How to calculate the size of the roof. How to calculate roof area: methods for different types of roofs. Roof with one slope - or two identical ones
Before calculating the roof area, it is necessary to draw up an accurate plan with all dimensions plotted in uniform digital indicators. In addition, you need to know what roofing material will be used for the device roofing covering, waterproofing, vapor barrier, thermal insulation. Having calculated the roof area, each developer will be able to economically build his own roof.
Roofs can have different shapes:
- one, two or four slopes
- hip or half-hip
- forceps;
- multi-slope
The easiest way to calculate roofs is those 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 also be irregular rectangles, rhombuses and other geometric shapes.
Therefore, if your school knowledge of geometry is still fresh in your memory, you can calculate the roof area yourself, and if you have been at odds with geometry for a long time, then it is better to order a calculation of the roof area from a knowledgeable specialist or use special online tools. We will talk about this in our article.
Drawing up a roof plan
If the rafter system is already ready, but there is no design of the house where the roof plan should be, then you will have to draw up a roof plan yourself.
drawing up a roof plan
The entire roof is measured and a drawing is drawn up showing 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 draw, it’s better to do additional drawing roofs in projection for better clarity.
With such a drawing, it is easier to imagine the appearance of the future roof, decompose it into its component 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 of roof overhangs, where they are assumed.
Examples of calculations of the area of various roofs
A pitched roof is calculated simply - you need to measure the width and length of the building, add the values of the estimated overhangs and multiply the resulting numbers. But with pitched roofs such an approach will be incorrect, because here you need to take into account the angle of inclination of the roof and all individual elements (dormer windows and other similar structures).
- Before calculating the roof area, everything complex elements roofs are divided into separate components - triangles, squares, etc.
- Calculating area gable roof you need to multiply the area of each slope by the cosine of the angle of inclination of the roof. This refers to the angle formed by the slope and the ceiling.
- The length of the slope is taken from the ridge to the extreme line of the eaves
- All other roofs that have several slope planes are calculated in the same way. The area of each slope is found separately and multiplied by the cosine of the angle formed by the slope and the straight line parallel to the ground.
- After this, all the obtained values are summed up, and the total roof area 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 obtained.
Let us give an example of calculating a gable roof for a house (8 x 6 m), length rafter leg- 3.68 m, overhang length - 0.5 m, gable overhang - 0.5 m.
We calculate the area of one slope - Sabcd = Lcd x Lbd = (8 + 0.5 + 0.5) x (3.68 + 0.5) = 37.6 m2.
The area of the entire roof is S = 37.6 x 2 = 75.2 m2.
When calculating, roofing elements such as chimneys and ventilation ducts, attic, dormer windows or skylights, parapets. If the shape of the roof is very complex or the developer is not able to make calculations on his own, you should turn to specialized web resources that offer to calculate the roof area online .
Roofing Factor
In addition to calculating the roof area, you also need to make calculations roofing material, which is required to cover this area. In this case, the figures for the roof area and the area of the required roofing material will differ significantly. The fact is that individual roofing coverings are laid with overlaps, and therefore the consumption of materials increases. When calculating the roofing material required to cover complex roofs, it is better to use a roof area calculator.
If you plan to cover the roof with slate, then the calculation is made as follows: S= (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* - roof slope angle. If the length of the house is 15 m, the width is 10 m, the width of the eaves is 0.5 m, the cosine of 30 degrees is equal to 0.87, the total roof area is equal to 202.2 kW m.
- How to find the roof area if metal tiles are used as a covering?
useful formulas for calculating area
You should take into account such nuances as the total length of the ridges, valleys, overhangs, and cornices. When using metal tiles or profiled metal for complex roofs as a covering, you must keep in mind that inevitable and very significant waste will follow.
If for less complex roofs experts recommend buying roofing material with a reserve of 7-15%, then for complex roofs the supply of material should be increased to 20%.
Calculation soft roof produced according to the same formula as for slate. The consumption of roofing material depends on its type and installation technology. The areas of ridges and valleys are considered separately and must be ordered separately, because they are no longer measured in square meters, and in uniform.
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, material consumption increases depending on the amount of overlap and the angle of inclination of the roof. Since, than larger angle slope, the less overlap of roofing material is allowed.
roof slope coefficient table
When calculating the area for complex configurations roof and a large number of differences, you can make a calculation by applying slope correction factors from the table to the horizontal projection area (or individual sections)
You should not start laying roofing material without having it laid out on paper in front of your eyes. In this case, errors in installing the roofing will be minimized, and you will not have to purchase the missing material to replace the damaged one.
