Half-hipped roof truss system: advantages and disadvantages
This option is known as the “Dutch roof”, due to its very widespread occurrence in the Netherlands. Its main distinguishing feature is the presence of a shortened hipped and trapezoid pediment. Because of this, this roof becomes a cross between the two-and four-slope option. Thanks to such a merger, it acquires the advantages of two types of roof at once, which makes it much more attractive than other varieties.
Design features of the half-hipped roof truss system: pros and cons
The rafter system of a half-hipped roof includes the two most frequently erected types of roof. This modification allowed to expand the list of advantages with such features:
- Attic room.
Due to its design, this variety allows you to use this room not only as a utility room. After carrying out hydro and thermal insulation works, it can be used as a full floor with living rooms.
- Opposition to hurricane gusts of wind.
An exception to the design of convergence of planes at an acute angle gives it a more streamlined shape. Therefore, it withstands much stronger gusts of wind much better, air flows smoothly “envelope” it passing along the platforms, and do not “crash” directly into them.
- Customization of the design to individual requirements.
In general, all types of roofing have this feature and this option is no exception. Depending on weather conditions at the location of the building, it will be erected either at a steeper angle with a shortened long overhang (for snowy winters), or at a flatter angle and with an extended long overhang (for mild winters).
- The complexity of installation work.
This design does not belong to the group of the most difficultly constructed options. Although it has its own design features, which complicate the installation task a little. And the consumption of materials in this case is average.
The half-hipped roof truss system under consideration does not have distinctive drawbacks in its design. Minor disadvantages available to her can be attributed to any kind of roof. Therefore, they are not able to influence the final choice of a particular option.
The process of assembling the frame of this type of roof
Despite the fact that the rafter system of a half-hipped roof consists of two parts that relate to different types of roofs, the installation of its frame is not so complicated. This process goes as follows:
- On the side walls of the building and on the upper horizontal line of the pediment, a seismic belt is laid. In it (before laying the Mauerlat) a two-layer waterproofing is laid. Most often in this case, an ordinary roofing material is taken.
- When filling the seismic belt, studs are installed in it, on which the main horizontal beams will be fixed. Please note that they should not be located in those places on which they will rely in the subsequent time of the rafters. Otherwise, the structural strength will be weakened.
- Further put on the protruding metal bars of the Mauerlat. The individual segments are connected to each other by a spike-groove method.
- In the middle along the building, either a load-bearing wall or another type of support should be placed. On them lies. On it are installed horizontal supports for the installation of a ridge beam. The distance between the gables and the sides of the ridge beam is chosen at its discretion, but most often it is equal to half the length of the upper horizontal line of the pediment.
- After fixing the ridge run, they proceed to the installation of the side inclined bars. Their upper edges rest against the run, and the lower edges – into the horizontal support beam. The joint is adjusted on the spot, or is performed using the template selection. The length of the elements is always taken with a margin so that there are no problems due to its shortage (it is easier to simply cut off the excess).
- The upper edges of the inclined bars are cut at an angle and lean against the run, fixed with nails. Grooves are cut out at the lower edges, after which they are finally fixed using metal corners.
- After installing the side elements, the corner elements are mounted. Their lower edge is flush with the edge of the Mauerlat. Then the diagonal beam is expanded additionally for the installation of the overhang.
- Inclined parts of a half-hipped begin to be installed from the center of the site. The central part abuts against the convergence point of the angled inclined elements. All other parts will rest against the plane of the corner rafters with their upper edges and be placed at an equal distance from each other.
- The almost final stage of the arrangement of the frame will be the installation of cornice filly on the inclined sides of the pediment. Then they are interconnected by wind boards.
The last finishing stage of the erection of the roof includes work related to the installation of the lathing, as well as sewing it with roofing materials. Remember that the choice of material depends on the angle of inclination of the ramps. Roll and soft materials are mounted on flatter planes, and hard and heavy (for example, metal tiles) are mounted on steeper slopes.
Design and Installation Features – Repair Tips
In modern construction, it is practiced the installation of several types of roofs, different in their appearance and design. One of the most popular and aesthetic is Dutch. The rafter system of a half-hipped roof can be made with either two or four slopes. We consider in detail all the features of such a design and methods for self-assembly of a half-hipped roof.
Semi-hipped roof for a residential building
All pitched roofs have one common feature – the presence of an attic, which, if properly finished, can be used as a living. This design allows you to significantly expand the living space without an extension. The semi-hipped roof also has excellent technical characteristics: it withstands powerful wind loads and provides reliable protection of the house fronts from precipitation.
Depending on the design features, half-hipped roofs are divided into two main types:
- semi-hipped gable roof;
- semi-hipped four-pitched roof.
Photos of houses with a half-hipped roof are presented in large numbers both on specialized sites and on construction forums.
Advantages and disadvantages of a half-hipped roof: photos of beautiful houses
What makes a semi-hipped roof different from a hipped roof? At the hipped roof, two large slopes have the shape of a trapezoid, and smaller slopes have the shape of triangles. In a half-hipped roof, everything is arranged a little differently, and the slope line takes on a broken shape.
The design of such a sloping roof largely depends on the shape of the house itself, the presence or absence of a dwelling in the attic, the type of roofing material that will cover the surface, and even the climatic features of the region.
Moreover, it is climate that plays a decisive role in creating the structure, because in regions with snowy winters, precipitation will especially accumulate on the surface of the ramp, forming a kind of “snow cap”. Therefore, for such an area, roofs with a steep slope and minimal overhangs are more relevant. If snow drifts are an irrelevant problem, then the minimum angle of inclination is quite acceptable.
