Installing a roof frame on a house. Self-construction of the roof of a private house
When designing any residential building, architects Special attention pay attention to the roof, since it performs not one, but several functions at once, depending on its design features. It must be said that not all future homeowners are satisfied with an ordinary gable roof, although it can be called the most reliable, since it has only two pitched planes and one joint between them. Many people are more attracted to complex designs, which add special attractiveness and originality to the building. Other, more practical homeowners prefer attic structures, which can simultaneously serve as a roof and a second floor.
The basis of any roof is an individual rafter system, which has its own design features. It will be much easier to choose the right roof frame if you figure out which ones in advance. types and diagrams of rafter systems used in construction practice. After receiving such information, it will become more clear how difficult such structures are to install. This is especially important to know if you plan to build the roof frame yourself.
Main functional tasks of rafter systems
When settling in pitched structures roofs, the rafter system is a frame for covering and for holding materials " roofing pie" With proper installation of the frame structure, the necessary conditions for correct and non-insulated types of roofs that protect the walls and interior of the house from various atmospheric influences.
The roofing structure is also always the final architectural element of the exterior design of the building, supporting it with its appearance stylistic direction. However, the design features of rafter systems must first of all meet the strength and reliability requirements that the roof must meet, and only then the aesthetic criteria.
Frame rafter system shapes the configuration and angle of the roof. These parameters largely depend on natural factors characteristic of a particular region, as well as on the desires and capabilities of the homeowner:
- Amount of precipitation in different periods of the year.
- Direction and average speed winds in the area where the building will be erected.
- Plans for the use of space under the roof - arranging residential or non-residential premises, or using it only as air gap for thermal insulation of rooms below.
- Type of planned material roofing.
- Financial capabilities of the homeowner.
Atmospheric precipitation and the strength of wind currents place a very sensitive load on the roof structure. For example, in regions with heavy snowfall, you should not choose a rafter system with a small slope angle, since snow masses will linger on their surface, which can lead to deformation of the frame or roofing or to leaks.
If the area where the construction will take place is famous for its winds, then it is better to choose a structure with a slight slope of the slope so that sudden gusts that occur do not tear off individual elements of the roof and roofing.
Main elements of roof structure
Parts and components of rafter systems
Depending on the type of rafter system chosen, the structural elements used can vary significantly, however, there are parts that are present in both simple and complex roof systems.
The main elements of a pitched roof rafter system include:
- Rafter legs that form the roof slopes.
- - a wooden beam fixed to the walls of the house and used to fix the lower part of the rafter legs on it.
- A ridge is the junction of the frames of two slopes. It is usually the highest horizontal line of the roof and serves as the support to which the rafters are anchored. The ridge can be formed by rafters fastened together at a certain angle or fixed on a ridge board (purlin).
- Sheathing is slats or beams mounted on rafters with a certain pitch and serving as the basis for the flooring of the selected roofing material.
- Supporting elements, which include beams, purlins, racks, struts, ties and other parts, serve to increase the rigidity of the rafter legs, support the ridge, and connect individual parts into an overall structure.
In addition to the mentioned design details, it may also include other elements, the functions of which are aimed at strengthening the system and optimally distributing roof loads on the walls of the building.
The rafter system is divided into several categories depending on different features of its design.
Attic space
Before moving on to considering different types of roofs, it is worth understanding what an attic space can be, since many owners successfully use it as utility and full-fledged residential premises.
The design of pitched roofs can be divided into attics and attics. The first option is called this way because the space under the roof has a small height and is used only as an air layer insulating the building on top. Such systems usually include or have several slopes, but located at a very slight angle.
An attic structure that has a sufficiently high ridge height can be used in different ways, be insulated and not insulated. Such options include an attic or gable option. If you choose a roof with a high ridge, then it is imperative to take into account the wind loads in the region where the house is built.
Slope slope
To determine optimal inclination roof slopes of a future residential building, first of all you need to take a closer look at the already built low-rise neighboring houses. If they have been standing for more than one year and can withstand wind loads, then their design can safely be taken as a basis. In the same case, when the owners set a goal to create an exclusive original project, unlike the nearby buildings, it is necessary to familiarize yourself with the structural and operational features various rafter systems and make the appropriate calculations.
It should be taken into account that the change in tangential and normal values of wind force depends on how large the slope of the roof slopes is - the steeper the slope angle, the higher value have normal forces and less tangent forces. If the roof is flat, then the structure is more affected by the tangential wind load, since the lifting force increases on the leeward side and decreases on the windward side.