- 9 degrees – coefficient. 1.01;
- 14 degrees – coefficient. 1.03;
- 18 degrees – coefficient. 1.05;
- 23 degrees – coefficient. 1.08;
- 27 degrees – coefficient. 1.12;
- 34 degrees – coefficient. 1.20.
Naturally, there is an overhang.
Calculation for a hip roof
For a square: a x a.
a is the length of the side.
b – width of the figure.
a – the base of the figure,
h – height of the figure,
How to calculate the roof area of a house
When starting construction, the question always arises: how to quickly and correctly calculate the roof area? This operation seems simple only at first glance. In practice, it turns out that the calculation can be quite difficult even for experienced craftsmen. Since the total amount of money spent on roof construction directly depends on its correctness. Considering the high cost of building materials and the cost 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 calculation.
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Main stages of work
Calculating the roof area should always start with:
- familiarization with the future project of the roof of the house and remembering the most key parameters: ridge length, slope angle, height, width and length;
- determining the type of roofing material to be used.
One of the most important characteristics is a special calculation coefficient, which is present in absolutely all formulas. Its value depends on the angle of the roof slope and is determined by the following relationships:
- with a slope 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 roof angles is the most popular options used in construction in our latitudes. The parameters of a structure with a complex geometric shape can be determined by breaking it down into separate small figures, which can be easily calculated by summing up the resulting values at the end. Experts recommend adding about 10% to the result obtained, which is a standard margin in construction.
Formulas and definitions
The simplest calculation option is to determine the area of a pitched roof with any slope. Houses with this kind of roofing are usually covered simple materials, and the most common shape is a rectangle. To calculate the roof area, we need to know the length of the slope and its width, which should be multiplied among themselves with a predetermined calculation coefficient.
We should not forget that the area of the overhang of the slope, which is mandatory for roofs of this type, should be added to the area of the shed roof of the house.
To calculate area gable roof at home, there are significantly more values and factors to consider. So, for a slope length of 6 linear meters and a ridge of 9.5 linear meters, the calculation formula will be next view: 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 calculate 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 may differ significantly. For this reason, each particular case requires the use of an individual approach, careful analysis and competent calculation. Most a difficult situation arises when it is necessary to calculate the square footage of roofs of complex shapes. 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 the ventilation ducts, skylights, chimneys, parapets, hatches and other elements. If this rule is violated, there is a high probability of a shortage of building materials when installing the roof. Correct and competent calculation of the area will provide all the conditions for the optimal expenditure of financial resources associated with the purchase and cutting of material when constructing the roof of a house.
How to calculate the roof area of a house. Formulas, diagrams and calculations
Calculating the roof area will not be difficult for those who know how to use a tape measure and a calculator. Because the whole calculation comes down to calculating the areas of individual slopes, and if the roof of the house is not complex, but an ordinary two- or four-slope one, then calculating the area will be even easier.
There are a huge variety of types and geometric shapes of roofs of private houses, but the roof slopes themselves usually come in four geometric shapes:
- rectangle
- trapezoid
- equilateral triangle
- parallelogram
In this article we will consider the area only pitched roofs, we will not calculate the area of flat and inverted roofs, because the area of such roofs, in most cases, will be equal to the area of the house or its part located under this roof.
And if you learn to calculate the area of each such slope separately, the formulas for which are presented below in the diagrams, then it will be very easy to calculate the total roof area.
It must be remembered that the more slopes there are on the roof, the correspondingly more difficult it will be not only in terms of construction, but also insulation of the roof, its finishing and maintenance. And during the construction itself, there will be a lot of unused scraps left, which will become unnecessary financial costs.
And so, before you take out the calculator and start counting, you need to have a roof plan at 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, but here I will tell you how to correctly apply the area calculation to a specific type.
Calculation of the area of a pitched roof
This is the simplest calculation that can be done without detailed plan roofs of the house.
It is necessary to measure the length C and width D of the slope.
It is not difficult to calculate the length of the slope; you need to measure the length of the building and do not forget to add roof overhangs on both sides. If for some reason it is not possible to measure the width of the slope, 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 a gable roof of a house
Calculating such a roof, I think, will also not be difficult.