Among the advantages of a half-hipped roof are:
- the presence of additional premises, which can be used as residential or attic;
- aesthetic appearance, with the possibility of an unusual design of the house due to the creation of an original form of construction;
- reliable protection of the house from the influence of weather conditions: snow, rain, strong wind.
In order to increase the usable area of the attic, you can use a design with different slope angles.
Among the shortcomings of a half-hipped crumb worth noting:
- the presence of certain difficulties in the construction process: a large number of ribs, struts and stops makes the erection of the rafter system a long and laborious process;
Residential building, the roof of which is covered with ceramic tiles
- during the construction process of such a rather complex structure, not only a greater amount of forces is consumed, but also materials;
- the process of laying the roofing also acquires some difficulties.
But, despite the shortcomings, houses with a half-hipped roof look unique. All the difficulties and expenses are worth it to give the roof an original and memorable appearance. If you are not afraid of the difficult installation of the rafter system, you can safely get to work. Among the photos of private houses, half-hipped roofs are quite common, so choosing the option you like will be easy.
Semi-hipped mansard roof
An attic roof means a structure that has two peaks, in the form of cut triangles. If the house has a square shape, then the roof will be pyramidal. This type of roof has increased strength. On rectangular houses, the attic roof has two triangular sides and two trapezoidal. The slopes are located at the same slope, which allows them to be mounted symmetrically to the axial beams.
For this type of roof, the following advantages and disadvantages are characteristic:
- increased strength allows you to use this design in regions with extreme climatic conditions, for example, on the seashore or places that are characterized by strong winds;
- aesthetic appearance allows such a roof to look appropriate on the background of absolutely any landscape;
- low profile provides increased resistance to vibration;
- due to the shape of the structure, certain difficulties may arise with the cleaning and repair of the surface;
- the attic floor of a half-hipped roof can be used to equip living rooms;
- additional forced ventilation must be considered, which entails costs.
How the rafter system of a half-hipped roof is arranged: diagram and photo examples
Like any other roofing structure, a half-hipped roof consists of many layers, which are stacked one after another. Among these structural elements can be identified:
- rafter system, which acts as a base for holding all the elements;
- Mauerlat – lower support beam for rafters;
- materials providing heat-, hydro- and vapor barrier of the roof;
- roofing that provides mechanical protection.
The rafter system itself also has several constituent elements: a ridge, rafter legs, racks, struts, lathing and much more. Each of these elements performs its function, providing the roof with additional rigidity and strength. This is especially important when creating a semi-hipped dormer roof.
Diagram of a half-hipped roof and rafter system
Installation of a half-hipped roof should begin with laying the Mauerlat on the supporting walls of the house. For brick buildings, a reinforced belt is installed, which provides additional strength and evenly distributes the load. At the concreting stage, vertical studs made of galvanized metal are inserted into it. Mauerlat is attached to the reinforcement by mounting.
The length of the studs should be sufficient to provide a ledge of 2-3 cm from the beam. The fastening step should be 120 cm. The minimum diameter of the reinforcement used to fasten the bars is 10 mm.
Useful advice! Position the studs in such a way that they are between the rafters and in the future do not complicate the work process.
Installation of the rafter system on the bearing walls of the house
To protect the reinforced belt, it is covered with at least two layers of roofing material and only after that they put the beam on the studs. How to do this, you can see the drawings. The half-hipped roof, due to this stage, is more durable.
The selection and installation of Mauerlat is one of the most important stages of the preparatory work. The cross section of the beam used for this purpose should be 150 × 150 mm or, in extreme cases, 100 × 150 mm. All the necessary holes are drilled on the ground, after which the wood is treated with specialized antiseptic agents to protect against moisture and the development of fungi.
Half-hipped roof truss system: installation basics
The half-hipped roof device includes the installation of a ridge, rafters (both sloping and diagonal) and fasteners, for example, metal brackets and special cuttings.
Ideally, the diagonal rafters should be a continuation of the ridge, which at the top is divided into two parts and goes down to the corners of the house. Outriggers are also attached to the diagonal rafters, which makes these elements take on all the main load and weight of the structure. That is why for their manufacture using double boards 50 × 150 mm, thus providing a reinforced base.
Due to this, the bearing capacity of the sloping rafters increases, which allows the use of long, whole beams for very large roofs. In addition, the same boards can be used for diagonal and ordinary rafters, which makes it possible to facilitate the work process.
Useful advice! It is better not to fill the space remaining under the ridge with mounting foam. So the air circulation will not be disturbed, and the likelihood of decay of the wooden part of the ridge will be significantly reduced.
When the installation phase of the rafters is over, and all the elements are securely fastened with the Mauerlat and the ridge beam, it’s time to start installing the ordinary rafters. The upper part they will rest against the ridge, and the lower in the Mauerlat. Before you begin, be sure to check out the affordable designs of houses with a half-hipped roof.
Useful advice! The distance between the rafters should take into account the width of the insulation material that you will use.
In order to make the structure stable, cuts are made at both ends of the rafters. This allows you to fix the elements. As an additional mount, metal brackets and corner pads are used. If the roof of the house is very long, then you definitely need to create additional stops in the form of struts. To support the diagonal rafters, truss trusses are used.
If the floor slab is made of reinforced concrete, then all the props and racks can be supported directly on it. Otherwise, it is necessary to install additional tightenings on the joists, otherwise the half-hipped roof structure will turn out to be unreliable.
