How to make a roof frame with your own hands. Metal rafters for the roof - features of the device and installation

Roof construction is one of the most important stages in the construction of a house. The rafter part of the roof requires special attention, both at the design stage and at the stage of direct assembly. Before proceeding with the installation of the roof truss system, you will have to understand all the intricacies of the issue. Calculations are best left to professionals. In the design of the roof, a huge number of factors are taken into account, these are wind and snow loads, the weight of the truss system and roofing materials, the geometry and technical parameters of the structure.

There are specialized computer programs for calculating the optimal roof design and counting the amount of building materials needed. Loads and impacts can be specified in the SNiP 2.01.07-85 of the same name. Adjustment coefficients for individual regions are also given there. Almost all calculations need to be increased by 10% to create a margin of safety.

After the roof project is ready, the question arises of the correct installation of the roof rafters. Roof trusses, in most cases, are a triangle. This is the most durable and cost-effective form. Rafters can be made of various materials: wood, metal or reinforced concrete.

A combination of different materials in one design is also allowed.

Rafter connections

Roof trusses can be made independently, in accordance with the project, or ordered factory-made. Making to order does not impose restrictions on the shape, volume and size. At the factory, both the entire truss system and individual elements for subsequent assembly directly on site can be made. Fastening industrial rafters is usually performed using metal plates provided by the manufacturer. Rafters made independently are connected by a groove-thorn pattern and reinforced with nails, bolts, brackets and clamps.

It must be borne in mind that the wooden elements of the truss system must have a moisture content of no higher than 20%. The material may shrink. Fastening roof rafters with nails or staples is only permissible for dry material. If the percentage of moisture causes even the slightest doubt, it is worth choosing bolting. They can be tightened over time, but the bolt holes weaken the strength of the rafters.

Design requirements

There are three main requirements for the design of the roof truss:

• Rigidity;
• Optimal weight;
• The quality of materials.

The requirement of rigidity directly relates to the joints and fastenings of all elements of the truss system. As mentioned above, the rafter system is a system of triangular trusses installed parallel to each other. The triangular shape itself provides structural rigidity, but the rafters must be securely fastened relative to each other. Even the slightest mobility can lead to disastrous consequences.

The requirement of weight optimality is fulfilled at the stages of calculations. The total weight is made up of all elements of the truss system, hydro-steam and thermal insulation, roofing material. For example, natural tiles weigh 40-60 kg/m2, slate 10-14 kg/m2, shingles 6-8 kg/m2, and metal tiles 3.5-4.5 kg/m2. supporting walls of the building, taking into account constant and variable loads, because the effects of wind and the volume of snow will be added to the mass of the roof itself.

The quality of materials can be assessed in several ways. The grade of wood should be 1-3 grades, with a minimum number of knots. Preference is given to conifers. The allowable length of the board of their coniferous wood is 6.5 m, of hardwood - 4.5. Mauerlat, pillows and girders are made from hardwood.

Regardless of the cost and quality of materials, it is necessary to remember about the waterproofing and treatment of all wooden elements with antiseptics and flame retardants.

The main parts of the construction of the truss system

Mauerlat- this is the basis of the truss system. Mauerlat evenly distributes the load on the outer walls of the building.

rafter leg- rigidly fixes the elements of the roof, is responsible for the angle of inclination of the slope. The appearance of the roof depends on the location of the rafter legs.

Run- fastens the rafter legs. The ridge run is located at the top, the side runs are on the side.

puff- fastens the rafter legs in the lower part and prevents them from "driving around". Racks and struts - provide the truss system with additional rigidity.

Sill- located below, parallel to the ridge and serves as a base and support for racks and struts.

crate- arranged perpendicular to the rafter legs. It is made from boards or bars. It is designed to transfer the load from the roofing material to the rafter legs and serve as the basis for the roofing material.

Part Names

Roof ridge- the junction of two roof slopes. A continuous crate is stuffed along the ridge to reinforce this part of the structure.

Filly- are arranged to organize an overhang.

Eaves- this is the distance from the wall of the house to the edge of the roof, designed to protect the house from excessive rainfall on the walls.

Forms of roofs and truss systems

The shape of the roof is determined primarily by the geometry of the building. Different forms of roofs can be combined in cases of complex buildings.

Roof shapes

Roofs with a slope of 2.5 to 10 degrees are called flat. Not every building can be covered with a flat roof. The dimensions of the building and variable loads characteristic of the construction region are important.

