One-pit roof for garage by own hands

You can only envy those car owners who have or have the opportunity to build their own real garage. Knowing the mentality of our men, we can say with a high degree of certainty that the vast majority of "lucky beggars" will take up the handwriting of the "house" for their car. In our time, there are many opportunities for choosing materials for building a garage - both from the standpoint of the ease of independent construction, and in terms of maximum economy.

Single-pitched roof for the garage with their own hands

Any building is always crowned by a roof, and if, again, to focus on minimum costs, then the single-stage construction becomes the best option. In addition, the problems of some special decorativeness, as a rule, recede into the background, giving way to the reliability of the design and the speed of its installation. It is these qualities that this option has. So, a single-pitched roof for the garage with your own hands: from carrying out the necessary calculations to the installation features - in this publication.

What are the advantages of a saddle roof, are there any disadvantages?

So, in most cases the garage is treated exactly as a utilityth technical room, so in its design and construction are usually dominated by a utilitarian approach - simplicity, reliability, creation of effective protection of the vehicle from falling precipitation. That is why such popularity in this case have single-pitched roofs.

• This design is not difficult for self-calculation. At its base lies the triangle - the most "rigid" of all two-dimensional figures, which is described by simple and understandable geometric relationships.

Single-pitched roof is a simple construction for calculations and self-erecting

• The cost of materials and components is always much lower than for even the simplest gable roof. It is important that saving sawn timber in this case does not in any way affect the reliability of the structure.
• Installation of a single roofing system is simple and intuitive. For the independent construction of such a construction does not necessarily have to be a qualified master - with the observance of technological recommendations with a similar task, any garage owner can cope. This is another "plus" in terms of the cost-effectiveness of construction - there is no need to resort to hiring specialists.
• Another advantage - the speed of work. The garage can be closed with a saddle roof in a matter of days, while choosing a more complex rafter system and time will require considerably more.

However, the owner of the garage when choosing a saddle roof will have to accept some of its drawbacks:

• A single-pit roof is more susceptible to snow load, due to a slight slope, drifts can form on its surface. This must be taken into account when making calculations.
• Such a design does not at all imply an attic space, or its operational capabilities will be substantially limited.

Attic with a single-deck roof structure or not at all, or it will be small and not very functional.

• There are certain difficulties in ensuring high-quality thermal insulation of such a garage, especially if the project does not assume the presence of even a small attic space.
• Finally, not everyone likes the appearance of a single-pitched roof, not suggesting any decorative delights. However, this is a matter of taste, and if desired, a single-pitched roof can be fully integrated into the overall "architectural ensemble" of its suburban possessions. For many, this shortcoming is not essential at all.

Garage Slope Options The single-pitched roof system is a series of rafters stacked parallel to each other, arranged in such a way that one end of them is raised relative to the other to a certain height to create a slope. The rafters become the basis for installing the necessary crate, and already it, in turn - for the flooring of the selected roofing.

Exceeding one end of the rafters on the other can be provided in several ways:

• Even in the process of designing a garage, one of the walls is planned to be higher than the opposite one by the amount( the calculation of this excess will be described below).Two other walls in this case are given a trapezoid shape.

One wall of the garage is immediately erected above the opposite.

This approach is often practiced in wireframe construction. Even during the drawing up of drawings it is provided that the height of the supporting vertical racks of the frame on one side will be higher. Thus, at different heights, with the necessary ΔH, there will also be bars of the upper strapping, which will play the role of Mauerlat. As a result, a ready-made system of a single-pitched roof is immediately laid, on which only the rafters will need to be assembled, and then - the necessary crate.

In frame construction, the slope of the roof slope is provided by the difference in height of the vertical columns of the opposite walls.

Which walls will differ in height, of course, will depend on the chosen direction of the ramp.

- This can be a transverse slope, towards one of the sides of the garage. This method is attracted by the fact that the rafters are shorter, and you can often do with the simplest scheme, without creating additional supports for them.