Useful advice! Before installation, all wooden roof elements must be treated not only with an antiseptic that protects the wood from moisture, but also with fire-fighting liquid.
How to make a semi-hipped roof with your own hands: calculating the number of rafters and the step between them
In order for the rafter system to turn out reliable and to function fully over the years, before starting work, it is necessary to carry out calculations that will become the basis for installation. As an example, you can use the photo of a half-hipped gable roof with a house width of 9 meters.
The step is called the distance between the two rafter legs, and usually for residential country houses this figure ranges from 0.6–1 m. This depends on many factors, therefore, calculations must be made individually based on your own indicators. To calculate the required number of rafters, use the following algorithm:
- Measure the length of the roof slope and divide by the required step factor between the elements.
- Then add one to the result, round the resulting number to a higher value. This will be the number of rafter legs that is necessary to finish one slope of the roof of a given length.
- If you divide the entire length of the slope by the resulting integer, then as a result you get the distance that you need to keep between the axes of the rafters (this is the rafter step).
It is useful to know that although ideally the axis should pass through the center of the rafters, in practice errors are permissible, depending on changes in the slope angle of the surface of the future roof. This is clearly visible in the photo of a half-hipped gable roof.
Before you begin, you need to calculate the exact number of beams used based on the project
As an example, consider this calculation: the length of the roof slope is 16 m. In this case, the step between the rafters will be 0.6 m. Based on the above algorithm, 16 ÷ 0.6 + 1 = 27.66 = 28. This means that for a slope of 16 meters in length we need 28 rafters.
Useful advice! The width of the rafter step directly depends on the angle of the roof. So, the greater the steepness of the roof, the greater the step of the rafters must be maintained. This is due to the fact that the load distribution on steep roofs is uneven, and to a greater extent falls on the bearing walls.
As an option, you can use special online calculators for calculations, although it is much better if you have a plan or a drawing of a half-hipped roof with your own hands, because having a clear example is much easier to carry out calculations and work.
Installation of a half-hipped roof: the final stages of construction
When all the wooden elements are laid and fixed, all that remains is to worry about the heat, steam and waterproofing of the roof. To do this, a crate is made, and the selected material is rolled out from above.
It is difficult to say which materials are best to be preferred, but aluminum foil will definitely perform its function well in terms of vapor barrier. Using a construction stapler, the foil is attached to the rafters so that the glossy side is turned inward, that is, into the attic.
For insulation, synthetic cotton (mineral or stone) is most often used, which is sold in rolls or mats. The insulation is laid out in the gaps between the rafters and covered with a layer of waterproofing. Previously, roofing material was used for this purpose, but today it has given way to a diffusion membrane.
If the space under the ridge of the roof was not covered, then natural ventilation will not allow fungi and mold to develop inside the “pie”.
Of course, in matters of installation, a gable semi-hipped roof is significantly superior to a gable roof due to its simpler design and lower installation costs. But if we talk about the final result, then nothing can compare with the complex beauty of a gable roof. Photos of a half-hipped four-pitched roof well demonstrate the beauty of this decision.
And with all this, the second option gives much more space for attic equipment, which can be equipped with instructions, photos and videos of the half-hipped roof truss system provided on the Internet.
Choosing a roofing material for a half-hipped roof
Of great importance in creating a beautiful and reliable roof is the choice of roofing material. Let’s look at some of the most popular solutions, and how they meet the requirements.
In the process of installation and operation, the roofing has to deal with a number of external factors that affect it in different ways. Among them: precipitation, strong winds, “snow caps”, exposure to ultraviolet radiation and significant temperatures. The selection of suitable material should be guided by these data.
Asbestos-cement sheets , or slate, are an inexpensive and fairly durable roofing material. It has a number of advantages, such as fire safety, high resistance to temperature extremes, resistance to corrosion and the development of mold and fungi. Slate will never rot or lose its appearance in the sun. To give a more aesthetic appearance and improve technical characteristics, asbestos-cement sheets can be painted.
Slate is a fairly resistant roofing material.
For a half-hipped roof, this material is not suitable for two reasons:
- such an inexpensive coating will not look advantageous on such a complex design;
- Slate is a rather fragile material and its precise cutting will take a lot of time and effort.
Metal is also quite affordable material, but much more attractive. The long service life (up to 30 years, taking into account the service) and excellent technical characteristics made this coating a leader in its price category. The material is completely not afraid of temperature changes or mechanical stresses. A wide range of colors on the market allows you to choose a shade for every taste.
The main plus of the metal tile is its low weight and, accordingly, a small load on the rafter system of a half-hipped roof.
Metal – the best option in terms of price and quality
Among the shortcomings of this material, one can single out the integrity of the sheets, the trimming of which for a half-hipped roof requires a certain skill and dexterity. And, of course, a very low rate of sound insulation. After all, we all know the sound of raindrops hitting a metal coating.
Composite tile – one of the subspecies of metal, which is widely found on sale. Such a coating is more expensive, but it has the best technical characteristics. Of the disadvantages, only a large weight of material is noted.
Flexible roofing is ideal for a half-hipped roof. Shingles are sold in rolls and are easily cut into pieces of the right size. This makes it easy to design areas with high architectural complexity. Among the technical characteristics can be identified:
- light weight material;
- fire resistance and water tightness;
- a huge selection of color and stylistic solutions;
- resistance to mold and rot.