Winter snow load should also be taken into account when designing the roof. Usually this factor is considered in conjunction with the wind load, since on the windward side the snow load will be much lower than on the leeward slope. In addition, there are places on the slopes where snow will certainly accumulate, putting a large load on this area, so it should be reinforced with additional rafters.
The slope of roof slopes can vary from 10 to 60 degrees, and it must be selected not only taking into account the consolidated external load, but also depending on the roofing covering that is planned to be used. This factor is taken into account because roofing materials differ in their mass; to secure them, it is required different quantity elements of the rafter system, which means the load on the walls of the house will vary, and how large it will be also depends on the angle of the roof. Of no small importance are the characteristics of each coating in terms of resistance to moisture penetration - many roofing materials in any case require one or another slope to ensure the free drainage of storm water or melting snow. In addition, when choosing a roof slope, you need to think in advance about how the cleaning process will be carried out and repair work on the roof.
When planning a particular angle of the roof slopes, you need to know that the fewer joints between the sheets of roofing, and the more airtight they are, the less you can make the slope of the slope, of course, if it is not intended to be arranged in attic space residential or commercial premises.
If a material consisting of small elements is used to cover the roof, for example, ceramic tiles, then the slope of the slopes must be made steep enough so that water never lingers on the surface.
Considering the weight of the roofing material, you need to know that the heavier the covering, the larger the angle of the slopes should be, since in this case the load will be correctly distributed over the rafter system and load-bearing walls.
Can be used to cover the roof following materials: or profile sheet, galvanized steel, corrugated asbestos concrete and bitumen-fiber sheets, cement and ceramic tiles, roofing felt, soft roof and other roofing materials. The illustration below shows the permissible slope angles for various types roofing coverings.
Basic designs of rafter systems
First of all, it is worth considering basic types rafter systems relative to the location of the walls of the house, which are used in all roof structures. Basic options are divided into layered, hanging, and combined, that is, including elements of both the first and second types of systems in its design.
fastenings for rafters
Layered system
In buildings where internal load-bearing walls are provided, a layered rafter system is often installed. It is much easier to install than a hanging one, since the internal load-bearing walls provide for its elements reliable support, and in addition, this design will require less materials.
For rafters in this system, the defining reference point is the ridge board, on which they are fixed. The non-thrust type of layered system can be arranged in three options:
- In the first option, the upper side of the rafters is fixed on a ridge support, called a sliding one, and their lower side is fixed by cutting to the mauerlat. Additionally, the rafters in the lower part are fixed to the wall using wire or staples.
- In the second case, the rafters in the upper part are cut at a certain angle and connected to each other using special metal plates.
The lower edge of the rafter legs is attached to the Mauerlat with movable fasteners.
- In the third option, the rafters are rigidly fastened in the upper part with bars or treated boards located horizontally, parallel to each other on both sides of rafters connected at an angle, and a ridge girder is clamped between them.
In the lower part, sliding fasteners are used to secure the rafters, just as in the previous case.
It is necessary to explain why sliding fasteners are often used to secure rafters to the mauerlat. The fact is that they are able to relieve load-bearing walls from excessive stress, since the rafters are not rigidly fixed, and when the structure shrinks, they have the ability to move without deforming general design roofing system.
This type of fastening is used only in layered systems, which also distinguishes them from the hanging version.
However, in some cases, for layered rafters, a spacer system is used, in which the lower end of the rafters is rigidly fixed to the Mauerlat, and to relieve the load from the walls, tie-downs and struts are built into the structure. This option is called complex, as it includes elements of a layered and hanging system.
Filimonov Evgeniy
Reading time: 8 minutes
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How to build a roof frame house, choice of material. Staged work, roof insulation. Roof installation technology, types of frame house roofs.
The roof of a frame house is of great importance in the construction process. After all, protection from external conditions aggressive environment.
This article highlights the design features of the roof. What you need to do before you take on the roof installation job. What types of roofs frame houses, the required slope of the slopes. How to choose the right material for a reliable roof, the correct installation of rafters: pitch, length, section. Competent creation of sheathing and counter-lattice. How to install the roof of a frame house.
What you need to decide before building the roof. How to choose the right roof configuration. Required amount stingrays The correct installation of the crossbar, how to connect the rafters in the ridge. Correct fastening of the rafters to the mauerlat and fastening of the crossbar to the rafters.
What is the essence of the structure of the roof and roof of a frame house. How to build gable roof frame house. Construction technology hip roof. How to perform competent installation of an attic (broken) roof of a frame house.
