If optical requirements are used, a gutter guard should be installed horizontally. It is therefore not necessary to mount the gutter at a particular gradient. The applicable DIN regulation is also right of these optical aspects. Only when metal roofing is concerned, the roof gutter slope must be taken into account during installation. A longitudinal slope must be maintained.
However, if the slope is to be taken into account during the installation of the gutter, it is necessary to calculate the slope of the gutter in advance so that the distances at the end can also be adjusted and the roof drainage can be ensured. If, for example, a gutter guard is used, which has a total length of 12 meters and a gradient of 5 mm is used as the basis, an overall gradient of 60 mm is obtained with the correct calculation formula. The height difference, which results from the beginning to the end of the rain gutter, is 6 cm in this example.
Why the slope for the gutter guard must be well calculated
Every DIY enthusiast should know that he is never allowed to calculate the gutter guard slope too small. However, it is equally important that the slope of the gutter is not too strong. If the gutter gradient was calculated incorrectly, the result is an optically comic-looking image.
What is even more important, the water could overlap and this is not the purpose and purpose of the roof drainage. Even if many experts advise to provide the gutter perfectly horizontally, it is also advised against it as often. If the gutter is installed completely horizontally, the rain gutter can no longer perform its self-cleaning function reliably. It is, therefore, better to set the longitudinal direction and calculate the slope of the gutter in this way.
Calculate longitudinal slopes for the new gutter
The guideline for a suitably designed gutter slope in the longitudinal direction means that the slope should be between one and three mm per one meter of gutter guard. Practical experience shows, however, that the self-cleaning process of the gutter only begins when the gutter slope has arrived at five mm per meter of gutter guard.
As a rule of thumb, the gutter should be installed with a longitudinal gradient between 3 and 5 mm per meter of gutter guard. This is the only way to prevent the rain gutter from filling with leaves and dirt and creating mud and the like at the bottom of the gutter.
How the longitudinal gradient of the gutter is calculated in detail
In order to obtain the correct dimensions for the installation of the gutter guard, the difference in height is initially calculated for the slope of the gutter. If the height is clear, it is still necessary to install the gutter brackets correctly. Here, the home improvement can help by the tensioning of a cord. The most important tool for an exact gutter guard slope is the water balance, the height and distances exactly indicated.
As a formula for calculating the gutter guard gradient, the exact length of the gutter guard must be multiplied by the value of the gutter guard slope in mm. At th, end you get the total gutter guard slope and know how the gutter is to be finally installed.
The calculation of the gutter slope can be illustrated in the following table:
|THROAT LENGTH||1 MM SLOPE||3 MM SLOPE||5 MM INCLINE|
|1 meter||1 mm||3 mm||5 mm|
|2 Meters||2 mm||6 mm||10 mm|
|3 meter||3 mm||9 mm||15 mm|
|4 meters||4 mm||12 mm||20 mm|
|5 meters||5 mm||15 mm||25 mm|
|6 meters||6 mm||18 mm||30 mm|
|7 meters||7 mm||21 mm||35 mm|
|8 meters||8 mm||24 mm||40 mm|
|9 meters||9 mm||27 mm||45 mm|
|10 meters||10 mm||30 mm||50 mm|
|11 meters||11 mm||33 mm||55 mm|
|12 meters||12 mm||36 mm||60 mm|