How to measure square meters of a house roof. We calculate the roof area correctly. Calculation of the area of ​​a complex roof with numerous slopes

Correct calculations when planning new construction or carrying out repairs can significantly save on basic and consumables. The roofing pie is one of the key components of the house. In the process of designing it, you need to know how to calculate the area of ​​the roof and be able to calculate the area of ​​each of its elements. There are special computer programs for this. But, unlike machine calculation, manual calculation gives a more accurate result, since it allows you to take into account the nuances further installation roofing material.

Geometric roof shapes

Diversity geometric shapes the top of the house determines the difficulty of calculating its area. The most common stingray shapes:

• rectangle;
• trapezoid;
• isosceles triangle;
• parallelogram.

Calculating the roof area is quite simple if it has one, two or four slopes. The more elements, the more complicated it is, the more measurements and mathematical operations need to be done.

The calculation can be done in two ways:

1. Make calculations based on the plan of the top of the cottage. All linear dimensions of each slope must be written down on it. All that remains is to calculate the area of ​​each element and find their sum.
2. Take “live” dimensions from already finished roof and perform mathematical operations. This option is more accurate, since an absolutely exact match between the actual dimensions of the top and its plan is very rare.

In both cases, you need to pay attention to symmetrical slopes. This primarily applies to elements of two or four pitched roof.

Calculation of the area of ​​​​one- and two-slope roofs

These two types are the simplest, since the slopes of the single-pitched and double-pitched roof of the house usually have rectangular shape. Calculating their area can be done even without a detailed plan. It is also quite easy to take measurements.

The area of ​​a pitched roof is equal to the area of ​​one roofing rectangle:

A and B are the width and height of the slope, respectively.

These parameters can be found even without climbing to altitude. It is enough to find out the length and width of the house and add the overhangs of the top of the house to them. Next you need to measure the height of the roofing pie and use the Pythagorean theorem to calculate its length. Now you can multiply the obtained parameters and get the desired result.

Using a similar scheme, the area is calculated gable roof. It can always be imagined as two single slopes. Accordingly, and similarly, the dimensions of this type of roof are taken. If the slopes are symmetrical, you can remove the parameters of only one of them. Knowing the length, you can calculate the area of ​​the gable roof gable, especially if it is planned to be lined with corrugated wall sheeting or siding.

The result for each roof element is determined using the same formula for the area of ​​a rectangle:

Having found out the area of ​​​​both elements, by simply summing them up one can calculate general meaning for a gable roof surface.

Calculation of the area of ​​a hip, hip and half-hip roof

These roofing options have a more complex configuration, so to calculate the area mansard roof it takes more time. They are all hipped, which means more measurements need to be taken.

A type of roofing surface composed of two trapezoids and two triangles is called hip. In most cases, its opposite sides are equal, and the triangles are isosceles. For such a symmetrical hip roof, it is enough to calculate the value for only two adjacent elements and multiply the result by two. If the dimensions of each are different, you will have to measure the entire roof.

After the measurements have been taken, you can calculate the value for each element. For trapezoidal elements you need to use the following formula:

S=(a+b) x h / 2, where

a – width along the lower overhang,
b – width along the ridge,
h – height.

For triangular elements the formula is used:

S= a x h / 2, where

a – width of the slope along the lower overhang,
h – slope height.

Well, in the end, as in previous cases, the sum of the results of calculating all elements is calculated.

The half-hip design differs from the hip design in that instead of trapezoidal elements it has hexagonal, Bottom part which are in the shape of a rectangle, and the top is a trapezoid. Accordingly, the measurement process is slightly different. In a hexagonal element, you need to measure its two components separately, and also do calculations separately. The formulas can be found a little higher in this article. Again, the total area of ​​a half-hip roof is the sum of the calculation results of all its elements.

The traditional tent top is made up of four isosceles triangles. Usually it is symmetrical, so measurements can only be taken on two adjacent elements. It is only necessary to find out the height of each of the slopes and their width along the lower overhang. Next, using the formula given just above, each element is calculated and the final calculation of the hip roof is made.

