How to calculate the area of \u200b\u200ba pitched roof. We calculate the roof area correctly

Calculation of the roof area is a simple geometric puzzle for people involved in construction. However, novice builders may have some problems in order to get all the operations right. Especially if such calculations are made by a person for the first time. Any minor mistake here can lead to the loss of a considerable amount of money. Therefore, in order to answer the question of how to calculate the area of \u200b\u200bthe future roof correctly, it should be understood that the material is more important than the type of roof. The figures obtained by the theory, ultimately, differ slightly from the real state of affairs. Accordingly, the material should always be purchased more than calculated by the formulas.

In this article

Necessary preliminary preparation

Let's take a look at what you need to have on hand:

Calculator, formulas. It will significantly free you from unnecessary gestures, because you just need to drive in ready-made measurements there. You can find such calculators on the Internet.
Roof plan. At least approximate. It is needed to know which of the types will be raised. The plan must contain the angle of inclination, the length of the skate. Based on the finished house plan, mark the width and length of each ramp. In calculating almost every type of roof, you also need to know the height of the entire structure. A constant is often introduced - a calculation factor that depends on the angle of inclination. Here is a list of the most common tilt angles:

9, 14, 18 degrees - p.k \u003d 1.01 and steps of 0.02
23 deg. - p.k \u003d 1.08
27 degrees - r.k. \u003d 1.12
34 deg. - r.k. \u003d 1.20

The general calculation technology for any type of roof boils down to the fact that complex geometric shapes are divided into simple two-dimensional: triangles, parallelograms. For simplicity, even all parallelograms are often divided into triangles, rectangles, trapezoids.

Shed

First, measure the length of the ramp (A). To do this, add the length of the overhangs (ac) to the length of the building (ap, it is the length of the larger wall of the house).

Width (B) is calculated according to the school curriculum (T. Pythagoras), do not forget to add the length of the slopes (bc). We use the projection of a triangle, where the legs are the height of the roof (h) and the width of the building (bп, it is the length of the narrow wall of the house).

B \u003d bc + √ (bп 2 + h 2)

Total, the roof area can be easily calculated: S \u003d A * B

Gable

We apply the same formulas as for the single-slope, with the exception that ap will be equal to the length of the ridge, and half of the length of the narrow wall (bp) will act as the second leg when calculating the width of the slope.

Roughly speaking, we are calculating a pitched roof again. It should be remembered about the overhangs. If you plan to install any window, chimney, then you do not need to take away the area they occupy: it is too easy to make a mistake here and, as a result, there may not be enough material.

The area of \u200b\u200bthe roof of the house will be equal to the sum of the areas of the slopes: S \u003d S1 + S2.

Calculation of the area of \u200b\u200bthe hip roof

The elementary form is called in another way the four-slope or hipped-roof for a reason: here we will have to simply sum up the areas of all the slopes again. But, if rectangles were the previous simple shapes, then here we are dealing with four triangles. The most effective option is to count pairs of triangles using the same school geometric formulas. In any case, all triangles will be isosceles. This means that the area of \u200b\u200beach is calculated by the formula:

St \u003d (m * h) / 2, where m is the base and h is the middle line of the triangle.

Or: St \u003d √p * (p-m) * (p-n) * (p-c), where p is the sum of all sides of the triangle (m, n, c), divided by 2:

As a result, we get the calculation of the entire roof area:

S \u003d 2 * St1 + 2 * St2

Composite hip, structurally divided into two trapeziums and two triangles. The sum of the areas of the triangles is also calculated. We consider the trapezoid as follows:

Strap \u003d (m + b) * j / 2, where m and b are the lengths of the two bases of the trapezoid, and j is the distance between them. If we represent j as a line, then it is perpendicular to both sides.

Calculation of complex roof areas

It is produced in a similar way. If the shape formed by the slopes is not a triangle, rectangle or trapezoid, then it is divided on paper into these simple ones. Further, it is already considered on the basis of their above geometric properties. For example, parallelograms are usually divided into trapezoid, triangles, rectangles.

Roof surface

In order not to be mistaken, the right decision would be to take more material. For such a popular material as slate, there is even a special calculation formula:

S \u003d (2 x ap + ac) x (2 x bp + bc) x cos (y.n). S - the area of \u200b\u200bthe required coverage, the index "c" - overhangs, "p" - the length of the wall surface, a - the length of the slope, b - the width. This area usually exceeds the “empty” roof area by 12%

Metal tiles are considered more complex in calculations: we take into account the ridge, valley, cornices. Often it exceeds the "empty" area by 20%. To understand what area you need to collect material, you need to know its consumption.

