Calculation of the length of the gable roof rafters online. Calculation of the truss system of a gable roof

At the design stage gable roof there is a need to calculate the roofing material. To do this, find the area of ​​\u200b\u200ba gable roof, taking into account gable and cornice overhangs, superstructures, ventilation, etc. To calculate the area, it becomes necessary to calculate a number of roof parameters. The main parameters are:

• roof pitch;
• length along the ridge run or cornice overhang (which is one and the same);
• slope length;
• height from ceiling to ridge.

Calculation of the angle of the roof

The slope of the slopes is determined at the design stage and depends on the choice of roofing, climatic conditions, type of attic space (cold or attic), 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. In the case of building a house in regions with heavy rainfall, the slope is made significant (up to 60 °) in order to reduce loads from snow, melt and rainwater.

However, there is a need to know the value of the slope angle on the erected roof. In this case, an inclinometer or simple trigonometric formulas are used.

But, most often, a novice builder does not have an inclinometer at hand, and geometry comes to the rescue. Let's take a gable roof and consider its section along the ridge. The resulting cross section is shed roof, whose shape is a 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's 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 the gable roof is found from the following expression:

where A is the angle of the roof slope;

c - half the width of the house;

b is the 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:

cosA=4÷10=0.4.

The resulting value is the radian measure of the angle. To convert radians to degrees, we 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 to 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 height is calculated in the first way using the values ​​​​of the angle of inclination and half the width of the house. Let's consider 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 a value in the Bradis table, you can use the engineering calculator that is installed on any operating system!

The second option for determining the height of the ridge is to use the ratio table below.

Here, each angle of inclination corresponds to a certain relative value, expressed as a percentage. The height is found by multiplying half the width of the span of the house by the relative value. Let's look at an example for clarification. Take a house with a span of 7 meters and a slope of 27°. The height of the skate will be:

(7÷2)×0.509=3.5×0.509=1.78 m.

Determination of the area of ​​\u200b\u200ba gable roof

When finding the area of ​​\u200b\u200ba 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, but there are cases when slopes in a gable roof may differ in one or more parameters (sizes). In this case, the calculation of the area of ​​each slope is performed separately. The total area is found by summing the areas of individual slopes;
• It should be noted that if the roof slope is an irregular rectangle (that is, at least one of the corners of the quadrilateral is not equal to 90 °), then you should “break” the slope into simpler shapes and find areas for them. When such a situation arises, the slope is divided into a rectangle and a right triangle;
• When finding the area, do not take into account chimneys, auditory and skylights, holes for ventilation;
• Gable and cornice overhangs, parapets, firewall walls are taken into account.

Consider finding the area on simple example. The box of the house has dimensions of 7 × 9m, the length of the rafter leg is 4 meters, the eaves overhang is 0.4 meters, the gable overhang is 0.6 meters. The area of ​​one slope will be:

S=(L dd +2×L fs)×(L c +L ks);

where L dd is the length of the house (9 meters);

L fs - the value of the length of the gable overhang (0.6 meters);

L c - the length of the rafter leg, i.e. slope length (4 meters);

L ks - the length of the cornice overhang (0.4 meters).

Find the desired 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 a tile or rolled material, the length of the slopes will decrease by 0.6-0.8 meters.

Roofing area

Square gable roof calculated in order to find out the required amount of material to be laid on the roof. The steeper the slope of the roof, the more material will be required to cover it. It is recommended to purchase material with a margin of 8-15%. This overspending is caused by the overlap with which the material is laid. To determine the missing material, you should use the table, which takes into account the slope and determines the material safety factor.

When calculating the area of ​​\u200b\u200ba gable roof, it is necessary to correctly make all measurements and use the roofing calculator on the Internet to check the self-calculation. In addition, if the calculation is done correctly, you will not have to buy additional material.

Another name for a gable type of roof is a gable roof.

It has two identical inclined surfaces. The structure of the roof frame is represented by a truss system.

At the same time, pairs of rafters leaning against each other are combined with a crate. At the ends, triangular walls are formed, or in other words, tongs.

A gable roof is quite simple .

In this case, a very important point for installation is the correct calculation of the necessary parameters.

