The roof is one of the most complex and important architectural elements of a house. Its construction must be approached very responsibly - mistakes are too expensive. It is not for nothing that roofers are considered the most paid builders; the durability and comfort of a building largely depends on their skill. The construction process itself consists of several steps.
Step 1. Select a project
The main differences between roof projects are not design, although they are primarily striking, but structural. When selecting a specific project, the maximum number of technical characteristics structure and the climatic zone of its location.
What roofing options are offered to developers today?
| Roof type | Short description |
|---|---|
| The simplest one, used in small houses. The advantage is a simple rafter system. The disadvantage is the lack of residential attic space. It is rarely used in our country; such houses can be seen more often in Scandinavian countries. |
| A universal roof for houses, allows you to build attic spaces, can be simple or broken. In terms of complexity, cost and manufacturability, most developers are satisfied. By changing the angle of inclination, the load on the elements is adjusted rafter system. |
| More complex design, it is recommended to install on large houses. The rafter system must be installed taking into account all building codes and regulations, and preliminary calculations must be made. |
| It differs from the hip one in that the sizes of the slopes are not the same. Two slopes are large, and two trimmed ones are small. The technical structure is somewhat more complicated than the hip roof, but such roofs increase the volume of the attic space. |
| All slopes have the shape of equilateral triangles, and their vertices converge at one point. The roof can be installed on square-shaped houses. |
| The most complex of all the roofs listed, it is rarely used and only on multi-story buildings. |
Step 2. Selecting materials
Once a specific roof option has been selected, you need to decide on the materials for the construction of the rafter system and the type of roofing coverings.
Important. At the same stage, you need to decide whether the roof will be warm for living quarters or cold.
Rafter system
The rafter system requires only high-quality materials of at least second grade.
Practical advice. To save money for the rafter system, you can buy wet boards rather than dry ones; they are much cheaper. But it should be remembered that raw lumber must be used no later than 7–10 days, during which time the rafter system must be installed and the roof covered. The boards will dry optimally under load, and strong mechanical connections will prevent them from warping.
Prices for various types of construction boards
Construction boards
The Mauerlat is made from 100×100 mm timber or 50×200 mm boards. Rafter legs are made from boards 50×150 mm or 50×100 mm. The linear dimensions of the rafter legs must take into account the maximum possible static and dynamic forces. The width of the boards can be changed by using various vertical and angular stops. Each rafter system has its own characteristics; the master must have extensive practical experience in order to correctly solve problems that arise during construction. And, of course, a project must be ordered for a residential building; a self-built building is considered illegal and will not be accepted for use. This means that light and heating cannot be connected to it, such a room is not registered, it cannot be given or bequeathed. The project, among others, has working drawings of the rafter system; it is necessary to strictly follow the engineers’ recommendations.
The type of lathing depends on the type of roofing; for soft roofing materials it is necessary to make a continuous one, for hard ones any kind is suitable. For a solid one, you need to prepare sheets of plywood or OSB, the thickness is at least one centimeter, but it can be changed depending on the pitch of the rafter legs.
Prices for OSB (oriented strand boards)
OSB (oriented strand board)
You can make a continuous sheathing from edged slats, although this option is difficult to consider optimal - it is very expensive and time-consuming. For solid roofing materials, the sheathing is made of slats or unedged boards. Unedged lumber must be sanded.
Roofing materials
For residential buildings the most budget options bituminous or metal shingles are considered.
Less commonly used are profiled sheets or roll coverings.
Very rarely natural or artificial piece tiles.
The rafter system largely depends on the type of materials. At the design stage, it is necessary to take into account the weight and fastening features of roofing coverings.
Prices for various types of roofing materials
Roofing materials
Insulation materials
Warm roofs are installed only in cases where attic spaces are planned to be converted into residential attics. Currently, two types of insulation are used: mineral wool or polystyrene foam.
The distance between the rafter legs should take into account the factory width of the insulation, thereby reducing the amount of unproductive waste and speeding up work.
The weight of insulation is minimal and can be neglected during the design of the rafter system. But you should keep in mind the climatic zone where the house is located; the thickness of the insulation and, accordingly, the width of the rafter boards depend on this.
Practical advice. For all climatic regions, the thickness of the insulation should be at least 10 cm; for the middle zone, this parameter increases to 15 cm. If the insulation layer is less than the recommended values, then the efficiency of heat saving sharply decreases.
Additional roof materials
If the roof is warm, then it is necessary to provide for the installation of steam and water protection, and the installation of counter-lattice to ensure natural ventilation under-roof space. The range of materials is huge, but by and large they are not much different from each other. Performance characteristics are influenced to a greater extent by compliance with installation technology than by physical indicators roofing membranes. Even very cheap material can be used in such a way that it satisfies all building codes and requirements. Conversely, the most modern innovative material can be mounted in such a way that, apart from harm, there will be no positive effect.
And the last thing you should think about when planning the construction of the roof is the drainage system and special elements for bypassing chimney and ventilation pipes. For some linings and snow retainers, it is necessary to provide additional fixation points on the rafter system. It is much more expedient to do this at the stage of its construction than after fixing the roofing materials. Although modern technologies allow the use of both options for installing additional and special roof elements.
This completes the preparatory stage. If all building materials are prepared, the type of roof and roofing coverings are selected, and the rafter system is designed, then you can begin the actual construction of the roof.
Construction of the rafter system
Important. Mistakes made during the construction of the rafter system are very difficult to correct. Most of them will become noticeable already during the operation of the building, this is extremely unpleasant. There are situations when it will take more money to correct the shortcomings of the rafter system than to build a new roof. And this is also the case when, due to leaks, there is no need to repair the interior.