Calculation of roof area with slopes with complex geometry

Multi-pitched roofs with elements with complex geometry no longer surprise anyone. These are the so-called dome and multi-gable structures. These top of house solutions are very attractive. Calculating the roof area of ​​this configuration is much more difficult than in the case of conventional hipped options. But an accurate calculation is necessary, since there is a large number of stingrays, each of which has different shapes. The construction of such structures is quite expensive and the slightest mistake will inevitably lead to additional expenditure of money and time.

The main difficulty in the process of calculating a multi-slope roofing surface is the dimensioning stage, and the more elements in the structure, the more difficult it is to take measurements. You can't do this without climbing onto the roof. In any case, it is necessary to make a drawing of the roof and measure each slope. For each of them separately, it is necessary to calculate the area using the formulas given above, then, summing up the data obtained, find the total area of ​​the roof.

The issue of calculating the roof area must be approached very carefully. After all, roofing materials are quite expensive and errors in calculations will lead to unnecessary costs. It must be remembered that when purchasing roofing materials, you need to make a small margin, since they are laid with an overlap, and this is not taken into account when calculating the roof area.

To order the correct quantity of metal tiles and optimal cutting of its sheets, it is important to correctly measure the roof. The easiest way to measure is single-pitch roofs with standard geometry, but such structures are becoming increasingly rare. More often, roofs have a complex shape, additional elements, and the outlets of pipes and auxiliary structures are located on the surface of the slopes. All this complicates measurements.

General requirements

Compliance with safety regulations. Measurements are carried out at heights, and therefore it is important to ensure that such work is carried out safely. To do this, you need to use a strong, stable ladder, comfortable shoes with non-slip soles, and a safety belt. It is better to take measurements with at least two people.

High quality measuring instruments. To take measurements of the roof, you will need a square, a building level, a tape measure, and a building cord. In some cases, it is more convenient to use a laser measuring tool. All accessories must be of high quality and give accurate measurement results.

Taking measurements on the outer surface of the slopes. The most accurate result will be if the roofing for metal tiles is measured after installation of the rafter system. Even if the customer has a detailed roofing project, finished design It is better to measure it to ensure the accuracy of its dimensions and their compliance with the design dimensions. Measurements are made not on the internal, but on the external surface of the slope, taking into account the slope, the actual geometry, and the corners of individual elements obtained during installation of the rafter system.

Preparing for measurements

If the roof has a complex shape, each of its elements must be “broken” into simple geometric shapes. For this purpose, a overall plan roofs and drawings of individual slopes and sections. It is important to carry out this division in an optimal way so that the final number of figures is minimal, and they themselves have as many simple form. The more shapes you get, the more complex their shape, the more waste will be left during installation. In addition, the number of joints will increase, which can reduce the reliability of the roof structure. Finally, when ordering metal tiles, sheet sizes and price are related to each other: the more small-area elements you need, the more expensive the roofing will be.

According to the experience of the Rufstroy company, it is easiest to work with single-pitched and gable roofs without additional elements: Each of the slopes has the shape of a rectangle. More complex are hip roofs, roofs with protruding elements, consisting of large number structural elements.

At the stage preliminary preparation The roof surface is divided into the following shapes:

• rectangles, squares (to calculate the area, the length is multiplied by the height);
• isosceles or right triangles(the product of the legs is divided in half to obtain the area value);
• regular trapezoids (the area is calculated by adding the lengths of the sides, multiplying by the height and dividing by two);
• parallelograms (quadrangles with indirect angles; it is important to control the correspondence of the angles to the design drawings especially carefully; the area is calculated by multiplying the height by the length of one of the sides).

Carrying out measurements for different types of roofs

Single-pitch. The simplest option, the slope is shaped like a square or rectangle. For such a roof, the length of the slope from the ridge to the overhang and its width are measured. Additionally, it is worth checking the diagonals (they should be equal to each other) and measuring the resulting slope angles.

Gable. Measurements are performed in the same way as for a pitched roof. To calculate the total amount of material, the resulting areas of the slopes are added up.

