Calculation of attic roof area calculator. Calculation for the construction of an attic roof
Online calculator mansard roof will help calculate the angles of inclination of the ridge and side slopes of the roof, the number and minimum cross-section of rafters, the volume of sheathing and materials that will be needed to construct the roof. Before you design attic floor, read SNiP 2.08.01-89 “RESIDENTIAL BUILDINGS”.
The calculations of this calculator take into account the parameters given in TKP 45-5.05-146-2009 and SNiP “Loads and Impacts”.
A mansard (also sloping, sloping) roof is a roof that has two slopes with different slopes on each side. This technique helps to optimize the space under the roof and create a comfortable room under the roof (attic or attic floor). Similar roofs have been known since the 17th century. Today, the attic roof has many varieties. The attic can contain both utility and residential premises.
A mansard roof can be built either at the first stage of construction or added to an already completed building. Thus, the building can have more living space without the need to build a full second floor.
When building an attic roof, you need to take into account its specifics: steep slopes of the side slopes require increased costs for arranging the roof. Also, the attic floor needs larger windows and additional thermal insulation, especially if the premises in it are intended for living.
By filling out the fields of the calculator, you can check the additional information, marked with an icon.
At the bottom of this page you can leave feedback, ask your own question to the developers, or suggest an idea to improve this calculator.
Explanation of calculation results
Angle of inclination of side rafters
The side (steeper) rafters and the side slope of the roof are inclined at this angle. The calculator not only takes into account the angle you specify, but also determines how compatible it is with the roofing material you choose. To change the angle of the slopes, you need to change the Laying Width (A1, A2) or the Height of the Rise (B1, B2).
Angle of inclination of ridge rafters
The upper (hanging) rafters and the upper (sloping, ridge) slope of the roof are inclined at this angle. The calculator not only takes into account the angle you specify, but also determines how compatible it is with the selected roofing material. To change the angle of the slopes, change the Laying Width (A1, A2) or the Height of the Rise (B1, B2).
Roof surface area
Total roof area (including overhangs of the specified length). Determines the amount of roofing and insulating materials that will be needed for the work.
Attic floor area
Total attic area ( living space attics). Does not include space under the side roof slopes.
Approximate weight of roofing material
The estimated total weight of roofing material required to completely cover the roof area.
Number of rolls of overlapping insulation material
Total insulating material in rolls, which will be required for roof insulation. The calculations are based on rolls 15 meters long and 1 meter wide. An overlap of 10% is taken into account.
Load on the side/ridge rafter system
Maximum load on the side/ridge rafter system. The calculations take into account the weight of the entire roofing system, the shape of the roof, as well as the wind and snow loads of the region you specify.
Side rafter length
Measured taking into account the overhang of the roof to the junction with the ridge rafter.
Ridge rafter length
Measured from the joint with the side rafter to the ridge of the roof.
Number of side and ridge rafters
The total number of side and ridge rafters required to construct a roof at a given pitch.
Minimum cross-section of side/ridge rafters, Weight and Volume of timber for rafters
The tables show the recommended dimensions of rafter sections (according to GOST 24454-80 Lumber coniferous species). The calculations take into account roofing material, area and shape of the roof structure, as well as the loads exerted on the roof. The adjacent columns display total weight and the volume of rafters based on their use for the entire roof structure.
Number of side/ridge rows of sheathing
The total number of side and ridge rows of sheathing required for the roof being calculated.
Total number of rows of sheathing
The total number of rows of sheathing for the entire roof. To determine the number of rows of sheathing for half of the roof, just divide the resulting value by two.
Uniform distance between side/ridge sheathing boards
To evenly install the sheathing and avoid unnecessary waste of materials, you should use the value indicated here.
Number of sheathing boards standard length
To sheath the roof you will need the number of boards indicated here. For calculations, a standard 6-meter board length is used. The number of boards for the entire roof is indicated.
Volume of sheathing boards
The volume of boards in cubic meters will help you calculate the cost of sheathing. The total volume of sheathing for the entire roof is indicated.
Approximate weight of sheathing boards
Estimated total weight of all sheathing boards. The calculations use average values of density and moisture content for coniferous wood.
The attic space in the attic space is a usable part of a residential building. If necessary, an attic can be built on an already finished building, thereby increasing the living space.
To calculate the roofing material attic space, take into account many factors that play important role for a durable and reliable design. Having the final design of the building, it will not be difficult to determine the amount of building materials required for the construction of the roof. Many design organizations mark the required values on the roof drawing.