As an example, we will look at step-by-step instructions for one of the most complex roofs - a hipped roof. Understanding the construction technology of this rafter system, it will not be difficult to understand the technology and assemble simpler single-pitch or gable roofs yourself.
Step 1. Take two long boards, with their help it is easier to determine the length of the rafter legs, the angle of the slopes and the height of the roof. Temporarily fix the boards to a vertical support on the wall of the house. Raise or lower them until you find an acceptable position. If the size of the house allows, then it is better to design the rafter system so that the length of the legs does not exceed 6 m. Such lumber can be purchased, there will be no need to increase it. Building up not only takes a lot of time, but also weakens the structure and requires the installation of additional supports.
Step 2. Fill the reinforcing belt. It not only increases the height of the attic space, but also makes it possible to extend the overhang of the rafters and additionally protect the facade walls from precipitation. The width of the belt should be at least 30 cm, the height depending on the size of the house.
How to fill a reinforcing belt?
Important. The difference in height at the corners of the reinforcing belt should not exceed ± 2 cm. To check, you need to pull the rope, with its help it is much easier to level the concrete surface.
Allow at least three days for the concrete to harden. Remember that it will gain 50% strength only after two weeks, only then can the structure be fully loaded. If the weather is very warm and windy, then the concrete belt should be watered generously with water at least twice a day. Concrete gains strength not during drying, but during favorable development chemical reactions, this requires constant moisture.
The construction of a rafter system conventionally consists of four stages: installation of the mauerlat, installation of the ridge beam, installation of rafters (hip and diagonal) and arrangement of the sheathing.
Mauerlat installation
Work begins after the concrete of the reinforcing belt has gained sufficient strength and the formwork has been dismantled. For the Mauerlat, 200×100 mm timber is used. This is a very important element of the rafter system; it serves to support the rafter legs and uniformly distribute point loads over the entire area of the façade walls.
Step 1. Place the timber next to the reinforcing belt, accurately mark the exit points of the anchors. It's easier to do this without a tape measure. Turn it over with the narrow side down and place it on your belt, using a pencil to mark the position of the anchors. Then transfer the marks to the wide side of the beam; holes must be drilled in these places.
Practical advice. If there are doubts about the accuracy of taking measurements, then drill holes for anchors with a diameter 2–3 mm larger than the diameter of the studs. It won't have any effect negative impact on the strength of the Mauerlat fastening, but will make it much easier to install it in place.
Step 2. Drill holes, hold the drill as vertically as possible, do not allow distortions. The work must be carried out by an experienced carpenter. A beginner can ruin the beam; all the holes will have to be shifted by reducing its length.
Practical advice. If there are doubts about the strength of the concrete of the reinforcing belt, then do not tighten the nuts with great force. They can be tightened later during the construction of the rafter system.
Step 3. Prepare strips of waterproofing under the Mauerlat; it is better to buy ordinary cheap roofing felt. The strip is cut from the roll; there is no need to roll it out. The material is perfectly cut with a grinder and a metal disc.
Step 4. Spread strips of waterproofing on the reinforcing belt. Making holes is much easier with a hammer. Place the roofing felt on the anchors and use a hammer to carefully punch holes in the waterproofing for the studs. You just need to do this carefully, you can’t hit it too hard. Otherwise, there is a risk of damaging the upper threads and problems will arise when tightening the nuts. If you are afraid, then before laying the roofing material on all the studs, screw the nuts; after unscrewing, they will automatically align the damaged turns.
Step 5. Install the beam onto the anchors and tighten with nuts. Be sure to place large diameter washers under them. If the Mauerlat fits tightly onto the studs, you will have to hammer it in with a sledgehammer. This situation indicates insufficient qualifications of roofers.
It is better to make Mauerlat from pine rather than spruce; it contains much more resin, and accordingly, it is not damaged by putrefactive diseases longer. How to distinguish pine from other coniferous woods? For several reasons. First, the wood smells of resin and turpentine. Second - the pine has a bright yellow tint, large and lively knots. Third, the presence of black spots on pine lumber indicates a high resin content; it acquires this color after oxidation in air. Spruce is whiter, lighter in weight, has few knots and has an unpleasant smell of cat feces.
At the corners and along the length, the beams are connected into half a tree; it is advisable to fix these places with long nails or self-tapping screws made of stainless alloys.
Installation of a ridge beam
For horizontal support, vertical posts and the upper ridge girder, you can use 50x150 mm timber. The lower element must be secured with anchors, and waterproofing must be placed between the concrete floor slab and the wood. All fastenings are made with nails; they should be driven in obliquely. If you wish, you can use metal corners. To calculate the size of the ridge beam, you need to subtract its width from the length of the house, the resulting value is the length of the element. Calculation is needed to ensure that all four overhangs are the same.
Installation of rafters
This is the most difficult stage of building a rafter system. The system will be without thrust; special cuts are made on the rafter legs to rest against the mauerlat. In this position, they do not push the walls apart, but press them together; this rafter system is more stable than a layered one.
Step 1. Install diagonal rafters. For their manufacture, a 50×150 mm board is used; if the length is not enough, then the materials should be spliced. During splicing, it is necessary to strictly follow the existing recommendations, while at the joints it is necessary to install a support in the future; this should be kept in mind when choosing the location for the extension. Make sure that all four elements are located at the same angle. If the overhang size is slightly different, this is not a problem; the parameter can be easily adjusted to the required value using fillets.