Advantages of frame houses and roof insulation, hanging layer system technology.
The roof structure of a frame house is one of the simplest, so its independent construction will not take much effort and time.
This article will help you if difficulties arise during the work process. In it we will look at the features of roof installation, we will give practical recommendations on the choice of material, design elements, and compliance necessary standards and requirements during the work process.
Before starting construction, you need to decide:
- With roof type and slope angle
- Type of roofing material
- Length, cross-section of rafters and distance between them
- Length, pitch and cross-section of sheathing and counter-lattice elements
- Type of insulation
Type of roofs of frame houses
Roofs are:
- Flat
- Pitched (with one, two or more slopes)
- Attic (with two and four slopes)
- Pincer, conical, multi-pinion, etc.
The choice of roof is made not only based on the conditions of its appearance. Important to consider functionality designs. Main advantages and disadvantages of roofs different types are given below.
Frame house with flat roof
Flat roofs are not popular in private construction. Their construction does not cause difficulties, but the shortcomings cover everything. They require careful care. After rain, water remains on the roofs, and in winter you have to remove the snow yourself. This increases the likelihood of moisture penetrating into the room. On houses with a pitched roof, you can use the attic as an additional room.
But during installation flat roof you can save a lot on building materials and sunbathe on it in the summer.
During installation, it is necessary to maintain a slope angle of 2-3 degrees relative to the horizon.
Multi-pitched and single-pitched roof of a frame house
The slope angle of the slopes starts from 10 degrees. The number of slopes is from 1 to 4.
Pitched roofs are very popular and are used everywhere. In spring, snow does not stay on them for a long time, water calmly flows down the gutters, and a lot of additional space appears in the form of attic space, where you can arrange an additional room.
The load on the structure is also reduced, and with it the possibility of leaks.
Mansard roof
It can be semi-hip (double slope with two small slopes) and hip (four slope). This type of roof is also widely used.
The advantages are as follows: additional space under the roof, the ability to install windows, unique appearance at home, low load on the structure in winter. Disadvantages - high costs for materials, heating, a lot of snow on window structures in winter, faster destruction of rafter structures due to insufficient ventilation.
Multi-gable roof
The multi-gable roof is considered one of the most popular. It differs from others in the large number of slopes and the presence of valleys. Installed if the house has a complex layout.
Advantages - the design can withstand significant loads, it becomes possible to equip an additional room, and a unique appearance. Disadvantages: high consumption of material, leaving a lot of waste, difficulty in DIY installation, and high financial costs.
Conical roofs
A conical roof is installed when the building is made in the shape of a circle. In Russia, few people build such roofs.
Advantages: interesting appearance, ease of maintenance. Disadvantages: complexity of calculations and installation.
We suggest choosing a roof with two slopes. In this case, it will be possible to significantly reduce the cost of materials and maintenance, while the appearance of the structure will not be affected.
It is worth understanding that the more slopes, the more beautiful the roof, but also more expensive. But if you are not used to saving and want the best, then install a roof of any type.
Rafters perform a number of significant roofing functions. They set the configuration of the future roof, absorb atmospheric loads, and hold the material. Among the rafter's duties are the formation of smooth planes for laying the covering and providing space for the components of the roofing pie.
In order for such a valuable part of the roof to flawlessly cope with the listed tasks, information is needed about the rules and principles of its design. The information is useful both for those who are constructing a gable roof truss system with their own hands, and for those who decide to resort to the services of a hired team of builders.
In the construction of the rafter frame for pitched roofs, wooden and metal beams. The starting material for the first option is a board, log, timber.
The second is constructed from rolled metal: channel, profile pipe, I-beam, corner. There are combined structures with the most heavily loaded steel parts and wood elements in less critical areas.
In addition to its “iron” strength, metal has many disadvantages. These include thermal qualities that are unsatisfactory to the owners of residential buildings. The need to use welded joints is disappointing. Most often, industrial buildings are equipped with steel rafters, and less often, private cabins assembled from metal modules.
In the matter of independent construction of rafter structures for private houses, wood is a priority. It is not difficult to work with, it is lighter, “warmer”, and more attractive in terms of environmental criteria. Moreover, to fulfill node connections not required welding machine and welding skills.
Rafters - a fundamental element
The main “player” of the frame for constructing a roof is the rafter, which among roofers is called a rafter leg. Beams, braces, headstocks, purlins, ties, even a Mauerlat may or may not be used depending on the architectural complexity and dimensions of the roof.