Ceramic tile is perhaps the oldest of the proposed materials. The roof is laid out from individual elements that were burned at a very high temperature. It is an environmentally friendly material that is resistant to both high and low temperatures. Undoubtedly, this material has the longest service life – up to 150 years.
Such a coating is perfect for a half-hipped roof, subject to high strength and reliability of the rafter system, since the ceramic tile has a very considerable weight.
Another feature of this material is the fragility of individual elements. However, this is offset by ease of repair and the ability to replace each individual part.
The most durable roof option is ceramic tile
Wood flooring or shingles . Eco-friendly and very beautiful option. The constituent elements are small planks of all kinds of wood – oak, beech, aspen and all kinds of conifers.
Decking . This material owes its popularity to good characteristics, combined with an affordable price. The main advantage of such a roof is profitability, but there are other advantages:
- light weight;
- simplicity of transportation and laying;
- long service life;
- resistance to corrosion damage;
- large selection of shades.
Galvanized corrugated board has an affordable price and good strength characteristics
However, like metal, this material is quite noisy when it rains and hails. It can also be susceptible to corrosion provided there are mechanical damage resulting from improper transport and installation. In addition, laying corrugated board on a semi-hipped roof, as well as other sheet materials, is complicated by the need to cut individual elements.
As we can see, creating a half-hipped roof with your own hands, although not an easy, but quite feasible task. Having thought through all the steps and gradually following the algorithm, you can give your home an original look, making it even more comfortable and beautiful.
Rafter system and coating
Semi-hipped roof, the rafter system of which is complex, belongs to the category of hipped structures. In it, the hips are not set to the full height of the ramp. Today, this version of the roof is often used, as it has a beautiful appearance and an interesting shape.
The semi-hipped roof is excellent protection against strong winds and excess moisture.
Such a roof is original due to the use of additional parts (towers and other elements).
In most cases, such a roof is installed on houses with a small area, since the space under it is often used as an attic. Under this roof, you can easily arrange an additional room, and in some cases more than one. The semi-hipped roof is excellent protection against strong winds and excess moisture.
The disadvantage of this type of structure is the high cost and complexity of the calculation of materials. The roof has a large surface, so there will be considerable labor costs.
How to calculate a similar roof?
Formula for calculating the required amount of material for the half-hipped roof truss system.
Determining the roof area is very simple. To do this, divide the roof into several figures.
When calculating the Dutch design, it is necessary to break the slopes into rectangles and trapezoid. The area of the first figure can be calculated by multiplying its sides. To determine the area of the second figure, you need to multiply the sum of the bases by the height and divide the product by 2. Next, you need to add the obtained values and multiply them by 2. As a result, you can get the area of the slopes.
Next, the area of the triangles is calculated. To do this, multiply the length of the base of the figure by height and divide by 2. At the end, the area of the slopes should be added to get the total area of the structure.
To calculate the Danish roof, you need to divide the ramp into a rectangle and several triangles. The area of the first figure should be calculated by the method indicated above. The area of the triangle is equal to the product of its legs, which will need to be divided by 2. Next, you need to add the values of the area of the first figure and several triangles. As a result, it will be possible to obtain the area of the ramp. The resulting value must be multiplied by 2.
Next, you need to calculate the area of the hipped slopes. The resulting value must be multiplied by 2. If you add these values, you can get the roof area.
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Existing types of half-hipped roof truss systems
The half-hipped roof scheme is shown in Fig. 1. This product has a complicated device. Trapezoid in this case will be replaced by polygons.
By type of hipped roof can be divided into:
- Dutch. In the lower part of the hipped is trimmed, and to the eaves overhang there is a pediment in the form of a trapezoid.
- Danish. They are performed in the reverse order. A trapezoid-shaped hipped extends from the eaves, and small triangular pediments are placed above it.
Dutch roof construction
An attic is located under the ceiling of the attic, in which ventilation will be provided by windows. These elements need to be mounted in pediments.
To build this roof, you will need to prepare a lot of materials. In the process of erecting a semi-hipped four-gable roof, various elements will be used, the main of which are the following: rafters of various types, emphasis, struts and trusses.
Installation is not easy, so the first thing you should do is design the roof and perform calculations. The half-hipped roof truss system should be constructed as follows:
Figure 1. Scheme of a half-hipped roof.
- Before laying the Mauerlat, you will need to make a reinforced concrete belt around the perimeter of the private house with the installation of fasteners under the bar. As fasteners, you can use studs, which are placed in increments of 10-12 cm. To simplify installation, it is recommended to insert the studs in places that do not coincide with the fixing of the rafter legs to the bar.
- Next, you need to lay a layer of insulation material and mount the Mauerlat. This is the bar that is needed to bind the walls to the roof of the building. He will distribute the load from the rafters to the top of the private house. The Mauerlat is secured with nuts, which are screwed onto the studs. In this embodiment, the Mauerlat should be laid on the side slopes. On hipped slopes it is mounted on the upper part of the gables and secured with anchors. The element can be made from a bar 150×50 mm.
- The next step is to install a ridge rail. This is an important part of the rafter system. It is a horizontal bar that is installed in the upper part of the roof. It should be placed between the slopes. The element is needed to fasten the rafters.
- In the Dutch roof, the rafter system provides for the installation of hipped slopes using various rafter legs, the length of which can vary in accordance with the design. The sloping rafters are mounted from the corners of the building to the end of the ridge run. They will have the maximum load.
- Nose elements are mounted in one part on the Mauerlat pediments placed under the hip, and the other is fixed to the end of the ridge bar.
- The ordinary rafters of the side slopes are fastened to the main Mauerlat and the ridge.