Shed roofing has the simplest truss system and a slope of 14 to 26 degrees. Such a roofing device is ideal for outbuildings, verandas, small structures in which one of the parallel walls is higher than the other.

shed roof

A roof with two slopes has a more complex system of rafters. The under-roof space can be both non-residential, attic, and attic, landscaped. The slope of the gable roof is taken in the range from 14 to 60 degrees. The gable roof truss systems also differ in type. They are hanging and layered, depending on the dimensions and geometry of the building.

Types of truss systems

A four-pitched roof is called a hip or half-hip roof. The slope of such a roof is allowed from 20 to 60 degrees, and the length of the overlapped span can be up to 12 meters. This design requires internal supports. The absence of gables significantly saves materials, but the construction and installation of the truss system requires more attention and money than in the case of a gable roof.

Sloping roofs in the lower tier can have a slope of up to 60 degrees, while the upper tier is usually more gentle. Most often, a sloping roof is used to build an attic. Permissible house width up to 10 m.

Such a roof is called a broken roof.

Rafter systems can also vary in shape.

Various truss systems

The shape of the truss system is determined by the dimensions of the structure and the purpose of the roof space. Struts, racks and rafters themselves can be used as decorative elements of the interior or attic.

decorative elements

Types of truss systems

Among other things, rafter systems also differ in type. They are hanging and layered. The choice of the type of truss systems depends, like everything in the roof, on the dimensions of the structure to be covered and the position of the load-bearing walls.

Hanging rafter system

hanging rafters

A system with hanging rafters is chosen if the building does not have internal load-bearing walls, and the span does not exceed 6 meters. In the upper part, the rafters rest on each other, and the Mauerlat acts as a support from below. Mauerlat is installed in a stone or brick house. In the case when the house is built using frame technology, the rafters are attached to the upper trim. In log cabins or beams - to the upper crown. The spread of the rafters is reduced by tightening. Beam puffs can serve as the ceiling of the upper floor.

The drawstring is located at the very bottom. If it is placed higher, then it is called a crossbar. In cases where the overlapped span is more than 6 meters, the system with hanging rafters is supplemented with support posts and braces. Filly is used to organize the overhang. Experts recommend building up the rafters with a mare, even if it is possible to organize an overhang due to the own length of the rafter leg. Such an extension will allow the rafters to be supported on the Mauerlat with the entire available cross-sectional area. And the section of the filly is chosen less than the section of the rafters.

Sloped truss systems

Rafters

The main requirement for organizing a layered truss system is the presence of an internal load-bearing wall or columns in the building. A roof with rafters can cover spans from 10 to 16 meters. In this case, the slope is selected based on the weather conditions of the area. In the upper part, the rafters are supported by a ridge run, and in the lower part, by a Mauerlat. Parallel to the ridge run, a bed is arranged on which the racks rest. This allows you to do without puffs and crossbars. If the rafter leg does not have a brace or support, its length should not exceed 4.5 meters. The elements of the layered truss system must have a thickness of at least 5 cm.

Regardless of what type of truss system was designed, it is important:

• You cannot add nodes "from yourself" to the roof project. Even if it seems that it will be more reliable. The displacement of loads, the most insignificant at first glance, can lead to a distortion of the structure and possible collapse.
• Mauerlat must be aligned in a horizontal plane relative to the walls of the house. Next, they also strictly horizontally join it with the rafter leg. Vertical and horizontal levels are extremely important in order to avoid distortions.
• Rafter legs, racks and struts are placed strictly symmetrically.
• In order for the rafters not to rot, air vents are provided in the attics, and gaps in the attics.
• It is important to comply with the technology of insulation and vapor barrier of the roof.
• The joints of wooden elements with stone walls must be lined with waterproofing materials.
• When calculating the truss system, it is important to consider the location of the chimneys. This can affect the pitch width of the rafters.

Connecting elements

A system of fastening elements by cutting is allowed, but it should be remembered that this is not the most economical way. The cutting requires a rather large cross-sectional area so that the structure as a whole does not lose its strength. And this means that both the weight of the entire roof and the cost of building materials will be much higher. In this regard, most often the nodes are fastened with dowels and bolts.

Fastening

Fasteners are often used with steel perforated plates. A huge number of such fasteners are on sale, various in shape and purpose. Perforated pads have a special coating that protects them from corrosion. Fasten them with nails.

truss system

The roof of a frame house has a fairly simple design, so even self-construction does not have to spend a lot of time and effort. Today we will try to deal with the main difficulties that may arise during the construction process. We will give practical recommendations on choosing the type of roof, roofing material, as well as talk about the rules and regulations that must be observed in the process of work.