Rafters used in the construction of gable roof frames are divided into:
- Layered rafter legs, both heels of which have reliable structural supports under them. The lower edge of the layered rafter rests against the mauerlat or the ceiling crown of the log house. The support for the upper edge can be a mirror analogue of the adjacent rafter or a purlin, which is a beam laid horizontally under the ridge. In the first case, the rafter system is called spacer, in the second, non-spacer.
- Hanging rafters, the top of which rests against each other, and the bottom is based on an additional beam - a tie. The latter connects the two lower heels of adjacent rafter legs, resulting in a triangular module called a rafter truss. Tightening dampens the tensile processes, so that only vertically directed load acts on the walls. Although a structure with hanging rafters is braced, the bracing itself does not transmit to the walls.
In accordance with the technological specifics of rafter legs, the structures constructed from them are divided into layered and hanging. For stability, the structures are equipped with struts and additional racks.
To support the top of the layered rafters, planks and purlins are installed. In reality, the rafter structure is much more complex than the elementary templates described.
Note that the formation of a gable roof frame can generally be done without truss structure. In such situations, the supposed planes of the slopes are formed by slabs - beams laid directly on the load-bearing gables.
However, we are now interested specifically in the structure of the rafter system gable roof, and it can involve either hanging or layered rafters, or a combination of both types.
Subtleties of fastening rafter legs
Fastening the rafter system to brick, foam concrete, aerated concrete walls is carried out through the Mauerlat, which in turn is fixed with anchors.
Between the Mauerlat, which is a wooden frame, and the walls made of the specified materials, a waterproofing layer made of roofing felt, waterproofing material, etc. is required.
The top of brick walls is sometimes specially laid out so that along the outer perimeter there is something like a low parapet. This is so that the mauerlat placed inside the parapet and the walls do not push apart the rafter legs.
The rafters of the roof frame of wooden houses rest on the upper crown or on ceiling beams. The connection in all cases is made by notches and is duplicated with nails, bolts, metal or wooden plates.
How to do without mind-boggling calculations?
It is highly desirable that the section and linear dimensions wooden beams were determined by the project. The designer will provide clear calculation justification for the geometric parameters of the board or beam, taking into account the entire range of loads and weather conditions. If available home handyman design development no, his path lies to the construction site of a house with a similar roofing structure.
You don’t have to pay attention to the number of floors of the building being constructed. It is easier and more correct to find out the required dimensions from the foreman than to find out them from the owners of a shaky self-built building. After all, in the hands of the foreman is documentation with a clear calculation of the loads per 1 m² of roof in a specific region.
The installation pitch of the rafters determines the type and weight of the roofing. The heavier it is, the smaller the distance between rafter legs. For styling clay tiles, For example, optimal distance between the rafters there will be 0.6-0.7 m, and for corrugated sheets 1.5-2.0 m is acceptable.
However, even if the pitch required for proper installation of the roof is exceeded, there is a way out. This is a reinforcing counter-lattice device. True, it will increase both the weight of the roof and the construction budget. Therefore, it is better to understand the pitch of the rafters before constructing the rafter system.
Craftsmen calculate the rafter pitch according to design features buildings, simply dividing the length of the slope into equal distances. For insulated roofs, the pitch between the rafters is selected based on the width of the insulation slabs.
You can find it on our website, which may also help you a lot during construction.
Rafter structures of layered type
Layered rafter structures are much simpler to construct than their hanging counterparts. A reasonable advantage of the layered scheme is to ensure adequate ventilation, which is directly related to long-term service.
Distinctive design features:
- It is mandatory to have support under the ridge heel of the rafter leg. The role of support can be played by a purlin - a wooden beam resting on posts or on the internal wall of the building, or the upper end of an adjacent rafter.
- Using a Mauerlat to erect a truss structure on walls made of brick or artificial stone.
- The use of additional purlins and racks where rafter legs are required due to the large size of the roof additional points supports.
The disadvantage of the scheme is the presence structural elements, affecting the layout of the internal space of the used attic.
If the attic is cold and it is not intended to organize useful rooms, then the layered structure of the rafter system for installing a gable roof should be given preference.
Typical sequence of work for the construction of a layered truss structure:
- First of all, we measure the heights of the building, the diagonals and horizontality of the upper cut of the frame. When identifying vertical deviations of brick and concrete walls, we eliminate them cement-sand screed. Exceeding the heights of the log house is cut off. By placing wood chips under the mauerlat, vertical flaws can be combated if their size is insignificant.