The attic roof is often formed by two side slopes located at different angles of inclination. In most cases, it consists of the following parts:
- roof covering;
- waterproofing material;
- lathing with wooden boards;
- rafters with thermal insulation;
- attic horizontal floor (ceiling).
The building materials used can vary widely. This depends, first of all, on the type of roof.
Important!
The main part rafter system are the rafter legs. They are laid along the roof slope. Subsequently, the sheathing is attached to them.
Based on the number of stingrays truss structure It can be single or gable, as well as hip, broken or tent type. The hip roof has four pitched planes. IN hip roof triangular slopes come together at one vertex. In sloping roofs, the rafter legs are positioned in the same way as in gable roofs, with the only difference being that the sloping structure has 2 tiers.
The rafters are connected and cut into the so-called tie of several boards or beams laid along the perimeter of the walls. Structural elements performing auxiliary functions are secured in accordance with the degree of expected load.
What parameters are taken into account when calculating the roof for an attic?
Calculating the quantity and determining the dimensions of the materials needed to construct a roof presents certain difficulties. This is largely due to the features of its design.
When performing it is necessary to take into account the dimensional parameters of all constituent elements rafters and roofing structure:
- length and number of rafters;
- parameters of their longitudinal section;
- rafter laying step;
- area of element planes;
- pitch and size of sheathing boards;
- dimensions roofing and the overlap of its sheets;
- type of heat, hydro and vapor barrier layers.
Accurate calculation and design during construction is a critical stage that ensures its safety and durability. This largely determines the strength of the entire building.
Sequence of calculation of materials for the attic
This type of roof consists of more elements rather than regular roof. Residential attic room often equipped additional windows, balconies and even terraces, the parameters of which are taken into account to calculate the total need for materials.
The main stages of calculating building materials for the construction of an attic roof include calculation:
- total weight of required materials;
- the area of all roof planes;
- quantity of materials.
Calculation of the weight of the roofing system for the attic
To calculate the weight of 1 m²each layer mansard roof, first you need to find out the sum of the values specific gravity everyone components. Then the resulting number is multiplied by the coefficient 1.1 established by the current norms and rules.
Important!
In residential buildings, the expected load is not allowed to exceed 50 kg/m². For greater safety, it is recommended to provide a safety margin for the roofing system.
A sufficient margin of safety is also necessary when replacing old coating material with new one. This is due to the fact that with the installation of a new roof, the overall load will increase significantly.
Having calculated the weight of the roof, we begin to determine the height of the attic roof, the longitudinal section of the rafters and the angle of inclination of the slopes. In most cases, the angle does not exceed 45 degrees.
Calculation of the area of the attic roof planes
IN modern architecture In residential buildings, the attic roof can take a wide variety of shapes. In order to correctly calculate the area of a complex broken roof surface, it must first be depicted in the form of separate figures.
The easiest way to calculate the area of an attic roof with one slope is to multiply its length by its width. For more complex structures with broken planes, calculate the area of its constituent figures using known formulas. Next, the obtained values are summed up.
Choosing roofing material
The composition of the sheathing, as well as the angle of installation of the roof slopes, must correspond to the characteristics of the roofing used. This is because technical features various materials for roof covering affect the service life and safety of the roof as a whole.
The lathing can be continuous, laid at a certain distance between the boards, or mixed. The use of combined lathing is often permitted. Ondulin and roll covering It is advisable to place it on a continuous type sheathing. The tiles and slate sheets are placed on a sparse sheathing.
An important consideration when choosing the type of roofing is climatic features building construction zones. In addition, the force of wind, the weight of snow and other factors acting on the roof possible options loads can make certain adjustments when planning the project and determining parameters necessary elements for the roof of an attic room.
Attic – design diagram, loads, DCS
Attic – calculation in SCAD, selection of sections of elements
We would also like to offer you a convenient calculator for calculating an attic roof. With its help you will receive all the necessary data and be able to build the correct roof.