Before starting work on the installation of the roof, it is worth deciding on the type of structure itself, its slope and the type of material that will be used for decoration. It is equally important to choose a heater in advance.

Types of roofs of a frame house

The roof of a frame house with your own hands can be: flat, single-pitched, double-pitched, broken.

They choose a roof not only in appearance, but also based on its features and functionality. The roof of a frame house has its advantages and disadvantages, and each type has its own.

Flat roof

A frame house with a flat roof has an unusual appearance; basically, this technology is not used in private construction. Unlike other types of roofing, it requires minimal effort to erect.

Flat roof.

The main disadvantage is the need for careful maintenance. So, if snow and rain leave on their own from a pitched roof, then on a flat structure it will stagnate and require constant care. Untimely cleaning of wet snow can provoke a collapse of the structure, in addition, high humidity is observed in rooms with such roofs.

shed roof

A frame house with a shed roof is simple, the design is not afraid of strong wind loads. Unlike a roof with two slopes, it requires a minimum of building materials and does not require special skills and knowledge for construction. As such, the design has no drawbacks, while do not forget that if the slope area is too large, snow pressure will increase.

gable roof

The gable roof of a frame house is the most popular option in frame construction. When using this design, an additional attic room appears, in which, with proper insulation, you can organize an additional room. The load from the structure is evenly distributed around the entire perimeter of the frame house. There is no need to remove snow and water, due to the angles of the slopes, precipitation rolls off on its own.

With a gable roof.

broken roof

A frame house with a sloping roof is an option that is chosen when organizing an attic room. The advantages of this design include: additional space under the roof, an unusual spring view, low load on the house in winter. The mansard roof also has its drawbacks: a lot of building materials are needed for construction, poor ventilation leads to the rapid destruction of the rafters, it requires special thermal insulation, otherwise all the heat from the house will leave through the roof.

On a note

We advise you to opt for a gable roof. It has an attractive appearance, while the construction does not require a lot of building materials. You can always buy ready-made roof projects for frame houses, this will greatly facilitate the construction process.

Roof device

Regardless of the type of roof that you decide to choose for a frame house, it is worth remembering that it has two main elements: the actual slopes and the rafters of the frame house.

Slope slope

The most optimal is a slope of 30-45 degrees. It not only ensures the maximum durability of the roof, but also reduces the load on the entire structure from wind and snow. Roofs with a slope of 30-45 degrees are considered the safest, and in appearance they are not inferior to their competitors.

rafters

You can calculate the rafters using a special online calculator, which is easy to find on the net. It allows not only to make correct calculations, but also to significantly save time, especially for novice builders.

Rafter system.

A suitable section of the rafters is selected depending on the following characteristics: standard wind and snow loads on the cover, which are individual for each region; type, weight and size of the material to be used for roofing; roof slope - the smaller the slope, the less the load will be due to uniform distribution; the length of the rafter legs and the step with which they will be installed from each other.

The truss system of a frame house is the frame of the entire roof, so it is necessary to pay maximum attention to the calculation of all parameters. You can choose a suitable section yourself, or using special construction tables. The tables take into account the installation step of the rafters and the length of each rafter carried by the roof of the frame house (video).

The choice of roofing material

According to the step-by-step instructions for building a frame house with your own hands, at the final stage of the construction of the structure, roofing work is carried out. There is a huge range of roofing materials on the market, the choice depends on the needs and financial capabilities, however, we advise you to follow the following rules:

• The finishing material must match the configuration of the roof.
• Consider the climate in the region where construction is underway. If hail often occurs where you live, you should not give preference to materials that, after the first rainfall, will become unusable.
• The service life of the roofing material should be close to the service life of the roof itself.
• The material must meet aesthetic needs and financial possibilities. If you are a beginner, you should not choose roofing material that is difficult to install. If you want, just hire professionals.

roof elements

Roof elements include: gable roof truss system, roofing and materials used for installation.

Gable roof overhangs.

As mentioned above, the basis of any roof, regardless of the type chosen, is represented by a truss structure. The frame itself is represented by a set of trusses, which are interconnected by a crate and a ridge run. Often, ready-made trusses are used, which are installed directly during work on the roof of a frame house.

Frame houses under a roof of two slopes include the following structural elements:

1. The base of the truss structure, which is made by tying beams - maerlat.
2. The legs of the rafters are supporting structures fixed on the Mauerlat and on the ridge run.
3. For general reinforcement of the entire roof structure of a frame house, a horizontal beam is used, with which the upper part of the rafters is fastened - a wind bolt.
4. Longitudinal beams for connecting all rafters to each other.
5. Lathing - a special base made of dry boards, on which the roofing material is subsequently installed.