Calculation of the area of a hip, half-hip and hip roof of a private house
To calculate, you need to mentally divide the hip roof into four separate slopes, as shown in the diagram, and then count each slope separately.
After breaking you should have two trapezoids and two equilateral triangles if the opposite slopes are equal.
Now let's calculate the areas of these geometric figures using simple geometric formulas, then add up the resulting areas of the figures. This completes the calculation; as you are convinced, there is nothing complicated here.
Half hip roof area a private house is considered exactly the same, except that the triangular slopes will be smaller than those of a hip slope, and the main large slopes must be divided into two geometric shapes, a trapezoid and a rectangle, calculating their area separately.
Counting technology area hip roof at home is no different from a hip roof, we also divide the roof into four slopes, only here we should now have four equilateral triangles. We calculate the area of these triangles in the same way as in the previous examples.
Calculation of the area of a 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 calculations are very simple, it will still not be easy to calculate the area of such 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 complex the roof, the more difficult it will be to do this. Having an accurate roof plan can make the task easier.
Technology for calculating the area of a complex roof
First, we divide the roof into separate flat slopes. As was already said 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 roofing material is much more difficult than calculating the area of the roof itself. Sometimes the roof area is half less area ordered material. In order not to make a mistake in the calculations and not to buy too much, and it can be even worse when there is not enough material, you need to contact specialists from the company from which you will order the material. Most organizations offer this service free of charge. They will very accurately calculate the number and size of sheets and give you a layout of them on the roof.
Since roofing materials usually have rectangular shape, and roof slopes are not always the same, you will have to cut the sheets and adjust them to the angles of the slope. And what more difficult roof, the more unnecessary scraps you will have. It is necessary to remember, no matter what material you choose for roofing, during installation the layout of the sheets should always be at hand so that when cutting you do not cut off the wrong sheet.
How to correctly calculate the roof area
The construction of every house does not begin with digging pits or pouring foundations.
Construction begins with project development and calculations.
With a roof, everything happens in a similar way: before starting to install it, a careful calculation of the height, the size of its surface is carried out, 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 installation, depend on the correctness of the calculation.
Surface calculations always start with:
- measurements of the main parameters of the roof: angle of inclination, ridge length, length, width and height;
- determining the type of roofing material that is planned to be used in the future when constructing the roof.
One of the most important characteristics is a calculated coefficient used in almost all formulas in calculations.
The value of this coefficient depends on the angle of inclination of the slopes on your house.
For the most popular tilt angles, the coefficient is:
- 9 degrees – coefficient. 1.01;
- 14 degrees – coefficient. 1.03;
- 18 degrees – coefficient. 1.05;
- 23 degrees – coefficient. 1.08;
- 27 degrees – coefficient. 1.12;
- 34 degrees – coefficient. 1.20.
If the shape of the roof is complex, irregular in shape, then during calculations its surface is divided into separate regular shapes, the area for which is calculated in an elementary way.
And at the end, the results obtained are summarized.
Calculation procedure for a pitched roof
This is geometry from a school course.
Houses where they arrange pitched roof, are usually covered with simple materials.
And 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.
Calculating a gable roof
Calculations for the surface of a gable roof are more complicated.
And many more factors should be taken into account when making such calculations.
To begin with, all complex elements, as mentioned, are divided into separate simple figures: rectangles, squares, triangles.
After all, on the roof, each corner is formed only by the ceiling and the slope.
Therefore, in order to calculate the roof surface, it is necessary to multiply the area of each slope by the cosine of the angle of inclination.
With this calculation, the length of the slope is the distance from the ridge to the eaves line.
Any roof with any number of slopes is calculated in exactly the same way.
You just need to sum up the resulting surfaces of all slopes, multiplied by the cosines of their angles.
If the roof element has a complex irregular shape, then it is also divided into several simple geometric shapes and the area of each of them is calculated.
Then all surfaces are summed up.
Let's look at how this is done using the following example: a house has dimensions of 10 x 8 meters.
The rafters are 4.5 meters long.
Naturally, there is an overhang.
The standard overhang length is 50 cm.
First, let's calculate what surface one slope has:
S = (10 + 0.5 + 0.5) x (4.5 x 0.5) = 55 square meters.
Since the building has two such slopes, the total area will be 55 x 2 = 110 square meters.
Despite the fact that on any roof there are ventilation ducts, chimneys, dormer and attic windows, parapets, they are not subtracted from the resulting area value.
We consider the 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 a pyramid is used.