Hip. The roof consists of four slopes. They can be different in shape, but most often the opposite sides of the structure are the same in geometry and size. This roof consists of two triangles and two trapezoids. If the triangles are equilateral, the trapezoids will be equal in area. When taking measurements, it is necessary to determine the length of each of the slopes, their width at the overhang and at the ridge (for trapezoids). The angles of the resulting figures are also controlled separately. For half-hip structures, rectangles on triangular slopes are additionally measured.

Tent. Formed by four equilateral triangles, which should be equal in height, length of the legs and base. If possible, it is better to measure each of the triangles separately to make sure that the geometry of the structure is correct.

Roofs of complex geometry. Dome, multi-gable and other roofs require more complex measurements. Each of the slopes in this case is measured separately. If there are symmetrical elements, their geometry and dimensions must be the same. The compliance of the angles with the project must be monitored.

Measurements for additional elements

When taking measurements on the roof, you should immediately take the dimensions necessary to order some additional elements.

Ribs, skates. Close the top joint of the slopes. All sections of such joints are measured by length. When calculating the quantity ridge strips take into account that they are laid with obligatory overlap.

Endovy. If the slopes fit together, forming internal corner, it is covered with valleys and grooves. The length of such joints is measured from the top to the bottom point.

Cornice strip. Installed along bottom edge stingray To calculate the number of such strips, the edges are measured and overlaps are taken into account.

End strip. Covers the ends of the slopes above the gables. Its length corresponds to the length of the slope.

Connections, wall strips. Used at the junction of the roof and walls of pipes, chimneys, etc. When performing measurements, the location of such joints is determined in advance, and their length is measured.

Currently, throughout the world, including in Russia, such an industry is developing at a rapid pace. National economy like construction. Since ancient times, this type of activity has been highly valued and in demand. And to this day nothing has changed. Every year thousands of new houses are built, new ones are furnished and renovated. Owners of private houses who decorate their properties are of particular interest in construction. It can be small dachas, small houses or large cottages. One of important stages construction - this is a roof covering.

Construction of a house is never complete without a roof, so you should carefully approach the design of this part of the house, because... It is this that protects the house from precipitation and other natural influences.

Home, that is, his appearance, is largely determined by it. The roof can be covered with various materials: slate, metal tiles, metal sheets and so on. The work requires accurate calculations of the material and necessary tools. Both specialists and the owner of the house can cover it, it all depends on desire and skills. Plus, you can save a lot of money. Let's take a closer look at how to calculate the area of ​​this part of the house, because this is one of the main and most important preparatory stage during work.

Main types of roofs and their advantages

Before making a roof, you need to decide what materials will be used for roofing, thermal insulation, waterproofing and so on. It is necessary to draw up an accurate plan on which all dimensions will be plotted, it is advisable that everything is in digital values. It is not necessary to know the area; this is necessary in order to accurately calculate the amount of material for construction and not overpay. Once all the information has been collected, the developer can begin installing the roof for the house.

Any specialist in this field should know what types there are. They come in single-slope, double-slope, tri-slope, hip, half-hip, gable and multi-slope types. The easiest way to count those that do not have kinks. But increasingly, builders are making multi-slope and hip roofs, so the material has to be carefully calculated. If in simple roofs All surfaces are presented in the form of regular triangles or trapezoids; in the latter case, they can have a variety of geometric shapes.

How to make a roof plan

Scheme of a pitched roof.

If there is no plan for the house itself yet, but rafter system is already ready, then you need to start taking measurements. In this case, it is necessary to measure all of it. First, its height is measured from the ridge to the ceiling. If the roof consists of several levels, then they are all calculated. It is recommended to make a drawing for greater clarity, preferably in profile. Having all this, the future roofing process will be much easier and faster. It must be remembered that even if all the components into which it is decomposed are simple, you do not need to limit yourself to measuring only the perimeter of the roof; in addition, the dimensions of the overhangs of the future roof are also taken into account.

Let's take a closer look at how a pitched roof is calculated, how it is broken down into components, what formulas are used for this purpose, and the like.