It is not necessary to build a frame house from the foundation to the roof on your own, now some companies manufacture structural elements using an industrial method, the buyer only has to assemble all the elements according to the type of constructor directly on the site.

Roof insulation

Insulation of the roof of a frame house is not difficult to produce, the main thing is to comply with a number of requirements. So, it is important to choose the right material for size. This is what guarantees that the inside of the house will be cool in summer and warm in winter. For insulation, you can use various materials presented on the modern market, most often ordinary mineral insulation is used.

Roof insulation with mineral wool.

If you use a flat roof structure, it is better to use expanded clay as a heater, the material is also used to insulate the structure of a frame house between floors. When installing the insulation, gaps are necessarily created, they allow you to avoid the accumulation of condensate due to active ventilation.

Heat-insulating materials are attached closely to the frame elements, especially for solid heaters: polystyrene foam or polystyrene foam.

Instruments

Before starting construction, it is necessary to prepare tools and building materials in order to get really high quality. This list may vary depending on the layout of your home.

Roof mounting tools.

• A set of measuring tools (ruler, caliper);
• Universal tools (hammers, compressors, spray guns);
• Cutting tools;
• Tools for working with rafters;
• Nails;
• Wood set;
• Perforator;
• Roofing material;
• insulation;
• waterproofing material;
• Sealants of various types.

Roof installation sequence

The construction of the roof in a frame house begins with the marking of the lower trim. At the next stage, the necessary calculations are carried out and the parallelism of the installation of the entire structure is checked; the last stage of preparation for the construction of the roof is the alignment of the strapping boards.

Double roof.

Roof technology:

1. Strive to ensure that the roof obtained as a result of construction is as close as possible to all the parameters specified in the technical documentation. Be sure to carry out additional strengthening of the structure in regions where strong winds are observed;
2. The ridge beam is mounted on supporting supports. It is extremely important that they are installed exactly in level, you can check the correctness with the help of a stretched building cord;
3. The length of the ridge beam starts from 11 meters, the design itself is prefabricated, it consists of 4 boards;
4. The rafters must have the same appearance and be made according to a single template;
5. Take care of your own safety when working at height;
6. When working with soft tiles, a roofing carpet or a membrane is used.

We examined the main points that should be emphasized during the installation of the roof in a frame house. The main condition is to strictly adhere to the sequence of actions, and then there should be no problems with installation. The roof is considered one of the easiest structures, but not the roof of a frame house with your own hands, the video will help you get acquainted with all the nuances of installation, and avoid gross mistakes.

It is better to give preference to a gable roof, it is considered the best option for any region. The main condition for long-term operation is the choice of suitable slope angles, it is equally important to insulate the roof well, otherwise all the heat will come out through the cracks. The heat-insulating material is laid in several layers.

The roof frame of the house is one of the key elements of the building. And if the frame was erected taking into account all the rules and compliance with building standards, then it is likely that this building will serve its owners faithfully for decades.

The arrangement of the foundation and the erection of the walls of the house is approaching the finish line, and the novice builders are faced with the question: how to build the roof of the house? In fact, the choice of roofing and waterproofing material is quite large, and you can always purchase it, taking into account your financial capabilities. But the roofs of the house require special attention. To begin with, you will need to decide what kind of roof you see and choose its type: single-pitched, gable, hipped or broken.

There are many advantages to making a roof frame with your own hands. First, you will have a great opportunity to save on payments for hired craftsmen. And secondly, you yourself will control the entire construction process and in the future you will be able to prevent possible repairs.

After you decide on the choice of the type of roof, you can safely proceed to its construction. As an example, the process of erecting a gable roof frame is given, since this type is the most common among most buildings of private houses.

Choosing a truss system

As you know, absolutely any truss system is a connection of two truss beams at the top of the structure. In the lower part of the structure, the rafters are fixed due to the presence of a lower screed, and it can serve as an additional support that fixes the integrity of the structure.

There are two main types of truss system: inclined and hanging. It is the inclined truss system that is used in the construction of private housing. The choice of truss system is usually due to some design features of the building itself. So, for example, if the distance between the two main load-bearing walls of the house is at least 6 meters, you can safely equip a hanging truss system. Then the walls of the house will take over the main load-bearing mass. If the width between the walls is more than 6 meters, then there is a high probability of subsequent sagging of the rafters. In this case, you need to take care of installing an additional support.

Choosing a material for a strong frame

Before you make a roof frame, it will be useful for you to decide on the choice of material.