If all the slopes have the same dimensions, then it is enough to calculate the area of one of them and then multiply by four.
In the case where the hipped roof has complex shape, then it is divided into simple figures and the surface of each of them is calculated separately.
After all, such a roof has different stingrays The angles of inclination may vary significantly.
It should also be remembered that dimensions are taken not along the perimeter of the building, but along the overhangs of the eaves.
Calculating a hip roof
In order for the calculation of the hip roof to be carried out correctly, it is necessary to take into account the following:
- window size and chimney size;
- the length of the slope (between the ridge and the cornice);
- parts that are not included in the roofing covering (overhangs, parapets, etc.);
- When performing calculations, the junctions of roofing slabs, paving ledges, and standing seams are not taken into account.
Calculating the surface of a hip roof consists of finding the area of two end triangles and two trapezoids.
In any case, if hip roof has a complex shape, it is divided into several simple figures and calculations are performed separately for each of them.
And then the calculation results for each figure are summed up.
You should know that even though hip roof- This is the best roofing solution, its installation is not cheap.
Calculation for a hip roof
A hip roof is one of the varieties of a hipped roof.
So let's say this is a classic roof with four slopes.
The basis of this design is a quadrangle.
And the slopes are isosceles triangles converging at the central top point.
This type of roof is the most economical, since it has no gables at all.
More about installing a hip roof with your own hands.
About Unikma soft roofing here. The entire range is presented construction company"Unikma".
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 the triangular slope.
Calculation of a broken attic roof
The area of a sloping attic roof, despite its 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 length of the side.
b – width of the figure.
a – the base of the figure,
h – height of the figure,
a and b are the dimensions of the upper and lower bases.
After the area of each of the simple figures into which the broken line is divided is calculated mansard roof, the results obtained are summarized.
Video about a construction calculator for calculating a roof.
Sergey Novozhilov is an expert in roofing materials with 9 years of experience practical work in area engineering solutions in construction.
A gable roof is complex and large in area. building construction, requiring a professional approach to the design and execution of work. The largest costs go to building materials for rafters, sheathing, insulation, waterproofing, and roofing material. Our gable roof calculator will allow you to calculate the amount of material.
Using a calculator saves time when designing a roof, and your money. The final 2D drawing will guide you through the work, while the 3D rendering will give you an idea of what the roof will look like. Before entering data into the online calculator, you need to have an idea about the elements of the roof.
Rafter parameters
To make a calculation rafter system gable roof, you need to consider:
- roof load;
- step between rafters.
- type of roofing
- 100-150 mm with a span length of no more than 5 m, and with additional supports.;
- 150-200 mm with a span length 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 at 1 m, but with a roof slope of more than 45 degrees, the pitch of the rafters can be increased to 1.4 m. For 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, take either a board with parameters 50x150 mm, or timber 150x150 mm (to distribute the load)
Lathing parameters
For metal tiles, a sparse lathing is created with a board, the width of which is 100 mm, and the thickness is 30 mm. The board is packed in increments that must correspond to the longitudinal axis of the metal tile module - 35 cm (Super Monterrey).
For flexible tiles the sheathing is carried out with a large step, since OSB or plywood will be laid on top of it as a continuous carpet.
Important! When choosing materials, pay attention to moisture resistance and minimum thickness.
When installing warm roofs Between the waterproofing and the roof, a counter-lattice is made with a block, 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 amount of overlap.
- Metal tiles for hard roofing are produced in a width of 118 mm (working 110), but the length can be different. The manufacturer can cut any length to order.
- Flexible tiles for soft roofing have different sizes, so you need to look at specific material
- As for the choice of insulation, for Russia the recommended thickness is at least 100 mm, and the correct one would be 150-200 mm.
At the design stage of a gable roof, it becomes necessary to calculate the amount of roofing material. To do this, find the area of the gable roof, taking into account gable and eaves overhangs, superstructures, ventilation, etc. To calculate the area, it becomes necessary to calculate a number of roof parameters. The main parameters include:
- roof angle;
- length along the ridge girder or eaves overhang (which is the same thing);
- length of slopes;
- height from ceiling to ridge.
Calculation of roof slope angle
The slope of the slopes is determined at the design stage and depends on the choice of roofing, climatic conditions, type attic space(cold or attic), the design of the roof itself.
If the house will be built in places with strong wind loads, then they try to make the slope small in order to reduce the load on the roof. When building a house in regions with heavy rainfall, the slope is made significant (up to 60°) in order to reduce the load from snow, melt and rain water.
