I am currently trying to understand how roof rainwater infiltration systems technically work from the roof down to the infiltration point. We have quite long distances… from the farthest downpipe to a possible infiltration tank, it would be about 24 meters (79 feet). In total, we have 4 downpipes. If we wanted to direct the water alternatively into a soakaway, the distance would even be 40-50 meters (131-164 feet). Considering the slope, the rainwater would end up quite deep, wouldn’t it? From where should the starting point be measured, in other words, where is my zero reference? At the point where the downpipe enters the ground? Would I possibly need two infiltration chambers (one in front of the house and one behind the house) to halve the water’s travel distance? Where can I read more about this? Any tips? What is the best way to manage the drainage?
Our roof covers a footprint of about 160 m² (1,722 sq ft).
We are located statistically in a rather dry area, with around 600 mm (24 inches) of annual rainfall.
Best regards,
Steffi33
Our roof covers a footprint of about 160 m² (1,722 sq ft).
We are located statistically in a rather dry area, with around 600 mm (24 inches) of annual rainfall.
Best regards,
Steffi33
Hello,
from a practical point of view, water follows the path of least resistance, so a straight installation or one with a 0.5% slope is usually enough to drain the water. I wouldn’t worry too much about minimal standing water. However, this may not necessarily comply with the relevant regulations.
With a 1% slope (which I believe meets the regulations), over 24 meters (79 feet), that’s only 24 cm (9.5 inches).
You should also install the drainage pipe a little below ground level near the downpipe so you can easily cover it later with paving stones or grass.
On the other hand, you should have the infiltration capacity calculated more precisely. This depends on your soil type, rainfall, and other factors. Many common online stores for such systems also offer this calculation service.
from a practical point of view, water follows the path of least resistance, so a straight installation or one with a 0.5% slope is usually enough to drain the water. I wouldn’t worry too much about minimal standing water. However, this may not necessarily comply with the relevant regulations.
With a 1% slope (which I believe meets the regulations), over 24 meters (79 feet), that’s only 24 cm (9.5 inches).
You should also install the drainage pipe a little below ground level near the downpipe so you can easily cover it later with paving stones or grass.
On the other hand, you should have the infiltration capacity calculated more precisely. This depends on your soil type, rainfall, and other factors. Many common online stores for such systems also offer this calculation service.
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