Practical advice. To increase the strength of the diagonal rafters, it is recommended to knock down two beams, as a result the thickness will increase to 100 mm. It is necessary to knock down with a shift, due to this the length of the element simultaneously increases.
Step 2. Proceed with the installation of ordinary rafters. In the places where the mauerlat stops, you need to saw down the platform, the upper end is fixed to the ridge girder.
Drive all connections onto three nails at an angle. Two nails are driven into the sides and one into the edge of the beam.
Important. If the roof is insulated, then the rafter spacing is 60 cm, which is exactly the width of most insulation materials. But dimensions should be taken not along the lateral planes of the lumber, but along the axis of symmetry.
To increase stability, additionally secure the rafters with metal corners. It is not necessary to screw in self-tapping screws; it is much more convenient to use nails; this does not reduce the stability of the structure. The fact is that they work for cutting, and not for pulling out.
The rafters must be positioned under the rope. First, the two outer legs are mounted and their position is carefully checked. Everything is within normal limits - stretch a rope between them and install all the remaining elements under it.
Step 3. Align the overhang of the rafters under the cornice. It should be marked with a construction rope; it is easier to cut with a gasoline saw.
Practical advice. If piece tiles are used to cover the roof, then the rafter structure will have to be strengthened. This is not difficult to do; you just need to install additional purlins and rest your feet on them.
Installation of sheathing
As we mentioned above, the type of lathing depends on the type of roofing. But in all cases, it is recommended to treat the lathing materials with antiseptics. The fact is that they work in conditions difficult for natural ventilation; additional protection against rotting is very important. Building codes require that all wooden elements be impregnated with fire protection; now there are dual-action preparations that protect against both fire and rot. The requirements must be fulfilled. But in practice, both protected and unprotected houses burn with equal success.
Video - Installation of lathing under metal tiles
Roof installation
The technology depends on the selected materials. For all cases, there is universal advice - you need to cover the house as quickly as possible. If insulation is installed, it must be done from inside the building, thus eliminating the risk of the mineral wool getting wet. Wet wool is a problem for roofers. It will have to be removed for drying; during dismantling, a large amount becomes unusable, and the total time for constructing the roof of the house increases significantly.
Prices for mineral wool
Video - DIY metal roofing installation
Video - Errors in installing metal tiles
Installation of a drainage system
Video - Installation of gutters
If you are building your own house and have already reached the stage of erecting the roof, then from our article you can learn how to do it yourself. The roof is the most important element of any residential structure, so it should be given special attention. Not only the comfort in the house in terms of temperature, but also the overall safety of the building depends on the quality of the roof. So, let's look at the step-by-step instructions for building this house assembly.
Preparation and calculations
It is important to understand that the roof of a house is a complex and important structural element. To construct it, it is necessary to clearly calculate the amount of material, as well as take into account future loads. We invite you to familiarize yourself (in the table) with the average options for building materials for construction gable roof.
Be sure to calculate the exact volume of material based on the size of the roof of your house. You can purchase material with a small reserve, taking into account possible errors and defects. It is recommended to draw up a drawing of the future structure. To do this, by the way, you can use modern computer programs that will help calculate the amount of material needed. After the calculations, we proceed to the actual execution of the work.
Mauerlat is actually a load-bearing beam that is installed on the top of the erected walls and plays the role of support for the entire roof structure. For the Mauerlat we choose a beam with a cross section of 100×100 mm or 150×150 mm, depending on the size of the frame and its future weight.
The Mauerlat can be installed in several ways. The most common of these is to attach the timber directly to the top of the wall. To do this, metal studs are attached to the wall, and holes are made in the timber for fastening. A layer of insulating material is placed under the Mauerlat, after which the beam is “put on” the studs and secured with bolts. If the wall is wide, the beam can be covered with brick, which will give the roof base greater strength.
You can also fix the Mauerlat using concrete putty, but the best option There will still be fixation of the timber on special studs. However, for greater strength, you can use several installation options at once.
The gable roof of a house is made with your own hands strictly step by step. After installing the Mauerlat, we proceed to the collection and installation of the rafter system. In our roof version, this design is an A-shaped element that works on the principle of expansion. Loads must be taken into account, so before installing the system it is necessary to strengthen the opposite walls. For this, a beam is used (the cross-section can be selected similar to the Mauerlat), which is attached at the level of the ceiling beams.
By the way, the ceiling beams are laid before installing the rafters. The beams are fastened using corners. The installation step of ceiling beams depends on technical features your home, but should not be less than 30 cm. Fix the beams securely and constantly check the strength of the structure.
If it is possible to lift a fairly heavy load to the roof level, the system can be assembled on the ground. Otherwise, the system is assembled on the ceiling. We take the beams necessary for the rafter legs and form a triangular structure, connecting the parts with nails. The triangle is installed with rafters on the mauerlat. Be careful and be sure to take into account the desired roof height right away so that you don’t have to redo the triangles in the future. Do not forget to check the vertical installation using a level and securely fix the structures to avoid distortions. You can temporarily use additional fasteners in the form of nailed boards, which can be easily dismantled at the end of the work.
Important: First of all, we install side structures on each side of the house.
We firmly attach the rafter leg to the mauerlat. For this we use metal pads. You should end up with a securely fixed triangular structure, which will act as a kind of “template” for continuing work. Taking into account the size of the beam and the angle of inclination of the rafters, we assemble new triangles and install them one by one on the mauerlat. The number and pitch of rafters depends on the size of the roof.
We strengthen the sides of the triangle with transverse boards (we nail them in the center of each side) and install the racks on the beds. They will play the role of additional support and will prevent the roof from deforming. We attach a ridge girder to the top of the entire system.