- Another option when the facade wall of the structure is higher than the rear, and then the slope of the ramp is organized backwards. The length was built in this case, with reference to the garage, already reaches 5 ÷ 6 and even more meters, and without their amplification it is no longer necessary.

• If both walls of the building are of the same height, or the saddle roof is erected on the previously constructed structure, then the rafters can be organized by placing them under the same height in the same side of the rails ΔN.Racks on top are usually combined by a bar of strapping, which will become a function of the Mauerlat.

Walls of the same height, and from one side under the rafter legs are installed racks.

In this case, the facade part of the roofing structure and the gable triangles remaining open after mounting the rafter system are simply sewn with wood or other material, at their discretion.

Artificial facade wall of a single-pitched roof - racks with upper strapping beam, and planking.

This approach often allows to achieve savings in the construction of the capital walls of the garage - less bricks or blocks will leave, and the masonry process will be faster - there is no need to remove additional lateral trapezoidal walls of the pediments.

• If the walls are of the same height, then they resort to another method - on the "ground" they mount truss racks, and then install them with certain steps on the Mauerlat.

The roof structure is a "suite" of installed truss racks

Usually, during the work, one such farm is made, carefully tried and adjusted to the place. Well, then it becomes a template for "cloning" - according to its model the rest are made, in convenient conditions on the ground. When all the farms are ready - go to the final installation. The lower corners of the trusses are attached to the Mauerlat, the upper ones are tied together by a bar, creating a single rigid structure.

This approach is especially useful when a large distance between the walls obliges the builder to reinforce the rafters. And the farm itself is a rigid constructive element, because it combines a kind of overhead beam, and a rafter's leg, with reinforced crosspieces - struts or struts between them.

The trussing system combines the properties and joists of the roof, and the truss of the

. Another obvious convenience is that it will be much easier to sew the ceiling in this garage, if necessary, also insulating it - the horizontal beams of the farms provide all the possibilities for this.

Another option - when the garage is attached to the finished solid wall of the previously erected capital building.

Another option - the garage is attached to the previously erected building.

In this case, one end of the rafters rests on the brackets or support bar installed on a wall at a certain height, and the second one on vertical racks with strapping - in the case of a frame structure, or on a mauerlat attached to a nearby wall. In any case, this fulcrum is again located with a calculated height difference ΔH.

Garage with a gable roof is attached to the house

If necessary, instead of rafters, roof trusses can be attached to the wall of the house, in analogy with the previously considered case.

The main parameters of the gable roof of the garage, carrying out their calculations

So, if the decision is made to build a roof over a garage, then it is necessary to determine its basic parameters.

From the initial data, as a rule, there are only dimensions of the "box" of the garage - its length and width. From here we will begin to "dance".

The initial data for calculations is the length of the garage( D), its width( L), the planned direction of the roof slope.

Direction of roof slope

First of all, it is necessary to determine in advance the direction of the slope of the ramp, guided not only by considerations of convenience and ease of installation of the truss system, but also taking into account the prevailing wind direction in the construction site.

The roof slope is recommended to be carried out on the windward side, so that the air movement does not create a lifting force, but, on the contrary, it presses the roof structure downwards. Although the garage is usually a low construction, and can almost completely bury itself from the effects of winds from other buildings, nevertheless, the prevalence of wind can be caused by the peculiarities of the terrain or neighboring buildings - open spaces, forest clearings, etc. And, of course, a specific role in the choice of the direction of the slope may be played by the specificity of the site - the general "background" of the design of the territory, the location of the elements of the storm sewage system or other factors.

Defining the steepness of the ramp

The next step is to determine the steepness of the ramp, that is, with the angle α.

For single-skinned roofs, this angle usually does not exceed 25, a maximum of 30 °.With too much steepness, the structure itself looks ridiculous, and most importantly - the roof becomes very vulnerable to wind load. Too small inclines, less than 10 °, are also undesirable, since in this case the importance of snow load on the ramp sharply increases, outflow of water is difficult, especially during the thaw period or the beginning of mass melting of snow.

