For areas where windy weather is not uncommon, a half-hip roof is ideally suited, because a rafter system of this design is characterized by greater reliability and resistance to weathering. The semi-hip roof looks like a pitched roof, but has small overhangs from the ends. This design makes it more resistant to winds and precipitation. The roof usually has a very attractive appearance through the use of additional elements.
Advantages and disadvantages
The half-hip roof design, unlike the hip, has a much more intricate design. Trapeziums turned into polygons, and hips mutated.
This design is a symbiosis of gable and hip roofs. The slopes of the hip roof are quadrangles, trapezoids and two triangles, and the slopes of the half-hip roof form a broken line. A structure with such a roof is not only decorative, but also very justified. It has a number of undeniable advantages. Due to the height of this design, it is possible to equip an additional room in the attic. To increase the useful area of the room, the upper plane of the ramp is sloping and long, and the lower one is almost vertical.
Half-hip roof structural elements:
- rafter system;
- Mauerlat;
- heat, steam and waterproofing system;
- roofing.
In addition to the main elements, the roof structure includes a lot of additional ones: crossbars, racks, stops. All this requires a significant consumption of wood, it is difficult to install the frame of the rafter system. But precisely because of this peculiar structure, the roof has strength and durability..
The rafter system of a half-hip roof is quite complicated: a significant number of ribs, intermediate rafters, stops, rails, struts, spurs, sprengels. Such a device requires a significant waste of materials. Therefore, before installation, you should make a calculation, make drawings, pay attention to quality control of the purchased material. It is important that the wood does not have cracks or knots, and is also dry.
Design Varieties
There are two options for semi-hip roofs: double and four-pitched.
By type of hip, the roofs are divided into:
- Dutch.
- Danish.
The names appeared due to the popularity of the first variety of roofs in Holland, and the second - in Denmark.
Dutch half-hip roof
The gable semi-hip roof of the Dutch variety is arranged as follows: under the ceiling of the attic there is an attic space in which small windows located on the gables are made for lighting and ventilation. The scheme of this option is more convenient, since the attic ceiling has bevels only on two sides, and in the Danish version of the roof - on four.
Danish half-hip roof
The scheme of the four-sloped half-hip roof is a combination of elements of the gable and hip roofs. As with the gable roof, a large attic space can be used to equip the living room.
This type of roof is even more laborious and complex than the first option.. However, if everything is done strictly according to calculations and the right materials are selected, then such a roof will be much more beautiful than the Dutch one. The design will last a very long time, providing reliable protection for the building.
Calculation of the roof area
To determine the necessary amount of material for covering the roof, you should know the surface area.
The semi-hip roof has a difficult decorative shape, but, despite this, calculating its area will not be difficult.
This can be done by dividing the roof plan into separate geometric shapes. It is necessary to calculate the area of each figure separately, using the formulas known to everyone from the school geometry course, and then add the results.
Mounting
The construction of the roof is carried out in several stages:
- Wood processing.
- Install Mauerlat.
- Installation of rafters.
- The final stage.
Wood sheeting
In the production process, wood is treated with antiseptics and flame retardants according to the original method with its preliminary heating. Similar manipulations on the processing of wood can be made in domestic conditions.
Refractory and antifungal coating of the rafter system is an invariable rule of roofing.
With a brush or sponge, the surface of the beams is carefully treated with an antiseptic. The tool is able to form a protective layer, the effect of which lasts up to 2-8 years.
Mauerlat
The assembly of the roofing system begins with the installation of the Mauerlat. In some cases, a concrete screed is made around the perimeter of the load-bearing walls, into which the reinforcing studs are immersed, subsequently a Mauerlat beam will be attached to them with further fixing of their ends with nuts and washers.
In order not to complicate the subsequent joining of the rafters with the Mauerlat, the studs should be placed in the correct order. Before laying the bars, the concrete screed should be covered with two layers of roofing material.
Installation of rafters
After the Mauerlat is installed, the ridge and the racks under it are strengthened. Racks must be strictly vertical, so a plumb line should be used.
The ends of the ridge through the diagonal rafters are connected to the corners of the house. Diagonal rafters are longer than ordinary rafters and should have a large cross-sectional area.
Then, in increments of 60-120 cm, ordinary rafters are installed. The installation of outdoor rafters is done with an emphasis on mowing. It is necessary that the load be evenly distributed along the diagonal rafters. Therefore, when calculating the load on the structure, it should be noted that the support points on the surface of the rafters must be different.
Then make reinforcement with additional struts with support on floors, beams or support stands. Rafter rafters should be strengthened with a truss truss.
To increase the reliability of the roof of the rafters, it is necessary to additionally fasten it to crutches hammered into the wall.
In the space under the ridge, do not use mounting foam to ensure free air circulation. This is important for the preservation of wooden structures.
Final installation phase
In conclusion, installation work is done:
- crate;
- vapor barrier using a film coated with foil;
- waterproofing with roofing material;
- mineral wool insulation;
- laying of roofing material.
Coating Materials
Often, corrugated roofing or metal tiles are used to cover a half-hip roof. These materials facilitate installation and repair of the coating, have a low weight and an affordable price. Meanwhile, they are quite strong and durable, and also have a completely decorative look. For a Dutch roof, a metal profile will cost less than for a Danish one. Material has fewer sections and less waste. And the use of tiles in both cases will entail the same costs.
Any kind of half-hip roof has both its pros and cons. You can only decide on the basis of personal preferences. In order to make installation of the structure without problems, it is necessary to make accurate calculations, to know the installation rules, especially the materials used. The combination of all these factors determines how long and efficiently the roof will serve.