- The floor surface for laying the bed must also be leveled. It, the Mauerlat and the girder must be clearly horizontal, but the location of the listed elements in the same plane is not necessary.
- We treat all wooden parts of the structure with fire retardants and antiseptics before installation.
- On concrete and brick walls We lay waterproofing under the installation of the Mauerlat.
- We lay the mauerlat beam on the walls and measure its diagonals. If necessary, we slightly move the bars and turn the corners, trying to achieve the ideal geometry. Align the frame horizontally if necessary.
- We mount the Mauerlat frame. The beams are joined into a single frame using oblique notches; the joints are duplicated with bolts.
- We fix the position of the Mauerlat. Fastening is done either with staples to wooden plugs placed in the wall ahead of time, or anchor bolts.
- Mark the position of the prone position. Its axis should recede from the mauerlat bars at equal distances on each side. If the run will rest only on posts without supports, we carry out the marking procedure only for these posts.
- We install the bed on a two-layer waterproofing. We fasten it to the base with anchor bolts, with internal wall We connect with wire twists or staples.
- We mark the installation points of the rafter legs.
- We cut out the racks to uniform sizes, because... Our bed is exposed to the horizon. The height of the racks should take into account the cross-sectional dimensions of the purlin and beam.
- We install racks. If provided by the design, we secure them with spacers.
- We lay the purlin on the racks. We check the geometry again, then install brackets, metal plates, and wooden mounting plates.
- We install a test rafter board and mark the cutting areas on it. If the Mauerlat is set strictly to the horizon, there is no need to adjust the rafters on the roof after the fact. The first board can be used as a template for making the rest.
- We mark the installation points of the rafters. For marking, folk craftsmen usually prepare a pair of slats, the length of which is equal to the clearance between the rafters.
- According to the markings, we install the rafter legs and fasten them first at the bottom to the mauerlat, then at the top to the purlin to each other. Every second rafter is screwed to the Mauerlat with a wire bundle. IN wooden houses The rafters are screwed to the second crown from the top row.
If the rafter system is made flawlessly, the layer boards are installed in any order.
If there is no confidence in the ideal structure, then the outer pairs of rafters are installed first. A control string or fishing line is stretched between them, according to which the position of the newly installed rafters is adjusted.
The installation of the rafter structure is completed by installing fillets, if the length of the rafter legs does not allow forming an overhang of the required length. By the way, for wooden buildings the overhang should extend beyond the contour of the building by 50 cm. If you plan to organize a canopy, separate mini-rafters are installed under it.
Another useful video about building a gable rafter base with your own hands:
Hanging rafter systems
The hanging variety of rafter systems is a triangle. The two upper sides of the triangle are folded by a pair of rafters, and the base is the tie connecting the lower heels.
The use of tightening allows you to neutralize the effect of the thrust, therefore, only the weight of the sheathing, roof, plus, depending on the season, the weight of precipitation, acts on walls with hanging rafter structures.
Specifics of hanging rafter systems
Characteristic features of hanging type rafter structures:
- The obligatory presence of a tie, most often made of wood, less often of metal.
- Possibility to refuse to use the Mauerlat. A timber frame can be successfully replaced by a board laid on double-layer waterproofing.
- Installation of ready-made closed triangles – trusses – on the walls.
The advantages of the hanging scheme include the space under the roof free from racks, which allows you to organize an attic without pillars and partitions. There are disadvantages.
The first of them is restrictions on the steepness of the slopes: their slope angle can be at least 1/6 of the span of a triangular truss; steeper roofs are strongly recommended. The second disadvantage is the need for detailed calculations for the proper installation of cornice units.
Among other things, the angle roof truss You will have to install it with pinpoint precision, because... the axes of the connected components of the hanging rafter system must intersect at a point, the projection of which must fall on the central axis of the Mauerlat or the backing board replacing it.
Subtleties of long-span hanging systems
The tie is the longest element of a hanging rafter structure. Over time, as is typical for all lumber, it becomes deformed and sags under the influence of its own weight.
Owners of houses with spans of 3-5 meters are not too concerned about this circumstance, but owners of buildings with spans of 6 meters or more should think about installing additional parts that exclude geometric changes in tightening.
To prevent sagging, there is a very significant component in the installation diagram of the rafter system for a long-span gable roof. This is a pendant called a grandmother.
Most often it is a block attached with wooden pegs to the top of the truss. The headstock should not be confused with the racks, because its lower part should not come into contact with the puff at all. And the installation of racks as supports in hanging systems is not used.