The angle of the ramp is also seriously affected by the type of roofing. If the owner of the garage prefers a particular material for the roof in advance, for example, to withstand the overall design of the territory, then he must follow certain rules in calculating the slope of a saddle roof.

Below is a diagram showing the permissible types of roofing for various angles of the steepness of the roof slope.

Chart of the dependence of the angle of the ramp from the linear dimensions, the permissible types of roofing

Note that the steepness of the slope in the diagram is shown in three different versions - in degrees and in the ratio of the lifting height( ΔH) to the base length( D or L), which, inturn, can be expressed in fractional ratio or in percentage. Having such a scheme at hand, it will be easy to transfer one unit of measurement to another.

The numbers in the circles indicate the types of roofing, and the arrow from them indicates the minimum allowed for the roof slope at which they can be used.

How to give the slope a given angle of gradient?

The next question is how to give the slope the desired angle of inclination.

If the α and with the direction of the slope of the slope were determined, then knowing the initial parameter of the length or width of the garage() , it is not difficult to determine the required height difference ΔN , which has already been mentioned many times.

If the walls have a certain thickness( for example, laid out of blocks or bricks), then we measure the linear parameters of the D and L construction along their outer edges.

To calculate, we use the known trigonometric formula:

H = L ( D ) × tg α

In order not to force the reader to search for tangent values ​​and perform independent calculations, a calculator is placed below which will allow calculation in seconds. If desired, you can "play" values ​​to find the optimal permissible option.

Calculator for calculating the wall excess to ensure the necessary slope of the sill roof

Determine the length of the rafters

The next step is to determine the length of the rafters

Find it easy - according to the trigonometric formula

S = Δ H / sin α

or using the well-known Pythagoras theorem:

S = √( L ²( D ²) + Δ H ²)

When calculating it is prudent to immediately increase the length of the rafters to obtain the required roofing overhang that prevents direct atmospheric precipitation from reaching the garage walls.

The size of the cornice overhang is usually linked to the material of the walls of the building. The table below shows the minimum overhang width depending on the type of walls:

However, the overhang can be formed and otherwise - lengthening the rafters with the help of so-called filly. In this case, the din rafters are calculated only between the attachment points.

Variants of the organization of the lateral overhang of the roof - due to the lengthening of the rafter( a) and by increasing the length of the fillets( b)

Below is a calculator that will quickly calculate the length of the rafter legs for both one and the second version.

Calculator for calculating the length of rafters for a single-roof

In any case, if the choice is given, the minimum length of rafter legsbetween points of support).In this case, it becomes possible to use a material with a smaller cross-section( this will be discussed below), which in itself provides considerable cost savings. In addition, the structure itself is simplified.

Rafters up to 4.5 meters long can be supported by two points without requiring additional reinforcing elements. When the length of the rafters is of the order of 5 ÷ 6 meters, their reinforcement with struts( with the feet) is already necessary. It will be even more difficult if the span is more than 6 meters - it will require the installation of racks that rely on powerful beams overlapping or on the capital base, and several struts.

Complication of the construction of the rafter system with increasing span length

1 - Mauerlat bar;

2 - rafter leg;

3 - a support bar( a ladder);

4 - a sub-strut( a leg under the feet);

5 - floor beam( the support can be on the main wall);

6 - vertical stand

Cross-section of rafters, installation step

The next question, probably, is one of the most important and complex - a cross-section of the beam or log from which the rafter legs will be made and the step of their installation.

The length, cross-section and step of the installation of the rafters must correspond to the anticipated loads on the roof structure.

The cross-section of sawn timber suitable for making rafter legs depends on the load falling on them. The total loads that must be able to withstand rafters, are composed of several values:

• The weight of the rafters themselves, the crates, the rebound, the insulation, the waterproofing. This value can be calculated, but it, as a rule, is embedded in the indicator of 30 ÷ 40 kg / m² - it will not be a big mistake to operate with such a value.
• Weight of the roofing. Here the differences can be quite significant. The average values ​​of specific gravity of different types of roofing are given in the table:

• Finally, loads of a natural nature. It is primarily the pressure of snow masses accumulating on the roof with a slight slope, to which all the single-pitched roofs fully belong. The second factor is the wind load, For low-profile single-pitched roofs, it is not significant, but you can take it into account.