In the attic truss system there are the following elements:

• Mauerlat. This element serves as the basis for the entire roof structure, is attached along the perimeter of the walls from above.
• Rafter. Boards of a certain size, which are attached at the required angle and have support in the Mauerlat.
• Skate. These are designations of the place of convergence of the rafters in the upper part.
• Crossbars. They are located in a horizontal plane between the rafters. They serve as an element of adhesion of the structure.
• Racks. Supports that are placed in a vertical position under the ridge. With their help, the load is transferred to the load-bearing walls.
• Strut. Elements located at an angle to the rafters to divert the load.
• Sill. It is similar to Mauerlat, only it is located on the internal load-bearing floor.
• Fight. A bar located vertically between the supports.
• . Roof construction.

Calculation of the gable roof truss system - online calculator

Field designations in the calculator

Specify roofing material:

Select a material from the list -- Slate (corrugated asbestos-cement sheets): Medium profile (11 kg/m2) Slate (corrugated asbestos-cement sheets): Reinforced profile (13 kg/m2) Corrugated cellulose-bitumen sheets (6 kg/m2) Bituminous (soft , flexible) tiles (15 kg/m2) 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 board (5 kg/m2) Keramoplast (5.5 kg/m2) Seam roof (6 kg/m2) Polymer-sand tile (25 kg/m2) Ondulin (Euro slate) (4 kg/m2) Composite tile (7 kg/m2) ) Natural slate (40 kg/m2) Specify the weight of 1 square meter of coating (? kg/m2)

kg/m2

Enter the roof parameters (photo above):

Base Width A (cm)

Base length D (cm)

Lift height B (cm)

Length of side overhangs C (cm)

Front and rear overhang length E (cm)

Rafter:

Rafter step (cm)

Type of wood for rafters (cm)

Working section of the side rafter (optional) (cm)

Lathing calculation:

Purlin board width (cm)

Lathing board thickness (cm)

Distance between decking boards
F(cm)

Snow load calculation (pictured below):

Choose 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 building ridge

5 m from 5 m to 10 m from 10 m

Terrain type

Open area Closed area Urban areas

Calculation results

Roof pitch: 0 degrees.

Tilt angle suitable for this material.

The angle of inclination for this material is desirable to increase!

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

Roof surface area: 0 m2.

Approximate weight of roofing material: 0 kg.

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

Rafter:

Load on the truss system: 0 kg/m2.

Rafter length: 0 cm

Number of rafters: 0 pcs

Lathing:

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

Uniform distance between the boards of the crate: 0 cm

Number of batten boards standard length 6 meters: 0 pcs

Volume of boards of an obreshetka: 0 m 3 .

Approximate weight of the boards of the crate: 0 kg.

Snow load region

Description of calculator fields

It is quite simple to make all the calculations before starting work on the construction of the roof. The only thing what is required is scrupulousness and attentiveness, you should also not forget about checking the data after the process is completed.

One of the parameters, without which the calculation process cannot be dispensed with, will be total roof area. It should be initially understood what this indicator represents, for a better understanding of the entire calculation process.

There are some general provisions, which it is recommended to adhere to in the calculation process:

1. The first step is to determine the length of each of the slopes. This value is equal to the intermediate distance between the points in the uppermost part (on the ridge) and the lowest (cornice).
2. Calculating such a parameter all additional roofing elements must be taken into account, for example, an overhang and any kind of structure that adds volume.
3. At this stage also material must be defined from which the roof will be constructed.
4. Doesn't need to be taken into account when calculating the area, ventilation and chimney elements.

ATTENTION!

The above points are applicable in the case of a conventional roof with two slopes, but if the house plan suggests an attic or other type of roof shape, then it is recommended that calculations be carried out only with the help of a specialist.

The best calculator to help you with the calculations truss system gable roof.

Calculation of the gable roof truss system: calculator

Calculation of rafter parameters

In this case, you need to push off from the step, which is selected taking into account the design of the roof individually. This parameter is affected by the selected roofing material and the total weight of the roof.

This indicator can vary from 60 to 100 cm.

To calculate the number of rafters you need:

• Find out the length of the slope;
• Divide by the selected step parameter;
• Add 1 to the result;
• For the second slope, multiply the indicator by two.

The next parameter to determine is the length of the rafters. To do this, you need to remember the Pythagorean theorem, this calculation is carried out according to it. The formula requires the following information:

• Roof height. This value is chosen by each individually, depending on the need to equip the living space under the roof. For example, this value will be equal to 2 m.
• The next value is half the width of the house, in this case - 3m.
• The quantity to be known is triangle hypotenuse. Having calculated this parameter, starting from the data for the example, it turns out 3.6 m.

Important: to the result of the length of the rafters, you should add 50-70 cm with the expectation of washing down.

Besides, it is necessary to determine what width to choose rafters for mounting.

