The design of the hip roof is unusual. Today it is often used in private housing construction. And the reason is not only in the form. It is easy to locate a room under the roof, saving a lot on the construction of a new living space. The main thing is to correctly carry out thermal insulation measures. But it must be noted that a roof of this type is not an easy structure. Therefore, it is important to accurately calculate the hip roof, taking into account the large number of different nuances. Even small inaccuracies can reduce the reliability of the design.
Roofing device
Hip roof belongs to the category of hipped roofs. Her two opposite slopes are trapezoids, two are triangles. They are joined together by the so-called corner rafters, which create boundaries between the slopes. These are the bearing elements of the hip roof, the bearing capacity of the structure as a whole depends on the section of which.
In addition to the corner rafters in terms of supporting structures, there are other elements in the hip roof:
- ridge beam, which is a support for the main number of rafters;
- the rafter legs are central, they rest on the roof Mauerlat with one end, the other on the ridge, are located in the plane of the trapezoidal slope;
- hip rafters, form hip slopes, rest against the upper ends on the corner rafters.
Pros and cons of a hip roof
Before starting any construction, everyone wants to get acquainted with the features of the structure under construction.
Experts consider the following to the main advantages of a hip roof:
- there are no vertical sides in the structure. This feature allows you to more reliably withstand the pressure of air masses. Therefore, if strong winds prevail in your area, then a hip roof is what you need;
- the structure of the rafter system itself makes the roof quite strong and not subject to deformation. But this will be true if the calculation of the hip roof is done correctly;
- the presence of four slopes makes it possible to create overhangs around the entire perimeter of the house, which makes it possible to more reliably protect the walls from the effects of precipitation;
- has an attractive appearance.
The latter circumstance can significantly help if you decide to build an attic floor into an already operated building. In this case, the hip roof will visually reduce the height of the house, which will improve its aesthetic appearance.
But this design is not without its drawbacks. First of all, as mentioned above, this is a rather complex device. It can only be possible to build such a shelter if you have certain skills. In addition, a large amount of materials increases the construction cost of the facility.
Another disadvantage of a hip roof is that the slopes around the entire perimeter of the house will take up a lot of free space. This circumstance can prevent the construction of a large room on the attic floor.
Remember! A hip roof is a fairly common option. It is often used if you want to have an attic floor or in places with high wind loads. This type of roofing is a solid structure that can withstand significant atmospheric influences. But having decided to choose him, you need to prepare for some difficulties. First, the hip roof is quite complex. Second, you must be prepared to spend more. But the most important thing is to make the correct calculation of the hip roof.
The angle of inclination of the slopes
This is one of the most important indicators that is calculated first. It all depends on the type of roofing material planned for the project to cover the roof structure. Because not all roofing materials can withstand the required loads from atmospheric precipitation without taking into account the slope of the slope.
Here are some ratios:
- the angle of inclination of the slopes when laying corrugated board on them should not be less than 12 °;
- - 14 °;
- slate - 22 °;
- bituminous tiles - 11 °;
- ondulina - 6 °;
- roll roofing materials - 3-5 °.
Note! The amount of material used to cover the roof depends on the slope of the slopes. The cooler the design, the more costs. At the same time, not only the amount of roofing material increases, but also the elements of the sheathing, the length of the rafter legs, the amount of insulation and protective polymer films.
Therefore, when calculating the hip roof, it is necessary to determine the amount of building materials used. To do this, you will have to calculate the area of \ u200b \ u200bthe roof.
Roof slope area
Everything here is quite simple because the shape of the slopes is geometric shapes, the areas of which are known.
Trapezium area: S = (a + b) h / 2, where “a” is the length of the ridge bar, “b” is the length of the cornice, “h” is the height of the slope, that is, the distance from the ridge to the cornice in a straight line.
Area of the triangle: S = hb / 2, where "h" is the height, that is, the distance from the cornice to the end of the ridge, "b" is the length of the cornice of the hip slope.
Substituting the values of the size of the shelter in the formulas, the actual area of the rays is determined. And since there are two pitched structures, their values are multiplied by "2". Then both obtained results are summed up. This will be the total area of the hip roof.