Wood is used as a material for rafters, namely edged board and timber. It is best to give preference to coniferous wood, since this material contains resin, which acts as a kind of natural antiseptic that prevents decay. The size of the edged board must correspond to the following parameters 50x150 mm, and the timber - 150x150 mm.

Also remember that the rafter system is not only the rafters themselves, racks and runs under them. They also include an attic floor, a crate and a counter-lattice. If you plan to use the attic as a warehouse and do not plan to make additional living space out of it, then 50x150 mm boards will fit perfectly for the attic floor. And if you have always dreamed of an attic, then you should buy a bar measuring 150x150 mm.

For counter-battens and battens, a beam with dimensions of 40x40 mm will fit, this is quite enough to support the weight of any roof. The main requirement for such a material is its sufficient straightness, because if the timber has deviations, the frame crate will turn out to be uneven and the weight of the roof will be distributed unevenly.

Required inventory

In addition, you will need the following materials and tools:

• special metal studs, which, thanks to their thread, securely fix the support beam (Mauerlat);
• brackets and brackets for fixing the rafters to the support beam;
• various fasteners (galvanized nails, self-tapping screws and small diameter studs);
• drill;
• saw;
• hammer;
• roulette;
• axe;
• plane;
• level or plumb.

Stages of building a roof frame

The main stages of building a roof frame for a house are as follows:

1. Wood processing. Since you will not have the opportunity to process the lumber in the future, it is best to do this at the initial stage of construction work. Process the material with two compositions. The first, antipyretic, is able to reduce the flammability of wood. The second, antiseptic, helps prevent rotting of wooden elements. Remember that after processing, the lumber must dry thoroughly.
2. Mauerlat installation. Mauerlat is commonly called a beam, which acts as a support for the entire frame structure. It must be laid directly on the load-bearing walls of the house. And its main function is the uniform distribution of the load associated with the weight of the roof.
3. To lay the support beam, it is necessary to erect a solid concrete blind area around the perimeter of the entire building. After the concrete screed has dried, it is necessary to lay a waterproofing material on its surface in several layers, the roofing material is excellent for this purpose. Further, special metal studs with a diameter of at least 10 mm are installed in the concrete blind area. After that, the support beam is “put on” on the installed studs, for this it is necessary to drill holes in it in advance. Remember that the ends of the studs will need to protrude at least 10mm. Subsequent fixation is carried out by means of nuts.
4. We install rafters. Experts advise: if you work alone, then to facilitate work, it is best to collect rafters on the ground. If you have an assistant, then you can safely assemble the structure directly on the roof of the house. To begin with, it is necessary to make grooves in the support beam for installing the rafter legs. The distance between the grooves must be determined in advance, based on the dimensions of the structure itself, however, they should not be more than 1.5 m. Otherwise, the structure will have insufficient rigidity.
5. Rafters are installed from the front-end part of the building. Then it is necessary to pull the cord between the ridges of the two end rafters. Thanks to this technique, it will be easy for you to navigate while setting the vertical of the remaining intermediate rafters.
6. Next, the rafter legs must be inserted into pre-prepared grooves. Fastening is carried out through the use of complex fastening: transverse and longitudinal. Transverse fastening is carried out through the use of steel brackets, and longitudinal - through the use of special brackets that securely fix the rafters to the Mauerlat. During the installation of the rafters, make sure that they protrude from the perimeter of the building by about 40 cm.
7. We fix the lower part of the truss system, using for this purpose the strapping - the base of the attic floor. If necessary, the strapping can be increased with additional bars, overlapping them.
8. Between themselves, the rafters must be connected by two pairs of studs. The presence of two, and not one, studs is due to the fact that when fixed with one fastener, the rafters will rotate around their axis.
9. We give the structure greater rigidity and install an additional transverse beam. Now the rafters will outwardly resemble the shape of the letter A, this technique is relevant in cases where the distance between the walls is more than 6 m. The dimensions of the transverse beam can have the following values: 50x150 or 50x100 mm. Fixation is carried out using self-tapping screws.
10. We install the ridge beam at the top of the rafters. If necessary, you can strengthen the upper node with an additional transverse beam.
11. After all the rafters have been erected, you can safely proceed to the crate and counter-crate. Today, there are two options: thinned and solid, depending on what roofing material you plan to use. The thinned crate is a horizontally stuffed beams on the rafters with a certain distance. Any roofing material of increased rigidity (slate, corrugated board, etc.) can be laid on such a crate. With a continuous crate, sheets of moisture-resistant plywood are stuffed on the surface of the rafters, this design is great for laying a soft coating (roofing material or any other rolled roofing material).