Rafters can be made by hand, you can read how to do it.

For this parameter, you need to consider:

Determining the angle of inclination

It is possible for such a calculation proceed from roofing material, which will be used in the future, because each of the materials has its own requirements:

• For the size of the slope angle must be more than 22 degrees. If the angle is smaller, then this promises water to enter the gaps;
• For this parameter should exceed 14 degrees, otherwise, sheets of material may be torn off by a fan;
• For the angle can be no less than 12 degrees;
• For shingles, this figure should be no more than 15 degrees. If the angle exceeds this indicator, then there is a possibility of material slipping from the roof during hot weather, because. attachment of the material is carried out on the mastic;
• For roll-type materials, the variation in the angle value can be between 3 and 25 degrees. This indicator depends on the number of layers of material. A larger number of layers allows you to make the angle of inclination of the slope larger.

It should be understood that the greater the slope angle, the greater the area of ​​​​free space under the roof, however, more material is required for such a design, and, accordingly, costs.

More details about optimal angle tilt you can read.

Important: the minimum allowable slope angle is 5 degrees.

The formula for calculating the angle of the slope is simple and obvious, given that initially there are parameters for the width of the house and the height of the ridge. Having presented a triangle in a section, you can substitute data and perform calculations using Bradis tables or an engineering-type calculator.

You need to calculate the tangent of an acute angle in a triangle. In this case, it will be equal to 34 degrees.

Formula: tg β \u003d Hk / (Losn / 2) \u003d 2/3 \u003d 0.667

Determining the angle of the roof

Calculation of loads on the truss system

Before proceeding to this section of calculations, you need to consider all kinds of loads on the rafters. , which also affects the load. Types of loads:

Types of load:

1. Constant. This type of load is constantly felt by the rafters, it is provided by the roof structure, material, lathing, films and other small elements of the system. The average value of this parameter is 40-45 kg/m 2 .
2. Variable. This type of load depends on the climate and the location of the building, since it is formed by precipitation in this region.
3. Special. This parameter is relevant if the location of the house is seismically core. But in most cases, additional strength is enough.

Important: the best when calculating strength, make a margin, for this, 10% is added to the value obtained. It is also worth taking into account the recommendation that 1 m 2 should not take on weight more than 50 kg.

It is very important to take into account the load exerted by the wind. Indicators of this value can be taken from SNiP in the section "Loads and impacts".

• Find out the snow weight parameter. This indicator varies mainly from 80 to 320 kg / m 2 .;
• Multiply by a factor that is needed to account for wind pressure and aerodynamic properties. This value is indicated in the SNiP table and is applied individually. Source SNiP 2.01.07-85.
(in this example) that will need to be purchased for construction.

To do this, it is necessary to divide the resulting value of the roof area by the area of ​​\u200b\u200bone sheet of metal.

• The length of the roof in this example is 10m. To find out such a parameter, you need to measure the length of the skate;
• The length of the rafter was calculated and equals 3.6m (+0.5-0.7m.);
• Based on this, the area of ​​\u200b\u200bone slope will be equal to - 41 m 2. General value area - 82 m 2, i.e. the area of ​​one slope, multiplied by 2.

Important: do not forget about allowances for roof peaks of 0.5-0.7 m.



Roofing kit

Conclusion

All calculations are best checked several times to avoid errors. When this painstaking preparatory process is completed, you can safely proceed to the purchase of material and prepare it in accordance with the received dimensions.

After that, the installation process of the roof will be simple and fast. And our gable roof calculator will help you with the calculations.

Useful video

Video instruction for using the calculator:

In contact with



Before the construction of any object, you should accurately imagine the number necessary materials. Knowledge of such information will make it possible to calculate the amount of funds that will need to be spent on the purchase of material. Existing techniques allow you to calculate the required amount with great accuracy.

Priority tasks

To get an objective figure, you first need to understand what the area of ​​\u200b\u200bthe roof will be.

The main factors affecting the installation process:

• rafters and beams;
• fasteners and screws;
• architectural specifics of the building;
• surface area to be covered.





Modern materials for the roof, as a rule, they are laid using the "overlap" method, this circumstance must be taken into account when calculating the number of sheets for the roof. Usually any construction material bought with a small margin spent on various pruning.

The craftsmanship of the builder is characterized, among other things, by the minimum amount of material purchased “in reserve”. You can implement this task if you have a complete understanding of how to make an accurate calculation. To do this, you should know thoroughly all the subtleties of the technology of building a house.