Or just fill in the fields of the online calculator below, the system will do everything
Hip roof- This is a type of attic roof. It is often installed in houses where it is planned to equip additional residential or non-residential space. Hip roof structure hipped. Two side parts - slopes, have a trapezoidal shape, two end parts - hips - triangular.
Hip roof advantages:
- Ability to resist even strong gusts of wind;
- Rigid construction minimizes roof deformation;
- Aesthetic appearance, the ability to visually make a building more compact;
- The ability to equip large side eaves overhangs, thus providing additional protection to the walls of the building from the effects of precipitation.
The disadvantages of hip roofs include the complexity of the design and installation, high cost.
- this is the basis of the roof. The rafters are most often made of coniferous wood, treated with a special compound to prevent rotting and insect settling in it.
To support the rafters on the hip roof, a Mauerlat is installed - a beam designed also to distribute the load on the walls of the building. The central element is the ridge of the hip roof, to which most of the rafters are attached.
There are three types of them:
- Central (privates) - attached to the ridge bar at the same distance from each other;
- Diagonal - docked with corner rafters;
- Corner - attached to the ridge beam and connected to diagonal rafters at different heights so that the structure gains additional strength.
After installing the rafter system, the crate is mounted, insulating materials and a covering are laid on it. At the same time, chimneys, drainage systems, ventilation are being equipped.
Rafter hip roof- the structure is complex, requiring careful calculations before the installation process. One of the important parameters is angle of inclination of the hip roof... It depends on the expected load on the roof, the strength of external factors, for example, wind, snow. Also, roofing materials affect the angle of inclination of the roof. The maximum recommended for slate is 22 °, the minimum for multilayer roll material is 5 °. The material that can be used to cover a hip roof at any angle of inclination is a membrane roof.
Precise preliminary calculation of the hip roof will allow you to avoid unnecessary costs and unpleasant moments during installation. There are several calculation methods, as well as many online calculators for determining hip roof area, hip roof height and other design parameters. But the best results are demonstrated by the use of special software. In a few minutes, by entering the basic data, the user will receive accurate, reliable calculations, based on which you can safely start construction. The good thing about the programs is that they provide all the parameters for the most objective calculation.
Hip roofs are becoming increasingly popular among private house owners. This is not surprising, since such a scheme will differ in a number of indisputable advantages of the operational property, and in addition, it looks very original, giving the house a special aesthetics.
Some DIY homeowners may be intimidated by the fact that the hip roof truss system looks too complex. Yes, it is certainly not as simple as or a conventional gable roof. Nevertheless, this rafter system is completely subject to the laws of geometry, and it is quite possible to make a preliminary calculation of it. Installation, of course, will require some experience in carpentry work, but with good helpers, and even better - with a qualified consultant, you can take on this large-scale event.
What are the advantages of a hip roof?
Four-pitched roofs are the most popular option in modern private construction. Often, developers have a question: how to calculate the area of a hipped roof. This is necessary to determine the amount of roofing material, waterproofing and insulation.
Today, calculations can be made using computer programs designed for all types of roofs. This has its advantages: high accuracy, the ability to choose different design options, convenience. However, some builders choose to rely on their own wits, rather than spending money on what they can do on their own.
Before proceeding with the calculation of the roof area, a detailed plan should be drawn up, where all dimensions will be applied. Not a single roof element should be overlooked. In addition, already at the stage of designing a house, you should decide on the choice of roofing material, since the slope of the roof depends on this. The sharper the angle of inclination, the longer the roof slope. This means more material consumption. In addition, each roofing material is different. For example, profiled metal sheets require much more overlap during installation than, say, natural tiles. 
Having an accurate calculation of the roof area of a house, you can choose the most profitable roofing material, as well as insulation, steam and waterproofing.
Four-pitched roofs can vary in shape:
- directly hipped;
- half-hip;
- hip;
- four-slope gable.
The easiest way to calculate are the areas of roofs, the slopes of which are regular trapezoids and triangles and do not have any kinks on the slopes.
However, in modern construction, hip roofs are increasingly being erected, with many slopes, the surface of which can consist not only of triangles and trapezoids, but also rhombuses, rectangles and other geometric shapes.