The main thing to remember here: the more difficult the roof is in the device, the more expensive the construction is.

The strict geometry of roof coverings defines how the total roof area is calculated as an arithmetically simple task. But the mass of various types of roof construction and the personal preferences of the owner of the home leave many questions and doubts about the correct choice of the method for calculating the area.

The desire to organically fit the house into the surrounding landscape is dictated by the most elaborate roof designs. Tent, mansard, multi-gable projects complicate the calculations. So how can you reliably calculate the area of \u200b\u200byour roof? We will cover this issue in detail from the point of view of the final consumer of roofing.

In this article

Roof type classification

The choice of the type of roof depends on how the under-roof space will be used. In the case of an auxiliary, technical room, the choice is usually stopped on a pitched roof. In the case of a residential attic space, a mansard-type structure is chosen, or, given the presence of natural light, a complex multi-gable roof is built.

Naturally, the roof area is significantly increased, and it will be more difficult to calculate it. Before you start designing a roof, you need to know what they are.

Based on the shape and number of slopes, roofs are divided into the following main types:

a pitched roof is used for baths and utility rooms, less often for residential buildings, which acquire an original and non-standard appearance;
gable roof, one of the most popular solutions in suburban construction, is practical, easy to install and maintain;
the attic type of roof has certain advantages due to the presence of an additional living attic space;
the hip roof is a four-pitched roof, which consists of two trapezoidal and two triangular slopes and is characterized by increased resistance to wind loads;
hipped roof has four or more triangular slopes; it is used in the construction of both residential premises and all kinds of gazebos;
multi-gable roof - a complex broken structure that has an attractive appearance and allows you to use the under-roof space for housing;
the domed roof is used as an architectural element or as a roof for religious buildings.

Such a variety of designs gives a wide scope for the owner's imagination and the ability to combine different types of roofs in one structure. Determining the area of \u200b\u200ba sloped roof is a rather difficult technical task, but we will try to simplify it.

Calculation of the area of \u200b\u200ba simple roof

Before calculating the roof area, it is necessary to know in advance not only the dimensions of the roofing, but also the dimensions of the overhangs on the pediments and cornices. Otherwise, it will not be possible to optimally arrange the sheets and calculate the required stock of material.

Buying additional coverage in case of its shortage, you run the risk of purchasing it from another batch, which can lead to a discrepancy in colors.

When determining the area of \u200b\u200bthe roof of a house, it is necessary to prepare a number of tools and devices in order to draw up a detailed drawing. On its basis, the true area is found, which may differ from simple rectangular shapes. For measurements you will need:

construction tape;
attorney level;
square to determine the squareness of the slope;
pencil and notepad.

The area of \u200b\u200bthe slope, provided it is rectangular, is calculated by simply multiplying the length by the width of the roof. The parameters are fixed taking into account the gable and eaves overhangs, then the amount of required roofing material is calculated, without losing sight of the correction for the overlap of the sheets.

The length of the slope can also be calculated using the Pythagorean formula, measuring the height of the ridge and the width of the house, taking into account the eaves overhang. If the roof is not strictly rectangular, we calculate the area by summing the area of \u200b\u200bthe rectangle and two triangles.

When the house has a gable roof, it is necessary to calculate the quadrature of each slope separately and sum them up to calculate the overall result.

Calculating the area of \u200b\u200bthe hip roof

Complex roofs include multi-gable, hip and domed types of structures, the square of which is the sum of the area of \u200b\u200bvarious geometric shapes. As an illustration, you can consider the calculation of the quadrature of the hip roof. It consists of two isosceles triangles and two trapezoids.

The area of \u200b\u200ba triangle is calculated using the following formula:

S 1 \u003d (a x h): 2,

where S 1 is the area of \u200b\u200bthe triangle, a is the length of the base and h is the height of the triangle.

The area of \u200b\u200bthe trapezoid is calculated using the following formula:

S 2 \u003d [(a + b) x h]: 2,

where S 2 is the area of \u200b\u200bthe trapezoid, a and b are the base of the trapezoid, and h is its height.

Thus, the total square of the hip roof will be equal to:

S total \u003d (S 1 + S 2) x 2

Calculation of the area of \u200b\u200broofs of complex configuration

In the case of calculating the quadrature of more complex roofs, the method of breaking down into simple geometric shapes also fully justifies itself. The drawing made after the measurement will allow you to accurately calculate the squaring of the fragments and, by adding, get the overall result. If a slope or a fragment of the roof has the shape of a parallelogram, you can calculate the overall result using the formula:

where S is the area of \u200b\u200bthe fragment, a is the side length and h is the height of the parallelogram.