Any type of construction first of all needs reliable and high-quality supporting structures, which include the foundation, the frame of the house and the supporting frame of the roof. It is these building elements and their arrangement that are responsible for the final quality and reliability of the entire construction of the house. Among the described elements, special attention should be paid to the supporting frame of the roof, with which you can make the highest quality roof of the house.

The frame of the house and the roof is an important element in the construction of any building. However, the roof experiences the greatest loads (snow, rain, wind), so it must be of high quality and reliable.

Varieties of frame structures

It is immediately worth recalling that the roof frame can have several basic types, which depend on the design features of the roof:

• rafter-type frame structure, which is made of lumber and is ideal for pitched roof systems of houses;
• metal roof frame made of beams and designed for industrial-type houses;
• a concrete-type frame made of special slabs and used in the construction of flat roof systems of houses.

The roof frame made of lumber is most often used in the construction of a private house and the organization of gable roofing systems. The other two types of frame structures are of no interest to private construction, which makes them irrelevant in this article.

Rafter frame system and its types

Before starting construction work related to the organization of the frame system of houses, it is necessary to choose the correct type and device of the truss type structure. The entire load-bearing capacity of such a frame system of houses is transferred to roof trusses, which are most often called simply rafters. To organize a truss truss, a wooden beam is used, the cross section of which should not be less than 150x50 millimeters. It is on these trusses that the further fastening of the roof lathing system takes place.

In such cases, a layered system is required with a finished central load-bearing wall or support-type metal columns. It is this feature that will allow organizing a high-quality roof frame, which will not sag over time under its own weight, as well as the weight of the roofing material.

Optimal building materials for the frame

In the event that the master decides to make a roof frame with his own hands, he needs to understand the basic elements of the construction process, as well as to know the availability of all the required tools and building materials that may be required for this business. So, to organize a high-quality and extremely reliable frame of the roofing system with your own hands, you will need to have:

For building a house, it is necessary to choose high-quality lumber, without damage - cracks, knots, blue and stains.

• wooden beam with a section of 15x5 centimeters, which will be used for the construction of roof trusses;
• wooden beam 10x10 centimeters, which will be required for the manufacture of Mauerlat;
• boards for the batten system, which is selected depending on the roofing material used;
• various consumables that are needed for attaching the Mauerlat and the entire truss system.

Of the construction tools, the master will need a hammer, saw, electric drill, tape measure, ax and a plumb line. In other words, no special tools are required for this type of DIY construction, making the construction process extremely simple and economical. Special attention should be paid to the acquisition of extremely high-quality wood, which is the key to the quality and durability of the entire supporting frame of the roof.

All lumber must be treated with special impregnations that affect the durability and quality of the supporting frame, the device of which was described above. As a rule, such substances protect the tree from decay, as well as from harmful insects that can spoil the wood in an extremely short time.

In other words, do-it-yourself processing of used lumber is an integral part of the construction process. Profile metal roof frames require the use of completely different materials and tools, but the use of such structures in private construction can be considered irrelevant.

Correct installation of the Mauerlat

It is worth recalling that the Mauerlat is the main supporting structure not only of the future frame, but of the entire roof as a whole. It is this element of construction that takes on all the roofing loads with its own hands, evenly distributing such loads on the load-bearing walls of the house.

This allows you to increase the life of the entire building, because in the absence of such a bar, the load of the roof will destroy the walls in certain places. It is safe to say that the Mauerlat is the main supporting element of all known truss systems.

This support element is not required only in the construction of wooden houses, in which the final row of logs or beams is used as a Mauerlat. The described supporting element must be mounted flush with the inside of the load-bearing walls, which will simplify the finishing work of the internal type.

From the outside, the Mauerlat must be closed with brickwork or a strip of metal, which will protect the lumber from environmental influences. The top row of brick or block masonry needs a high-quality concrete pavement, which is covered with several dense layers of roofing material or bituminous mortar.

The roofing material is needed so that all the moisture in the walls stops in front of the support beam, which can suffer from an excess of moisture, as evidenced by its device. The simplest and most reliable way to attach the support beam to the walls of the house can be considered the use of peculiar metal studs, which will connect the Mauerlat and the load-bearing walls.

Holes of the required diameter are drilled in the masonry, into which prepared metal studs are lowered, made of simple steel reinforcement. By attaching the prepared support beam to such studs, you can mark the places for drilling holes.