- Rafter rafters are fixed with sloping legs.
The most suitable tree species for the half-hipped roof truss system is pine.
If it was decided to build a semi-hipped roof on your own, then you should be responsible for the choice of material for the manufacture of rafter system parts. It is recommended to use slats with a section of 150×50 mm. The most suitable tree species is pine. If you have to choose from hardwood, then you should give preference to larch. The material must be dry to prevent deformation of the device during future use. Additionally, it will be necessary to perform the processing of the tree with a composition against microbes.
If there are large spans, it will be necessary to strengthen the system with the help of stops. Rafter legs are strengthened in most cases with the help of trusses.
Braces and stops are additional bars that support the elements of the main structure. Sprengel is a beam or fixture that strengthens the main building. All these parts will be based on slabs or floor beams. In the latter case, you will need to use puffs.
Next, you will need to begin the final stage of construction work: the installation of the crate, waterproofing material and roof.
How to make a Danish roof of this type?
Figure 2. The construction scheme of the Danish roof.
A similar roof is a structure that combines an ordinary gable roof and a hip. The large attic, as in the Dutch design, can be used as an attic.
The construction of the Danish design is a more expensive option compared to the Dutch. However, in the case of an accurate calculation, such a roof will have an excellent appearance and will be able to provide reliable protection for the entire building.
To install the Danish roof truss system, you will need such elements:
- ridge bar;
- hip, ordinary and angular rafter legs;
- supporting boards;
Installation of these elements is carried out according to the same rules as for the Dutch roof, however there are some differences. The Danish roof is a product with complex ramps. The diagram of this building can be seen in Fig. 2.
In the Danish design, the rafters of the ramps in the form of a trapezoid do not fit the ridge bar, but rest on the upper part in the timbered bar, which is placed on the bases of the gables and fixed to the rafters of the side ramps. At the bottom, the elements will rely on the Mauerlat.
Pribinu can be fixed with nails. To strengthen this block in the places of fixation, you will need to use struts. They are mounted on the bottom of the base.
Small gables should be formed along the upper part of the hipped slopes, in which in most cases a small window is installed. Light windows can be built in the hipped part of the ramps.
Rafter legs, beams and a block of a ridge should be constructed of material of the same wood species and have the same cross section.
Otherwise, the design will become more complicated, distortions may appear and it will be necessary to carry out repair work.
A gable roof or any other half-hipped roof is difficult to construct, but if you follow the technology, then there will be no problems in the construction process.
Half-hipped roof rafter system
Half-hipped roof truss system: detailed installation instructions
A semi-hipped gable roof is an attic (or as it is called “tent”) roof for houses, utility rooms and other buildings, which has two cut triangular peaks that are located above the end walls. This design is very simple, but at the same time is durable. The square semi-hipped tent roof has the shape of a pyramid.
The half-hipped on houses can have two triangular sides and two trapezoidal ones. The half-hipped of a rectangular plan has four trapezoid walls. They are almost always located with the same slope, which makes them symmetrically located relative to the axial beams of the roof. Tent surfaces have a constant fascia level, so the gutter system can be installed in a circle around the roof. In most cases, the owners also mount mansard slopes or windows.
Advantages and disadvantages of a half-hipped roof:
- With such a construction, the attic space is much smaller than when constructing a gable roof;
- It is more difficult to clean, carry out scheduled repairs;
- In addition, for servicing a half-hip, special aerators with a forced ventilation function will be needed;
- The main advantage of this design is strength. Such a roof can be installed in extreme climatic conditions, areas with strong winds or nearby the sea;
- She has a very beautiful view, she looks spectacular both in the city and in the conditions of a holiday village;
- Due to the low profile, such a roof has a good vibration resistance.
How to build a half-hip
Projects of houses with a half-hipped roof can be easily developed at home, if you have a drawing. This is the basis of any construction, at home you can use the AutoCAD program for free.
The technology for building the roof is quite simple, we suggest considering how to build a half-hipped roof with your own hands with a photo:
- Measure the length of common rafters, hipped beams and spinal boards. After that, you need to calculate the perimeter of the roof of the building. Common rafters are those that go from the top wall to the top of the roof. Half-hipped pass along the ridge, where the two sides are connected on the roof. The spinal board runs along the upper part of the roof and where the common rafters and hipped are combined. It is very important that the length of the rafters matches the size of the roof.
- Measure the size of the common rafters, and calculate the necessary parameter in accordance with the desired area, or the angle of the roof.
- Cut the rafters to the desired size. We advise adding 50 cm to the required length of rafters, this error is necessary to create;
- After that, cut the support beams, and make a frame out of them. For future crate. You need to position the rafters with an interval of 50 centimeters. This indicator can vary upward depending on the area of the roof and the material used for coating;
- Mark along the wall the areas where the rafters will be located;
- Position the rafters along the perimeter of the roof, set the skate at the desired height;
- Using special brackets, mount the beams on the wall. This is necessary to provide them with additional protection and rigidity;
- Further, the circuit changes direction a little. The crate is placed from the center of the roof, when you position approximately 50% of the boards, you need to start working with the hipped walls. To do this, we lay a beam from the corner of the wall to the ridge, a diagonal plane forms, we do the same with the second wall. The boards are fixed on the ridge and at the base with self-tapping screws and stands. For a pitched roof, the angle of inclination is of great importance. The hipped slope is often the same as the attic. On average, it is from 35 to 60 degrees;
- Next, you need to build a roofing cake.
