One of the most important stages of building a house is the construction of the roof. The most common designs include gable roofs. If you decide to start arranging such a roof, you should study the instructions. But the functional parameters will depend not only on compliance with the technology, but also on what materials were used for insulation, as well as at the stage of finishing.
It is important to decide at the construction stage not only with the project, but also with the type of truss system. It can be hanging or layered. In this case, you must resolve the issue, which is to level the expansion force.
Calculating the angle of inclination
Calculation of a gable roof must be accompanied by the determination of the angle of inclination. Making calculations is a fairly simple step. It may also include the determination of the amount of material. This stage must be overcome even in the process of designing a house. The slope will depend on the roofing, the type of attic space and climatic conditions. If the house will standin a place of strong wind load, then the angle should be made small in order to reduce the load on the roof. When a building is built in a region with heavy rainfall, the slope becomes significant and can reach 60˚. This reduces the load from rainwater as well as snow.
Features of calculations
But it also happens that the value of the slope angle is determined on an already erected roof. In this case, trigonometric formulas and an inclinometer should be used. If the width of a house with a gable roof is 8 m, and the length of the rafter leg is 10 m, then the slope can be found using the following formula: cos A \u003d c ÷ b, in which the slope angle is denoted by the letter A, c is half the width of the building, and b is the length of the rafter.
The slope is calculated as follows: cos A=4 ÷ 10=0, 4. In this example, 1/2 of the width of the building is 4 m, this value can be obtained by dividing 8 by 2. Now you can calculate the slope. This value is the radian measure of the angle. To convert radians to degrees, you should use the Bradis table, which is available to builders. From it you can find out that the desired slope is 66˚.
Height detection
The height of the gable roof is determined in the next step. If you are familiar with the height of the ridge, then using trigonometric expressions you can determine the length of the slope, which is the length of the rafter. Height is calculated in one of two ways. The first involves the use of a rectangulartriangles, while the second one is angle-percentage ratio tables.
Before you build a gable roof with your own hands, you must calculate the height. Based on the first method, the calculation is carried out using the values of the angle and half the width of the building. For clarity, consider a specific example. If the width of the house is 12 m, and the slope is 40˚, then half the width of the house is 6 m. The height of the ridge is calculated using the formula for a right triangle:, 05 m. In order to find the tangent of 40˚, you should use the Bradis table.
Expert Tips
Before you build a gable roof of a house with a rectangle at the base, you will need to calculate the height of the roof. Some builders do not use the Bradis table for this at all, you can also use the engineering calculator installed in the operating system. Another option with which you can determine the height of the skate is to use a ratio table.
Each angle of inclination in it corresponds to a relative value. It is expressed as a percentage. The height can be found by multiplying half the span width by the relative value. If you have a house with a span of 7 m and a slope of 27˚, then the height of the ridge will be 1.78 m, which can be determined using the following calculations: (7 ÷ 2) × 0.509=3.5 × 0, 509.
Used rafter systems
The gable roof truss system may consist of layeredelements. This design provides for the installation of an additional support beam, located in the center between two load-bearing walls. Rafters in this case are leaning on a beam or internal partitions, transferring the load from the roof. This method is relevant for heavy floors or for the case when the house has an impressive area, and the step from wall to wall is more than 10 m.
Gable mansard roof may consist of hanging rafters. They have differences from the layered ones, because they rely on the side ceilings. This method of organizing rafters creates a bursting effect, but it can be eliminated by puffs. Floor beams often act as them. Puffs are lower or upper. When setting the top draw, you will need to back off the ridge by 500mm or more.
Quite often, developers today choose a gable roof. The rafter system for it can be made from hanging or layered elements. They are equally reliable, and the attic roof provides for their joint use. Before work, professionals create a drawing, which is a plan that reflects the location of all elements.
Create design and project
By looking at gable roof designs, you will be able to figure out which design is right for you. For example, this part of the building may provide for the presence of lucarnes. If you also want to save money, then it is better to use metal tiles for covering, as it fits with a minimum amount of waste. Such a design canuse for buildings with a rectangle base.
Gable roofing is better suited for houses with an attic. Windows can be placed in gables, which will provide not only ventilation, but also illumination. When drafting a house with a gable roof, you can pay attention to buildings that provide for a broken structure with an increased angle of inclination of the lower canvas. This value can vary from 65 to 80˚. The upper part has an angle of inclination ranging from 25 to 30˚. This technique is a great way to increase the attic space.
These structures include a vaulted roof, the shape of which has a circle at the base. Such a roof will decorate the protruding parts of the building. If you want to get an inexpensive house, then you should choose ready-made projects without lucarnes (facade windows in the attic). Sometimes the former are replaced by the latter. These windows look attractive, but make the installation of the roof more expensive.