This element is the front "wall" of the roof, continuing the existing wall of the house. In order for the gable roof of a house to look beautiful and be strong with your own hands, it is necessary to strictly maintain the vertical levels of the gables and, accordingly, the rafter system. It is also important to ensure reliable fixation, since the roof will be exposed to precipitation and wind, which can lead to distortions. You should also take into account the weight of the future roofing, so you should never neglect attention to the reliability of fastening.
The pediment looks like a triangular structure, which can be assembled both on the ground and directly at the work site. You can provide for a window at the gable. The pediment is attached from below to the mauerlat, and from above to the ridge girder. You can sew up the pediment both at this stage and at any subsequent ones. As a rule, boards of 50×100 mm or 50×150 mm are used for this. The boards can be mounted either vertically or horizontally - your choice.
The inside of the pediment must be insulated and covered with an insulating layer. You can use materials and technology that we will describe in the next section. As for the outside of the gable, you can leave it as is, or you can cover it with siding, which will give your roof a beautiful look.
Lathing and insulation
To make your own gable roof reliable, be sure to insulate it. Various materials can be used as insulation, for example, the very popular mineral wool or other options based on it. Be sure to provide a vapor and waterproofing layer.
We lay the waterproofing layer directly on the rafters and fix it. Next, we lay mats of heat-insulating material, placing them between the rafters with reliable fixation. Next, we lay a layer of vapor barrier, which we place with inside roofs. We fix the connections of the layers using a special adhesive tape. You can immediately install a finishing layer on top of the insulating material, or you can postpone this stage until later.
Now let's move on to the sheathing. We lay counter-lattice along the existing rafters. The task of this element is to create a gap between the roofing material and the insulation. This helps remove moisture that results from the convection of warm air from the ceiling and attic.
Next, we install the direct sheathing. Here everything depends on what kind of roofing material you are going to choose. For example, for tiles the sheathing pitch should be about 50 mm, and for slate or wide tiles - from 100-150 mm. In other words, it is necessary to take into account the size and weight of the future roofing material. In some cases, it is possible to make a completely continuous sheathing. By the way, this option is considered universal, that is, suitable for any type of coating. But this significantly increases the consumption of building material and the weight of the entire roof.
Installation technology differs depending on the type of coating. For example, when installing bitumen shingles, you should first of all lay an underlayment carpet on the sheathing with an overlap of the layers of approximately 150 mm and securely fix it. The carpet can be laid both along and across the existing sheathing, the main thing is to fix it securely.
Next, we install the cornices, if they are included in the project. The cornice strip is attached directly to the lining and secured with nails or self-tapping screws. Do not forget to install special brackets into the cornice for installing the drainage system. After this, attach the end strips to the ends of the roof and proceed to laying the tiles.
We start laying from the center of the eaves overhang, in both directions to the edges, moving layer by layer to the top of the roof. The tiles have an adhesive layer protected by film - tear it off and glue each tile to the lining. We fix it with nails in four places. Next, we repeat the procedure with each subsequent tile. At the ends, the protruding edges of the tiles must be carefully trimmed and the edges sanded. Don't forget to make roof penetrations - special holes for, for example, an antenna or chimney. To do this, the tile is drilled in the required place, and the hole is reinforced with rubber around the edges.
A special ridge tile of a suitable shape is mounted on the roof ridge. Here it is necessary to overlap the laying by about 5 mm to avoid rainwater from getting under the material. Installation of roofing using other materials is carried out in approximately the same way, taking into account certain nuances for each coating option.
Your DIY gable roof is ready. Now you can move on to the interior decoration of the attic and the work of covering the wood with varnish, paint or other suitable materials. As you go, there is nothing complicated in this process: you will need the necessary materials, several assistants, tools and 2-3 days to work.
In this article I will try to describe in detail how a gable roof is built. This form is practically the simplest, suitable for a private house, and its construction, from the point of view of monetary costs, is more profitable compared to other more complex roof configurations.
- in the second case, the rafters rest on the floor beams of the floor below. A gable roof made according to this option will be described here.
Let's take a brick box house as an example. Its dimensions are 8x8 meters, height 3 meters. The construction of any roof with your own hands begins with the installation of maeurlat (Fig. 1). Methods for attaching it to the walls were described in the article, which you can read
We install the Mauerlat flush with the inner surface of the walls. It should be bricked up on the outside so that it is not visible. In this case, the upper surface of the Mauerlat should be 2-3 cm higher than the top surface of the facing brick, so that the entire load from the roof is transferred only to the Mauerlat. No need to load.
Next we install the floor beams. We do this in the sequence shown in Fig. 2. First of all, we install the beams indicated by the numbers 1,2,3,4. Their extension determines the width of the cornice. We usually take it from 40 to 50 cm at the request of the customer. As beams we use a beam, the cross-section of which is determined by making a simple calculation described in detail. In our case, it will be a beam of 100x200 mm.
After securing the outer floor beams, we pull the string along the upper plane and set the remaining beams, if necessary, tightening the Mauerlat under them, or, on the contrary, placing thin plywood (you just often order timber with a height of 200 mm, and they deliver it from 190 to 210 mm, this is what we have on our sawmills equipment). We select their pitch taking into account the pitch of future rafters. When using 50x150 mm floorboards as rafters, take a step of 60-70 cm (it is better to take 60 cm, since roofing insulation has this width).
Having installed all the long beams, we install the short ones (Fig. 2). Their step is enough to take about 1 meter. This diagram is slightly different from what we are used to seeing in similar pictures. We came to it after the gable ebb on one of our first roofs sagged, although the ebb fillers were quite securely fastened. In this scheme, the possibility of sagging is completely eliminated.