Specify roofing material:
Select a material from the list -- Slate (wavy asbestos cement sheets: Medium profile (11 kg/m2) Slate (corrugated asbestos-cement sheets): Reinforced profile (13 kg/m2) Corrugated cellulose-bitumen sheets (6 kg/m2) Bituminous (soft, flexible) tiles (15 kg/m2) From galvanized sheet (6.5 kg/m2) Sheet steel (8 kg/m2) Ceramic tiles(50 kg/m2) Cement-sand tiles (70 kg/m2) Metal tiles, corrugated sheets (5 kg/m2) Keramoplast (5.5 kg/m2) Seam roofing (6 kg/m2) Polymer-sand tiles (25 kg/m2) m2) Ondulin (Euro slate) (4 kg/m2) Composite tiles(7 kg/m2) Natural slate (40 kg/m2) Specify the weight of 1 square meter of coating (? kg/m2)
kg/m2
Enter roof parameters:
Laying width A1 (cm)
Laying width A2 (cm)
Base length D (cm)
Lifting height B1 (cm)
Lifting height B2 (cm)
Length of side overhangs C (cm)
Front and rear overhang length E (cm)
Rafters:
Rafter pitch (cm)
Type of wood for rafters (cm)
Working area of the side rafter (optional) (cm)
Lathing calculation:
Sheathing board width (cm)
Sheathing board thickness (cm)
Distance between sheathing boards
(cm)
Calculation snow load:
Select your region
1 (80/56 kg/m2) 2 (120/84 kg/m2) 3 (180/126 kg/m2) 4 (240/168 kg/m2) 5 (320/224 kg/m2) 6 (400/280 kg/m2) 7 (480/336 kg/m2) 8 (560/392 kg/m2)
Wind load calculation:
Ia I II III IV V VI VII
Height to the ridge of the building
3592 0 0
Calculation of the rafter system of an attic roof - very simple about difficult calculations
Are you planning to install an attic in the under-roof space? In this case, you need to know that the roof frame bears heavy loads, which will have to be calculated before starting construction work. I'll cover the basic calculations you'll encounter when designing roof frame. As a result, you will be able to independently find out the parameters for designing a roof.
Roofing for the attic, what is it like?
A mansard roof is a universal solution, since it serves as an enclosing structure and at the same time is used as a full-fledged living space.
| Illustrations | Varieties and their descriptions |
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Gable roof. The diagram shows a symmetrical frame gable roof. Rafter truss formed by two solid diagonal beams connected at the ridge. The walls and ceiling of the living space are formed by a tie rod and side posts.
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Broken gable roof. The rafter system is based on side posts installed on the floor beams and connected at the top with a tie. Upper and lower rafters are built along the perimeter of the rectangle, forming a characteristic break in the center of the slope.
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What loads act on the attic?
| Illustrations | Types of loads in accordance with SNiP 2.01.07-85 |
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Snow. Falling snow has a significant impact on the roof structure.
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Wind. The wind affects the roof with different sides and the consequences of such an impact can be different, starting with the breakdown of the coating and ending with the overturning of the entire structure. |
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Weight of people, furniture and other interior elements. When using the attic, the weight of people and furniture will affect the ceiling. This load is important when calculating the parameters of floor beams.
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Total roof weight. The total weight refers to the load that will be placed on the load-bearing walls. This effect is formed by weight rafter legs and rows of sheathing, the weight of thermal insulation and the weight of the roofing. |
Snow pressure calculations
We calculate the snow load using the formula in Table 1. In order to find the coefficient μ, we calculate the length vertical stand trusses and divide this number by the length of the sloped rafters.
According to the obtained number, we find the appropriate value in the left column of Table 2. The opposite column indicates the angle of inclination α. Further, if α≤30°, then the coefficient μ = 1; if 30°<α<60°, то коэффициент μ = 0,033.
Please note that in a broken roof we only take into account the upper part, since this is where the weight of the snow cover falls.
The Sg standard is determined according to SNiP 2.01.07-85 or according to the snow cover intensity map. For example, for Moscow and the region this value is 180.
Wind pressure calculation
We calculate the wind pressure using the formula in Table 3. We take the maximum value of 0.8 as the aerodynamic coefficient.
We find the coefficient of change from Table 4, taking into account the characteristics of the place where construction is taking place. The standard value of Wo can be determined by SNiP, or can be found in the wind pressure map.
By inserting the appropriate values into the formula, you will calculate the wind load parameters for a particular area. In accordance with the obtained value, it will be possible to adjust the angle of inclination of the slopes or strengthen the rafters at the design stage.
Calculation of roof weight
To calculate the load that the roofing system will have on the load-bearing walls of the first floor, you need to add the weight of the diagonal beams, sheathing, rough flooring and the mass of insulating materials, including insulation and waterproofing.
The necessary data can be found in Table 5. The data is presented on the basis of kilograms per square meter of roof slope.
We add the mass of the roofing to the calculated weight. This parameter is listed in Table 6.