Example of roof area calculation

The roof slope has the shape of a rectangle (ABDC). The area of ​​such a rectangle is equal to the product of the lengths of its two adjacent sides.

The roof area to be covered with slate is calculated using a simple formula. If the roof is gable, then the area of ​​the slope is first calculated, and the resulting figure is multiplied by half. Most often, the roof slope has the shape of a rectangle. The area of ​​a rectangle is equal to the product of one side, that is, the length, and the other side (the width of the house).

For example, if the size of the house is 8x6 m, the length of the rafter leg is 3.38 m, the length of the eaves overhang is 0.5 m, the size of the front overhang is also 0.5 m, then the area of ​​one slope is 37.62 meters.

The calculation was carried out as follows: (8 + 0.5 + 0.5) x (3.68 + 0.5) = 9 x 4.18 = 37.62 m. Then the entire area will be equal to 37.62 x 2 = 75, 24 m. Thus, the lengths of the overhangs and rafters must be taken into account.

If the roof is single-pitched, the dimensions of the house are 8x6 m, the length of the rafter leg is 7.35 m, the length of the overhangs is 0.5 m, then the area of ​​the roof slope will be 66.15 m: (8 + 0.5 + 0.5) x 7, 35 = 66.15. For hipped roof everything is a little more complicated. In this case, you need to calculate the area of ​​an isosceles triangle, and then multiply the result by the number of triangles, that is, 4. Its area is equal to the product of its height and half the length of the base. Here, the length of the rafter leg, the base of the roof and the dimensions of the ridge are also taken into account. The length of the altitude of a triangle is calculated using the Pythagorean theorem. It is equal square root from the difference between the square of the length of the rafter leg and the square of the length of one side of the roof base.

How to calculate roof area for slate roofing

Depending on the roof configuration, there are various ways laying slate.

When building a roof, it is important not only to calculate the area of ​​the roof itself, but also the area required roofing, that is, material. The thing is that some roofing materials require a large overlap, so they may not coincide with the data obtained from calculating the roof surface area. Thus, material consumption increases. When calculating roofing coverage, the easiest way is to use a roof area calculator.

There is a formula to determine the coverage area. It is suitable if you plan to cover the roof with slate. It looks like this: S = (2 x A + B) x (2 x A + C) x cos 30, where S is the total roof area, A is the width of the overhang, B is the length of the building, and C is its width, 30 - roof inclination angle. Here it is important not to make mistakes in the calculations and sequence of actions. Even a schoolchild can carry out similar calculations. An interesting fact is that for everyone building material There are formulas and methods for obtaining reliable data. Therefore, before doing anything, it is important to decide on the choice of building material.

How to calculate the material and area to cover with tiles

When calculating the required amount of metal tiles, it is necessary to take into account the type and technology of installation, as well as the angle of the roof.

Along with slate, metal tiles are a very popular material in the construction industry. When calculating areas, you need to take into account some subtleties. If in the previous case there was no need to take waste into account, then here it is very relevant. If at regular work with a simple roof the percentage of production waste is approximately 7-10%, then for complex and fancy designs this figure increases to 20%. Calculation soft roof done according to the above scheme. The type and technology of installation are taken into account. The areas of skates are measured separately and not in square meters, but in linear meters.

You always need to remember how the roofing material is supposed to be connected; the size of the overlap and, accordingly, the volume of the roof depend on this. Much depends on the angle of the roof. The higher it is, the less overlap is planned. There are so-called correction factors for complex roof configurations. It is not recommended to start work without having a roof diagram and drawings with calculations on paper, otherwise you may not get what you want.

We can conclude that covering a roof with one material or another is a fairly simple matter. Be sure to select required material, take measurements, following all instructions, calculate required amount roof and compare it with previous measurements. The basic principle underlying calculations is the breakdown of large and complex surfaces into smaller geometric structures, for example, regular triangles, squares, trapezoids. This is not necessary, but it will make things easier and save you a lot of time. If your abilities in mathematics are weak, then it is best to seek help from specialists who know a lot about this matter. They will do everything quickly and efficiently.