The length of the studs should be such that after mounting the Mauerlat, the reinforcement protrudes beyond the timber by at least 1.5 centimeters. At the ends of the reinforcement, it is necessary to make a thread, which will be required for the final fixing of the support beam with your own hands using extremely wide washers and nuts. This process of fastening the support bar can be simplified and done with a simple welding machine, which is used to weld a metal bar or washer to the bars.

truss type system

The organization of the truss system is the next stage in the construction of the supporting frame of the roof of the house. To make roof trusses with your own hands, you need to prepare dry lumber that will not succumb to deformation during operation.

The truss consists of two rafter legs and a lower tie, which is attached to the legs with bolts or anchor elements, which can be easily made only with your own hands. Each finished truss truss must be installed and secured to a support beam, which is extremely easy to make.

To do this, it is necessary to make the required number of grooves of the correct size in the Mauerlat, into which the rafters will be inserted, which are not difficult to assemble. The step between the trusses depends on the final size of the roof structure of the house, but most often such a step should be done no more than 1 m. Some roof structures may require the use of vertical rafters. As a rule, this applies only to those roofs whose height exceeds three meters.

The timber framing system is the ideal linking element of the framing structure, but before organizing such a system, care must be taken to ensure the stability of the installed rafters. To do this, in their upper part they are fixed with a ridge beam, and a temporary strapping is made along the lower part, which is dismantled after the crate system is organized. The crate can be safely considered an extremely important element of the frame structure of the roof of the house, because the reliability of fixing the roofing material depends on this element.

The step of the crate depends on the angle of the roof and the material with which it will subsequently be covered.

The rafter system is divided into two main types: solid and intermediate, and the right choice depends only on the choice of the roofing material itself. All sheet and dense roofing materials require an intermediate lathing, which is performed with a certain step between the boards or bars.

All roofing materials of soft or roll type need a solid type crate, which is necessary for high-quality installation and operation of the material. For example, soft tiles cannot be mounted on an intermediate crate, because this will be the result of sagging and damage to the roofing material.

Materials such as slate, metal tiles or galvanized sheets can be mounted on an intermediate crate, the spacing between the elements of which depends on the roofing material used. For example, metal tiles require fastening in certain places, which indicates the correct arrangement of the elements of the crate system. It is most correct to make miscalculations before organizing the crate, which will allow you to organize the correct design of the entire frame.

Processing lumber with additional compounds

As mentioned above, any lumber must be protected from moisture, insects and fire. To do this, it is worth using solutions such as antiseptic and antipyretic. The second composition allows you to increase the protective qualities of wood, which are associated with resistance to high temperatures. Antiseptics are able to protect wood from moisture, decay and harmful insects.

Processing of all lumber is carried out before installation, which allows you to process the entire surface of the board or timber. In this way, you can count on increasing the life of the wooden supporting frame of the roof of the house.

Rafters and lathing - the roof frame, which bears the brunt of the roofing cake, thermal insulation, snow load, so they must have a high bearing capacity, strength. The idea of ​​using metal rafters to make the roof structure more rigid is not new, but in the past it was mainly used to cover industrial or utility structures. Now the rafter frame and the metal profile crate are considered a real alternative to wooden roof elements if the slope length exceeds 10 meters.

The design of the roof truss frame consists of many interconnected elements that form trusses. The step, the size of the section between the rafters and other supports determines the calculation of the loads to which they are subjected during operation. The roof frame performs the following functions:

1. Load distribution. Interconnected nodes, reinforced with corners, evenly distribute the weight of the roof, which can reach up to 500-600 kg, taking into account the snow load. The larger the cross section of the rafters and the smaller the pitch between them, the greater the bearing capacity of the structure.
2. Giving slope and shape. The rafters, located at an angle to the base of the roof, form an inclined plane of slopes, so that snow and water do not accumulate on the roof surface.
3. Formation of the base for fixing the roofing material. The top coat of the roofing pie is fastened to the roof frame. The crate acts as a basis for fixing the coating, distributing its weight evenly over the rafters.

Note! What should be all the nodes, rafters and lathing of the roof structure determines the engineering calculation. To determine the required bearing capacity of the frame, it is necessary to calculate the total load to which it will be subjected. To do this, add up the weight of the roofing material, insulation, waterproofing, the maximum snow load with the weight of the truss system.