When calculating the total amount of coverage, it must be borne in mind that in triangular and trapezoidal sections of the roof, material losses can reach 20% or more.

Hip roofs consist of four isosceles triangles, the quadrature of which is summed up to obtain a general result. Dome roofs can consist of individual sheets of complex shapes, but nevertheless they are calculated by reduction to separate geometric components for a simple calculation of the amount of coverage. It must be said separately that in the case of using flammable roofing materials, it is necessary to provide the workplace with fire protection means.

When calculating the required amount of roofing material, it is not necessary to take into account the outlets of ventilation, chimneys and window openings, by this we reduce the risk of a lack of coverage, since waste on complex roofs can be from 8 to 30%.

On a detailed drawing of a multi-gable roof, individual geometric shapes must be carefully measured, which can be:

parallelogram;
trapezoid;
triangle;
rectangle.

The position of these figures on the roof should be clearly and unambiguously recorded on the drawing, which will allow in the future to draw up a scheme for cutting the coating in relation to its overall dimensions. This will avoid large financial losses and optimally lay the roof.

Complementary roof elements are calculated separately, it is best to do this with the participation of a qualified seller who can check your calculations of the roof square and give additional recommendations. In addition, there are special calculators on the Internet for calculating the area of \u200b\u200bcomplex roofs.

Output

Thus, we talked about the correct calculation of the area of \u200b\u200broofs of various types. Carefulness and thoroughness of measurements, as well as the drawn up installation scheme, will allow you to avoid miscalculations and gross errors. And then the roofing work will take place without financial loss and will bring joy.

Introducing a free gable roof calculator. Online calculation of the battens, the angle of inclination of the rafters and the required amount of materials.

Please indicate the roofing material:

Select a 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) roof 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 tile (25 kg / m2) Ondulin (euro slate) (4 kg / m2) Composite tile (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 D (cm)

Lift height B (cm)

Side overhang length C (cm)

Length of front and rear overhang E (cm)

Rafters:

Rafter pitch (cm)

Wood grade for rafters (cm)

Side rafter working area (optional) (cm) "\u003e

Crate calculation:

Sheathing board width (cm)

Sheathing board thickness (cm)

The distance between the boards of the crate
F (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 \u200b\u200b(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

Roof angle: 0 degrees.

The angle of inclination is suitable for the given material.

It is desirable to increase the angle of inclination for this material!

It is desirable to reduce the angle of inclination for this material!

Roof surface area: 0 m 2.

Approximate weight of roofing material: 0 kg.

Number of rolls of insulation with 10% overlap (1x15 m): 0 rolls.

Rafters:

Load on the rafter system: 0 kg / m2.

Rafter length: 0 cm.

Number of rafters: 0 pcs.

Lathing:

Number of rows of battens (for the entire roof): 0 rows.

Uniform distance between battens: 0 cm.

Number of battens with a standard length of 6 meters: 0 pcs.

Volume of crate boards: 0 m 3.

Approximate weight of crate boards: 0 kg.

Additional information about the calculator

The online gable (gable) roof calculator will help you calculate the slope angle, the size and number of rafters, the number of lathing, as well as the amount of required materials online. Such common roofing materials as metal tiles, slate, ondulin, tiles made of ceramics, bitumen, cement and other materials are pre-entered into the calculation base.

Note! Calculations are made based on SNiP "Loads and Impacts" and TKP 45-5.05-146-2009, taking into account the standards contained in these documents.

Gable roof (there are also spellings "gable roof", "gable roof") - a version of the roof with two slopes, going from the ridge to the outer walls of the building. Today it is the most common type of roof, due to the simplicity of execution, low cost and attractive appearance.

The rafters in the structure of such a roof are supported in pairs on each other and are connected by a crate. The end sides of a structure with such a roof are in the shape of a triangle and are called pediments (sometimes tongs). Usually, an attic is arranged under a gable roof, and small attic windows are made on the gables for lighting.

When filling out the calculator fields, pay attention to the "Additional Information" icon, under which explanations for each item are hidden.

The calculation results are also accompanied by explanations, which you can find below.

Explanations of the calculation results

Roof angle

This is the name of the angle at which the slope and rafters are inclined to the plane of the ceiling. The calculations were made taking into account the fact that it is planned to build a symmetrical gable roof. By entering an angle, you can not only calculate the required amount of materials for a given angle, but also check whether it is possible to build a roof at this angle from the materials you selected. You can decrease or increase the angle by changing the width of the base or the height of the rise: these parameters are rigidly interconnected.