The bottom line is that the headstock hangs, as it were, on the ridge assembly, and a tightening is attached to it using bolts or nailed wooden plates. To correct sagging tightening, threaded or collet-type clamps are used.
The tightening position can be adjusted in the area of the ridge assembly, and the headstock can be rigidly connected to it by a notch. Instead of a block on non-residential attics For the manufacture of the described tension element, reinforcement can be used. It is also recommended to install a headstock or hanger where the tie is assembled from two beams to support the connection area.
In an improved hanging system similar type The headstock is complemented by braced beams. The stress forces in the resulting rhombus are extinguished spontaneously due to the proper placement of vector loads acting on the system.
As a result, the rafter system is stable with minor and not too expensive modernization.
Hanging type for attics
In order to increase the usable space, the tightening of the rafter triangles for the attic is moved closer to the ridge. A completely reasonable move has additional advantages: it allows you to use the puffs as a basis for lining the ceiling.
It is connected to the rafters by cutting with a half-pan and duplicating with a bolt. It is protected from sagging by installing a short headstock.
A noticeable disadvantage of the attic hanging structure lies in the need for accurate calculations. It is too difficult to calculate it yourself; it is better to use a ready-made project.
Which design is more cost effective?
Cost is an important argument for an independent builder. Naturally, the price of construction for both types of rafter systems cannot be the same, because:
- In the construction of a layered structure, a board or beam of small cross-section is used to make rafter legs. Because layered rafters have two reliable supports underneath them; the requirements for their power are lower than in the hanging version.
- In the construction of a hanging structure, the rafters are made of thick timber. To make a tightening, a material with a similar cross-section is required. Even taking into account the abandonment of the Mauerlat, the consumption will be significantly higher.
It will not be possible to save on the grade of material. For the load-bearing elements of both systems: rafters, purlins, beams, mauerlat, headstocks, racks, 2nd grade lumber is needed.
For crossbars and tensile ties, grade 1 will be required. In the manufacture of less critical wooden overlays, grade 3 can be used. Without counting, we can say that in the construction of hanging systems, expensive material is used in greater quantities.
Hanging trusses are assembled in an open area next to the facility, then transported, assembled, upstairs. To lift weighty triangular arches from timber, you will need equipment, the rental of which will have to be paid. And the project for complex nodes of the hanging version is also worth something.
Video instruction on the installation of a hanging category truss structure:
There are actually many more methods for constructing rafter systems for roofs with two slopes.
We have described only the basic varieties that are actually applicable for small country houses and buildings without architectural tricks. However, the information presented is enough to cope with the construction of a simple truss structure.
During the construction of any structure, its load-bearing parts are subject to special requirements strength. Basic load-bearing elements– foundation, walls and roof. In this article we will talk about how to properly make a roof frame, what installation methods are used today and how you can save on construction work.
There are several types of roof frames, the choice of which depends on the type of roof, the nature of the covering and the purpose of the building.
Roof frames are:
- wooden - a rafter system that is used to create pitched roofs in residential construction. The most common type;
- metal - a metal roof frame is used mainly for industrial construction, since installation is very expensive and involves large volumes and areas;
- reinforced concrete - a flat roof, the supporting base of which is made of reinforced concrete slabs.
In this article we will not dwell in detail on metal roof frames, since it is almost impossible to do such work with your own hands. This type is not suitable for housing construction, so we will tell you about all the intricacies of construction wooden frames.
Types of rafter system
Before you begin building your own roof frame, you need to determine what type of rafter system you will use. The main purpose of the rafters of any pitched roof is to be a support. Rafters or rafter legs are wooden beams with a cross-section of 150x50 mm. The sheathing and roofing are laid on top of the beams.
Distinguish the following types roof frames depending on the connection of the rafters:
- layered;
- hanging.
For private construction, both of these types can be used, the only difference between them is that a mauerlat is used to support the rafters in a hanging system. The Mauerlat is a longitudinal beam 100x100 mm. If you use layered rafters, their upper part will rest on the central load-bearing wall, and not connect with each other.
To select one of these types of systems, it is necessary to take into account the planning and structural characteristics of the building. For example, if the distance between the load-bearing walls to support the rafters is 6 meters or less, it is more advisable to use hanging frame roofs. For spans between supporting walls with a distance of more than 6 meters, it is better to use a layered system with the construction of an additional “intermediate” wall in the center of the building. This way the rafters will not sag over large spans. But this condition applies only to wooden frames; for metal spans, they can remain without an additional wall.