In addition to the listed factors that determine weight, you need to decide in advance whether skylights will be used in the system. Their weight can be obtained from the manufacturer and added to the calculated weight of the roof.
We calculate the total load
After all the calculations have been completed, we sum up the weight of the roof at the rate of kilogram per square meter. meter, snow and wind pressure for the same square. meter.
The weight of people and furniture in the attic floor is taken into account only when choosing the section of floor beams. This parameter does not directly affect the selection of rafters.
When summing up load parameters, non-integer numbers are rounded up. Taking into account the maximum wind and snow pressure, you can protect yourself from sagging or breaking of the roofing material.
Choosing the pitch between the rafters
When calculating the roof frame, we pay special attention to the spacing with which the rafters will be installed. The distance between adjacent beams depends on the length of the beam and the dimensions of its cross section. To simplify the calculations and not resort to formulas, I propose Table 7, which shows the average ratios of the parameters of interest to us.
Please note that for a sloping roof, the pitch is determined by the length of the upper slanted rafters. For systems with conventional straight slopes, the length from the ridge to the overhang is taken into account. The step between the sheathing boards along the entire broken slope is the same.
Calculation of rafters taking into account loads
The cross-section of lumber that forms the slanted rafters in the upper part of the roof is calculated using the following formulas:
- If α<30°, то H≥8,6×L×√Q/(B×R)
- If α>30°, then H≥9.5×L×√Q/(B×R)
- H - rafter section width
- B - section thickness
- R - density of lumber (in kg/m²)
For example, the density of grade 2 pine, which is widely used for assembling rafters, is 130 kg/m².
The ratio of the thickness and width of softwood lumber produced by the domestic industry can be found in Table 8. The cross-sectional parameters calculated using previously proposed formulas will be averaged, therefore, if the numbers are not integers, we round them up.
Let's sum it up
To calculate the parameters of the rafters, you can use an online calculator. But the instructions proposed in the article allow you to perform calculations more accurately and find out the dimensions of structural elements with minimal errors. If you have any questions about calculations, ask them in the comments to the article.
January 12, 2018If you want to express gratitude, add a clarification or objection, or ask the author something - add a comment or say thank you!
Thoughtful calculation of the roof of a frame house allows you to create a reliable and durable roof that will last for a very long time
Calculating the area of the attic roof makes it possible to determine not only the type and material of the attic supporting system, but also to calculate its future usable area. Moreover, in addition to designing the attic roof, the attic space is also calculated, including the usable and blind area.
Before constructing attics of private houses, it is imperative to prepare a high-quality design and calculate the roof structure. The design must clearly describe the structure of the rafter system, since it is the skeleton of the roof, its basis.
Attic roof rafter system
Attention should be paid to all elements:
- nodes,
- racks,
- rafters,
- rafter step,
- rafter material.
Correct calculation of load-bearing structures will allow you to build a durable and reliable attic roof that protects from bad weather. You can calculate the roof structure using special calculators located on many websites dedicated to the construction of private houses, but you should not rely entirely on such programs. The program cannot take into account all the nuances. Another option is to order a calculation from a specialized design organization. If you are going to build an attic yourself, it is better to choose simple roof structures. For example, a gable roof with a pediment.
A gable attic roof is an excellent option for obtaining a sufficiently large living space
Types of mansard roofs
The rafter system and its elements are different for different types of attics. The roof must be light so as not to load the walls of the houses, while the reliability and strength of the structure must meet the requirements. The following structures are distinguished by types of mansard roofs:
- Gable. Two slopes and two pediments.
- Broken. Having two or more planes at different angles of inclination. It is much more difficult to erect a broken roof.
- Hip. With triangular slopes.
- Half-hip. The slopes of the facades cover part of the pediment area.
- Dome. Typical for houses with a round or polygonal structure.
- Vaulted. With an arched pediment projection.
In addition, roofs are divided according to design features into ventilated and non-ventilated. This or that option is chosen depending on the climatic characteristics of the region and the design of private houses.
Advice!
With large amounts of precipitation and high humidity, roofs with natural ventilation should be preferred. In addition, the air layer inside plays the role of additional insulation.
Roofs without natural ventilation are more often used in dry climate zones.
A broken mansard roof makes it possible to realize a wide variety of dreams and design ideas
Features of the attic roof
The peculiarity of attic roofs is that the attic roof is affected not only by external weather factors, but also by internal ones:
- heat from the living space;
- evaporation;
- condensation formed from the temperature difference in the attic and outside.