Roof surface area

The total area of \u200b\u200bthe roof slopes, including the area of \u200b\u200bthe overhangs of a given length. Determines the amount of roofing and under-roofing material required for roof construction.

Approximate weight of roofing material

Estimated total weight of the roofing material.

Number of rolls of insulation material

The required amount of roofing material, taking into account the required overlap of 10%. In our calculations, we start with rolls 15 meters long and 1 meter wide.

Load on the rafter system

The maximum possible load, taking into account wind and snow loads, falling on the rafters.

Rafter length

The rafters are measured from the base of the ramp to the ridge of the roof.

Number of rafters

The total number of rafters required for the roof rafter system at a given pitch.

Minimum rafter section

To provide the roof with sufficient strength, you must select the rafters with the cross-sectional options suggested here.

Number of rows of crate

With the parameters you specified, this number of rows of crate is required. If you need to determine the number of rows for one slope, then this value must be divided by 2.

Uniform distance between battens

To eliminate waste of materials and save yourself from unnecessary trimming work, you need to choose a given distance between the battens.

Volume of crate boards

The number of planks required for the lathing of the entire roof (in cubic meters).

Before calculating the roof area, it is necessary to draw up an accurate plan with the application of all dimensions in uniform digital indicators. In addition, you need to know what kind of roofing material will be used for roofing, waterproofing, vapor barrier, thermal insulation. With the calculation of the roof area, each developer will be able to build their roof economically.

Roofs can be of various shapes:

one, two or four-slope
hip or half-hip
gable;
multi-slope

The easiest way is to calculate roofs that do not have kinks on the slopes and are regular triangles or trapezoids. But modern builders are increasingly using multi-slope or hip roofs, where, along with triangles, there may be irregular rectangles, rhombuses and other geometric shapes.

Therefore, if the school knowledge of geometry is still fresh in your memory, you can calculate the roof area yourself, and if you are not at ease with geometry for a long time, then it is better to order the calculation of the roof area to a knowledgeable specialist or use special online tools. We will talk about this in our article.

Roofing plan

If the rafter system is already ready, and there is no house project where the roof plan should be, then you will have to draw up the roof plan yourself.

drawing up a roof plan

The entire roof is measured and a drawing is drawn up, which will show the roof in plan. In addition, you need to measure the height of the roof, from the ridge to the ceiling. If the roof is multi-level and has different heights, measure everything and mark on the drawing where the height of the roof is. If you have the ability to sketch, it is better to make an additional drawing of the roof in the projection, for better clarity.

With such a drawing, it is easier to imagine the appearance of the future roof, decompose it into its constituent geometric elements and calculate the roof area . The dimensions of the future roof are not limited to the dimensions of the perimeter of the house. To them you need to add the values \u200b\u200bof the roof overhangs, where they are supposed.

Examples of calculating the area of \u200b\u200bvarious roofs

A pitched roof is calculated simply - you need to measure the width and length of the building, add the values \u200b\u200bof the estimated overhangs and multiply the resulting figures. But with pitched roofs, this approach will be wrong, because here you need to take into account the angle of inclination of the roof and all individual elements (dormers and other similar structures).

Before calculating the roof area, all complex elements of the roof are divided into separate components - triangles, squares, etc.
When calculating the area of \u200b\u200ba gable roof, you need to multiply the area of \u200b\u200beach slope by the cosine of the roof slope. This refers to the angle that is formed by the slope and overlap.
the length of the slope is taken from the ridge to the extreme line of the cornice
All other roofs with several slope planes are calculated in the same way. The area of \u200b\u200beach slope is found separately and multiplied by the cosine of the angle, which is formed by the slope and a straight line parallel to the ground.
After that, all the values \u200b\u200bobtained are summed up, and the total area of \u200b\u200bthe roof of the house is obtained. .
If the roof slope is an irregular rectangle, it should be divided into regular geometric shapes and calculated separately for each , then add up all the data received.

Here is an example of calculating a gable roof for a house (8 x 6 m), the length of the rafter leg is 3.68 m, the length of the overhang is 0.5 m, the gable overhang is 0.5 m.

We calculate the area of \u200b\u200bone slope - Sabcd \u003d Lcd x Lbd \u003d (8 + 0.5 + 0.5) x (3.68 + 0.5) \u003d 37.6 m2.

The area of \u200b\u200bthe entire roof S \u003d 37.6 x 2 \u003d 75.2 m2.

When calculating from the total area, such elements of roofs as chimneys and ventilation ducts, dormers, skylights or skylights, parapets are not subtracted. If the shape of the roof is very complex or the developer is not able to make calculations on his own, you should contact specialized web resources, where they offer to calculate the roof area online .

