New building with a flat roof, the façade is clad with the PREFA Siding.X façade panel with edges in bronze, the flashings, as well as the square downpipe, and the PREFA square downpipe are made of anthracite.

Square downpipe

Square, practical, attractive! The innovative roof drainage system for modern architecture.

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The square all-in-one system made of aluminium sets new standards in roof drainage. It is ideally suited for use in modern buildings due to its elegant minimalist design. The drain can be perfectly integrated into the architecture, embellishing any building. The innovative aluminium products are not only particularly robust but also visually eye-catching. Through brackets on the rear side, the square down pipe skilfully blends into the façade without any visible fasteners.

Façade clad with the PREFA FX.12 façade panel in anthracite, aluminium panels on the façade with the square downpipe, the square downpipe from PREFA in anthracite.

Advantages of the PREFA square downpipe

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Concealed fitting

with continuous fixing rail for fasteners on the back

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Elegant minimalist design

suitable for use in modern buildings

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Robust design

thanks to 1.6 mm thick, powder-coated extruded profiles

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Concealed fitting

with continuous fixing rail for fasteners on the back

Icon for advantages

Elegant minimalist design

suitable for use in modern buildings

Icon for advantages

Robust design

thanks to 1.6 mm thick, powder-coated extruded profiles

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No leaching of heavy metals

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40-year guarantee

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No leaching of heavy metals

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40-year guarantee

Robust design

The innovative aluminium products are outstanding due to their robust design. Thus, the square downpipe with 80 mm or 100 mm side length made of 1.6 mm thick, powder-coated extruded profiles is ideal for any construction project.

Indirect fastening

In addition to the innovative design, the concealed fastening by means of the fasteners with M10 thread on the back emphasises the reduced appearance on the façade.

The perfectly coordinated range of accessories supports easy and quick installation on the building.

  1. Continuous fixing rail for fasteners
  2. Fastener
  3. Cover cap
  4. Drive screw pin hot-dip galvanized according to standard
The picture shows the PREFA square downpipe on the back with the continuous fixing rail for the fastener, concealed fastening of the downpipe

Tip from the experts: Use rainwater sensibly : Also save money and resources in the garden.

The valuable rainwater does not have to seep away unused or be fed directly into the sewage system. Rainwater is perfect for watering plants because it doesn’t contain any lime. To enable rainwater to be used as irrigation water, the PREFA water collector is recommended for the square downpipe: it diverts the rainwater into a rain barrel. Good to know: If the rain barrel is full, the water runs off in the downpipe and overflowing of the collection container is thus prevented.

Please note: Rainwater flowing over certain roof and drainage materials (e.g. copper or zinc) should only be used to a limited extent. If you have large copper or zinc surfaces, you should check the rainwater to see if it is contaminated with heavy metals. Tar paper roofs with a bitumen coating could also be potentially harmful to plants, garden ponds, or the environment. It is best to obtain information from the manufacturer!

The square all-in-one system for your roof drainage

Regardless of whether the square downpipe is used in combination with a leader head or a parapet outlet connector for drainage of a flat roof or in combination with the curtain-type box gutters for drainage of a pitched roof, PREFA provides you with a comprehensive all-in-one system as usual.

Modernes Einfamilienhaus mit Flachdach und schmalen Fenstern. Die Fassade ist mit der PREFA Siding.X Fassade im faltigen Look in der Farbe Bronze verkleidet. Die Anschlüsse wurden in Anthrazit gemacht. Zur Dachentwässerung dient das PREFA Quadratrohr mit dem dazu passenden Wasserfangkasten in Anthrazit.

PREFA square downpipe in anthracite with leader head on a Siding.X façade in bronze

Colour range of the PREFA square downpipe

The PREFA square downpipe is kept in stock as standard in the P.10 colours brown, anthracite and light grey.
It is available to order in the colours P.10 black, P.10 Prefa white, P.10 nut brown, P.10 dark grey and in all other RAL colours. Please allow for delivery times and a surcharge.

Colour overview (9)




01 Braun

P.10 brown


02 Anthrazit

P.10 anthracite


03 Schwarz

P.10 black


07 Hellgrau

P.10 light grey


10 Prefaweiß

P.10 prefa white


11 Nussbraun

P.10 nut brown


PREFA dunkelgrau ähnlich DB 703 oder RAL 7043

P.10 dark grey


12 Silbermetallic

metallic silver


13 naturblank

plain aluminium


  • The RAL values stated are merely approximate values (~), some of which may differ vastly from the original PREFA colour and, under certain circumstances, may not reflect the subjective perception of the colour. 
  • Above all for colour quality P.10, it is almost impossible to define values due to the surface structure. In addition, the PREFA Siding colours P.10 stone grey, P.10 sand brown, P.10 patina green, natural oak, patina grey, walnut and grey oak are based on natural colours made up of several different shades.
  • Coils and metal sheets plain aluminium: The guarantee does not cover surface appearance alterations caused by processing and environmental influences. Follow the instructions.
  • Metallic colours may vary in shade.
  • To identify exact colours for complementary components please consult original samples.

Technical information

Square downpipe dimensions (piece lengths: 3 m and 1.5 M)

100 × 100 mm (square)
80 × 80 (square)
radii corresponding to PREFA box gutters

Square downpipe thickness

1,6 mm. With continuous fixing rail for fasteners (similar function to brackets)

Planning & Application

Our installers and architects can download specification documents for the PREFA square downpipe here. Installation instructions and mounting instructions for roof drainage, ÖNORM guide, information sheets on roof drainage and a calculation guide for dimensioning roof drainage can be found by our installation partners in the Service Area. (For tinsmith and roofing partner firms only – please have your log-in details ready. Not received your log-in details yet? Please contact your Local Sales Manager).


The perfectly coordinated range of accessories comes from a single source and supports quick and easy installation on the building. The radii of the square downpipes are adapted to the radii of the box gutters. Various downpipe elbows with a 72° bend, parapet outlet connectors and leader heads with a square outlet result in a consistent drainage system that was well thought out from A to Z.

For a complete, detailed list of accessory products, see our price list (only for processors).

Square downpipe elbow 72° (long)

□ 80, 100; dimensions 1.000 × 196 mm (visible)

Square downpipe elbow 72° (short)

□ 80, 100; dimensions 196 × 196 mm (visible)

Square downpipe fastener

fastener for square downpipe with M10 thread without pin

Square downpipe lightning protection clamp

With integrated stainless steel clip (cable clip) including fastening clamp; cable clip ⌀ 8–12 mm

PREFA Wasserfangkasten für das PREFA Quadratrohr

Square downpipe leader head

□ 80, 100

Square downpipe outlet

□ 80/250, □ 80/333, □ 100/333, □ 100/400

PREFA Speiereinmündung für das Quadratrohr

Parapet outlet square downpipe connector

□ 80, 100; suitable for high-temperature pipe NW 75 or 110

Square-to-round adapter 80

□ 80 ⌀ 98 mm, □ 80 ⌀ 115 mm

Square-to-round adapter 100

□ 100 ⌀ 98 mm, □ 100 ⌀ 115 mm

Square downpipe with access pipe

□ 80, 100

Square downpipe water collector

□ 100