The calculation of the roof is carried out according to the following scheme:

• according to databases in the form of tables, the permissible load per linear meter is determined;
• the total footage is considered;
• the number of beams is calculated.





Calculation method for single-slope and dual-slope construction

With an increase in the angle of inclination, the amount of material required increases. When designing an object, the area in which the building will be located should be taken into account. If there is a lot of precipitation in the region, then the angle of inclination increases, and vice versa.

With a gable roof, the calculation is carried out according to the formula: tga = h/b. Where the span width is denoted by the letter - b, height - h. Using the calculator, the inverse value a = arctg (h / b) is found.

Multiplying b by the length of the roof makes it possible to determine the area of ​​\u200b\u200beach slope. The angle of inclination of the roof usually varies from 22 to 45 degrees.





bituminous tiles

With the help of shingles, it is possible to cover large areas of the roof of the most complex configuration. With the right business, you can achieve minimal costs and do all the work yourself.

The base figure is: one pack of roofing material, soft tiles enough to cover an area of ​​three square meters.



This maxim is expressed by the formula: N \u003d S x K x 3, where N is the number of rolls of soft roofing, S is the area of ​​the surface to be treated in square meters, K is the complexity factor of the "landscape" of the roof. This formula takes into account all the nuances that are required to perform quality roofing work. It takes into account the amount of material that is spent on "overlaps", as well as the complexity of the roof of the object itself. If everything is calculated correctly, then it will not be necessary to spend extra money on the purchase of additional sheets "in reserve".





Ondulin

To perform ondulin coating, you should first of all have a good idea of ​​the geometric dimensions of the sheets. Ondulin sheets are overlapped, so the usable area is reduced from 1.65 sq. meters to 1.61 square meters.





It is very important to have initial data, that is, to clearly know what the area of ​​\u200b\u200bthe roof itself is. This figure can be called the base one, because, knowing it, then it will be possible to easily calculate the number of sheets needed for a full-fledged work, as well as determine with accuracy how much lumber is needed.

metal tile

The most popular roofing material is metal roofing. The formula that allows you to objectively estimate the amount of material needed is not very complicated.

The metal sheet of the tile is 1181 mm wide. The calculation of the number of sheets required for work is calculated by the formula: N = (Lck



It should be taken into account that the dimensions of the cornice are also added to the length of the slope. Do not forget about the "overlaps", they also consume a certain amount of material.

rafters

In order to adequately calculate the amount of wood needed, you should first of all be able to calculate the load that the roof can withstand.

It consists of three indicators:

• the weight of the roof itself;
• snow weight in winter;





Based on the parameters of the structure, its area, it will be possible to understand:

• section of rafter fasteners, their number;
• what kind of crate is required;
• thickness and length of boards per crate.

The work is complex, each element of this “puzzle” plays an important role, so the calculations must be correct.



The lion's share of wood materials goes to the rafter system. For a correct calculation, the wind load must be taken into account. You need to know: how large is the useful area of ​​​​the object, are there attics and attics. The larger the area, the greater the consumption of building materials.

Each object has a unique feature. There are roofs in which there is a significant number of ventilation ducts. In this case, the consumption of lumber is significantly reduced.

Thickness

An important factor is the total thickness of the roof, which can create a serious load on the truss system. The step of the rafters is calculated according to certain tables, in which all fundamental parameters are taken into account.

Let's say there are loads of 2.3 tons per square meter. Accordingly, the load "falls" within 100 kg per linear meter. From this follows the calculation of the total length of the rafters: 2400 x 100 = 24 m.

In the event that the length is about three meters, then it is easy to calculate the number of rafters: 24 x 3 = 8 pieces.





Pairs are counted in this way: 8 x 2 = 4 pairs of rafters.

Based on the data obtained, it is easy to understand the pitch of the rafters: 4.5 x (4 pairs - 1) = 1.5 meters.

You should always be on the safe side. Therefore, it is better to reduce the step, which will give an additional margin of safety: 4.5 x 5 \u003d 0.95 m \u003d 95 cm.

A lot of material is spent on the Mauerlat, it is calculated as follows: M = P x V. Here V is the volume of the Mauerlat, calculated by the formula: V = S x L, where S is the size of the beam in diameter, L is total length, P is the density of the material.



Using the data obtained, including the amount of necessary materials, it is easy to draw up a big picture in numbers. A professional approach to the calculation of materials for the construction of a roof drastically reduces unproductive timber costs.