Consequently, the requirements for attic roofs contain additional conditions. This includes laying vapor barrier materials, a heat-protective layer and waterproofing. In addition, it is necessary to arrange effective ventilation of the under-roof space, otherwise there is a risk of constant dampness in the room.
To reliably insulate an attic, mineral or eco-wool is usually used; in combination with a waterproofing and vapor barrier film, good protection against external and internal influences is obtained. And the air gap between the different insulators will ensure ventilation of the gable and roof.
The roof of the attic should be light, since in addition to its own weight, the walls of the houses are also loaded by the attic room itself with all its contents. Therefore, for attics, a material with a low specific gravity is selected:
- metal tiles;
- metallic profile;
- soft roof (for example, ondulin).
Heavier materials are used only when it is necessary to maintain uniformity between the house and neighboring buildings. But in these special cases it is necessary to additionally calculate the loads.
Important!
In addition to calculations, the project must contain information about the design of the rafters, a diagram for installing beams, calculation of the roof’s own weight and the expected load of natural factors (wind, snow, rain).
Attic roof project
As mentioned above, the key to a reliable and durable roof must be a well-designed project. As a rule, it consists of several sections and drawings. It contains calculations and all information about the roof structure:
- first of all, the project determines the main parameters - the shape of the roof, its dimensions, the slope of the slopes, the presence of a pediment;
- the second, and no less important point, is a list of all materials for each unit, indicating their quantity;
- a separate section should be devoted to the calculation of load-bearing structures, indicating the cross-section of rafter beams, the dimensions of floor elements and other components;
- drawings in various projections with details of the main components;
- section with calculations of the thermal properties of the roof structure and instructions on insulation and waterproofing with a list of recommended materials;
- recommendations for roofing material based on calculation of maximum loads on the structure.
Construction of a mansard multi-pitched roof
An important part of the attic roof calculations is the section devoted to insulation. To create an atmosphere suitable for living in the attic, the roof must be reliably and efficiently insulated. In addition, vapor barrier and waterproofing films are laid together with insulation. To prevent leakage from the outside and accumulation of condensation from the inside, special modern materials are used. In this way, a “layer cake” is formed, laid between the roofing and the attic room. Such a “pie” should include the following layers:
- Vapor barrier. Special, airtight film materials laid from the inside of the attic with sealing of the joints. The purpose of this layer is to prevent moisture from penetrating into the upper layers of the “pie”.
- Warming. Foam plastic or penoplex boards, mineral wool, eco-wool, etc. are used as heat insulators. Laying is done with an overlap or with subsequent sealing of the seams with construction foam.
- Waterproofing. Special film membranes that protect the insulation from precipitation and prevent the formation of condensation. They are laid along the rafters while maintaining an air gap between the film and the roofing material.
Insulation of an attic roof is one of the key stages in creating a reliable roofing pie that is designed for a long service life
Calculation of the attic roof
We emphasize once again that calculations should be carried out by a specialist with experience in designing such objects. Even small errors can lead to incorrect load distribution of load-bearing units and elements.
Important!
Excessive roof weight that exceeds the strength of the rafters can lead to a weakening of the overall structure and dire consequences.
For calculations, an important parameter is the area of the attic space and the size of its useful volume. The latter is calculated using lines connecting the points where the height from the floor to the ceiling plane is 90 cm. The rest of the space is considered to be non-living, suitable only for the construction of closets and storage rooms.
The total area is taken from the house and attic plans. The roof area is calculated based on the total area of the internal structures. The entire roof frame can be represented as a set of elements with different geometries. By calculating the area of such figures separately and adding the values, you can get the total area of the roof structure of the house. This value is necessary not only for further calculations of the strength and weight of the structure, but also for calculating the required materials.
Installing an attic roof on a house is the most effective solution that allows you to rationally and gracefully expand your living space
The next stage of calculations is to calculate the angle of inclination of the slopes, the dimensions of the pediment and the selection of roofing covering material. An incorrectly chosen slope of the slopes can lead to accumulations of snow crust, the weight of which can cause the roof to collapse. On the contrary, a slope that is too steep and a high structure is exposed to winds, which also negatively affects the integrity of the roof. Therefore, calculations must be carried out taking into account local climatic conditions.
An important section of the calculations should be the section devoted to insulation, waterproofing and ventilation. A properly equipped under-roof space will avoid the accumulation of condensed moisture and leaks. Proper insulation will create comfortable conditions for staying in the attic. All taken together will ensure the durability and reliability of the attic roof.