There is a formula by which calculations are carried out. It contains data such as the length and width of the house, the length of the rafter leg and the dimensions of the slopes. For this part of the house, it is important to measure the size of the overhangs and take into account the percentage of expected waste, most often it is 10-15%, which is a lot. The amount of work is largely determined by the type of house. Houses can be simple with pitched roof or with intricate outlines, respectively, the surface of the roof will be uneven. Great importance also has a styling technique. It’s one thing if professionals work, and another thing if inexperienced owners who do not know all the subtleties. Therefore, if you plan to cover the roof of your house with your own hands, then this material will help you do everything correctly and consistently. If difficulties arise, it is better to call a team of specialists.

After choosing a roof, everyone wants to estimate the budget required to purchase roofing material. To do this, you need to know the dimensions of the roof and be able to correctly calculate optimal quantity sheets of metal tiles. For a simple design, you can easily do it yourself.

Standard or custom metal tile sheets?

Many people do not know that sheets can be ordered in almost any length (usually from 0.5 to 6 m), and not just standard sizes.

Standard sizes of metal tile sheets of the most popular profile "Monterrey": 0.5 m; 1.15m; 2.25m and 3.65m. The lengths correspond to one-, three-, six- and ten-wave sheets.

Fig. 1: difference between standard and custom metal tile sheets

This fact allows you to purchase a roof with the maximum amount usable area and, of course, save on your purchase. Suppose (Fig. 1), we have a slope length of 6.5 m and we want to cover it vertically with two sheets. In this case, custom-made sheets will be 3.65m and 3m long (where 15cm is the overlap of the sheets). When standard sheets we will get two modules of 3.65 meters each, i.e. extra 65 cm from each sheet of metal tile.

When ordering sheets of metal tiles to fit the roof size, take into account the vertical overlap of approximately 15 cm.

Calculation of additional finishing elements

Let us immediately give an example of an image that shows all the necessary finishing elements for metal tiles:

The presented elements are used not only as components for metal tiles, but are also used in other roofing materials, having slight differences in shape.

The elements have a standard factory length of 2 meters. Since for greater tightness they are stacked on top of each other by about 10 cm, we will use the general formula to calculate them.

Quantity of a certain additional element for the roof = L/1.9. Where L - full length, which needs to be closed, 1.9 m - the useful length of the standard element. The resulting result is rounded up.

Example. Let's assume the length of the roof along the ridge is 7 meters. Then the number of skate slats will be 7/1.9=4. In a similar way, we independently calculate other metal tile finishing elements.

Number of screws for fastening metal tiles

A necessary element of any metal profiled roof is fasteners, thanks to which the material is securely held on the sheathing. For metal tiles, special self-tapping screws with a special rubberized washer are used. The most commonly used sizes are 4.8x28 and 4.8x35 mm, where the first value is the diameter, and the second is the length of the fastener. The average consumption of such self-tapping screws is from 6 to 8 pieces per square meter of roofing. Typically, fasteners are supplied in multiples of packaging. The average number of such screws in a package is 250 pcs.

The metal tile sheets are fastened together with 4.8x19 mm self-tapping screws at the top of the wave approximately 20-25 cm apart. They are packaged in multiples of 250 pcs.

For fastening additional elements (ridge, wind bar, upper valley and abutment strip) a 4.8x50 or 4.8x70mm self-tapping screw is used, also installed after 20-25 cm. Quantity per package - 100 pcs.

Calculation of metal tiles for rectangular slopes

There are many online services according to the calculation of metal tile sheets, but they, as a rule, do not take into account the dimensions of the sheet and, as a result, give the total roof area, which may differ significantly from the correct one. We need to know the exact number of sheets and their length. To calculate the material, it is necessary to “decompose” the roof into separate slopes, representing various geometric shapes. In most cases, the roof consists of slopes in the shape of rectangles, triangles and trapezoids. Let's start by calculating a rectangular slope.

To begin with, we clarify the full and usable width (taking into account the interlocking ceiling) of the metal tile sheet. The Monterrey profile has a total width of 1.18 or 1.19 m. Useful is almost always equal to 1.1 m.