If the attic is used as a living area, then it should be insulated. This, in turn, leads to a weighting of the overall structure and additional pressure on the m2 of walls.

If the attic is not used as a residential facility, then in this case the insulation is laid only in the area of ​​\u200b\u200bthe overlap. In such cases, the average density of the materials used, as well as the initial data of the project for the construction of this facility, are taken into account.





Waterproofing

The starting point for waterproofing is the base figure: nine rolls per square meter of roof. Waterproofing is calculated on the basis that one roll contains 7.6 square meters of material: Approximately twenty centimeters are taken for the overlap. Thus, according to the formula: N \u003d S x 65, you can make the most accurate calculation. Here N is the number of rolls that are required, S is the area to work with (in meters).





The calculation accurately reflects how much the necessary material should be purchased. You should also calculate the amount of thermal insulation. An instruction is attached to each unit of goods - a memo, which indicates the standards for material consumption per square meter. In this case, it is necessary to take into account the coefficient of thermal conductivity, which allows you to calculate the thickness of the insulation. One package is calculated on average for 5.8 square meters. meters.





Consider the number of layers that will be needed. And at least 12% of the material will go to allowances.

A beam with a cross section of 10 cm or more costs a lot of money, it is best to sew boards 3 cm thick, the cost of which is much cheaper. The maximum length of the rafters usually does not exceed 6 meters. For the manufacture of rafters, dried softwood is most often used. Raw materials must be treated with a primer - a special antiseptic.

You can use the online calculator to calculate the parameters necessary for construction:

• strapping beam;
• rafter length;
• crate;
• the total weight of the entire system;
• cash expenses.

In many cities there are special companies that are engaged in the preparation of projects for the construction and costing of the material. It is better for a person who is far from construction issues to contact such organizations, or even several, in order to guarantee himself the most objective picture.



Take advantage online calculator gable roof to calculate the amount of lathing, the angle of inclination of the truss system, the load (wind and snow) on the roof. Our free calculator will help you calculate the required amount of material for a given type of roof.

Specify roofing material:

Select a material from the list -- Slate (corrugated asbestos-cement sheets): Medium profile (11 kg/m2) Slate (corrugated asbestos-cement sheets): Reinforced profile (13 kg/m2) Corrugated cellulose-bitumen sheets (6 kg/m2) Bituminous (soft , flexible) tiles (15 kg/m2) Galvanized sheet metal (6.5 kg/m2) Sheet steel (8 kg/m2) Ceramic tiles (50 kg/m2) Cement-sand tiles (70 kg/m2) Metal tiles, corrugated board (5 kg/m2) Keramoplast (5.5 kg/m2) Seam roof (6 kg/m2) Polymer-sand tiles (25 kg/m2) Ondulin (Euro slate) (4 kg/m2) Composite tiles (7 kg/m2 ) Natural slate (40 kg/m2) Specify the weight of 1 square meter of coating (? kg/m2)

kg/m2

Enter roof parameters:

Base Width A (cm)

Base length D (cm)

Lift height B (cm)

Length of side overhangs C (cm)

Front and rear overhang length E (cm)



Rafter:

Rafter step (cm)

Type of wood for rafters (cm)

Working section of the side rafter (optional) (cm)

Lathing calculation:

Purlin board width (cm)

Lathing board thickness (cm)

Distance between decking boards
F(cm)

Snow load calculation:

Select your region using the map below

1 (80/56 kg/m2) 2 (120/84 kg/m2) 3 (180/126 kg/m2) 4 (240/168 kg/m2) 5 (320/224 kg/m2) 6 ​​(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 building ridge

5 m from 5 m to 10 m from 10 m

Terrain type

Open area Closed area Urban areas



Calculation results

Roof pitch: 0 degrees.

The angle of inclination is suitable for this material.

The angle of inclination for this material is desirable to increase!

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

Roof surface area: 0 m2.

Approximate weight of roofing material: 0 kg.

Number of rolls of insulation material with 10% overlap (1×15 m): 0 rolls.

Rafter:

Load on the truss system: 0 kg/m2.

Rafter length: 0 cm

Number of rafters: 0 pcs

Lathing:

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

Uniform distance between the boards of the crate: 0 cm

The number of boards of the crate with a standard length of 6 meters: 0 pcs

Volume of boards of an obreshetka: 0 m 3 .

Approximate weight of the boards of the crate: 0 kg.