However, there is a need to find out the slope angle of the constructed roof. In this case, an inclinometer or simple trigonometric formulas are used.
But, more often than not, a novice builder does not have an inclinometer at hand, and geometry comes to the rescue. Let's take gable roof and consider its section along the ridge. The resulting cross-section is pitched roof, the shape of which represents right triangle.
The first leg acts as half the width of the house. The second leg is the height from the ridge to the ceiling. The hypotenuse is the length of the slope. Knowing any two parameters, you can easily calculate the slope. Let us give an example for greater clarity and understanding.
The width of the house is 8 meters, the length of the rafter leg is 10 meters. The slope of a gable roof is found from the following expression:
where A is the roof slope angle;
c – half the width of the house;
b – length of the rafter leg.
In this example, half the width of the house will be c=8÷2=4 meters. Let's calculate the slope:
cos A=4÷10=0.4.
The resulting value is the radian measure of the angle. To convert radians to degrees, we will use the Bradis table, which is widely available on the Internet. The desired slope will be 66°.
Determining the height of a gable roof
After determining the slope of the gable roof, it is necessary to calculate the height of the ridge. Knowing the height of the ridge, you can use trigonometric expressions calculate the length of the slope, which is the length of the rafter leg.
Height can be calculated in two ways:
- using a right triangle;
- using a table of ratios of the angle of inclination to percentages.
The first method of calculating the height is using the values of the angle of inclination and half the width of the house. Let's look at an example for clarity. The width of the house is 12 meters, the slope is 40°.
Half the width of the house will be:
The height of the ridge is determined by the trigonometric formula for a right triangle:
a=c×tg A=6×tg 40°=6×0.84=5.05 m.
To find the tangent of 40°, the Bradis table was used, as in the example above.
In order not to look for the value in the Bradis table, you can use engineering calculator, which is installed on any operating system!
The second option for determining the height of the ridge is to use the table of ratios given below.
Here, each angle of inclination corresponds to a certain relative value, expressed as a percentage. The height is found by multiplying half the span width of the house by the relative value. Let's look at an example for clarification. Let's take a house with a span width of 7 meters and a slope angle of 27°. The height of the ridge will be:
(7÷2)×0.509=3.5×0.509=1.78 m.
Determining the area of a gable roof
When finding the area of a gable roof, the following points must be taken into account::
- The total area will be the sum of the areas of each of the slopes. Therefore, first find the area of one slope and multiply by two;
- Rarely, there are cases when the slopes in a gable roof may differ in one or more parameters (sizes). In this case, the area of each slope is calculated separately. The total area is found by summing the areas of individual slopes;
- It is necessary to take into account that if the roof slope is an irregular rectangle (i.e. at least one of the angles of the quadrilateral is not equal to 90°), then you should “break” the slope into simpler shapes and find the areas for them. When such a situation arises, the slope is divided into a rectangle and a right triangle;
- When finding the area, chimney pipes, dormer and dormer windows, and ventilation openings are not taken into account;
- Pediment and cornice overhangs, parapets, and firewalls are taken into account.
Consider finding the area on simple example. The box of the house has dimensions of 7x9 m, the length of the rafter leg is 4 meters, the eaves overhang is 0.4 meters, and the gable overhang is 0.6 meters. The area of one slope will be:
S=(L dd +2×L fs)×(L c +L x);
where Ldd is the length of the house (9 meters);
L fs – value of the length of the gable overhang (0.6 meters);
L c – length of the rafter leg, i.e. slope length (4 meters);
L ks – length of the eaves overhang (0.4 meters).
Let's find the required area of the slope:
S=(9+2×0.6)×(4+0.4)=10.2×4.4=44.9 m2.
The area of the gable roof will be:
S=2×44.9=89.8 m2.
In the case of using roofing tiles or roll material the length of the slopes will decrease by 0.6-0.8 meters.
Roofing area
The area of a gable roof is calculated in order to find out required amount material that will be placed on the roof. The steeper the roof slope, the more material will be required to cover it. It is recommended to purchase material with a reserve of 8-15%. This overspending is caused by the overlap with which the material is laid. To determine the missing material, you should use a table that takes into account the slope and determines the material reserve factor.
When calculating the area of a gable roof, you must take all measurements correctly and use a roofing calculator on the Internet to check self-calculation. In addition, if the calculation is done correctly, you will not have to buy additional material.