Roofing factor

In addition to calculating the roof area, you also need to make calculations of the roofing material that is required to cover this area. In this case, the figures for the area of \u200b\u200bthe roof and the area of \u200b\u200bthe required roofing material will differ significantly. The fact is that individual roof coverings are laid with overlaps, therefore the consumption of materials increases. When calculating the roofing material required to cover complex roofs, it is best to use a roof area calculator.

If it is supposed to cover the roof with slate, then the calculation is made as follows: S \u003d (2 x A + B) x (2xA + C) X cos 30,

where S is the total area, A is the width of the overhang, B is the length of the house, C is the width of the house. 30 * - the angle of inclination of the roof. If the length of the house is 15m, the width is 10m, the width of the overhang is 0.5m, the cosine of 30 degrees is 0.87, the total roof area is equal to 202.2 kV m.

How to find the area of \u200b\u200bthe roof if a metal tile is used as a covering?

useful formulas for calculating area

Consideration should be given to such nuances as the total length of the skates, valleys, overhangs, cornices. When using metal tiles or profiled metal for complex roofs as a covering, it must be borne in mind that inevitable and very significant waste will follow.

If, for less complex roofs, experts recommend buying roofing material with a margin of 7-15%, then for complex roofs, the material supply must be increased to 20%.

The calculation of the soft roof is made according to the same formula as for the slate. The consumption of roofing material depends on its type and installation technology. The areas of skates and valleys are counted separately and ordered separately, because they are no longer measured in square meters, but in linear meters.

Before calculating the area for any structures and roofing materials, a calculation is made for the connection of individual elements, which are almost always overlapped. In this case, the consumption of material increases depending on the size of the overlap, the angle of inclination of the roof. Since, the greater the angle of inclination, the smaller the overlap of the roofing material is allowed.

table of roof slope coefficients

When calculating the area for complex roof configurations and a large number of drops, you can perform a miscalculation by applying the slope correction factors from the table to the area of \u200b\u200bthe horizontal projection (or individual sections)

You should not start laying roofing material without having it laid out on paper before your eyes. In this case, the error in the installation of the roofing will be minimized, and you will not have to buy the missing material to replace the damaged one.

9 degrees - coeff. 1.01;
14 degrees - coeff. 1.03;
18 degrees - coeff. 1.05;
23 degrees - coeff. 1.08;
27 degrees - coeff. 1.12;
34 degrees - coeff. 1.20.

Naturally, there is an overhang.

Calculation for hipped roof

For a square: a x a.

a is the side length.

b is the width of the shape.

a - the base of the figure,

h - figure height,

How to calculate the roof area of \u200b\u200ba house

When starting construction, the question always arises, how to quickly and correctly calculate the roof area? This operation seems to be simple only at first glance. In practice, however, it turns out that the calculation is quite difficult even for experienced craftsmen. Since the total amount of money spent on the construction of the roof directly depends on its correctness. Considering the high cost of building materials and the cost of installation work, you can try to reduce the cost of the entire project. Let's try to figure out what is needed to perform the correct quadrature count.

Friends, U-ra, it happened and we are glad to present you with an online calculator for calculating the roof area, now you do not need to figure out anything on a piece of paper or in your mind, everyone just indicated their parameters and received an immediate answer. Now you will know exactly how much material you need to cover the roof. Here is a link to the calculator -\u003e Roof area calculator, online roof calculation. In addition, we have many other construction calculators, you can see a list of all on this page: Construction calculators

The main stages of work

Calculation of the roof area should always start with:

familiarization with the future project of the roof of the house and memorizing the most key parameters: the length of the ridge, the angle of inclination, height, width and length;
determining the type of roofing material to be used.

One of the most important characteristics is a special calculation factor, which is present in absolutely all formulas. Its value depends on the angle of the roof slope and is determined by the following ratios:

with a slope of 9 °, the coefficient will be 1.01;
for 14 ° - 1.03;
for 18 ° - 1.05;
at 23 ° - 1.08;
at 27 ° - 1.12;
for 34 ° - 1.2.

The indicated range of angles of inclination of the roof - these are the most popular options used in construction in our latitudes. It is possible to determine the parameters of a structure with a complex geometric shape by dividing it into separate small figures, which can be easily calculated by summing the obtained values \u200b\u200bat the end. Experts recommend adding about 10% to the result obtained, which is the standard amount of stock in construction.

