rafter legs.
When installing the frame, it is necessary to take into account the presence of a chimney and the obligatory ventilation of the ridge. The distance between the boards of the crate is on average 300 mm. This scheme is suitable for all types of solid roofs. When choosing a soft roofing material, the crate is made of solid sheets of moisture-resistant plywood.
The rafter system is ready. Now it's the turn of the installation of roofing material, internal insulation roof and attic arrangement (if provided by the project).
So, it's time to answer the main question of our topic: is it worth doing it all with your own hands? Do not believe anyone who tells you that it is easy and simple. But if you have golden hands and a great desire to make a high-quality roof "for yourself", then go ahead! We wish you good luck!
