Rainwater plates

All rainwater drains: vertical, horizontal and overflow, for cold and hot roofs. The associated accessories are the adhesive pieces to confirm the tightness, the water boxes or gargoyle adapters to collect the water coming out of the horizontal drains and prevent the runoff of water on the wall. The toadstool limits and slows down the obstruction of rainwater outlets by dead leaves.

Evacuation d'eau pluviale verticale PEHD

Evacuation d'eau pluviale verticale

Evacuation d'eau pluviale horizontale

Trop plein

Mastic PU noir

Pièce adhésive EPDM 45 x 45 cm

Boîte à eau

Crapaudine

Adaptateur Gargouille

Manage rainwater drainage

A flat roof is always surrounded by parapets or walls, so it is necessary to install a rainwater drainage system.

The solution is very simple:

1. The roof support must have a minimum slope of around 5%. Despite its name "flat roof", this minimum slope is absolutely essential. For large surface flat roofs, there are generally several slopes and possibly gutters if certain lower parts are not on the periphery of the roof.
2. In the lower part of the slope (or slopes) of the support, the water will be evacuated by the rainwater plates, also called rainwater outlets. These rainwater outlets must be provided in sufficient quantity and size in relation to the surface of the roof.
3. Finally, the rainwater outlets lead into a drainage system made up of water boxes, gargoyle adapters, rainwater downpipes. This system channels the flow to a water collector or directly to the public rainwater collection system.

The technical necessity

In the absence of an appropriate drainage system (total absence or insufficiency), rainwater causes a "pool" effect with prolonged stagnation of a large amount of water.

Too much water stagnating on the roof can damage the construction: by overloading the roof support, by excessive pressure on the waterproofing.

It should be noted, however, that the presence of small temporary puddles does not pose a problem, as they are eliminated naturally by evaporation.

Regulations

Legislation imposes certain constraints on all properties and constructions which can be supplemented by local regulations.

Article 681 of the Civil Code stipulates that the roof of a construction must allow the flow of rainwater on private land or public roads.

It is strictly forbidden for the water that accumulates on your roof to flow onto your neighbour's property.

Rainwater harvesting and the ecological issue

For ecological and economic reasons, the recovery of rainwater has many advantages, it is more and more often integrated into new construction or renovation work.

The recovery can be intended for watering the garden or crops, but also for domestic use for which it is still necessary to distinguish several categories:

1. non-food and non-corporeal use: flushing toilets, washing floors or vehicles.
2. sanitary use: personal hygiene and washing clothes.
3. food use: beverages, food preparation and tableware.

Sanitary and food uses are subject to strict regulations for the compulsory treatment of rainwater.

For more official information on rainwater harvesting: Public Service: Rainwater harvesting.