Rainwater downpipes

As part of a rainwater drainage system, NedZink produces a range of zinc rainwater downpipes suitable for various types of buildings such as new construction and renovation. Our downpipes are also suitable for the replacement of existing downpipes and the repair of downpipes. Zinc rainwater downpipes are made from NedZink NTZ® and must meet EN 612. Standard prefab lengths are 2 and 3 meters. Non-standard prefab downpipes must also meet EN 612.

Rainwater downpipes can be supplied as a rounded, square, or rectangular model. The longitudinal seam is welded and one of the ends is expanded. Table 3.1 below contains the standard rainwater downpipes. To collect rainwater in gutters NedZink offers a wide range of accessories.

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How to install a rainwater downpipe?

  • To install downpipes hang them from top to bottom. 
  • In principle, the downpipes are not soldered, they are slipped in to one another with a minimum overlap of 50 mm. 
  • The upper short length of piping must not be able to press against the gutter bottom and must therefore have at least 20 mm space. 
  • The outlet piece must be slipped into the downpipe by at least 50 mm, so that the projecting outlet piece must be 70 mm in length.
  • Each length of piping must be bracketed at least once. 
  • The brackets must be fastened at a maximum of 2 meters distance, and the upper bracket must be installed at least 1 meter under the gutter bottom.
  • The distance between the back of the downpipe and the  façade must be at least 30 mm. 
  • The distance between the brackets is 2 meters. 
  • To enable lateral movement of the gutter, the first hinge bracket must be placed 1 meter from the gutter bottom. 
  • The distance between the gutter bottom and the top of the downpipe must be at least 20 mm to allow for expansion of the pipe.

What are the possibilities with rainwater downpipes?

Downpipe bend

With a zinc downpipe bend you can easily deflect and / or extend the downpipe.
Both square and round bends are available.

Downpipe bracket double bead

The double bead is available in round and square sizes and is slid around a rainwater downpipe. Due to the use of a double bead, the zinc downpipe cannot
sink and gives a traditional look without soldering.

Downpipe connector

A connector is used to connect a shortened downpipe to another downpipe.
Because there is a widening at the top of the connector, a downpipe can be easily and quickly slipped around the shortened one.

Downpipe brackets

By means of a downpipe bracket the zinc downpipe is attached to different types of walls. Various types of downpipe brackets are available for attaching to, for example, wooden walls, stone walls and / or steel sheet piling. To obtain the original look with the downpipe, use a double bead.

Overflow

Overflow is used for the transition of the rainwater drainage from the flat roof to the downpipe.

Hopper head

A hopper head ensures that all rainwater from a (flat) roof is collected. It prevents blockages in the zinc rainwater downpipe, ensures that the water does not remain on the roof and that the gutters do not overflow. A hopper head can also serve as a transition from two pipes to one.

Rain diverter

The rain diverter is placed between downpipes. When open, it can for example, fill a rain barrel. When closed, the water simply flows through. Thanks to the integrated stainless steel grille, the rainwater valve also serves as a leaf guard.

Leaf guard

A leaf guard prevents blockages in the rainwater drainage. The leaf guard ensures that leaves and other dirt are led out through the grid. The leaf guard is installed in the rainwater downpipe itself.

Calculate the rainwater capacity

A correct calculation for determining the required capacity of downpipes and gutters is done according to the Dutch NEN 3215 and the NTR 3216. See our capacity calculation page to calculate these.

Standard rainwater downpipes

NedZink rainwater downpipes are available in NedZink NATURAL en NedZink NOVA.

Diameter Mass Thickness length
Round 80 mm 1,161 kg/m 0,65 mm 2 & 3 m
Round 100 mm 1,451 kg/m 0,65 mm 2 & 3 m
Square 80 mm 1,485 kg/m 0,65 mm 2 & 3 m
Square 100 mm 1,860 kg/m 0,65 mm 2 & 3 m

Table 3.1

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