Installation features
To answer the question “How to build a roof frame?”, You need to understand the theory of installation.
Roof installation can be done in two ways:
- Ready-made trusses are a system of reinforced rafters using tie-downs, racks and struts. First, the entire non-existent structure, consisting of the same type of elements, is assembled, and then it is installed on the roof of the building box. The whole process takes a minimum of time, but the involvement of lifting equipment is required, and, therefore, the costs will be quite high. It is advisable to install ready-made trusses for roofs with large overhangs and without supports.
- Assembling the frame on the roof is more affordable and budget method, but its implementation requires more time. The assembly takes place in stages, but you can completely do it on your own. We will describe how to assemble the roof frame in more detail below.
In the process of designing a roof frame scheme, the following important factors must be taken into account:
- The structure must withstand loads varying degrees, including the dead weight of the roof and all elements, the weight of snow in winter time, wind pressure, falling leaves, etc.
- Choose a roofing covering that is as waterproof as possible, especially if you live in an area with a humid climate.
- Insulate the roof with minimal heat loss. To do this, it is necessary to ensure complete waterproofing and vapor barrier, and also consider a ventilation system for the roof space.
- The attic space must be ventilated. This will prevent damage to the load-bearing elements of the structure, thereby increasing the life of the building.
Selection of materials
If you want to know how to make a roof frame with your own hands, first you need to get tools and materials.
To complete the work you will need the following:
- timber 150x50 mm for rafters;
- timber 100x100 mm for the mauerlat (for this purpose it is better to buy coniferous wood winter preparation without any visible flaws);
- slats 40x40 mm for sheathing;
- fastening pins for fixing the Mauerlat;
- studs 8 mm and 10 mm for rafters;
- staples;
- brackets;
- wood screws;
- hammer;
- plane;
- drill;
- saw;
- level;
- roulette;
- gloves;
- wood antiseptics;
- flame retardants.
Treating wooden structural elements with antiseptics and fire retardants extends the service life of the entire building and also reduces the flammability of wood, minimizing the risk of ignition.
Helpful advice: gas guns greatly simplify and speed up installation. In this video, the roof frame is made easily and quickly using modern technology. If the construction is one-time, it makes sense to rent such a gun.
To make a frame from metal profile You will need completely different tools, but since the weight of the materials and the complexity of the execution do not allow you to do such work yourself, it is most appropriate to start building wooden frames.
Gable roof frame
When you have purchased all the necessary materials, prepared the tools, processed wooden elements protective compounds, you can begin installation. The construction of a gable roof frame should begin with laying the Mauerlat. This beam will distribute and transfer the load from the rafters to the load-bearing walls. As a rule, the Mauerlat is laid on a concrete base according to inside load-bearing wall.
To prevent the wood from drawing out all the moisture from the concrete and then preventing it from crumbling, several layers of roofing material should be laid under the beams. WITH outer wall need to do brickwork to the level of the Mauerlat, and it, in turn, is attached to the concrete with nuts and studs.
Rafter system
After erecting and strengthening the base, you can build the roof frame, that is, install the rafters.
Installation of rafters consists of several stages:
Design features
How to make a roof frame is more or less clear, but in order for the results of your work to continue to please you for many years, you need to take into account some nuances during construction.
- Remember that the installation pitch of the rafters and the choice of cross-section are interrelated quantities. The smaller the cross section load-bearing beams, the smaller the step will be. This is useful if the dimensions of the timber do not correspond to the load.
- Rafters can be free or loaded (support floor beams).
- Connections of all components and fastenings must be as reliable as possible. For added rigidity, use reinforcement pads.
- There are several ways to attach the rafters to the mauerlat. Notches provide a more rigid fixation, and special sliding fastenings are ideal for log houses.
- To protect the outer walls, blind areas and foundation, the roof must extend beyond the box by at least 40 cm, and it is better to protect the end parts of the rafters with a frontal (wind) board.
- If you are using hanging rafters, remember the load they put on the walls, so fasten the rafter legs with a tie. This can be either a beam or a floor beam.
- Choose the pitch of the sheathing in accordance with the nature of the roofing. Different types coatings have their own application ranges depending on the degree of slope of the slope.
Construction Features gable roof, as well as tips on how to make a roof frame in the video materials below:
High demands are always placed on load-bearing parts. The main load-bearing elements are walls, foundation and roof.
The roof frame plays very important role. After all, it determines how long the roof will last.
The construction of a rafter system very often causes difficulties for novice craftsmen. This article will help you make a roof frame with your own hands.