For the calculation of these loads use the results of long-term meteorological observations. The entire territory of Russia is divided into zones according to the level of the average snow load per unit area, and by the strength of the prevailing winds.

The diagram below shows the zone distribution map for the snow load:

The zone load values ​​are indicated in the table:

Values ​​are given in kilopascals in kilogs per square meter, since in different sources can be used, and those and other values. For translation, you can use the approximate relationship:

1 kPa ≈ 100 kg / m²

The snow load of the on the roof is calculated by the formula:

Pcn = Pcn.txμ, where

Rd.t is the table value for this zone;

μ - coefficient taking into account the slope angle of the roof slope:

- when the steepness of the skates is up to 25 ° the coefficient is equal to one, since the snow almost completely remains on the roof;

- if the angle is more than 25 °, the coefficient is 0.7.

The wind load is also calculated based on the tabulated values. The following is a diagram of the zoning of the territory of the Russian Federation according to the level of wind pressure:

Map-scheme of zoning of the territory of Russia according to the level of wind pressure

The values ​​of wind pressure for each zone are listed in the table:

The value of the wind pressure for a particular building is calculated by the formula:

Pv = Pvt × k × n, where

Pvt - taprivate value for the particular zone;

k is a coefficient that takes into account the height of the building and its location.

n is a coefficient that takes into account the steepness of the slope and the prevailing wind direction.

The k is calculated for buildings of different heights, but since we are talking about a garage, we can reduce the table in a "truncated" form, since the height of the building will certainly not be too large.

Two lines are always given,, with a height of up to 5 meters.

There are three zones in the table - this is a general characteristic of the location of the structure:

The erected structure can be attributed to a particular zone if these characteristic features of the terrain are located no further than in the radius of the 30 × h , where h is the height of the building. Thus, for example, for a garage height of 4.5 m, a circle with a radius of 135 m is delineated.

The following factor - n , takes into account the dependence of the wind load on the direction of the wind and the angle of the roof slope. The ratio is quite complex, and all the multiple values ​​of the coefficient are distributed over several tables, depending on the area of ​​the roof and the prevailing winds - to the front or to the ramp. In our case, when calculating a low roofed roof( garage), to bring all the tables - it just does not make sense. Assume that the direction of the ramp, as recommended above, is selected on the windward side, and the steepness does not exceed 30 °.In a number of cases, the coefficient even takes on negative values, since the wind does not press, but on the contrary, the lifting effect on the roof.

Now, knowing all the required values, you can calculate the total external pressure on the roof for the most unfavorable circumstances - simply summarizing all possible impacts. This value will be obtained in kilopascals or in kilograms per square meter. But we should be more interested in the magnitude of the distributed load per meter of rafters - this will help determine its cross-section. And this indicator is already dependent on the chosen step of setting the rafter feet.

It is clear that the more rafters are installed, the less the load on each of them. Uniform recommendations for choosing the step of the installation is not - it largely depends on the type of torn roof - for different materials can have their recommended values. But usually rafters are not widely spread for a single-pitched roof - the step is kept in the approximate range from 500 to 1000 mm.

In order to estimate the load falling on the running meter of the rafters, the total value calculated per unit area is to be multiplied by the step expressed in meters. For example, calculations have shown that a roof load of 190 kg / m² can be applied to the roof under existing conditions. The step of installing the rafters is selected 600 mm. As a result, we receive a load on the rafter leg 190 × 0.6 = 114 kg / running meter.

Having this value on hand, it will be easy to find the optimal cross-section of the rafter - using the table below.

