From the investor’s point of view, it may seem that technical knowledge about the angle of the roof is irrelevant. However, the slope of the roof basically affects the body of the entire building and the convenience of its use, and even operating costs.
The roof angle indicates whether we are dealing with a flat, sloping or medium -sloping roof. Therefore, at an early stage of cooperation with the designer, reconstruction of an existing building or buying a ready design, it is worth knowing how much the roof slope is and how it determines, e.g. the selection of roofing, insulation materials or the choice of a roofing crew. We suggest how to calculate the angle of the roof for the investor’s needs and what the meaning it is. The building and the convenience of its use, and even operating costs.
The angle that arises between the roof roof and the level is called the angle of inclination of the roof. Its value is most often expressed in degrees or as a percentage. Typical single-family houses built in Poland have a roof slope of 30-45 degrees. Even in the case of a flat roof, we are dealing with a small slope, which is at least 3 degrees and serves to drain rainwater from the roof (this type of roof is also called a flat roof). Roofs with a larger angle of inclination, i.e. steep roofs having a angle of about 60 degrees, are usually built in mountainous areas, where rain and snow is recorded.
The roof angle is part of the building structure, so when ordering a single -family house design, it is worth discussing it with the designer, taking into account aesthetic, practical and financial issues resulting from a specific type of roof. The finished house design usually contains alternative inclination angles allowed by the author of the project. Increasing or decreasing the angle in relation to these proposals at a later stage of construction has many consequences for the investor, including Increased costs related to the roof structural solutions and even the building, the need to change the type of roofing, as well as re -dealing with formal matters related to obtaining a new building permit.
When considering choosing a roof type, it is worth remembering that:
Roof angle – table
The roof angle is a very important parameter, so it’s good to know its exact value. Depending on the approach, it can be given in degrees or as a percentage.
TABELA:
| wzniesienie dachy (w cm) | kąt nachylenia stopnie) | kąt nachylenia (procenty) |
|---|---|---|
| 25 cm | 14° | 24,9% |
| 30 cm | 17° | 30,6% |
| 40 cm | 22° | 40,4% |
| 45 cm | 24° | 44,5% |
| 49 cm | 26° | 48,8% |
| 59 cm | 28° | 53,2% |
| 75 cm | 37° | 75,4% |
| 84 cm | 40° | 83,9% |
| 90 cm | 42° | 90,0% |
| 100 cm | 45° | 100,0% |
The roof angle is given in two values: in degrees or as a percentage. Producers of roofing in the description of their products most often determine the minimum roof slope in the degrees, while the roofers use the percentage converter.
In order not to get lost in quite complex calculations, it’s best to use the ready table. The starting point is the calculation of the roof hill in centimeters, on the basis of which you can calculate or check in the table in degrees or as a percentage.
Even if the investor does not have technical knowledge, he can independently calculate the angle of the roof. How to do it?Even if the investor does not have technical knowledge, he can independently calculate the angle of the roof. How to do it?
Here are the corners of the roof inclination most often found in Poland:
The selection of a project with a specific type of roof – sloping or flat – largely determines the choice of roofing. That is why investors most often decide on medium -sloping roofs, which give the largest selection when it comes to the type of covering and specific models in a given style. What roof what cover can be used for?
Even a slight change in the angle of the slope, especially when we are dealing with border values, can make the model chosen by the investor not be used or you need to modify assembly techniques to increase the overall construction costs.
It is difficult to answer the question asked in this way, because the location of the building is key – the wind zone and the rainfall zone for its location. The roof should have such a angle of inclination so that it is possible to effectively drain the water and that it does not fall on the snow, which under the influence of frost becomes a considerable load for the roof structure.
In Poland, the most popular are medium-sloping roofs with about 30-45 degrees. They give additional space to use in the attic, thus increase the building size. Their additional advantage is the ability to use both panel metal tiles, roof tiles, concrete and ceramic tiles.
The minimum roof angle is determined for all types of roofing. In the case of roof tiles, it is 10 degrees, a metal roof tile 10-14 degrees (depending on the model), for a bituminous shingle about 10-11 degrees, for trapezoidal sheet 5 degrees and for flat sheet 3 degrees.