Formulas and definitions

The easiest calculation option is to determine the area of \u200b\u200ba shed roof with any slope. Houses with this kind of roof are usually covered with simple materials, and the most common shape is a rectangle. To calculate the roof area, we need to know the length of the ramp and its width, which should be multiplied with each other with a predetermined design factor.

It should not be forgotten that the value of the area of \u200b\u200bthe slope overhang, which is mandatory for roofs of this type, should be added to the area of \u200b\u200bthe shed roof of the house.

To calculate the area of \u200b\u200ba gable roof of a house, it is necessary to take into account much more values \u200b\u200band factors. So, for a slope 6 running meters long and a ridge of 9.5 running meters, the calculation formula will take the following form: the length of the ridge should be multiplied by the length of the slope and multiplied by the number of slopes (in our case, 2). If you need to calculate the amount of metal tiles for this roof, then you should first determine the dimensions of one sheet of roofing material. The formula that will allow you to count the number of sheets of metal tiles is as follows: the length of the ridge is divided by the width of the roofing sheet and rounded to a larger value. To carry out such calculations, it is important to know well the geometric parameters of the roof of the house and the geometric parameters of the roofing material.

Final conclusions

The area when using other materials can vary significantly. For this reason, each particular case requires an individual approach, careful analysis and competent calculation. The most difficult situation arises when it is necessary to calculate the quadrature of complex roofs. To get a reliable result, you should follow a few simple rules.:

You should know that when calculating the area, it is important not to forget to take into account ventilation ducts, skylights, chimneys, parapets, hatches and other elements. In case of violation of this rule, there is a high probability of a shortage of building materials when arranging the roof. Correct and competent calculation of the area will provide all the conditions for optimal spending of financial resources associated with the purchase and we will open the material when erecting the roof of the house.

How to calculate the roof area of \u200b\u200ba house. Formulas, diagrams and calculation

Calculate the roof area for those who know how to use a tape measure and calculator will not be difficult. Because the whole calculation comes down to calculating the areas of individual slopes, and if the roof of the house is not complicated, but an ordinary two- or four-slope, then it will be even easier to calculate the area.

There are a huge variety of types and geometric shapes of roofs of private houses, but the roof slopes themselves are, as a rule, four geometric shapes:

rectangle
trapezoid
equilateral triangle
parallelogram

In this article, we will consider the area of \u200b\u200bpitched roofs only, the area of \u200b\u200bflat and inverted roofs will not be calculated, because the area of \u200b\u200bsuch roofs, in most cases, will be equal to the area of \u200b\u200bthe house or part of it located under this roof.

And if you learn to calculate the area of \u200b\u200beach such slope separately, the formulas of which are presented below in the diagrams, then it will be very easy to calculate the total area of \u200b\u200bthe roof.

It must be remembered that the more slopes on the roof, the correspondingly it will be more difficult not only in terms of construction, but also roof insulation, decoration and maintenance. And during the construction itself, a lot of unused scraps will remain, which will become unnecessary financial costs.

And so, before you get a calculator and start counting, you need to have a roof plan on hand. If there is none, then you will have to take a tape measure, a sheet of paper, a pencil and start measuring the slopes.

What sizes of slopes are needed, and what exactly to measure, depends on the type of roof of a private house, which are described in detail in one of the previous articles, and here I will tell you how to correctly apply the calculation of the area to a specific type.

Calculation of the area of \u200b\u200ba shed roof

This is the simplest calculation that can be done without a detailed roof plan.

It is necessary to measure the length C and width D of the ramp.

It is not difficult to calculate the length of the slope, it is necessary to measure the length of the building and do not forget to add roof overhangs on both sides. If the width of the slope cannot be measured for some reason, then you will have to measure the height of the roof B and the projection of the slope A (according to the diagram). Then we apply the Pythagorean theorem and find the width of the slope C.

Calculation of the area of \u200b\u200bthe gable roof of the house

The calculation of such a roof, I think, will also not be difficult.

Calculation of the area of \u200b\u200bthe hip, half-hip and hip roof of a private house

To calculate, you need to mentally break the hip roof into four separate ramps, as shown in the diagram, and then calculate each ramp separately.
After splitting, you should have two trapezoids and two equilateral triangles if the opposite slopes are equal.

Now let's calculate the areas of these geometric shapes using simple geometric formulas, then add the resulting areas of the figures. This completes the calculation, as you have seen, there is nothing complicated here.

Half hip roof area a private house is considered in the same way, except that the triangular slopes will be smaller than those of the hip, and the main large slopes must be divided into two geometric shapes, a trapezoid and a rectangle, calculating their area separately.