Consider the same example:

Example of using a table for opsection of the rafters

Estimated load per linear meter of the rafter leg 114 kg - rounded to the table 125 kg. The calculations carried out earlier showed that the length of the rafters between the points of the support should be 4.4 m - lead to a tabular 4.5 m. Find the corresponding values ​​in the table( highlighted in the yellow area.)

On the left in the section "rafter section" in the corresponding row( highlighted in green), all the dimensions allowed in this case are shown: a log with a diameter of 160 mm, or a bar with a cross-section of 50 × 210, 60 × 200, 70 × 190, 80 × 180, 90 × 170 and 100 × 160.

If the calculated load exceeds the specified values(more than 175 kg / meter), or if there is a needMenenius, nothing to minimize the timber cross-section is in addition, as a step to reduce the installation of rafters, and thus enter the design parameters in the "desired frame».

	So, the garage of the blocks is built. The design of the building immediately took into account the necessary steepness of the ramp and its direction. Accordingly, one of the long sides is lined with an excess of ΔH. Two short sides( pediments) - a trapezoid shape.
	First of all, the Mauerlat is installed. For him, use a quality bar measuring 100 × 150 mm, laying it on the wall on the wide side. Mauerlat is usually placed on the inner edge of the wall - this will allow you to further close it from external influences near the brickwork. Between the wooden part and the block wall there must be a layer of waterproofing - roofing material.
	The ways of mounting the Mauerlate can be different. For example, when pouring the upper reinforcing concrete belt, bookmarks with vertical pins are immediately made. Another option is for anchoring fasteners, right through the bar. Another option, if the thickness of the wall allows - using steel corners - they are fastened with dowels to the wall, and already to the corners with powerful self-tapping screws - the Mauerlat itself( as shown in the illustration).
	By the way, at this stage there is nothing to prevent one from considering one possibility - the organization of future frontal and rear eaves by increasing the length of the Mauerlat bar and taking it front and back to the required distance beyond the outer limits of the building. At the same time for Mauerlat it is better to take the beam more simply - about 150 × 150 mm. There is another nuance - to the estimated number of rafters will need to add two more pieces.
	Now you need to prepare the rafters themselves. It will be more convenient to bring them to the "condition" on the ground, and for this you will need to make a template. For a template, you can take a board, for example, 50 × 200 mm, so long that it is enough for the entire length of the rafters, taking into account the side eaves. The template board in place can be immediately adjusted to the required length. The board is placed on the beams of the Mauerlatt strictly perpendicular to them( parallel to the sloping walls)
	The marks are made for the secure fixation of the rafters on the Mauerlate. With the help of a square, ruler, with level control, a cutout place is planned. In this case, proceed from the fact that the height of the sample( h) should not exceed ⅓ the height of the rafter beam. The width of the support flange( m) should ideally approach the width of the Mauerlat, but still the first requirement is considered paramount. Similar markings are made on both sides of the template. The ready-made template marks and cuts out all the necessary rafter legs.
	The bars of the Mauerlat are used to mark out the axes for installing the rafters with the calculated pitch. After this, go directly to the installation and fastening of the rafter feet. If the slanting walls are laid out as shown in the illustration, a gap of about 50 mm is left between the outer rafters and the wall.
	The rafters can be attached to the Mauerlate differently. For example, special steel corners are used, and the rafter leg itself is fixed to the corner either by nails or by a bolt skipped through, as in the figure.
	This illustration shows a similar connection using corners, but only with the use of nails. And on the right part of the picture - an option without a squeak( when it is unreasonable, for example, due to excessive weakening of the rafter). In this case, a support bar is fastened to the rafters from the bottom.
	Another option - the rafter is fixed to the Mauerlat with nails, slashed obliquely on both sides, and then the junction box is reinforced with a clogged steel bracket. An important condition - the clogged sharp ends of the bracket must be located in perpendicular planes.
	After mounting all the rafters, you can go over to the eaves. From two inclined sides for this, the filly will be installed. Mares are made from the same lumber as rafters. To do this, you can use the images that remain when cutting - this should be taken into account in advance. The details are cut in such a way that the upper edge coincides with the top of the rafters. Fix the filly to the rafters with two nails in the butt. Extreme fences falling to the level of the walls, it is desirable to additionally fix to the capital base using steel corners. We do not forget that there must be a ruberoid gasket between the filages and the wall.
	It is usually done in this way: two endless fillets are installed and completely fixed, a cord is fastened between them. ..
	. .. then all the others are also installed along the planned line in steps of approximately 800 ÷ 1000 mm.
	The next step along the entire perimeter of the construction on the fillets and the projecting ends of the rafter legs is a carved windboard. For this purpose a 25 × 200 mm board is used.
	Now - it's time to lay a brick looking side of the Mauerlat on a high wall( shown by arrows). From wood the masonry should be separated by a roofing material.
	Bottom curtain eaves need to be sewn. The filing can be a continuous board of 25 mm thick. In this illustration, only the skirting is shown with bows - later they will be attached to spotlights or strips of siding.
	Now it is mono to proceed to the flooring of the battens for the chosen roofing. For lathing under the corrugated board, unedged boards, section of approximately 25 × 100 mm, are also quite suitable. Here, on the quality of the material, you can save a little - buy second-grade material for the wire. But it is necessary to make sure that there is no bark left on the unedged boards, since nests with parasitic insect larvae, bark beetles, can remain in it. The cladding is installed either solid( for example, for a soft roof), or with a certain step, depending on the type of roofing material and the steepness of the ramp.
	And, finally, a roofing material is being assembled on the finished roofing, in this case - profiled sheeting.
Illustration	Brief description of the operation