We fasten all beams to the mauerlat with 150 nails; you can also use metal rafter corners and self-tapping screws. In general, the use of various fasteners for rafter connections makes the work easier. This is especially convenient for an inexperienced person; there is no need to make complex cuts and nicks. We have already talked about this in the article ““.
After installing all the beams, we lay (without fastening) boards on them, maybe floorboards, maybe inch boards. They are needed simply to walk on them calmly. In order not to clutter the drawing, I did not show them on it. The next step is to install the ridge beam.
First of all, we place racks made of 50x150 mm boards level or plumb and fasten them with temporary spacers. In Fig. The 3 spacers are shown on one post only, again to avoid cluttering the drawing. The pitch of the racks is no more than 3 meters. First we place the outer ones, then, pulling the laces between them, we place the intermediate posts. After the entire truss has been erected, the intermediate posts can be removed and you can easily create living rooms on the second floor.
The height of the racks is selected depending on the shape of the roof you want to achieve. I usually advise customers to take it equal to the height of the first floor along the facade (the distance from ground level to the mauerlat). This proportion is also shown in the figures.
Having installed the racks, we place the ridge beam on them and literally fix it with a couple of screws. We use a 50x200 mm board (in principle, 50x150 mm is also possible).
Now we move on to the installation of rafters. First we need to make a template from a 25x150 board. To do this, apply it to the end of the ridge beam and to the beam (Fig. 4) and draw two lines. Having sawed off a board along them, we get a rafter template.
Of course, it is very good when the foot of the house is laid out with high geometric accuracy and the floor beams are also installed. Then we can cut all the rafters at once according to the template and calmly install them. But to be honest, this is quite difficult to achieve, and even more difficult when a new roof is being installed on an old house.
In this case, we first make only the top cut on the rafter according to the template. Then we take the resulting workpiece, apply it to the desired beam and mark the bottom cut, as they say in place. All rafters are installed in this way (Fig. 5). Please note that after installing one rafter, we immediately install the opposite one in order to quickly remove the lateral load on the ridge beam (otherwise it will bend).
When the length of the roof slope is large and a standard 6-meter board is not enough, you can go in two ways. The first (I think it is preferable) is to order longer boards at the sawmill. Of course it will cost more. For example, at the end of autumn 2012, 1 cube of 6-meter boards cost about 5,500 rubles, and 1 cube of 7.5-meter boards cost 7,000. But installing rafters is easier and faster than using the second method.
The second method requires splicing two boards. This can be done by sewing on them a piece of board of the same section 1.5 - 2 meters long. See the figure for how this is done. It is better to make the joint at the bottom, and an additional stand must be installed under it.
We attach the rafter to the ridge beam with two or three nails. For fastening to the floor beam, we Lately We use metal mounting plates and screws and add a couple of nails. Sometimes we use staples. By the way, I have seen many times how people use staples, but they do it incorrectly. The bracket must work in tension. Below in the left photo - how not to do it, on the right - how to do it.
Having strengthened the truss, we begin to work on the gables. First, we install additional posts that will serve as the frame of the pediment (Fig. 7). The accuracy of installation is controlled by a string stretched along the bottoms of the rafters. Then we make a window opening (Fig. 8). You can make it any size and configuration you want. Please note that in the picture, the post standing in the center of the window (supporting the ridge beam at the beginning) was simply cut. It no longer bears virtually any load. Having finished with the frame, we sheathe the pediment with an inch (for example, 25x150 mm) (Fig. 9).
The next step is to hem the eaves boards around the entire perimeter of the house. The front board (sewn to the ends of the floor beams) is made from a 25x200 mm board. From the bottom to the cornices we sew two belts from a 25x100 board (Fig. 10). They are more than enough to secure the soffit when finishing the exterior.
Now if we are going to mount drainage system and use metal holders for gutters; they need to be installed on the footrails right now (under the waterproofing film). Moreover, it is also advisable to cover the front boards with siding at this stage. Then it will not be very convenient to do this. I didn't show this in the picture. In addition, we now only use plastic gutter holders that are attached directly to the front board. They are more convenient and can be installed after the roof is assembled.
Next we proceed to the sheathing. First of all, using a construction stapler, we attach the first strip of waterproofing film to the rafters (Fig. 11). It is more convenient to work if you already have scaffolding installed around the perimeter of the house. In any case, you will have to install them when you are doing the roofing, drainage, and sheathing the eaves with siding.
Having secured the film, we nail the counter-lattice slats (25x50 mm) to the rafters. The need to use a counter-lattice is described in detail here: . Do not forget to leave space for the overlap of the subsequent waterproofing strip.
Then we make the sheathing. Now I will not focus on the rules for its installation. This topic is for a separate article. In addition, any roofing is accompanied by instructions that describe in detail how to make the sheathing specifically for this material (the pictures schematically show the sheathing for metal tiles). I will try to prepare a new article on this topic in the near future.
In this way we cover the entire roof (Fig. 12). After this, all that remains is to make the gable overhang and gable ebb. The sequence here is:
Using self-tapping screws, we attach the wind board of the gable overhang (25x150 mm) from below to the protruding ends of the sheathing (Fig. 13);
We insert and secure with self-tapping screws the fillets of the gable overhang (board 25x150). The distance between them is approximately 1 meter (Fig. 14);
We sew two belts to the fillies from below (board 25x100). There are also enough of them to subsequently cover the gable overhangs with siding (Fig. 15);
From pieces of 50x150 boards of the required length we prepare triangular fillies for the gable ebb according to the figure (Fig. 16). Then, having secured them to the stems, we also nail two belts (25x100) to them.