Semi-hipped roof – DIY construction and installation
We install sheets of thin pre-treated coatings on the beams, most often it is plywood or a polymer film. Such an overlay is installed without overlapping, but it is advisable to treat the joints with a sealant.
Installation of rafter beams is carried out using special tools, we also advise you to show your calculations, drawings and diagrams to a specialist before starting work, he will help verify the correctness and accuracy of their implementation.
The half-hipped rafter system must be clearly calculated, for this you need the following formulas:
To find out the height of the roof you need: h = (ß tan a) / 2
To calculate the hipped diagonals, you must use the following equation:
e = b / (2 cosa)
Based on what we have, you can find out the area of the hipped roof to calculate the amount of material to cover:
d = (h3 + (b / 2) 2 + (b / 2) 2) 2
This was calculated by the area of one four-sloped triangular hip, in order to find out the total roof area, it is necessary to summarize the area of four triangular figures or two triangles and two trapezoids (with a rectangular half-hip).
For a more accurate result, all the roof openings must be taken away from the obtained number – these are chimneys, a dormer window, drainage systems, hatches for aerators.
How to cover the roof
The half-hipped roof device is strong enough to support the weight of any building material, but it is best to use roofing sheeting for coating. Before installing metallic material, be sure to leave a ventilation hole.
Tiles are also often used, which is much more profitable in this case, bituminous, it is lighter than ceramic and metal. In the classic version, wooden boards are used.
Such architecture looks great both on single-story houses and on two-story ones. Nowadays, a gable half-hipped roof is becoming more and more popular, but its device is quite complicated for independent execution, in addition, it is not advisable to mount it in strong winds.
Hipped roof: rafter system
Today you can choose from various types of roofing structures, because there is an opportunity to pay more attention to home design. Therefore, more and more often in suburban villages there are buildings covered with a four-gable roof. And although gable structures are still quite popular, the former are gradually ahead of their demand. This is understandable; you cannot forbid living beautifully. In addition, under four roof slopes, it is easy to organize a residential or office space, and install skylights on the slopes.
Three types of four-pitched roofs.
Let’s deal with all the designs, and more precisely with their rafter systems.
Hipped roof truss
To understand what elements the roof system of the hipped roof consists of (the diagram is located in the photo below), you need to understand what structural elements it consists of as a whole. These are four slopes in two equal pairs. Large slopes are trapezoidal, two small – isosceles triangles.
A ridge beam is necessarily present in the design, only it is shortened, that is, its length is not the length of the roof span. And since the shape of the roof slopes is different, the rafters used for its construction will also have different lengths so that it is possible to correctly form the pitched planes. The rafters themselves have their own names.
- The element that connects the ridge beam to the corner of the building is called the rafters.
- The shortened elements connecting the Mauerlat and the sloping rafter leg are called spiders.
- Rafters, one edge resting on the Mauerlat, and the second on the ridge beam, are called ordinary.
- There are rafter legs that abut the upper end against the end of the ridge beam. There are three of them: two from neighboring trapezoidal slopes, one from a triangular. They are connected at the top into a complex node, here four elements are joined at once. So these rafters are called central.
A hipped roof (rafter system) is a rather complex complex, which you can’t build with your own hands, if you are not an expert in this business. A large number of different elements require precise adjustment. In addition, there are a huge number of joints that require a special approach. Of course, with the advent of modern fasteners in the form of metal shaped products, the installation process has made it much easier. And yet this does not give the right to lay people to build a rafter system of a hipped roof – its scheme is not simple.
What else you need to pay attention to, starting to build a hipped roof with a rafter system. Of course, it is optimal if a project already exists on it. It solves all the problems associated with the number of rafters, their size, installation frequency and mounting requirements. But if a hipped roof is being built on a small building, then its drawing, made even with your own hands, will make it possible to correctly evaluate your strength. Plus, you can accurately calculate the required amount of all materials used, which will provide the right approach to the consumption of the construction budget.
So, the hipped roof (rafter system), the drawing of which is drawn, is prepared for assembly. For this, timber with a section of 100×100 or 200×200 mm is purchased for Mauerlat and a ridge beam, boards with a section of 50×150 mm for rafters. The required amount is indicated by the drawing or design of the roof.
Half-hipped roof truss
A half-hipped roof (rafter system) is a triangular slope in which pediments are present. It should be noted that this is the most complex construction of all four-slope. She came to Russia from the western northern countries, so today two structures are distinguished: Dutch and Danish. And already on their basis, many variations have been developed. In the photo below: Fig. 1 is a Dutch construction, Fig. 2 is Danish.
Consider the device of a half-hipped roof and its rafter system. It includes:
- Hanging or layered rafters that connect the Mauerlat and the skate of the building. In fact, they are central and at the same time ordinary. In this type of roof there is the largest number of them, because the main trapezoidal slope occupies a large place in the roofing system of the house.
- The sloped (angular) rafters in this design are shortened, because they do not connect to the ridge. Their upper end abuts against the last central rafter legs, where they are fixed. The size of the nakosnikov can be different, it depends on the chosen shape of the hip. That is, if the hipped is sloping, then the nakosniki should be of short length, if steep, then vice versa. With a steep hipped slope, the size of the pediment decreases.
- There are also shortened central elements in the half-hipped rafter system, which are the basis of the hipped ramp located under the pediment. The lower edges they abut against the Mauerlat, the upper edges in a special horizontal beam called a hole. They make it from the same board as the rafters themselves.