Calculation diagram of the attic roof
Calculation in SCAD, selection of sections of mansard roof elements
The main reason for the fairly widespread use of sloping roofs is that a conventional gable roof creates relatively little free space, which in most cases is not enough for use as a living space. At the same time, when erecting a sloping roof during the construction of a private house, it is possible to construct a full-fledged attic. At the same time, we should not forget that a sloping roof looks extremely attractive, giving a residential building an aesthetic and solid appearance.
Features of a sloping roof
The design of a sloping roof is a variation of the usual gable roof, with a small addition - there is a break on each slope. This essentially turns the roof into a hipped roof. The main purpose of such a change is to increase the under-roof space. Usually there is an attic, which is almost a full-fledged residential floor.
The construction of a sloping roof is somewhat more complicated than a regular gable roof, but is not very different from the construction of a hip roof. The main design feature of the roof in question is the presence of two types of rafters:
- Bottom (layered). In most cases they have a large angle, the value of which is equal to or greater than 60 degrees;
- Upper (hanging). The angle of their location is sharper, usually it does not differ much from 30 degrees.
Sloping roofs are most often used in private housing construction. Therefore, its width rarely exceeds 5-6 meters. This is explained by the much more complex design of the rafter system with a larger width, which complicates the work, increases its cost, making this design solution economically infeasible.
It should also be taken into account that the structure of a broken roof contains not only rafters, but some additional and auxiliary elements in the form of racks, struts, tie-downs, etc. Their dimensions are determined when calculating the rafter system. It is precisely because of their presence that the rafter system is somewhat more complex than that used with a gable structure.
We should not forget that an important advantage of a sloping roof is that it gives the appearance of the building a certain solidity, and simply looks much more attractive than a regular gable roof. It is this combination of high functionality of the building, expressed in the possibility of equipping an attic, and an extremely attractive and aesthetic appearance, which largely explains the reason for the popularity of the design in question, despite its relative complexity.
Calculation of roof dimensions
The calculation of the size of a sloping roof can be conditionally divided into two parts.
Calculation of roof covering area
This part is the simplest and most uncomplicated. To calculate the area, simply make a plan of it with all the dimensions. In this case, the diagram will be a set of simple figures - in most cases quadrangles, in particularly complex design solutions - and triangles. Calculating the areas of these figures is not difficult, nor is adding them up to obtain the total coverage area.
But even these procedures can be performed using numerous calculators, which greatly facilitate the second part of the calculations.
Calculation of the dimensions of elements and parts of the rafter system
Calculating the dimensions of a rafter system for a sloping roof is much more difficult, including due to the fact that it contains many connecting rather complex units. But without their correct calculation and implementation, long and reliable roof operation is impossible. The dimensions of the rafter system are influenced by many factors:
- weight of roofing pie components:
- battens and counter-battens;
- completed waterproofing and vapor barrier;
- thermal insulation material;
- the direct weight of the roof covering;
- geometric dimensions of the main roof elements:
- the span from the eaves overhang to the roof ridge;
- the angle of the upper and lower rafters;
- selected pitch of sheathing and rafters;
- operational loads (weight of people repairing and maintaining the roof, engineering and maintenance devices, fences, aerators, roof windows, etc.)
Based on the list of factors listed above that influence the size of the required rafter system, it becomes clear that its calculation is not a simple operation. That is why a large number of auxiliary online calculators have been developed, with the help of which it is quite easy to perform all the calculations.
Calculators will do an excellent job of calculating the total area of the roofing covering, as well as the required amount of material for hydro- and vapor barrier.
To calculate the rafter system, you must enter the appropriate data into the calculator, which should characterize each of the above influencing factors.
The approximate wind load is easily determined from the corresponding map for each region.
The resulting wind load value must be adjusted depending on the coefficient, which takes into account the height of the building being constructed and the type of area where the construction site is located.
The amount of snow load that can affect the roof is taken from the corresponding map containing relevant data for the regions of Russia.
Based on the area determined on the map, you can find out the amount of snow load required for calculation.
Most calculators independently calculate this parameter; it is enough to simply indicate the materials used and the main geometric dimensions of the designed roof, namely: the pitch of the rafters and sheathing, the angles of the slopes, the distance from the ridge to the overhang, as well as the material of the roof covering. The program will perform all other calculations offline.
After entering all the necessary information into the program, the calculator will display all the necessary dimensions of the elements and parts of the rafter system, as well as the roofing area and the necessary vapor and waterproofing materials.