That is why, before starting the calculation of the hipped roof, it is advisable to refresh your knowledge of the course of school geometry.
Self-calculation of the gable roof area
As mentioned earlier, the first step is to draw up a complete roof plan. If there is no house project or the rafter system has already been installed, then the roof plan will have to be drawn up according to the existing frame. All you need is a tape measure and an angle. This tool measures all roof lines, from ridge to floor. If the roof is multi-level and consists of different heights, then in the drawing it is necessary to reflect where what is the height. It is also advisable to draw up a plan of the roof in the projection. This will help to most clearly present the picture. However, it is only necessary to draw up a roof projection if you have drawing skills.
Having drawn up a detailed drawing, it will not be difficult to decompose the roof into separate geometric constituent elements. This is necessary for more accurate calculations.
Remember that the size of the roof cannot be limited only by its perimeter. It is also necessary to add the length of the roof overhangs where it is supposed.
Rules that must be followed when calculating a hipped roof:
The simpler the shapes are, and the more parameters you know, the easier it will be to calculate.
- The length of one slope is determined by measuring the distance from the extreme line of the eaves to the ridge.
- Each roof slope is calculated as follows: the area of the figure is multiplied by the cosine of the angle at which this roofing element is located.
- If any slope is an irregular rectangle, it must be divided into regular geometric shapes. And also carry out the calculation of each separately.
- After the calculations of each element have been made separately, the obtained digital values are summed up.
Calculation example.
For example, we will give the calculation of the roof of a hipped roof.
Suppose that our hipped roof consists of the following elements: two regular trapezoids and two isosceles triangles. The roof slopes are at an angle of 30 °. The cosine of this angle is 0.87.
Trapezoidal slopes have the following parameters: one side 10 m, the other 7 m, height 3 m.
Triangular slopes: two sides 3.34 m, one side 7 m. The height of the triangle is 4.8 m.
Let's get down to calculations.
The area of the trapezoid is found as follows: we sum up the length of the horizontal sides, divide by 2, and multiply by the height. That is, in our case: S = (10 +7) / 2 x 3 = 25.5.
Do not forget that the resulting number must be multiplied by the cosine of the angle, in our case by 0.87. As a result, the area of the trapezoidal slope is 22.185. Rounding up, up to 22.5 meters.
The final stage is the summation of all areas: S = 22.5 × 2 + 14.7 × 2 = 74.4. Round up to 75.
Thus, the area of the hipped roof, in our case, will be equal to 75 m2.
During the calculation, various small elements are not subtracted from the total area, such as: skylights, ventilation ducts, chimneys, parapets or skylights. Since their area is small, they do not entail special financial costs. In addition, it is quite possible to make a calculation error.
Calculation of roofing and other materials
After the calculation of the gable roof has been carried out, and the total area has been calculated, you can begin to calculate the required footage of the roofing material. The opinion is erroneous that the area of the roof drawing and the area of the required material are the same. The bottom line is that all elements of the roofing material must be overlapped. In addition, each roofing material has its own technical indicators of the size of the overlap. Accordingly, the costs of materials increase significantly.
When calculating the required amount of roofing material for a multi-level roof, it is advisable to seek help from a computer program. It will make calculations faster and more reliable.
But you can do the calculation of the required material for a simple roof yourself. This does not entail any particular difficulties.
Let's give an example of calculating the amount of slate for our four-pitched roof, the area of which we calculated earlier.
To do this, we need to make a proportion:
X - 15%, where S is the roof area, X is a margin equal to 15%.
After X is calculated, the resulting number must be added to the area S. As a result, the area of the required amount of material will be obtained.
Thus, in our case, the proportion will look like this:
X = 15 x 75/100 = 11.25. round up to 11.5.
11.5 + 75 = 86.25 (m2) - the area of the required roofing material.
In addition, when calculating the required material, it should be remembered that waste will invariably remain, they may require up to 20% of the material. That is, again, a proportion should be drawn up, where X is now the flow rate. We add the resulting result to the area.
It remains only to calculate the number of roofing sheets. To do this, the resulting total area of the entire roof should be divided by the area of one roofing sheet.