This completes our roof. What happened in the end and what will happen after completion roofing works and covering the gable and eaves with siding is approximately shown in Figures 17 and 18.
Erection of the roof is one of the most critical stages of construction. The durability of the building itself and the level of comfort of living in it directly depend on the reliability of the “umbrella” on top, on its resistance to precipitation and any external influences.
Of all the variety of roof designs, the gable roof can be considered one of the most popular, simply due to the relative ease of its construction. However, even behind this “simplicity” lies a lot of different nuances, the need to carry out certain calculations and follow technological rules. However, this publication has the main task: to show that installing gable roof rafters with your own hands is a completely doable task, even for a novice builder.
Let's go through all the stages of the process of installing rafters for such a roof, from the basics of preliminary design to an example of practical implementation.
General structure of a gable roof
Basic Concepts
Structural elements of a gable roof truss system
Let's say right away that this scheme, of course, cannot reflect the entire possible variety of designs, but the main parts and assemblies are shown quite clearly.
1 - Mauerlat. This is a board or beam that is rigidly attached to the upper end of the external load-bearing walls of the building. Its purpose is to uniformly distribute the load from the entire roof system onto the walls of the house, creating conditions for reliable fastening of the rafter legs at their lower support point.
2 – rafter legs installed in pairs. They become the main load-bearing parts of the entire roof system - it is the rafters that determine the steepness of the slopes, will be the basis for attaching the sheathing, roofing, and if the roof is planned to be insulated, then also the entire thermal insulation “pie”.
To make rafter legs, high-quality boards or timber are used; round timber can also be used. The cross-section of lumber, which will be sufficient to guarantee withstand all possible loads, will be discussed below.
The rafters can end at the mauerlat, but more often they extend beyond the perimeter of the walls of the house, forming a cornice overhang. However, lighter parts can also be used for this - the so-called “fillies”, which are used to extend the rafter legs to the required overhang width.
To form the eaves overhang, the rafters are extended with “fillies” 3 - ridge run. It could be a beam, a board, or even a composite structure. The purlin runs along the entire line of the ridge and serves to reliably connect the upper points of paired rafter legs, connecting all rafter pairs in order to impart overall rigidity to the entire roof structure. In various roof options, this purlin can be rigidly supported by racks, or linked only to the connection node of the rafter legs.
4 – tightening (contracts, crossbars). Horizontal reinforcement parts of the system, additionally connecting paired rafter legs to each other. Several puffs located at different heights can be used.
5 – floor beams, which will serve as the basis for installing the floor in the attic and the ceiling on the side of the room.
6 - and this beam simultaneously serves as a bench. This is a beam that runs along the entire length of the roof, which serves as a support for installing additional reinforcement parts for the rafter system. The beam can be installed as shown in the figure (like a floor beam), or it can be rigidly laid on a permanent partition inside the building.
7 – racks (headstocks) – additional vertical supports of the rafter legs, preventing them from bending under the influence of external loads. The racks at the top can rest against the rafters themselves, or into an additional purlin that longitudinally connects the rafter legs at a certain height.
8 – struts. Often, when the rafter legs are long, their load-bearing capacity is not enough, and reinforcement with racks alone does not provide the necessary strength. In these cases, diagonal reinforcing elements are used, resting on the bottom of the beam, creating an additional support point for the rafters. The number of struts and their installation location may vary in roofs of varying degrees of complexity.
Some differences between the hanging and layered gable roof systems
Gable roofs can be divided into two types of structures - with layered and hanging rafters. In addition, combined systems are widely used, in which both construction principles are combined. What is the fundamental difference?
Layered rafter system
This rafter system design is characterized by the presence of support on the internal main partition in the building. At the upper end of this partition, a bench is mounted on which the drains supporting the ridge girder rest. Thus, the rafter legs are “leaned” onto a vertical support, which makes the entire system as strong as possible.
This type of scheme is the most popular because of its reliability and relative ease of implementation. If it is possible to create an additional point of support in the center, then why not take advantage of it? True, if you plan to place living space in the attic, then vertical racks can sometimes become a hindrance. However, their presence is also sometimes “played up”, using, for example, to install an internal light partition.
Depending on the number and placement of internal partitions, the design of the layered rafter system may vary. Some examples are shown in the illustration below:
Fragment “a” shows the simplest option, which, by the way, on short rafter lengths (up to 5 meters) may not even have the shown struts - a row of central posts under the ridge girder is enough
As the width of the building increases, the system naturally becomes more complex, and additional reinforcing elements appear - tie rods and struts (fragment “b”).
Fragment “c” clearly demonstrates that the internal main wall does not have to be located exactly in the center, under the ridge. An option as shown in the illustration is also quite possible, but with the condition that the displacement of the bed relative to the ridge does not exceed one meter.
Finally, fragment “d” shows how a rafter system can be supported in a large building, but with two main partitions inside. The distance between such parallel beams can reach up to a third of the width of the building.
Hanging rafter system
Graphically, this roof diagram can be depicted something like this:
It is immediately noticeable that the rafters rest only on the lower part, and then are connected to each other at the ridge. There is no additional support in the center, that is, the rafter legs seem to “hang”, which determines the name of such a system. This feature imposes certain restrictions on the use of hanging rafters - usually this scheme is practiced when the distance between the load-bearing walls to which the Mauerlat is attached is no more than 7 meters. The installed puffs only partially relieve the load from the external walls.