About the calculator

The online calculator for a gable roof, also called a gable roof, will help you calculate the desired angle of inclination of the slopes, determine the cross section and number of rafters, the amount of materials per sheathing, the consumption of insulating materials, and at the same time take into account existing standards for wind and snow loads. You do not have to perform unnecessary additional calculations, because this calculator contains most of the existing roofing materials. You can easily calculate the consumption and weight of such common materials as shingles, cement-sand and ceramic tiles, metal tiles, bituminous and asbestos-cement slate, ondulin and others. If you are using non-standard material, or want to get more accurate calculations, you can specify the mass of your own roofing material by selecting the appropriate item in the drop-down list of materials.

Note!
The calculator makes calculations in accordance with the current SNiP "Loads and Impacts" and TKP 45-5.05-146-2009.


A gable roof (there are variants of the name "gable roof" and "gable roof") - the most common type of roof, in which there are two inclined slopes from the ridge to the outer walls of the structure. The popularity of this type of roofs is due to their moderate cost, ease of construction, good performance and attractive appearance.

In this design, the rafters of different slopes lean against each other in pairs and are sheathed with sheathing boards. The end of a building with a gable roof has a triangular shape and is called a pediment (the name “tongue” is also found). Usually located under the roof slopes attic space, naturally lit by small window openings located at the top of the gables.

When filling in the fields of the calculator, you can find additional information located under the sign.

For any questions or ideas regarding this calculator, you can write to us using the form at the bottom of the page. We will be glad to hear your opinion.

Additional information about the calculation results

Roof pitch

At this angle, the slope and rafters are inclined to the base of the roof. Roofing materials have individual limiting roof slope angles, so for some materials the angle may be outside the permissible limits. Whether your angle satisfies the selected material or not - you will find out in the calculation results. In any case, it is always possible to adjust the height of the roof (B) or the width of the base (A), or choose a different roofing material.

Roof surface area

The area of ​​the entire roof surface, including overhangs. To determine the area of ​​​​one slope, it is enough to divide the resulting value by two.

Approximate weight of roofing material

The weight of the selected roofing material from the calculation total area roofs (including overhangs).

Number of rolls of insulating material

The amount of insulation material required to build a roof. The quantity indicated in rolls is required for the entire roof area. The standard roll is taken as a basis - 15 meters long, 1 meter wide. The calculation also takes into account an overlap of 10% at the joints.

Load on the truss system

The maximum weight per rafter system. Wind and snow loads, the angle of inclination of the roof, as well as the weight of the entire structure are taken into account.

Rafter length

The full length of the rafters from the roof ridge to the edge of the slope.

Number of rafters

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

Minimum cross-section of rafters / Weight of rafters / Timber volume

1. The first column shows the sections of the rafters according to GOST 24454-80 Softwood lumber. Here are the sections that can be used in the construction of a given structure. The calculator proceeds from the total loads that can affect the structure of a given roof and selects the sections that satisfy them.
2. The second column shows the total weight of all rafters with the specified section, if they are used to build a given roof.
3. The third column shows the total volume of this timber in cubic meters. This amount will be useful to you when calculating the cost.

Number of rows of sheathing

The number of rows of lathing that will be needed for the entire roof with the given parameters. To calculate the number of rows of crates of one slope, you need to divide the resulting value by two.

Uniform spacing between boards

The volume of boards of the crate

The total volume of the crate for a given roof. This value will help you calculate the cost of lumber.

Online roof and roof calculators are must-have tools in the arsenal of architects and professional construction firms. Although, in principle, such calculators are also useful for simple owners of suburban areas who have started building a house with their own hands (here you will also need to calculate the roof). And it is not surprising, because the quality and accuracy of such calculations directly affect not only the durability of the entire roof structure but also on the general appearance of the house. This section of the site contains the best calculators for calculating the roof, which will help you in the most common cases when self construction at home! Here you will find useful tools for calculating the area of ​​the three-gable roof, the amount of slate, the area of ​​the hipped roof, the length of the rafter legs, the height of the ridge and much more! All online calculators were created by experienced specialists, each tool is accompanied by detailed explanations and instructions for calculating.

What are the advantages of our online calculators? They differ from their numerous (and often paid) counterparts in that they do not need to be downloaded to a local computer. Complex, carefully tested algorithms are used to perform calculations, and the results of calculations are displayed in a simple and accessible form. Another advantage is that you can add a page with an online calculator of interest to your browser bookmarks and use it at any time!

On a note! When making online calculations, construction standards, GOSTs and SNiPs are used, which are accepted in the Russian Federation and the world. In addition, the world practice of modern construction is taken into account.