When erecting a complex roof, you should take a stock of material not 15%, but not less than 20%.
The calculation of soft roofs is carried out according to the same formulas as the calculation of slate. Consumption depends on the type of roofing material and the technology of its installation. The areas of valleys and skates are counted and ordered separately, since they are measured not in square meters, but in linear meters.
The length of the roofing sheets, determined by the height of the slope, is calculated by the dimensions of the roof of the house. As a rule, metal tiles are produced in lengths up to 8 meters. In this case, the thickness of the sheets ranges from 0.2 to 0.4 cm. As a result, long metal sheets bend very strongly. This can complicate the transportation process, as the sheets may break on the road. Therefore, when ordering metal tiles, take into account the area of the roof, roofing sheets, choose the most suitable dimensions. Also, take into account the qualifications of the workers who will be involved in the installation of the roof. Thus, with a roof area of up to 150 m? it is recommended to purchase roofing sheets up to 2 m long with a roof area of up to 250 m? roofing sheets up to 4 m long are preferable, with a roof area over 250 m? acquire sheets over 6 meters long. Metal sheets over 6 meters long are difficult to lay, as they bend very strongly. Experienced roofers must be hired to install them.
When transporting long roofing sheets, the loading, transportation and storage of the material should be monitored.
Since the material consumption is high on complex roofs. It is preferable to purchase piece material. The piece is a soft roofing material such as flexible bitumen shingles. Thus, waste is minimized due to the small size of the elements. But with proper calculation and a responsible approach, the installation of the roof can be carried out in such a way that high costs can be avoided.
We draw your attention to the fact that soft roofs require the organization of continuous sheathing, as well as additional installation costs. At the same time, prices for these types of coatings are much higher.
Thus, the calculation of the hipped roof allows you to timely calculate the upcoming costs for the purchase of roofing material, insulation and waterproofing.
Using a calculator for calculating a hip roof, you can determine the angle of inclination, the number of battens and calculate the rafter system. You will also be given detailed information about the required amount of building materials. Perform an online calculation of the hip roof of a house.
Please indicate the roofing material:
Select material from the list - Slate (corrugated asbestos-cement sheets): Medium profile (11 kg / m2) Slate (corrugated asbestos-cement sheets): Reinforced profile (13 kg / m2) Corrugated cellulose-bitumen sheets (6 kg / m2) Bituminous (soft , flexible) tiles (15 kg / m2) Galvanized sheet metal (6.5 kg / m2) Sheet steel (8 kg / m2) Ceramic tiles (50 kg / m2) Cement-sand tiles (70 kg / m2) Metal tiles, corrugated board (5 kg / m2) Keramoplast (5.5 kg / m2) Seam roofing (6 kg / m2) Polymer-sand tiles (25 kg / m2) Ondulin (euro slate) (4 kg / m2) Composite tiles (7 kg / m2 ) Natural slate (40 kg / m2) Specify the weight of 1 square meter of coating (? Kg / m2)
kg / m 2
Enter roof parameters:
Base width A (cm)
Base length B (cm)
Roof inclination angle α (deg)
Side overhang length C (cm)
End overhang length D (cm)
Rafters:
Rafter pitch (cm)
Wood grade for rafters (cm)
Crate calculation:
Sheathing board width (cm)
Sheathing board thickness (cm)
The distance between the boards of the crate
(cm)
Snow load calculation:
Select your region using the map below
1 (80/56 kg / m2) 2 (120/84 kg / m2) 3 (180/126 kg / m2) 4 (240/168 kg / m2) 5 (320/224 kg / m2) 6 (400/280 kg / m2) 7 (480/336 kg / m2) 8 (560/392 kg / m2)
Wind load calculation:
Ia I II III IV V VI VII
Height to the ridge of the building
5 m 5 m to 10 m 10 m
Terrain type
Open area Closed area Urban areas
Calculation results
The angle of inclination is suitable for the given material.
It is advisable to increase the angle of inclination for this material!
It is desirable to reduce the angle of inclination for this material!
Lift height: 0 cm.
Ridge bar length: 0 cm.
Roof surface area: 0 m.
Approximate weight of roofing material: 0 kg.