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Construction is often called an exact science. One cannot but agree with this, because in fact, any building does not begin with preparing the base for the foundation, erecting walls or purchasing the necessary building materials. First of all, it is “built” on paper - a project is prepared, which includes sketches, drawings and all kinds of calculations.
One of the conditions for the “correct” construction of a roof is the choice of building materials and a well-drawn estimate for their purchase. This is why it is so important to know how to calculate the roof area. Many resort to this online calculators, which are widely presented on various sites on the Internet. Nevertheless, professionals recommend performing calculations “manually”, taking into account the characteristics of a particular object.
If you know how to calculate the roof area correctly, and in preparation project documentation adhere to the required scheme, then the roof will undoubtedly turn out to be quite strong and reliable. Moreover, this will allow you to avoid unnecessary financial costs when purchasing building materials and installing it.
What does roof calculation depend on?
The roof calculation scheme depends primarily on architectural features buildings. For example, for outbuildings They mainly use the easiest option for calculations - flat; attic ones - are more varied:, and others, and each of these types involves its own calculation method.
Among the defining parameters it should also be noted:
In almost any formula, calculations use the so-called design coefficient, which is selected based on the angle of inclination of the roof slope.
Geometric shapes
Upon careful examination, it becomes obvious that the range of the most common forms of individual slopes is limited to elementary geometric shapes, such as:
- rectangle/square;
- trapezoid;
- parallelogram;
- isosceles triangle.
Of course, design modern roofs much more diverse and, as a rule, does not do without serious complication of the roof structure: its shape and dimensions change. However, even in this case, the “three pillars” on which the calculation is based remain elementary figures. An area of any complexity to calculate is divided into a number of simpler ones. The required area, therefore, is nothing more than the sum of the areas of the constituent elements.
That is why, even if you have already graduated from school a long time ago, but are still in tune with elementary geometry, calculating the roof yourself will not be difficult for you.
Just in case, let us recall the formulas for the areas of the main figures:
How to measure slopes and calculate roof area
When there is no roof plan at hand indicating the exact dimensions, they are removed independently. You will need a tape measure, a calculator, and other equipment necessary when working at heights.
For roofs with symmetrical slopes, it is enough to measure only one.
Shed roof
To calculate the area, we use the formula for a rectangle:
S=K x L, where K is length, L is width.
You can measure the slope without climbing onto the roof - just measure the length and width of the house, taking into account the size of all overhangs:
- the width of the slope will be equal to the resulting length of the building;
- length - calculated using the Pythagorean theorem, taking the height of the roof and the projection of the slope as the dimensions.
Specify required dimensions in millimeters
X- width of the house
Y- roof height
C- overhang size
B- roof length
Y2- extra height
X2- extra width
Reference
The program is designed to calculate roofing building materials: quantities sheet material(ondulin, nulin, slate or metal tiles), roofing material (glassine, roofing felt), number of sheathing boards and rafters.You can also calculate some useful dimensions roofs.
The program works in two modes: a simple gable roof and a roof with two side gables (side roofs), type 1 and type 2.
Attention! If you have a roof with one side gable, then for the calculation use first type 1, then type 2. And from the data obtained, calculate the amount of building materials: rafters, sheathing boards, roofing and sheet materials.
Otherwise there may be an error in the calculation. After all, the program takes into account the cutouts in the main roof for the roofs of the side gables.
In the calculation you will see several numbers: the size or volume of the building material of half the roof and in brackets - the full size or volume.
In the calculation of an additional roof - the full size and volume, and in brackets there are two numbers: the size and volume of one and two additional roofs.
Attention! When calculating sheet roofing material, keep in mind that the program calculates by roof area.
For example, 2.8 rows times 7.7 sheets per row. During actual construction, 3 rows are laid.
To more accurately calculate the number of roofing sheets, you need to reduce the sheet height in the calculation until you get a whole number of rows.
Don't forget to set the amount of overlap more precisely.
When calculating the volume of material for the rafters of the main roof, in mode type 2, the program does not take into account the cutout for the side gable. This is due to some implementation difficulties in the program.
Maybe I'll solve this in the future.
However, the excess rafter material is unlikely to disappear, or make some adjustments to your calculations.
There will also be a separate program for more intelligent calculation of sheet roofing materials.
And don't forget what to buy Construction Materials it is necessary with some reserve for waste.