Types of truss systems

The most common material from which the crate and rafters of the roof frame are made is wood. However, if the weight of the roofing material is large enough, and the length of the slope is more than 6 meters, then the structure is too massive. Builders have to reduce the step between the rafter legs, increase their cross section, which is why the roof units acquire a lot of weight, increasing the load on the foundation. You can unload the load-bearing walls and the base of the building using stronger, but lighter metal rafters. According to the type of material used, the following types of truss systems are distinguished:

• Wooden. Rafters and lathing made of wood are used for the construction of roofs, the slope length of which does not exceed 7-10 meters. The fastening of the frame elements to each other occurs with the help of self-tapping screws, nails or movable metal elements. The step between the legs is usually in the range of 50-80 cm.
• Metal. Metal roof frames are made of zinc-coated steel profile, which is not afraid of moisture. The rafters and the crate made of this material are light, durable, so the step between them can be increased to 1.5-2 meters. The fastening of the metal profile is carried out by welding or fasteners. Metal roof units are used with a slope length of 10 meters or more.
• Combined. The truss frame, combining metal and wooden knots, is called combined. The combination of wooden and galvanized steel support elements allows for a cheaper structure with a high load-bearing capacity by increasing the spacing between the rafters.

Please note that metal and wooden frame elements cannot be connected to each other without a gasket made of waterproofing material or treated with an antiseptic preparation. Since the metal has a high thermal conductivity, its proximity to the tree leads to the formation of condensation and rotting of the rafters.

Fastening methods

Metal rafters are assembled into triangular, trapezoidal or arched trusses. Internal stiffeners are attached to the frame beams, which form corners that significantly increase the load-bearing capacity of the frame. Such a system allows you to take a step between the rafters more, taking into account the support capabilities of each truss. The fastening of the metal elements of the roof frame is carried out by one of the following methods:

1. Fastening by welding. If you weld the details of the truss system using a welding machine, you can get a rigid structure with high strength and bearing capacity. If you correctly calculate the roof, you can lighten the frame and reduce the load on the foundation of the structure. The disadvantage of this method is that only a professional with the help of special equipment can perform welding.
2. Fastening with bolts. Fixing the rafters with fasteners allows for less rigid fastening. This method of assembling a truss frame based on a metal profile is used in private housing construction, where the length of the slopes does not exceed 10 meters. Rejection of welding allows you to speed up the installation of the roof.

Experienced craftsmen rely on the fact that the rafters can withstand more weight than wooden ones, so you can increase the step between them and reduce the thickness of the section of the elements. Moreover, ready-made roof trusses are sold in hardware stores, the fastening of which was carried out by welding, suitable for overlapping buildings of standard width.

Advantages

The metal truss frame is used for the construction of roofs of any shape, any slope with a slope of 1-2 degrees. As the material from which the rafters and lathing are made, steel corners, pipes of round and rectangular cross-section, and tauri are used. In order to correctly select the thickness of the frame elements and choose the step between them, the calculation of the roof structure is performed, taking into account the permanent and temporary loads that are transferred to the rafter beams during operation. The advantages of a truss system made of this material are:

• Fire safety. Unlike wooden beams, metal frame beams are not flammable, which increases the fire safety of the building.
• Ease of maintenance. Zinc galvanized coating, which covers the steel corners, protects the roof frame from corrosion during the entire service life. They, unlike wooden ones, do not require annual antiseptic treatment.
• Zero waste. Although metal structures are quite expensive, it is considered cost-effective, since the fastening is carried out by welding, and there is practically no waste left.
• Long service life. If you correctly calculate the loads, then the metal roof frame will last more than 100 years, which exceeds the life of even the most stable roofing.

Professional roofers believe that it is advisable to use welded metal structures for the manufacture of a roof truss frame with a slope length of 10-12 meters. In this case, the main task is to correctly calculate the loads, and then determine the step between the legs in accordance with the climatic characteristics and properties of the roofing material.

disadvantages

Despite the obvious advantages, metal truss systems are not the most popular design solution in private housing construction. Even a large step between the rafters and a sparse crate at a high cost of metal cannot make the structure cheaper than wood. The disadvantages of metal rafters are:

1. High thermal conductivity. The metal has a high coefficient of thermal conductivity, so the rafters and form bridges are cold. From the point of view of energy efficiency, a metal profile frame is not the best solution.
2. Difficulty in transportation and installation. When choosing a metal rafter system, take into account that transporting, lifting and securing long and heavy elements is more difficult than standard length lumber rafters.
3. Difficulty of installation. To rise to a height and fix the trusses, special equipment is used, the rental or purchase of which is expensive.
4. Deformation under high temperature. Although metal is considered a non-combustible material, during a fire it is highly deformed, which usually leads to the collapse of the roof.

To determine whether it makes sense to use more expensive metal profile truss elements, you need to calculate the roof frame. If the slope length exceeds 10 meters, and the load is more than 450-600 kg, then the installation of a metal frame is economically feasible.

Video instruction