- And, of course, in the half-hipped roof there are spiders. They are located on all four slopes and abut their upper ends on the angled sloping rafters.
As for the gable part of the roof, it is formed by two central rafter legs and a hole on which the shortened central elements fit. In fact, this is a small-sized triangular opening that closes and is decorated. If it is large, then vertical racks are installed in it, if not, the sheet material is attached to the rafters.
The half-hipped roof assembly process is as follows:
- First mounted ridge beam. It is mounted on the support posts.
- Then the central rafters are laid on it.
- Next, nakosnye elements.
- After which the installation of the hole.
- And the last to be mounted are the spiders on all the ramps.
Truss roof structure
The roof rafter system is the simplest scheme, because it is four identical slopes in the form of isosceles triangles. Therefore, the number of rafters in it is not very much. There are four sloping elements, four central, which connect the Mauerlat and the connection point of all rafters. As well as several growths on each slope, which, as usual, rest against the nasal elements.
In fact, it is not difficult to assemble the rafter system of the tent roof with your own hands. The most difficult knot is the very point of connection of all the rafter legs. But if the roof being built is large, then additional elements come to the rescue, on which the rafters will rest. It is they who simplify the installation process itself. Usually, a support is installed in the center of the roof, on which the rafter elements lie with their upper edges. The support may be different. For example, a pillar, a quadrangular design with four pillars, and so on.
In addition to the rafter legs, the design of the tent roof with its rafter system includes other elements that make up its integral part. Namely:
- Crossbar. This element is an intermediate part of the connection of the rafters to each other on the ridge.
- The beds serve as Mauerlat mounted inside the roof structure. They are usually laid either on the wall, which turned out to be inside the building, or on the posts, which serve as supporting elements.
- Runs are horizontal bars located under the middle part (along the length) of the rafters. This element is usually used if it is possible to install supports under it.
- Sprengels are supporting posts made of logs, beams or double boards.
All of the above elements are parts of the rafter structure, and it is they that increase its strength and reliability. Their presence is an increase in the safety of roof operation in general.
Parameters of the rafter system
A hipped roof (rafter system), hipped or half-hip, is a set of rafter legs. But here the question arises, what is the optimal number of them to consider that the roof is reliable. This is influenced by a large number of different factors. For example, the distance between the legs, their cross-section, the type of roofing material, the height of the structure, how much snowfall falls in the region where the house is being built.
According to experts, the main parameter is the first of the above. Therefore, it is worth considering various combinations.
- If the length of the rafters is 3 m, and the cross section is 80×100 mm, then the distance between them should be within 110-135 cm.
- Length 3-4 m, section 90×100 mm, distance 140-170 cm.
- Length 4-5 m, cross section 80×200 mm, span 110×135 cm.
- The length is 5-6.5 m, the cross section is 120×220 mm, the gap between them is 110×140 cm.
This is not the whole list, but it already shows what and how it affects the laying of rafter legs. By the way, the heavier the roofing material, the more often the rafters fit, the same applies to the snow load.
Here is the hipped roof (rafter system) photo, which clearly shows how often the legs are laid, because the roof will be covered with heavy material. Together with snow, it will create decent loads that the rafters must withstand. If, for example, NS-75 brand flooring is used to cover the roof, then the rafters can be installed with an interval of up to 3 m. Because the profile flooring itself has a large bearing capacity.
As you can see, the roof truss system is a design that provides the whole house with reliability and safety of its operation. And it doesn’t matter what roof is being erected, what sizes and shapes, it is important to correctly calculate the size of the legs, choose their cross-section accurately, and correctly install. Do not forget that the fastening of the rafter elements is the most important component, on which the safety of the structure also depends.
The device and calculation of the rafter system of a half-hipped roof
Semi-hipped roofs (Dutch) are not among the most popular roof structures due to some complexity of execution. Such roofs successfully combine all the advantages of ordinary gable and tent roofs. The construction of half-hipped structures is justified in regions with strong winds, which allows to reduce the negative natural impact on the roof. In addition, such a roof allows you to significantly expand the useful attic space, which can be used as an additional living space.
Successful completion of the rafter construction allows you to start creating a “roofing cake”. The structure of which may vary slightly depending on the type of roofing material intended for use. However, the basic elements of a roofing cake remain unchanged:
The crate is mounted directly on the counter-lattice, and the roofing is laid.
Calculation of a gable semi-hipped roof frame
The most crucial moment in the construction of the roof is the calculation of the rafter system. They belong to the category of rather complex ones, because they must take into account not only the weight of the roof itself, taking into account the entire surface area, but also the technical characteristics of the roofing material, as well as the peculiarities of climatic conditions, including rain, snow and wind loads.
In addition, the design has several difficult points, which involve an overrun of roofing materials and rafters, which is due to a significant amount of waste in the assembly and covering of half-hips.
It is for this reason that it is advisable to entrust the calculation of the frame structure to professionals or to use special computer programs.
The device of the rafter system
Despite some features, the rafter structure of the Dutch roof is similar to roofs of any kind based on the installation of a Mauerlat. To this end, it is necessary to install formwork with pre-mounted studs on the upper part of the walls, for which a step of 120 cm and a diameter of the order of a centimeter are maintained. Next, the armopoyas is filled and after fixing the concrete base, the Mauerlat is installed.
The initial stage of the direct installation of the rafter system is characterized by the laying of the waterproofing layer, for which it is necessary to form holes in the support bars with a suitable diameter.