In the case of a gable roof, we have two rectangular slopes. Let's assume that each of them measures 9.5 x 6.5 m (see figure). Based on the calculation of the useful and full width of the metal tiles being 1.1 and 1.18 m, respectively, we get 8 full sheets of 3.65 m each and the same amount of 3 m in length. The width of the overlap will be 8.88 m. We perform similar calculations for another slope. The uncovered area of ​​the roof can be covered by cutting the sheets (3.65 and 3 m) lengthwise into 2 equal parts. As a result, for a given roof size you will need 16 sheets of metal tiles 3.65 m long and the same number of three-meter sheets. The area of ​​the roofing material will be: (3.65m + 3m) x 1.18m x 16 = 125.55m² (formula for calculating the area of ​​a rectangle S=a*b). Rectangular slopes have least amount waste metal tiles!

Please note that the area of ​​metal tiles will always be larger than the area of ​​the roof due to the longitudinal and transverse overlaps of the roofing sheets.

In a similar way, you can find out the number of sheets not only for a gable roof, but also for a mansard roof (broken), which has 4 rectangular slopes.

Calculations of metal tiles for a complex roof

With a gable roof everything is quite simple. But what if you have to count on the hip or hip roof? The first consists of two triangles and two trapezoids. In the second option - only triangles (see the article "roof shapes"). Such complex roofs will require more roofing material since the corners of the metal tiles will need to be cut. For more accurate calculations, specialized programs are needed, for example, “Roofing Pro”.

The program allows you to determine the number and length of roofing sheets for a roof of any complexity, as well as add the necessary cutouts in the slopes.

During construction, people face a lot of different problems. One of them is arranging the roof and calculating the amount of material required for its construction. You can find out only if you correctly calculate the area that needs to be covered.

Peculiarities

It will not be possible to calculate the roof area using some universal formulas. For a simple pitched roof, such calculations are the simplest, but there are always nuances, ignoring which leads to dire consequences.

Calculating area always involves:

• accurate height measurement;
• determining the degree of inclination;
• determining the volume of required building materials and fastenings to them (as the final stage).

Design forms

The area of ​​a pitched roof is calculated depending on what geometric shape the proposed roof corresponds to - most often these are isosceles triangles, trapezoids, rectangles and parallelograms. But it is important to consider that almost all roofs still consist of several slopes.

Single-pitch option calculated using the formula for a rectangle.

If there are two slopes, you just need to apply the same formula to each of them and summarize the results.

A roof of four slopes is calculated as the sum of a pair of trapezoids and a pair of triangles with equal sides.

If the form is very complex, you will need to spend more time, but the basic principles remain roughly the same. The first step is to break it down into simple geometric shapes. Then the same formulas are used to calculate the area of ​​any of them as in the standard case. We must not forget that the length of the slopes is measured from the final lines of the eaves to the ridge elements.

When the site irregular shape, it is advisable to divide it into even smaller fragments in order to radically simplify the calculations.

Do not subtract chimneys and ventilation ducts , windows built into the roof and other similar elements. When calculating the area flat roof for laying built-up roll materials The area of ​​the parapets is taken into account separately. It is necessary to take into account how the overhang will be located - along the perimeter, with a closed parapet or with a lower overhang and a three-sided parapet.

In the very in simple form square flat roof can be taken equal to the total area of ​​the building, with the addition of overhangs and other elements extending beyond the contour. But such a calculation scheme is acceptable only if there are actually no angles.

With due diligence, it will not be difficult to calculate the area of ​​the pediment yourself. To do this, there will be no need to even turn to online calculators. The configuration of the pediments is closely related to the geometry of the slopes: thus, triangular options most often accompany the formation of roofs with two slopes. When installing the structure, before preparing the rafter frames, the area and height of the gables must be calculated with special care.

Produce necessary calculations, as always, using “school” formulas helps. It is advisable to use electronic calculators only for self-testing.