Counting technology hip roof area the house is no different from the hip one, we also break the roof into four slopes, only here you should already get four equilateral triangles. The area of \u200b\u200bthese triangles is calculated in the same way as in the previous examples.

Calculation of the area of \u200b\u200ba complex roof with numerous slopes

Such roofs, as a rule, include domed and multi-gable roofs of private houses, containing a large number of different slopes.

Although the formulas for the calculations are very simple, it will still not be easy to calculate the area of \u200b\u200bsuch a roof. The whole difficulty will lie in a large number of measurements, because each slope will have to be measured separately, and the more difficult the roof is, the more difficult it will be to do it. Having an accurate roof plan can make the task easier.

Complex roof area calculation technology

First, we break the roof into separate flat slopes. As mentioned at the very beginning, the slopes of a complex roof can be in the form of three geometric shapes:

equilateral triangle
rectangle or square
trapezoid
parallelogram

Calculation of material for the roof of a private house

Calculating the material for the roof is much more difficult than calculating the area of \u200b\u200bthe roof itself. Sometimes the roof area is half the area of \u200b\u200bthe ordered material. In order not to make mistakes in the calculations and not to buy too much, and it is even worse when there is not enough material, you need to contact the specialists from the company from which you will order the material. Most organizations have this service free of charge. They will very accurately calculate the number and size of the sheets and give you the layout on the roof.

Since roofing materials, as a rule, have a rectangular shape, and roof slopes are not always, the sheets will have to be cut and adjusted to the corners of the slope. And the more complex the roof, the more unnecessary scraps you will have. It must be remembered, no matter what material you choose for roofing, during installation, the layout of the sheets should always be at your fingertips so that you do not cut off the wrong sheet when cutting.

How to correctly calculate the roof area

The construction of every house does not begin with digging foundation pits and pouring foundations.

Construction begins with project development and calculations.

With the roof, everything happens in the same way: before proceeding with its construction, a careful calculation of the height, the size of its surface is performed, the number of structural elements and the amount of material for the roofing cake are determined.

The strength and reliability of the roof, as well as the amount of financial resources that will be spent on its device, depend on the correctness of the calculation performed.

The surface calculation always starts with:

measurements of the main parameters of the roof: inclination angle, ridge length, length, width and height;
determining the type of roofing material that is planned to be used in the future when installing the roof.

One of the most important characteristics is the calculation coefficient, which is used in almost all formulas for calculations.

The value of such a coefficient depends on what is the angle of inclination of the slopes in your house.

For the most popular tilt angles, the coefficient is:

9 degrees - coeff. 1.01;
14 degrees - coeff. 1.03;
18 degrees - coeff. 1.05;
23 degrees - coeff. 1.08;
27 degrees - coeff. 1.12;
34 degrees - coeff. 1.20.

If the shape of the roof is complex, of irregular shape, then during calculations its surface is divided into separate regular figures, the area for which is considered elementary.

And at the end, the results are summarized.

Calculation procedure for a pitched roof

This is geometry from the school course.

Houses on which a pitched roof is arranged are usually covered with simple materials.

And the rectangle is the most common shape.

Therefore, it is enough to measure the length and width of such a rectangle and multiply them.

You should also not forget the coefficient mentioned above.

We calculate the gable roof

Calculations for the surface of a gable roof are more complicated.

And there are many more factors to be considered in such calculations.

To begin with, we decompose all complex elements, as mentioned, into separate simple shapes: rectangles, squares, triangles.

Indeed, on the roof, each corner is formed only by an overlap and a slope.

Therefore, in order to calculate the roof surface, it is necessary to multiply the area of \u200b\u200beach slope by the slope cosine.

With this calculation, the length of the ramp is the distance from the ridge to the eaves line.

Any roof with any number of slopes is calculated in the same way.

You just need to sum up the resulting surfaces of all slopes, multiplied by the cosines of their angles.

If a roof element has a complex irregular shape, then it is also divided into several simple geometric shapes and the area of \u200b\u200beach of them is considered.

Then all surfaces are added.

Let's see how this is done in the following example: the house measures 10 x 8 meters.

The rafters are 4.5 meters long.

Naturally, there is an overhang.

The overhang length is standard - 50 cm.

First, we calculate what surface one slope has:

S \u003d (10 + 0.5 + 0.5) x (4.5 x 0.5) \u003d 55 square meters.

Since the building has two such slopes, the total area will be 55 x 2 \u003d 110 square meters.

Despite the fact that there are ventilation ducts, chimneys, dormer and attic windows, parapets on any roof, they are not subtracted from the resulting area value.

We consider a hipped roof

Then you should determine how difficult each of them is.

The simplest hipped roof has a pyramidal shape.