There are several types of rafter systems. The choice of one type or another depends on the purpose of the building, the nature of the covering and the type of roof.
The roof frame can be:
- Metallic. Such a rafter system is usually constructed during industrial construction. This is due, first of all, to high costs. Also construction metal frame implies large areas and volumes;
- Wooden. This type of frame is used in the construction of residential buildings with a pitched roof. Is the most common type;
- Made of reinforced concrete slabs. They act as a load-bearing base during the construction of a flat roof.
Before you start constructing a roof frame with your own hands, you need to decide on the type of rafter system. Acting as a support is the main purpose of any rafter system.
Rafter legs or rafters are wooden beams having a cross-section of 150×50 millimeters. The sheathing is attached on top of them, and then the roofing material.
There are two types of roof frames: layered and suspended. They differ from each other in the way the rafters are connected. Both of these types are used in the construction of private houses. They differ in that in the hanging rafter system they use a mauerlat - a longitudinal beam with a cross-section of 100X100 mm.
The upper part should rest on the central load-bearing wall, and not connect to each other.
The structural and planning characteristics of the building under construction play an important role when choosing the type of rafter system.
It is advisable to use a layered rafter system if the distance between the supporting walls is too large. In this case, an “intermediate” wall is erected in the center of the building, which serves as an additional support. As a result, the rafters will not sag.
Otherwise, a hanging rafter system is usually used. But if the roof frame is made of metal, then additional walls are not needed.
Installation features
When designing a rafter system, the following points should be taken into account:
- If the climate in your area is humid, then it is better to choose a roofing material that has the best water resistance;
- It is necessary to ensure ventilation of the attic space. If this is not done, then after some time the load-bearing elements of the structure will fail;
- The structure must withstand not only the own weight of the roof and its elements. It must withstand a layer of snow, fallen leaves, and also withstand the pressure created by the wind;
Required materials and tools
When constructing a roof frame with your own hands you will need:
- Hammer;
- Drill;
- Plane;
- Level;
- Saw;
- Wood screws;
- Roulette;
- Gloves;
- Brackets;
- Fire retardants;
- Staples;
- Antiseptics for wood;
- Beam with a section of 150×50 mm (for rafters);
- Studs 8 mm and 10 mm (for rafters);
- Beam with a section of 100×100 mm (for Mauerlat);
- Mounting pins (for Mauerlat);
- Slats with a cross section of 40×40 mm (for lathing).
Wooden structural elements must be treated with an antiseptic and fire retardant. This will extend the life of the structure and also reduce the risk of fire to a minimum.
Roof frame with two slopes
You need to start installing the frame after:
- all tools are prepared;
- the necessary materials have been purchased;
- wooden elements are treated with antiseptics and fire retardants.
Laying the Mauerlat is initial stage construction of a gable roof frame. distributes and transfers the load from the rafters to the load-bearing walls.
It is important to note that wood can draw moisture from the concrete base, causing it to crumble. In order to avoid this, it is necessary to lay several layers of roofing material under the beams.
Construction of the rafter system
Installation of the rafter system includes the following steps:
- Determine the distance between the rafter legs. It is usually 80 - 90 centimeters. This distance corresponds to the dimensions of the sheathing beam;
- We make holes in the Mauerlat to secure the rafters;
- Construction of the roof frame usually begins at the gable of the building. It is necessary to install end rafters at both edges of the roof. After this, we stretch the cord between their skates. This cord will help to align the intermediate elements evenly;
- We fix all the rafter legs on the mauerlat using steel brackets and brackets. The protrusion of the rafters beyond the perimeter of the building should be approximately 40 centimeters.
- To fix the lower part of the rafters, you need to use a strap that rests on the Mauerlat. If the rafter is not long enough, then it needs to be increased. To do this, you should place another beam on the rafter with an overlap of at least 100 centimeters. Such a large overlap is necessary so that the roof does not lose its rigidity;
- It is necessary to install additional ties between the rafters if the roof frame has a six-meter span. They are attached between the supporting rafters;
- After all the rafters have been installed, we proceed to fixing the rafters in a strictly vertical position. For these purposes they use ridge beam. It is mounted at the top of the roof frame;
- When using soft roofing materials, you need to make a continuous sheathing. To do this, use moisture-resistant plywood or OSB boards. If the roof is made of metal tiles, slate, or corrugated sheets, then the sheathing should be thinned. To increase the strength of the roof, regardless of the roofing material used, a continuous sheathing is made near the ridge part.