Number of rolls of insulation material with 10% overlap (1 × 15 m): 0 rolls.
Rafters:
Load on the rafter system: 0 kg / m 2.
Side rafters length: 0 cm.
Diagonal rafter length: 0 cm.
Number of hip rafters: 0 pcs.
Reduce the rafter pitch!
Number of side rafters: 0 pcs.
Lathing:
Number of rows of battens (for the entire roof): 0 rows.
Uniform distance between battens: 0 cm.
The number of battens with a standard length of 6 meters: 0 pcs.
Volume of lathing boards: 0 m 3.
Approximate weight of crate boards: 0 kg.
About the calculator
The online calculator of the hip roof will help to calculate its parameters: the volume of roofing and insulating materials, battens, the strength of the rafter system, the correct angle of inclination of the roof slopes. The calculator database contains information about most roofing materials. These are metal tiles, bituminous, ceramic and cement-sand tiles, bituminous and asbestos-cement slate, ondulin and other materials. Therefore, using this calculator, you can more accurately calculate the structure and decide on the future construction. This calculator considers the classic version of a hip roof with equal slopes and equal angles of the slopes in relation to the base of the roof.
Before designing a hip roof, familiarize yourself with regulatory documents such as SNiP 2.08.01-89 "RESIDENTIAL BUILDINGS".
The hip roof is a kind of gable roof, but in profile it represents the shape of a trapezoid. At the ends of the hip roof there are slopes in the form of triangles (the so-called hips). The roof has a total of 4 slopes (two side and two end rafters) and 4 ribs (so-called diagonal rafters).
This design, although more complicated than conventional gable roofs, has its advantages, besides, the hip roof looks great.
There are also semi-hip roofs, in which the hip slopes are shorter in length and do not reach the eaves.
For finishing the hip roof, you can use all kinds of roofing materials. When choosing them, you should take into account the peculiarities of the climate in your region and pay attention to the performance characteristics presented by the materials.
When filling in the fields of the calculator, you can find out additional information located under the sign.
If you have any questions or suggestions for this calculator, you can write to us using the comments form at the bottom of the page. We would be glad to hear your opinion.
Additional information on the calculation results
Roof angle
Here you will see a message stating whether the specified roof slope angle complies with the roofing material standards. If the angle does not match, then you will be advised to change it.
Lifting height
The height of the roof from its base to the ridge (overhangs are not included).
Ridge bar length
The ridge bar will have this length between the hips.
Roof surface area
Total surface area including existing overhangs. This parameter will help you calculate the required materials for construction.
Approximate weight of roofing material
The total mass of the selected roofing material required for the roof of the given dimensions.
Number of rolls of insulation material
The required amount of insulating material. The number in rolls is indicated, based on the standard - 15 meters long, 1 meter wide. The calculation also takes into account an overlap of 10%.
Load on the rafter system
The maximum weight on the rafter system. The wind and snow loads of the selected region, the angle of inclination of the roof, as well as the weight of the entire structure are taken into account.
Side rafters length
The estimated length of the rafters, taking into account the overhangs.
The length of the diagonal (oblique) rafters
The length of each of the four diagonal rafters (ribs).
Number of side and hip rafters
The total number of rafters for side and hip rafters, excluding the four diagonal rafters.
Minimum cross-section of rafters / Weight of rafters / Volume of timber
- The first column shows the cross-sections of the rafters along GOST 24454-80 Softwood lumber... Here are the sections that can be used when building a hip roof with the given parameters. The starting point for calculations is the total load on the structure. After that, the corresponding section of the rafters, presented in this table, is determined.
- The second column shows the total weight of the rafters that would be obtained if they were used to erect the entire roof.
- The third column shows the total volume of the rafters in cubic meters. This indicator can be useful to you when calculating the cost.
Number of rows of crate
The number of rows of lathing that will be needed for the entire roof with the given parameters. Be sure to check the required number of battens for the selected roofing material, you can do this with the sellers of roofing materials.
Uniform distance between battens
To evenly space the battens, use the spacing shown here. It will provide the necessary strength of the roof and save material.
The volume of lathing boards
The volume of boards per lathing (for the entire roof). This value will help you when calculating the cost of lumber.
