The erection of the roof is the final stage in the construction of any building. It plays not only a technical role, but also is a decoration of the house. If you decide that your home will have a pitched roof, you should know that such structures are complex. Depending on the shape of the slope, the sloping roof can be gable, shed or hipped. Such structures can have a variety of shapes: steeple, pyramidal, conical, etc. Climatic conditions have made pitched roofs the most common in suburban construction.
General Description
The pitched roof promotes the natural runoff of melt and rainwater. The angle is determined by the angle at which the slope is inclined to the horizon. These structures have an angle of at least 5 °, however, they are also equipped in which individual sections have a right angle of inclination. Depending on what the general architecture of the house is, the climate, the finish, as well as the chosen material, a pitched roof may have a certain device. For example, if your area has a fairly large amount of rainfall, and the roofing is not verydense, then the slopes should be steep. In strong winds, the surface should be flatter to reduce pressure. If you choose the right slope, then you will be able to reduce the cost of construction and labor costs. Cool designs cost more because they use more materials.
Main types of pitched roofs
4-pitched roof refers to one of the varieties of the structures of the same name. Among them, single-pitched, double-pitched, half-hip, attic, domed, conical, pyramidal, and also four-gable ones should be distinguished. Sheds are the simplest in form, they will drain water in only one direction. They are used to cover small houses, porches, outbuildings, temporary structures and outbuildings. Structures in this case will not have an attic or space under the roof.
2-pitched roof is used in low-rise construction. It has a rectangular shape, and the side parts are called gables. The half-hipped roof differs from the hipped one in that in it the inclined planes cut off part of the pediment. Pyramidal roofs are used when the plan of the house is square or rectangular in shape.
Design and main units
Roofs of pitched roofs have two main elements, namely, enclosing and bearing. The latter are necessary to take loads from snow, wind and the roof itself. With their help, the weight is distributed on the load-bearing walls andseparately located supports. At the same time, quite stringent requirements are imposed on the strength of the bearing elements. The main components are the Mauerlat and the truss system. It should be noted that the device of a pitched roof implies fasteners in the form of racks, struts and crossbars. The required rigidity can be achieved using a truss truss.
Mauerlat is a beam that acts as a support for inclined wooden rafters. With the help of this element, the load from the roof is distributed. Mauerlat is a kind of foundation for the design. If you want to make a roof in its classical sense, then you should use a beam with a side of 15 cm for the Mauerlat device. The minimum value for a beam is 10 cm. A pitched roof can be made by a home craftsman. If it has a Mauerlat, then it should be placed along the entire length of the building or installed only under the rafters.
When using rafter legs of a small section, the system may sag during operation. In order to eliminate this problem, a grid should be installed, which will include crossbars, racks and struts. To make racks and struts, you should prepare a 15-centimeter board, the thickness of which should be 2.5 cm. You can use wooden plates made from wooden logs with a diameter of 13 cm or more. Mauerlat should be located along the upper edge of the wall, and also go towards the inner or outer edge.
One of the main nodes is Mauerlat
4-pitched roof has a mauerlat, which should be located 5 cm or closer to the edge of the outer planes of the walls. Fixing to the wall should be carried out in such a way as not to create windage, which will contribute to large loads in strong winds. Most often, wood is used as the material for the Mauerlat, but if the roof frame is made of metal, then you can use an I-beam or a channel.
Roof device in the Mauerlat area
If you are thinking about how to make a pitched roof with a Mauerlat, then the latter is laid on a waterproofing layer, which can be roofing material. 40 cm can be retreated from the upper part of the attic floor. Every 5 m, the runs are supported by racks, which are cut into the beds with their lower ends. The angle between the strut and the rafter should be approximately 90°. If, when constructing a pitched roof, the rafter leg will have a greater length, then the installation of additional supports should be carried out taking into account the support on the beds. Each link of the Mauerlat must be fastened with two links located next to each other and simultaneously fixed to the rafters. A reliable structure must be formed around the perimeter of the roofing system. But individual Mauerlat segments can be located under the rafter legs.
Rafter system device
4-pitched roof has a supporting structure in the form of a truss system, it consists of rafter legs, inclined struts,as well as vertical racks. Rafters are made of wood, mixed materials, metal or reinforced concrete. Fasteners are crossbars, struts, struts, as well as racks. The rafters are connected into trusses.