Therefore, when calculating its surface, the formula for the pyramid is used.

If all the slopes are of the same size, then it is enough to calculate the area of \u200b\u200bone of them and then multiply by four.

In the case when the hipped roof has a complex shape, then it is divided into simple figures and the surface of each of them is calculated separately.

Indeed, for such a roof for different slopes, the angles of inclination can differ significantly.

It should also be remembered that the dimensions are taken not along the perimeter of the building, but along the overhangs of the cornices.

We calculate the hip roof

In order for the calculation of the hip roof to be performed correctly, the following must be taken into account:

window size and chimney size;
the length of the slope (between the ridge and the cornice);
parts that are not included in the roofing (overhangs, parapets, etc.);
when performing the calculation, the abutment of roofing plates, cobbled ledges, standing seams are not taken into account.

Calculation of the surface of the hip roof consists in finding the area of \u200b\u200btwo end triangles and two trapezoids.

In any case, if the hip roof has a complex shape, it is divided into several simple shapes and calculations are performed separately for each of them.

And then the calculation results for each shape are summed up.

You should know that even though the hip roof is the best roofing solution, its device is not cheap.

Calculation for hipped roof

A hipped roof is one of the varieties of a hipped roof.

So let's say it's a classic roof with four slopes.

This construction is based on a quadrangle.

And the slopes are isosceles triangles, converging at the central top point.

Such a roof is the most economical, since the gables are completely absent in it.

More about the device of a hipped roof with your own hands.

About Unicma soft roof here. The whole range of the construction company "Unicma" is presented.

Since the slope is equal to an isosceles triangle, then:

b is the length of the base of the triangle;

S is the area of \u200b\u200bthe triangular slope.

Calculation of a broken attic roof

The area of \u200b\u200ba sloping mansard roof, despite the apparent complexity, is quite simple to calculate.

To do this, you should, first of all, make a roof plan indicating all dimensions.

The entire roof will be a set of simple geometric shapes: triangles, squares, rectangles, trapezoids.

For a square: a x a.

a is the side length.

b is the width of the shape.

a - the base of the figure,

h - figure height,

a and b are the sizes of the upper and lower bases.

After calculating the area of \u200b\u200beach of the simple figures into which the broken mansard roof is broken, the results are summed up.

Video about the construction calculator for calculating the roof.

Sergey Novozhilov is an expert in roofing materials with 9 years of practical experience in the field of engineering solutions in construction.

A gable roof is a complex, large building structure that requires a professional approach to the design and implementation of work. The biggest costs go to building materials for rafters, battens, insulation, waterproofing, roofing material. Our gable roof calculator will allow you to calculate the amount of material.

Using a calculator saves time for roof design and your money. The final 2D drawing will guide the work, and the 3D rendering will give an idea of \u200b\u200bwhat the roof will look like. Before entering data into the online calculator, you need to have an understanding of the roof elements.

Rafter parameters

To calculate the rafter system of a gable roof, you need to take into account:

roof load;
step between the rafters.
type of roofing

100-150 mm with a span length of not more than 5 m, and with additional props .;
150-200 mm with a span of more than 5 m, with a step of more than 1 m, and if the angle is not large.

Important! The distance between the rafters of a gable roof is usually set to 1 m, but with a roof slope of more than 45 degrees, the rafter pitch can be increased to 1.4 m.With flat roofs, the pitch is 0.6-0.8 m.

The rafter legs are attached to the Mauerlat, which runs along the perimeter of the house. For it, either a board with parameters 50x150 mm is taken, or a bar of 150x150 mm (for load distribution)

Sheathing parameters

For the metal tile, a sparse crate is created with a board, the width of which is 100 mm, and the thickness is 30 mm. The board is packed with a pitch that should correspond to the longitudinal axis of the metal tile module - 35 cm (supermonterrey).

For shingles, the sheathing is performed with a large step, since OSB or plywood will be laid on top of it with a solid carpet.

Important! When choosing materials, pay attention to the indicators of moisture resistance and minimum thickness.

When installing warm roofs, a counter-lattice is made between the waterproofing and the roof with a bar, the thickness of which should be 30-50mm.

Roofing parameters

To calculate the roof of a gable roof, you need to know the dimensions of the roofing material and the size of the overlaps.
Metal tiles for a rigid roof are produced with a width of 118 mm (working 110), but the length can be different. The manufacturer can cut any length to order.
Flexible shingles for soft roofs have different sizes, so you need to look at the specific material
As for the choice of insulation, a minimum thickness of 100 mm is recommended for Russia, and the correct one will be 150-200 mm.