The illustration below shows several options for a hanging system. However, some of them can rather be classified as combined.
Fragment “d” - hanging rafters are connected to each other by a tie at the level of the mauerlat or fixed to a powerful floor beam, forming a triangle with it. There are no other reinforcing parts. A similar scheme is acceptable with a distance between walls of up to 6 meters.
Option “w” is for a house of the same size (up to 6 meters). The tie (bolt) in this case is shifted upward, and is often used for lining the attic ceiling.
Options “e” and “z” are designed for a span between walls of up to 9 meters. Multiple tie-downs may be used (or a top tie-down in combination with a bottom joist). Another approach is to install racks under the ridge girder, similar to the layered system. Only, as the lower point of support, it is not the support on the main partition that is used, but the racks are supported by a tie or a floor beam. It is already difficult to call this option purely “hanging”, since here it is clearly a combination of parts from both designs.
To an even greater extent, this combination of two schemes is expressed in the “and” option, which is designed for large spans, from 9 to 14 meters. Here, in addition to the headstock, diagonal struts are also used. Often such trusses are assembled on the ground, and only then they are lifted and installed in place, connected to each other, thereby forming the entire roof frame.
So, when preparing for the construction of a gable roof, it is necessary to study the principles of the design of a particular system, evaluate their advantages and disadvantages, choose the optimal one for your conditions and draw up a graphical working diagram. It will be needed both when purchasing the necessary material and for carrying out the installation work itself. However, drawing up a drawing must still be preceded by some calculations.
Calculation of the basic parameters of a gable roof rafter system
Let's take another look at schematic diagram gable roof installations in order to highlight those parameters that will need to be calculated.
So, in the calculation process we will need to decide on the following values.
The initial data is the length of the side of the house along the gable part (highlighted in blue - F), and the length of the house along the ridge (purple - D). It is assumed that the owners have already decided in advance on the type of roofing - since there will be certain restrictions on the steepness of the roof slopes. (angle a).
- The height of the ridge above the plane of the Mauerlat (H – green color), or, conversely, decide on the angle of the slope, starting from the planned height of the ridge.
- The length of the rafter leg (blue color - L), and, if necessary, lengthening the rafters to form a cornice overhang of the required width (l).
- Calculate the total loads falling on the rafter system in order to determine the optimal cross-section of lumber for the manufacture of rafters, the pitch of their installation (red color - S) and the permissible length of spans between support points. All these parameters are closely interconnected.
- Once you have these calculated values in hand, it is no longer difficult to draw up a graphical diagram, determine the need and optimal location of reinforcement elements, and calculate the amount of material for their manufacture.
Chainsaw prices
chainsaw
We calculate the steepness of the slope and the height of the ridge
The steepness of the slopes can be determined by the owners according to various evaluation criteria:
- For purely aesthetic reasons - when “at the forefront” becomes appearance buildings. Many people like roofs with a high ridge, but we must not forget that the wind load on such a roof increases sharply. And there will be immeasurably more materials needed to make a high roof. At the same time, on steep slopes the snow load is reduced to almost zero - it is possible that for “snowy” regions this assessment parameter may become decisive.
- For reasons of beneficial use of the attic space. With a gable roof scheme, in order to achieve the maximum area of the attic, it is necessary to build slopes with a very large steepness, that is, with the same consequences as mentioned above.
- Finally, there may be a completely opposite approach - for reasons of economy, make a roof structure with a minimum height at the ridge. But in this case, you will have to focus on the minimum permissible slope angles for a specific type of roofing. Reducing the slope below the values recommended by the manufacturer means “planting a bomb” in your roof, both for reasons of its strength and durability, and from the standpoint of the waterproofing qualities of the coating.
Calculating the height of the ridge above the plane of the ceiling (mauerlat) is not difficult. The vast majority of components of any roofing system are based on a triangle, which, in turn, obeys strict geometric (more precisely, trigonometric) laws.
So, in our case, the width of the roof along the gable line is known. If the roof is symmetrical, then the ridge will be placed exactly in the middle, and for calculations you can simply divide the width F by two (the base of the triangle f =F/2). For asymmetrical slopes, you will have to project the top of the ridge onto line F, and measure the distances f1 and f2 from it to the edge of the triangle (to the Mauerlat) on each side. Naturally, in this case the slope of the slopes will be different.
N =f×tga
In order not to force the reader to look for tangent values and carry out calculations manually, below is a calculator in which the necessary tabular values have already been entered.
The roof becomes an important structure of the house. She completes the construction of the building frame, after which only finishing remains. The most common implementation scheme is with two slopes. You can make a gable roof with your own hands without much difficulty, you just need to understand the technology.
Roof structure
Before you begin installing a gable roof, you need to understand what it is. The design differs from all others in its pediments. The following varieties can be given depending on the method of assembling the rafter system:
- single-pitched - the pediments have the shape of a trapezoid or a right triangle;
- gable is characterized by triangular gables;
- hipped (hip) has no vertical edges.
The main elements of the gable roof system are:
- rafters;
- Mauerlat;
- crossbar;
- struts;
- racks;
- contractions (ties);
- sheathing;
- thrust bars and pads.
Rafters are the main load-bearing structures. When constructing with your own hands, it is important to choose the correct cross-section, otherwise an emergency situation may arise.
Preparing to start work
Before making a gable roof, you will need to select materials. Installation begins with the selection of wood. To build a reliable structure with your own hands that is resistant to external factors, you will need to follow the following recommendations:
For construction, it is better to choose first or second grade coniferous species - It would be right to choose softwood materials (spruce, pine, larch are more resistant to rotting);
- the structure is assembled from wood of the first or second grade, the use of the third for critical elements is unacceptable;
- it is better to choose those lumber that are produced in the northern regions; the more complex the growing conditions of the tree, the denser its structure;
- they try to choose the material that was cut down at the end of the cold period of the year (February-March).