To simplify the reader's task, the calculator for calculating the distributed load on rafters is below. By the way, it makes it possible to trace how the load parameters will change with increasing or decreasing the planned step of installing the rafters - so it is easier to come to the optimal solution.

Calculator for calculating the distributed load on the rafters of the saddle roof

Having obtained the desired value, go to the table to find the desired section of sawn timber.

Knowing the step of installing rafters, it's easy to calculate their number. To do this, the length of the wall perpendicular to which the rafter legs will be set, divided by a step, rounded up to an integer and added one. For example, the length of the garage is 6.4 m, the selected design pitch of the rafters is 0.6 m.

6.4 / 6 = 10.66 ≈ 11+ 1 = 12 rafters.

And now, finally, you can calculate the exact distance between the axes of the rafter legs, since we will place them evenly:

6.4 / 11 = 0.582 m.

The step turned out to be, it's understandable, a little less, but it's only on hand, sohow to create the necessary margin of strength of the roof structure.

Now it will be possible to proceed to the manufacture of rafter legs - all the dimensions for this are calculated.

Mounting of the gable roof of the garage

Actually, if everything is carefully calculated, all the necessary details of the structure have been prepared, then, having not even the largest experience of carpentry, it will not be such a difficult task to mount the roof gable roof system.

The options here can be a great variety, depending on both the construction material and the used roofing. About everything to tell - there is not enough publication, but these issues are detailed in the pages of our portal in the section "Roof and roof."In the same article, we will consider the option of building a roof on a garage, laid out of blocks and overlapped with corrugated board.

To properly determine the step of the flooring, you need to know the features of the roofing material. In this case, the corrugated board was considered, but the pitch of the crate was still not indicated. And this is because the varieties of this material can also vary significantly.

What you need to know about corrugated board?

This material is persistently moving to the heights of popularity among professional and individual builders. How to choose the corrugated board - read in the special publication of our portal. And another publication will help to carry out the independent installation of the roof from the corrugated board .

So, after reading the article, many people can come to the conclusion that the most crucial step is to calculate the future gable roof of the garage. So it really is - with correctly calculated parameters, well-chosen quality details, the independent construction of a single-pitch roof of a small structure will already become quite feasible operation.

At the end of the article - another example, now clear, in video format, the construction of a saddle roof:

Video: an example of mounting a single-pitched roof