For reference
The rafter system must be connected into a triangle, due to its rigidity and stability. For rafters, you can use a beam of different sections, which is determined by the length of the rafter legs, the calculated value of the loads, as well as the distance between the rafters. If we are talking about simple structures, then the size of the section can vary from 40x150 to 100x250 millimeters.
Do-it-yourself semi-hinged roof
If you decide to build a house, a pitched roof can be the best solution, one of the varieties of this design is a half-hip roof. Such roofs are suitable for regions with strong wind loads, as they protect the building from air currents, eliminating the erosion of the gable and blowing. The attic will be original, it can be used as a living space. Experts recommend adhering to a certain technology during construction. At the first stage, a screed is poured along the perimeter of the roof, studs with a diameter of 10 mm are installed into it every 120 centimeters or less. These fasteners are fitted with locking bars, tightened with nuts. This will allow you to form a Mauerlat, on which you will then install the truss system.
The next step is to install slanted rafters that will supporton the outer walls. In order to reduce the load on the last of them, a tightening should be performed connecting the rafter legs to each other. The edge will rest against the outer walls, while the inside will rest against the supports and inner walls.
The rafters are fixed on the ridge beam, which is laid on top. It will connect the supports together. At the hips, the beams are strengthened to the extreme supports. All the rest should be fixed to the ridge. Installation of intermediate rafters is carried out in the next step. The step between them should be equal to the width of the thermal insulation, this parameter varies from 60 to 120 cm. Next, you have to install the transverse beams.
Shed roofing
The first step is to determine what the angle of the roof will be. Intermediate values lie between 11 and 60°. Everything will depend on atmospheric phenomena, the materials at the base of the roof, as well as the architectural features of the house. For the northern regions, the slope should be equal to 40 °, while the snow will not linger on the roof. In strong winds, the angle of inclination should be small. In the steppe and coastal regions, this parameter ranges from 11 to 45°.
Method of work on the arrangement of a shed roof
For regions with strong winds, a flat roof may be suitable, a pitched roof must be given a certain slope. After that, you can proceed to the construction of the truss system. This roof unit can be sliding, hanging or layered. The latter is the simplest, with the rafters resting on the outer walls and the central beam. The length of the rafter leg can be equal to 4.5 m, but only if it is solid, it is unacceptable to connect elements to increase the length.
Hanging rafters are the most difficult in the device and in design, they are applicable if there is a need to get large spans. They are collected on the ground with their own crate, and then lifted up, leaning on the extreme supports. After that, attic ceilings are nailed to the crate, which gives the structure higher strength. For a shed roof truss system, it is best to use bars with a section of 30x150 mm. In this case, the distance between the beams should be 80 cm.
Slope should turn the bottom to the leeward side. The number of support beams should match, and the beams and rafter leg should form a triangle. The rafters are placed at one end in the Mauerlat nest, while the other end should be hammered into the timber with slate nails. To increase reliability, they are twisted with wire. Mauerlat for safety is tied to the wall or fixed with long anchor bolts.
Recommendations from a flat roof specialist
The next step will be the manufacture of lathing from planed boards, which are processed with fire-resistant and moisture-proof substances. The boards are located perpendicular to the rafters, the distance between them should not be more than 15 cm. For the crate, square bars should be used, with a side of 50 mm. Next, a vapor barrier is laid and fixed to the crate with small nails with a wide hat. Last sometimesare replaced by staples of a construction stapler. This will not only speed up the work, but also extend the life of the rafters.
At the next stage, thermal insulation and a waterproofing layer are installed, the roll of the latter of which is unwound perpendicular to the rafters. At the same time, it is important to ensure that the next strip overlaps the previous one, and the joints must be sealed.
Conclusion
Rafter systems, which are an integral part of pitched roofs, can include mansard trusses, trusses with complex upper chords, scissor trusses or gable trusses. The main element of the truss system are the legs, which act as support for the crate. They are laid along the roof slope.
The most suitable slope for a shed roof of a bathhouse that you want to cover with roofing material is considered to be from 10 to 15 °. In this case, a two-layer coating of the underlying and outer layer of roofing material will be sufficient. But when forming the truss system, you need to take into account the size of the building. If it is large, then the design must be supplemented with racks and fights.