Roofers should familiarize themselves with the installation instructions of the roof tile or metal sheet metal chosen by the investor to properly prepare under it a structure consisting of patches and counter data or rigid sheathing (formwork) properly insulated with a special membrane or roofing felt – as is the case with roofs with a small corner slopes (less than 20 degrees).
The gable and single -pitched roof are the simplest and fastest to build and the cheapest. The most popular in our climate zone is the gable roof, which copes well with the drainage of rainwater and snow and allows the attic for housing purposes. Due to the fact that there are no breakdowns requiring additional insulation and accessories (as it has on site in multi -hut roofs), the gable roof is a recommended solution in passive construction. Compared to a single -pitched roof, it has a much larger angle of inclination, and thus is more visible. The choice of material for covering and precision of finishing is of great visual importance in this case.
A single -pitched roof can be a flat roof (above 3 degrees) or an oblique roof, willingly used in outbuildings, outbuildings and modern residential buildings in a modernist style. A single -pitched roof has an uncomplicated structure, allows for effective use of the highest floor (no slants) and is an alternative to flat roofs. In recent years, the flat roof has been eagerly used by architects in more complex projects of modern buildings consisting of several solids. This type of roof can be the only reasonable solution when the building is located on the border of the plot and the outflow of rainwater cannot be directed to the neighbor’s plot. Single roofs are an aesthetic, cheaper solution than flat roofs and are suitable for the installation of photovoltaic panels.
A single-pitched roof appears in modern construction projects, as well as reconstruction of single-family houses popular in the 70-80, the so-called “box”. It is assumed that the minimum angle of inclination of a single -pitched roof is 3 degrees and the maximum 45 degrees. A larger slope means that the roof is more efficiently draining rainwater and gets rid of the snow.
Gable roofs are usually chosen for practical and economic reasons. They can have a medium -sloping or steep roof. The angle created by two tracts is usually 30-45 degrees, and in some areas even 60 degrees. With a large decrease in rainwater and snow, they do not pose a major threat to the tightness of the roof, but the reduction of the slope may require the installation of snow or snow fences.
Choosing a slope angle at the design or adaptation stage of the project should be well discussed with the architect and thought out with family members – building users. What is worth considering?
Yes, however, such a change requires fulfillment of specific conditions.
A professionally developed design of a residential or service building contains detailed information about the roof, including its shape with a degree of inclination, type of covering and the technology in which it is to be made. It happens, however, that the investor must correction of the project due to its adaptation to the local spatial development plan and building conditions or due to the need to change the way the attic used. First of all, such a change cannot be made independently and it requires the consent of the designer – author or architectural studio. If the change concerns 5 degrees angle of inclination, usually consent to such a change is recorded in the documentation attached to the project. A greater change requires the assessment and update of the design by an architect who takes into account the technical parameters of the building and aesthetic issues, such as maintaining the proportion of the building’s body. It may turn out that it is necessary to redesign the entire roof structure. Secondly, changing the angle of the slope belongs to the so -called significant changes in the construction design. If the investor has already received a building permit, he must again report to the office a modified project and apply for a new permit.
There are situations that the owner of the house decides to rebuild the roof, as is the case on the occasion of an older house. A possible change in the angle of the existing roof or raising the roof requires re -calculation of a qualified designer with permissions, because the reconstruction will change the load on the peak walls, foundations and the ceiling. Both the change in the angle of a slope by more than 5 degrees and raising the roof is a serious interference in the block of the building and requires obtaining a building permit.
When joining the construction, the investor must familiarize himself with the local spatial development plan (in short, the Local Plan), and if there is no – with building conditions (in short, WZ). These acts determined by the City Council or Commune define many detailed guidelines for investors, including The slope angle, maximum ridge height, cover color and even the color of the facade. Usually the permissible degree of roof slope is in the range of 15 to 30 degrees. The documents mentioned are available on the city or commune websites in the Public Information Bulletin. You can apply for building conditions without being the owner of the plot and thus filter the house designs that meet him.
If the investor has submitted an application for building conditions and they are unfavorable for him, he may appeal against the decision within 14 days on the basis of the provisions of art. 155 of the Code of Administrative Procedure and submit an application for a change in building conditions. It is worth making sure what documents should be completed, what consent to obtain and what stamp duty to make so that the submitted application has a legal value.