Preparation
Gable roof should be built taking into account snow and wind loads in certain climatic conditions. With a decrease in the angle of inclination, the design resists loads better. However, a small angle, which does not exceed 40 ˚, does not allow the use of the attic space to the fullest. The design and shape of the roof are developed taking into account the design of the house. For example, the main support points of the truss system must coincide with the points and lines of the location of the load-bearing structures of the floor that is under the roof.
It is important to take into account the width of the building, as well as the presence of a load-bearing wall,which is located along the center. If you do not plan to use the attic as an additional area for seasonal or permanent residence, you can make a roof using layered rafters. They will be fixed to the ridge run supported by the uprights. They rest on an internal load-bearing wall.
Gable roof can have hanging rafters, which are the most economical and practical for light buildings. The rafter legs in this case are connected in pairs with crossbars, they are horizontal jumpers and provide rigidity. A system with such rafters rests on the side walls of the house.
If the width of the building is more than 6 m, then racks and girders are installed. The latter are horizontal bars that act as an additional support for the rafters. The installation of the run involves the use of racks. They rely on beds - bars, located along the slope. They, together with the racks, serve as the frame of the attic walls. Such an inclined design allows you to make a spacious attic or attic used for household needs.
If the roof must be reliable and simple, then it is better to use a gable structure with a slope of 50˚. Such a truss system can be used for installation on residential buildings and buildings for various purposes. When calculating materials, it should be borne in mind that the truss system should be light, because only in this case it will not exert excessive load on the foundation, but it will remain quite strong. The cross section of materials is selectedtaking into account the dimensions of the truss system.
Installing Mauerlat
Gable roof suggests the presence of Mauerlat. It is from him that you should start installing the upper trim, which is located on the longitudinal walls of the building. This part of the roof will perceive the pressure of the roofing system and transfer it to building structures - the foundation and walls. At the heart of the Mauerlat is a beam, its cross section can be 50 x 150 or 150 x 150 mm. The material is treated with protective agents to prevent fire and decay.
There are many ways to make a Mauerlat for a gable roof. The first involves the installation of rolled wire in brickwork. With it, the beam can be fixed on the wall. The wire is threaded through special holes and twisted. Another way to install a power plate is to use long steel studs that are embedded in the masonry. Their diameter is 12 mm or more.
In the upper part of the wall it is necessary to install a monolithic concrete beam with embedded metal studs. The distance between them is 120 mm. The protruding end must have a height that is 20 mm greater than the thickness of the timber and waterproofing. Holes are pre-made in the beam, the element itself is put on the studs and attracted by nuts with wide washers.
Work on the truss system
A mansard with a gable roof is a design that is based on a truss system. It consists of elements combined into a single whole. FarmIt has the shape of the letter A and is a rigid structure that works on thrust. If the house was built from timber, then the construction of the roof is carried out in such a way that the opposite walls are reinforced with screeds. They are located at the level of the ceiling beams. The walls will not move apart under load.
Working on the overlap
When making an attic with a gable roof, you must mount the beds on the ceiling. They are elements of a square bar with a side of 150 mm. This setting can be larger. The beds act as a support for the racks, they redistribute the load on the floor surface. The installation of the beds is carried out along the lines of the walls of the attic room. If you do not plan to use the attic space, then the bed is laid under the ridge to install support racks. It is possible to splice the beam, but this must be done only in those places where the joint will be located on the beam. With the help of a steel plate or bracket, it will be possible to make a tenon connection.
Work methodology
When building a gable roof with a rectangle base, you will need to use repeating parts of the truss system that are identical to each other. This will allow you to build an isosceles roof, and its weight will be distributed evenly and under atmospheric loads. To do this, templates of identical parts are made. Boards are laid out on the floor of the building, this will make it possible to make a triangle with a given height. ATit will be based on rafter legs and rack boards.
The connection is made with a nail. The structure should be lifted up with the help of one or two people. A rack is installed on the central axis of the ceiling. Rafters will be located on the Mauerlat.
A gable roof with a rectangle at the base can have different heights, which change when the template elements are lengthened. Once you have decided on the size, you should make curly cuts on the rafters. They are performed in those places where the structure will be in contact with the strapping. The rafter leg firmly rests on the Mauerlat. For fastening, you can use several methods, you choose the most reliable and convenient. Specialists use metal linings more often.
When installing the hanging rafters, at the final stage you will need to remove the temporary racks. Such rafters end at the level of the Mauerlat, so fillies must be fixed to it, they will form overhangs. After that, you can start sheathing the gables and fixing the wind and cornice strips. It is important not to forget about the insulation of the coating, which is carried out before laying the finishing material.
In conclusion
The roof described in the article consists of inclined planes called slopes. They are connected in the area of \u200b\u200bthe ridge and are located at an angle to each other. This angle is the angle of inclination. The mechanical characteristics of the roof, the functionality and the choice of roofing depend on it.
Sthe end sides of the slopes form triangles, called gables. Once all the calculations are done, you can move on to the practical part. At its first stage, you will need to install a Mauerlat, which is the foundation for the roof.
