The first stage of each construction is the preparation of a detailed project. How is a roof project for a house built?
It must be said right away that design is a difficult job that requires knowledge of the theory and taking into account many important nuances that can affect the reliability of the entire building.
When calculating, it is necessary to take into account not only the features of the house itself, but also the climatic conditions of the area - wind loads, the amount of precipitation, etc.
It is imperative to take into account such a moment as the weight of the future roof itself, since the type of material for covering the roof is determined by the reliability of the foundation and load-bearing walls.
In addition, the design of the roof depends on the size of the future house and its layout. The simplest option is considered when the area of \u200b\u200bthe house does not exceed 6 × 6 meters.
In the event that it is planned to build a spacious house (for example, with an area of 200-250 square meters), and even at different levels, then the task is seriously complicated
Roof types
Before proceeding with the design, it is necessary to understand what types of roofs are used in modern construction.
They are usually divided into 2 large types:
- Attic, that is, having an internal space between the roof and the ceiling that separates the premises of the upper floor.
- Atticless, that is, without such space.
In addition, roofs are usually divided by shape into the following subspecies:
- Shed roof;
- gable;
- Multi-slope;
- Hip;
- Mansard standard roof;
- Tent;
- dome;
- Multilevel.
Roofs can also be classified according to the type of material that was used to cover the roof:
- Slate;
- soft;
- Tiled;
- metal;
- Reeds, etc.
When choosing ready-made roof projects or creating an individual project, you need to remember that the roof should not be a separate element, but a continuation of the overall project of the house.
That is, the roof should be in harmony with the design and appearance of the house.
Roof Design Tips
Here are some useful tips to keep in mind when designing a roof:
- Not everyone has the ability to draw and draw, therefore, in order to develop a project, it is worth using computer programs created for design. For example, Arkon or AutoCAD.In this case, it will be enough just to select the required type of roof, and the program will select standard blanks, in which you can make the necessary changes.
- It is necessary to approach the development of the truss system with special attention, because the strength and reliability of the structure depends on it.
- picking up roofing material and the color of the coating must adhere to the general style in which the house is built.
Design stages
The process of creating a roof, which begins with an idea and ends with construction work, can be divided into three large stages.
- Stage of preliminary design. This is the time when the image of the future structure is being comprehended, its appearance is presented - form, coating. In addition, at this stage it is necessary to coordinate the planned roof style with the overall project. That is, to put it simply, drawing up a draft design is the transfer of the architect's fantasies to paper.
- Stage of development of technical documentation. . This is the time for engineering calculations, development of documents. It is necessary to calculate the expected load on the roof, select the required number and thickness of the rafters. At the same stage, a drawing of the roof is made, all its main components are designed, and the most suitable design solutions are selected.
- Construction stage. This is the time to put the created project into practice. At this stage, no calculations are made anymore (except for additional and intermediate ones, if project shortcomings were identified during the work), but construction work is carried out, according to the drafted project.
How to calculate the area of the roof?
Knowing the area of the roof is necessary in order not to be mistaken with the amount of material purchased. Here is an instruction that will tell you how to calculate the area of \u200b\u200bthe roof:
- We calculate the area of \u200b\u200ba single-pitched roof. This is the easiest option, since the shape of such a roof is a rectangle, its area is equal to the product of the lengths of the sides, that is, you need to multiply the width of the house by its length.
Example: A house with walls measuring 8 and 6 meters, the length of the rafter leg is 7.35, taking into account the length of the overhang of 0.5 m
We add to the length of the house twice the length of the overhangs and multiply this value by the length of the rafter leg.
In our example, the area of \u200b\u200ba shed roof will be equal to:
(8m + 2 * 0.5m) * 7.33 \u003d 65.97 sq.m.
- Calculate the area of a gable roof. In this case, we need to calculate the area of one of the slopes, then multiply this value by two. Ideally, a gable roof is a rectangle. When calculating, it will be necessary to take into account the length of the gable and eaves overhangs, and the length of the gable overhang must be doubled.
Example: Let's calculate the roof area for a house with dimensions of 8 by 6 meters, and the length of the overhang (both cornice and gable) is 0.5 meters, and the length of the rafter leg is 3.68.
We add to the length of the house twice the length of the gable overhang, and to the length of the rafter leg we add the length of the cornice overhang. We multiply the resulting amounts.
(8m + 2 * 0.5m) * (3.66 +0.5) \u003d 9 * 4.16 \u003d 37.44 square meters. m.
We got the area of one overhang, in order to find out the area of \u200b\u200bthe entire roof, this value must be doubled:
37.62 sq.m. * 2 = 75.24 sq. m.
- In more complex cases, you will have to divide the roof slopes into simple geometric shapes, calculate the area of \u200b\u200beach of them, then sum up the amounts.It is most often possible to divide the roof area into triangles (the formula for calculating the area is S = (b x h) / 2, where h is the height of the triangle, and b is the length of the base) or trapezoids (the area formula S = ((d + b) / 2), where a and b are the lengths of the bases of the trapezoid h is its height)
Common mistakes when designing a roof
The created project must be repeatedly checked, since correcting errors at this stage will be much cheaper than if the shortcomings are identified at the construction site or already during the operation of the house.
Design errors can be divided into:
- architectural;
- Constructive.
architectural errors. The main mistake of this type is ignoring the issue related to ensuring the ventilation of the elements of the "pie" of the roof.
When constructing an insulated roof, it is important not only to protect the insulation from moisture as much as possible, but also to take care of the removal of the amount of water that the mineral wool has nevertheless absorbed, that is, it is necessary to plan such elements as eaves and ridge ventilation vents, wind vanes, etc.
The functioning of these devices is influenced by various architectural elements (attics, parapets, etc.), which greatly limit the possibilities of air intake. Therefore, it is necessary either to increase the height of the vents, or to abandon some decorative elements.
Another common mistake is the improperly organized removal of water from the roof that falls on it in the form of precipitation.
Design errors. This type of error concerns, most often, roof insulation (especially its attic version).
For example, placing plates of insulating material between the steel beams of the rafters is initially incorrect, since a "cold bridge" is created, which reduces the effectiveness of insulation.
conclusions
Designing a roof is a very difficult task, which is not easy to cope with without special knowledge. If almost everyone is able to come up with the shape and appearance of the roof, then it is better to entrust the development of the project and the calculations to the specialists.
Taking on independent design can only be recommended if the building area is small and the roof is planned to be of a simple shape.
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