- load from snow cover (snow region);
- weight of the roof covering;
- rafter pitch;
- span (distance between reference points);
- insulation thickness.
A thermal insulation layer is required when designing a residential space – an attic – in the under-roof space of a house. Most often, do-it-yourself installation of mineral wool material is done to improve the thermal insulation characteristics. In this case, it is important to provide a ventilation gap between the heat insulator and the roofing. The height of the rafter leg should not be less than the thickness of the insulation. To increase the clearance, a system element such as a counter-lattice is introduced - a block that is nailed parallel to the rafter and increases its height.
The most convenient pitch of rafters for a private house is one that provides a clear distance between them of 0.58 m.
This allows you to correctly install mineral wool slabs without trimming or additional elements. For such a step, the following recommendations for the cross-section depending on the span can be given:
- span 3 m – rafter size 40x150 mm;
- 4 m – 50x150 mm;
- 5 m – 50x175 mm;
- 6 m – 50x200 mm.
It is important to know the following: load-bearing capacity and bending resistance are more affected by height than width. If necessary, increase the load-bearing capacity more effectively by increasing the height.
Another element whose cross-section will need to be selected is the sheathing. The most optimal value would be a thickness of 32 mm. With increased load, the value is increased to 40 mm.
The remaining components of the house's rafter system are assigned structurally, based on what lumber is available. But it is still worth taking into account the strength requirements.
Immediately after purchasing the material, before assembling the system begins, you will need to treat all the elements with special compounds yourself.
A gable roof, like any other roof of a house, needs the following types of protection:
- antiseptic, carried out without fail, helps prevent the processes of decay and the occurrence of mold and mildew (even if installation is not planned some time after purchasing the wood, the treatment is carried out immediately);
- fire retardant, optional, but very important, it increases the wood’s ability to resist fire, thereby increasing the safety of the structure.
Installation of a house rafter system
To build the roof of a house with your own hands, you need to complete all the work in a certain order. Installing the elements is not difficult, but you need to control the quality of the components and connections. The most important areas are:
- fastening the Mauerlat to the wall;
- fastening the rafters to the mauerlat;
- fastening the rafters together.
To properly build a roof with your own hands, work should be done in the following order:
- Mauerlat installation;
- installation of rafters at the designed angle;
- fastening the legs at the top;
- fastening of load-bearing structures using racks, struts and contractions;
- installation of counter-lattice, sheathing, waterproofing;
- do-it-yourself insulation of the roofing system;
- installation of the bottom sheathing, installation of the roofing.
Attaching the Mauerlat to the wall
When installing it yourself, it is important to understand where to lay the Mauerlat. A beam with a section of 150x150 mm or 200x200 mm is installed on the inner edge of the external walls. It is important to ensure sufficient thermal insulation of such an area. The outer part of the fence in this area can be made of the same material as the walls.
In this case, the laying is performed at an angle equal to the slope of the slopes. The second option is to fill the space with expanded clay concrete. These methods are relevant for stone houses (brick, foam concrete, expanded clay concrete, etc.). If you plan to build a frame or wooden house the top frame or crown of the wall will act as a mauerlat.
You can do the job in several ways:
- Fastening with staples. To do this, wooden blocks are installed in the penultimate row of masonry, to which the lower part of the brackets will be attached, and the upper part is inserted into the mauerlat. Wooden plugs must be impregnated with an antiseptic.
- Fastening to wire. To carry out this option, you will need to lay a wire 3-4 mm thick in the masonry of the walls or a monolithic belt; its length should be such as to wrap the beam and twist the wire rod.
- Fastening with bolts or studs. The options are similar, but the first provides greater reliability. Fasteners are placed in a monolithic belt. After this, the timber is laid on studs or bolts. To make holes for them in the right places, lightly tap the Mauerlat. The resulting recesses will be places for drilling holes. After their preparation, the beam is finally installed in the design position and tightened with nuts.
When building a house, it is also important to know how to build up the Mauerlat. The standard dimensions of lumber are 6 m, and the walls can be longer. To connect two elements along the length, you will need to perform a direct lock. To do this, the lower part of one element is cut out, and the upper part of the other. Fastening is done with bolts. It is not recommended to cut at an angle in this case. Corner joints are also made using a straight cut.
The choice of method for attaching the Mauerlat largely depends on the material of the walls, or more precisely on its strength. For lightweight concrete, pouring a monolithic belt around the perimeter will be a mandatory step.
It is important to provide waterproofing between the wood and the stone material. For this purpose, roofing material, linochrome or waterproofing material are most often used.
There are two most common options for doing the work yourself when building a house:
- with a gash;
- without drinking.
In both cases, the rafters are additionally secured with metal corners on both sides. When using a system with a saw, you will need to process the timber at an angle corresponding to the slope of the roof of the house. When installing without cutting, you need to prepare a support beam with your own hands, which will not allow the system element to move across the Mauerlat. As an additional fixation, nails are hammered in and a twist of wire is inserted from the leg to the wall (this fastening can be done through one leg).
2 types of fastening rafters to the Mauerlat In order to obtain detailed and visual information on how to install a gable rafter at home with your own hands, it is recommended that you familiarize yourself with the series “Knots of wooden roofs of residential rural buildings.” This album contains a large number of options for securing all elements, which will help you complete the installation without errors.
