With only four important dimensions you can quickly find the right size for the new gutter. It depends only on the size of the roof surface, which should be drained reliably with the gutter.
Rain gutter important for the facade
The gutter protects the façade of the building from serious damage and at the same time prevents the house from penetrating moisture. But the gutter must be large enough to be able to absorb all the water even in a heavy downpour.
So that the dimensions of the gutter can be dimensioned sufficiently large, one must first know the dimensions of the roof. This size then decides on the respective dimensions of the appropriate gutter.
Dimensions for a rain gutter semicircular
- 60 to 70 millimeters in diameter Rain gutter up to 25 square meters of roof
- 100 millimeters in diameter Rain gutter up to 50 square meters of roof
- 125 millimeters in diameter Rain gutter up to 100 square meters of roof
- 150 millimeters in diameter Rain gutter up to 160 square meters of roof
Large roof - several downpipes
If the roof is larger than 160 square meters, you should use at least two downpipes. Even if you want to use a smaller diameter gutter, you should then compensate with two or more downpipes.
Higher capacity in the box shape
The box-shaped gutter takes up about ten percent more water than the standard semicircular trough. So you can safely use the box-shaped gutter. This is useful when the roof surface is at the boundary between two sizes of rain gutter.
Downpipe suitable for the size of roof and gutter
- 60 mm diameter downpipe up to 25 square meters of roof area
- 80 mm diameter Downpipe up to 50 square meters of roof area
- 100 mm diameter downpipe up to 100 square meters of roof area
- 100 to 120 mm diameter downpipe up to 160 square meters Roof surface
Although there are conversion tables for the old measures, the calculations have not adapted to today's often heavy downpours. The conversion tables also do not specify the diameter, but the sheet metal surface, which was installed in the gutter.