Then you should put the Mauerlat beam on the mounted studs and fix it with washers and nuts. From this moment begins the construction of the rafter system with the installation of rafters, which can be represented by a lay or hanging option.
The device of the rafter system
The choice of the rafter structure depends on the features of the structure, taking into account its size and the presence or absence in the building of intermediate supports of a bearing nature.
Structurally, the hanging rafters have an emphasis solely on the Mauerlat, which allows you to transfer significant spacer force to the walls. To prevent the destruction of these walls, the rafters must be equipped in the lower or upper part with special puffs.
The rafters differ in the emphasis on the Mauerlat – on the internal supporting elements or structures. Of course, the layered version of the rafter system has a lower weight, which contributes to significant savings when buying building materials. In addition, this type of gable roof is more resistant to strong wind loads.
Installation and mounting rules
To obtain a reliable and durable design, you should adhere to the installation technology and the basic rules for fastening all elements.
The general sequence of all actions performed during the construction of the rafter system of a half-hipped structure:
- farm installation;
- the lack of emphasis on the pediments allows you to install the ridge beam on temporary supports with the subsequent connection of the ridge edge with the corners of the pediment by means of braces;
- the junction of the ridge and the brace is equipped with a complex three-plane cut;
- fastening on installed sections of shortened rafter legs from the main slopes, as well as rafters from the half-hipped part;
- reinforcing the installed trusses by means of a pair of beams for the upper segment to compress, and the lower to stretch.
After attaching the cross beams, the installation process of the rafter frame is completed and it is necessary to equip the roofing cake.
The semi-hipped type of gable roof has some features that are due to the fact that part of the weight is taken by trapezoid gables. It is for this reason that this part of the frame should be made as durable as possible.
A feature of the ridge beam is the presence of an additional compression load, which requires the execution of this element from a bar with a larger section.
Despite the fact that the half-hipped roof does not have the simplest design and its installation is far from easy for everyone, the aesthetics and functionality of such a roof do not leave indifferent even inveterate skeptics.
Semi-hipped gable roof: rafter system and construction
The semi-hipped gable roof is not only beautiful from the point of view of architecture, but also a very practical solution that allows you to get a spacious attic floor and a reliable, durable roof at the same time. In addition to effectively protecting all parts of the building from the effects of rainfall, the half-hipped roof design provides high resistance to the most intense wind loads. All these advantages led to the high popularity of this type of roof in the field of individual construction.
Half Hipped Roof Options
When selecting the roofing material and the angle of inclination of the slopes of the half-hipped roof, first of all, the value of the normative snow load adopted by the construction climatology for the region in which the construction is carried out is taken into account. At high values, the slope of the ramps is increased, and the overhangs are made smaller; at low – on the contrary: slopes make more gentle, and overhangs increase.
The next factor affecting the slopes of the slopes and the shape of the roof is the purpose of the attic space. As you know, each slope of a half-hipped roof consists of two trapezoidal planes having a different slope. If the owner intends to use the attic space as a living space, the upper part of the ramp is made more gentle and longer.
The only drawback of a half-hipped roof is the complexity of the rafter structure, which includes, in addition to the main elements, many additional elements, without which the system would not have the necessary strength and rigidity.
The assembly of the rafter structure begins with the installation of the Mauerlat, whose task is to evenly distribute the load transmitted by the rafters to the upper plane of the wall. The cross section of the Mauerlat beam should have a width of 150 mm and a height of 100 or 150 mm.
Mauerlat is laid on two layers of rolled waterproofing and fastened to the wall: to the wooden – using staples, to the brick – using studs, monolithic in a reinforced concrete belt, which is specially built on top of the brickwork.
The studs are made of a metal rod with a diameter of 10 mm and installed with a pitch of 1.2 m so that upon completion of the installation of the entire rafter system, they are between the rafters. The length of the free end of the hairpin after laying the Mauerlat should be 2 – 3 cm. Drilling of the fixing holes in the Mauerlat, as well as the treatment of the timber with an antiseptic, are done in advance.
After laying and fixing the Mauerlat, the racks and the ridge are installed. The main requirement of this relatively simple operation is the strict verticality of the racks, which is checked by a plumb line.
At the next stage, diagonal (sloping) rafters are installed, connecting the ends of the ridge with the corners of the house. These rafters have a longer length than ordinary ones and carry an increased load, so they double their cross-sectional area. For this, as a rule, two boards or beams are fastened together, serving as material for ordinary rafters.
Rafters, based on diagonal ones, are called rafters. They, like ordinary rafters, are installed in the next step. At the end of the installation, the rafters are strengthened with support racks or struts, supported by slabs or floor beams; for truss rafters, a truss truss is used. The rafters are placed in such a way that they rest on the diagonal rafters at different points. In this case, the load will be distributed evenly over the entire length of the diagonal rafters. For greater resistance to wind loads, the rafters are additionally attached to crutches driven into the wall, for which wire strands are used. On the fixed rafter legs, they lay the crate.
Each wooden element prior to the assembly of the truss structure must be treated with antiseptic and fire fighting compounds.
Gable Roof Pie
The most important element of the roof is vapor barrier, the best material for which is considered a foil film. It is attached to the lower plane of the rafters with the foil down using a construction stapler. The foil must be made of aluminum, as it is not subject to corrosion.
The next layer – a heat insulator – is most often made of mineral wool, which is placed between the rafters. It is impossible to prevent crushing of mineral wool, it must be fixed with some tension.
The roofing cake is completed with a waterproofing layer and a roofing. Between them there should be a gap due to which ventilation of the under-roof space will be carried out.