The lengths of the end walls, divided in half, are multiplied with the tangent of the angle, which creates the slope and base of the roof. For non-residential premises under the roof the height will be much less than for one actively used by people. Wall triangular shape calculated by multiplying the height of the pediment itself and the length roofing base. This result should be reduced by 50%. In the case of a “trapezoid” wall, take ½ of the total length of the bases and multiply it by the height. The pentagonal pediment is conventionally divided into an upper triangle and a lower trapezoid - this simplifies the calculation.

Calculate the area of ​​an L-shaped roof with different slope It’s also not particularly difficult. By its nature, it is formed from a pair of typical gable structures, joined at right angles. To simplify calculations, the general configuration is divided into four similar rectangular trapezoids. The calculated areas are summed up and the final result is obtained.

You can simplify your work (eliminate measuring individual slopes and planes) if you have a carefully prepared plan in hand.

Calculation method

It will not be possible to calculate the square footage of the roof of a house correctly unless you figure out exactly what its shape is. In the absence of clear and unambiguous plans, you will have to prepare them yourself, drawing all the necessary drawings by hand. An equilateral trapezoid is calculated taking into account not only the width of the slopes, but also the lengths of the bases and height. The prepared roof plan must reflect all lengths, widths and heights with an error of no more than 1 cm. If it is possible to measure more accurately, you should definitely take this chance.

It is advisable to prepare a plan in several projections at once, and recheck each measurement and each step of the calculation. A mistake can be very expensive, in the literal sense of the word. You can determine the number of square meters from the ground, from the roof itself, and from the attic.

To increase the accuracy of measurements and calculations, it is recommended to pay attention even to the asymmetry of the edge, to the excessive width of the ridge, to changes in the angles of inclination in different places. A roof sloped at an angle of 9 degrees is 10% larger in size than an identical flat one.

If the slope increases to 56 degrees, the conversion factor already reaches 1.8, and its approximate change with an increase in the angle by 10 degrees is 15%. The slope angles of the slopes in houses covered with symmetrical gable roofs are determined depending on the length of the base of the isosceles triangle formed by the slopes. To calculate the overlap, you need to multiply the length of the house by the length of the rafters.

The area of ​​all slopes separately is determined as the length of the house with the addition of the front and eaves overhangs, multiplied by the length of the rafters + the length of the overhang. If the roof is pitched, there is no need to double the resulting number.

For the most accurate calculation of the footage of a triangle or any other geometric figure The results obtained from the formulas should be increased by 10-15%. This will compensate possible mistakes and defects when laying roofing material. It will be somewhat more difficult to calculate the roof area for subsequent fire retardant treatment and for impregnation with antiseptic compounds. The methods are approximately the same, but you will also need to take into account the coefficients recommended by the fire inspection. They will allow you to compensate for both calculation errors and overconsumption of impregnating mixtures.

The problem is that the special impregnation is not applied to the roof, and on the sheathing and upper parts of the floors, rafters, trusses and crossbars. But rafters, beams and other similar elements have a much smaller area than the roof itself. And therefore, in most cases, to accurately predict the need for treatment with fire retardants, you will have to enter a coefficient of 1.2. It will successfully “absorb” all the irregularities.

Application of impregnation

The angle of inclination of the roof is calculated between the inclined rafters and the ceiling. When calculating the surface area that sheets of metal tiles, slate or corrugated sheets will have to occupy, we must not forget that one of the waves is spent on connections with adjacent sheets. Therefore, you will have to add another 10% to the resulting area after all the calculations and adjustments. It is also taken into account that sheet materials are measured in linear meters, which must first be converted into square meters, and only then compared with the dimensions of the roof. Additionally, you can check yourself by using specialized online calculators directly from major suppliers of selected coverage.

If the roof does not have a wall gutter, add 7 cm to the slopes above the eaves. And in the case where there is a gutter, a cornice, and an overhang, the length can be reduced by 70 cm. It is additionally necessary to calculate the areas of parapets, a firewall and other structures that are not physically connected to the main covering. Take into account standing seams if single parts are covered roofing steel, not necessary.

Double standing seam

You can also ignore the bypass of the base beam roll coverings. Essentially, it does not play a role, just like the arrangement of aprons.