The construction of the roof is the final stage of 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, single-pitch or tent. Such structures can have a variety of shapes: spire, pyramidal, conical, etc. Climatic conditions have made pitched roofs the most common in suburban construction.
general description
The pitched roof contributes to the natural runoff of melt and rainwater. The angle is determined by the angle at which the ramp is inclined to the horizon. These structures have an angle of at least 5 °, however, those in which individual sections have a right angle of inclination are also equipped. Depending on what is the general architecture of the house, climate, topcoat, as well as the selected material, the pitched roof may have a certain device. For example, if in your region there is a sufficiently large amount of rainfall, and the roofing is not very dense, then the slopes should be steep. With strong winds, the surface should be more gentle to reduce pressure. If you choose the right slope, then you will be able to reduce the cost of construction and labor. Steep designs are more expensive, since they involve the use of materials in a larger volume.
The main types of pitched roofs
4-pitched roof refers to one of the varieties of the same structure. Among them, it is worth highlighting a single-slope, double-slope, semi-hip, mansard, domed, conical, pyramidal, and also four-edged. Single slopes are the simplest in shape; they will only divert water in one direction. They are used to cover small houses, porches, outbuildings, temporary structures and utility buildings. The structure in this case will not have an attic or space under the roof.
A 2-pitched roof is used in low-rise construction. It has a rectangular shape, and the side parts are called gables. A semi-hip roof differs from a four- pitched roof in that inclined planes cut off part of the pediment in it. Pyramidal roofs are used when in plan the house has a square shape or the shape of a regular rectangle.
Design and main components
Roofs of pitched roofs have two main elements, namely, enclosing and supporting. The latter are necessary to take loads from snow, wind and the roof itself. With their help, the weight is distributed on the bearing walls and separately located supports. At the same time, rather stringent requirements are imposed on the strength of the bearing elements. The main components are the Mauerlat and the rafter system. It should be noted that the device of a pitched roof implies fasteners in the form of racks, struts and crossbars. The necessary rigidity can be achieved using a truss.
Mauerlat is a beam that acts as a support for inclined rafters made of wood. With this element, the load from the roof is distributed. Mauerlat is a kind of foundation for the design. If you want to make the roof in its classical sense, then for the Mauerlat device you should use a beam with a side of 15 cm. The minimum value for the beam is 10 cm. The pitched roof can be made by the hands of a home master. If it has a Mauerlat, then it should be located along the entire length of the building or set only under the rafters.
When using rafters of a small section, the system may sag during operation. In order to eliminate this problem, it is necessary to install a lattice, which will include crossbars, posts and struts. To make struts and struts, a 15-cm board should be prepared, the thickness of which should be equal to 2.5 cm. You can use wooden plates made of wooden logs with a diameter of 13 cm or more. Mauerlat should be located on the upper edge of the wall, and also go towards the inner or outer edge.
One of the main nodes - Mauerlat
The 4-pitched roof has a Mauerlat, which should be 5 cm or closer to the edge of the outer planes of the walls. Fixation to the wall should be carried out in such a way as not to create a sail, which will contribute to large loads in strong winds. Most often, wood is used as the material for the Mauerlat, but if the roofing frame is made of metal, then you can use the I-beam or channel.
Mauerlat roof installation
If you are thinking about how to make a pitched roof with a Mauerlat, then the installation of the latter is carried out on a waterproofing layer, which can be a roofing material. 40 cm can be retreated from the upper part of the attic flooring . Every 5 m runs are supported by uprights, which are cut into the beds with their lower ends. The angle between the strut and the rafter foot should be approximately 90 °. If when installing a pitched roof, the rafter leg will have a large 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 in the neighborhood and simultaneously fixed to the rafters. A reliable structure should be formed around the perimeter of the roofing system. But individual segments of the Mauerlat can be located under the rafters.
The device of the rafter system
The 4-pitched roof has a supporting structure in the form of a rafter system, it includes 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. Rafters are connected to the farm.
For reference
The rafter system should be connected into a triangle, due to its rigidity and stability. For rafters, you can use a bar of different sections, which is determined by the length of the rafter legs, the estimated value of the loads, as well as the distance between the rafters. If we are talking about simple designs, then the size of the cross section can vary from 40x150 to 100x250 millimeters.
Do-it-yourself semi-hip roof
If you decide to build a house, a pitched roof may 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 pediment and blowing. The attic will be original, it can be used as a living. Experts recommend adhering to a certain technology during construction. At the first stage, a screed is poured around the roof perimeter, studs with a diameter of 10 mm are installed in 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 after you will install the rafter system.
The next step will be the installation of inclined rafters, which will rest on the outer walls. In order to reduce the load on the last of them, you should perform a puff connecting the rafters with each other. The edge will abut against the outer walls, while the inner part - against the supports and inner walls.
The rafters are fixed on the ridge beam, which is laid on top. He will connect the supports. On the hips, the beams are strengthened to the extreme supports. All others 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, it is necessary to install the transverse beams.
Shed roof device
At the first stage, you should determine what the angle of the roof will be. Intermediate values are between 11 and 60 °. Everything will depend on atmospheric phenomena, 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. With strong winds, the angle of inclination should be small. In the steppe and coastal areas, this parameter is from 11 to 45 °.
Methodology for the construction 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 this, you can proceed with the construction of the rafter system. This node of the roof can be sliding, hanging or layered. The latter is the simplest, while the rafters must rest on the external walls and the central beam. The length of the rafter leg can be equal to 4.5 m, but only if it is solid, connecting elements to increase the length is unacceptable.
The most difficult in design and construction are hanging rafters, they are applicable if there is a need to get large spans. They are collected on the ground with their own crate, and then they are lifted up, relying on the extreme supports. After that, attic floors are nailed to the crate, which gives the structure higher strength. For a rafter system of a shed roof, it is best to use bars with a section of 30x150 mm. The distance between the beams should be 80 cm.
The slope should be turned with the bottom towards the leeward side. The number of beam supports should match, and a triangle should be formed with the beams and the rafter foot. The rafters are laid at one end in the Mauerlat's 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 net is tied to the wall or fixed with long anchor bolts.
Recommendations of a flat roof specialist
The next step will be the manufacture of crates from planed boards that are treated with fire-resistant and moisture-proof substances. The boards are perpendicular to the rafters, the distance between them should not be more than 15 cm. For the battens, square-section bars with a side of 50 mm should be used. Next, the vapor barrier is laid and fixed to the crate with small nails with a wide hat. The latter are sometimes replaced by staples of a construction stapler. This will not only accelerate the time of work, but also extend the life of the rafters.
At the next stage, thermal insulation and a waterproofing layer are installed, the last of which is unwound perpendicular to the rafters. It is important to ensure the overlap of the next strip to the previous one, and the joints should be sealed.
Conclusion
Rafter systems, which are an integral part of pitched roofs, can include mansard farms, farms with an upper belt of complex shape, truss-shears or gable farms. The legs, which play the role of supporting the crate, act as the main element of the rafter system. They are laid along the roof slope.
The most suitable slope for the pitched roof of the bathhouse that you want to cover with roofing material is considered an indicator 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 rafter system, you need to take into account the size of the building. If it will be large, then the design must be supplemented with uprights and contractions.