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Interlocking cast iron channel drainage gratings.

Features and benefits:

  • Allows for the smooth, seamless transfer of water through the large drainage holes.
  • Has a period design reminiscent of the Victorian era.
  • Low maintenance and easy to clean.
  • Manufactured in the UK.
  • Can be supplied in bespoke finishes to match existing brickwork.
  • Fire and UV resistant.
  • Fully recyclable.
  • Available in various lengths up to a maximum of 1 m (whilst the 1 m variant has four screw holes, all shortened variants are supplied with only two holes at one end).


Suitable for:

  • Pavement and walkway drainage for removing surface water in domestic period properties and pedestrian areas.
  • Light vehicular use on driveways, patios and paths with block and flag stone paving, tarmac or concrete.

Fits into the Manthorpe plastic channel and range of channel accessories – consult manufacturer for details. Channels are to be specified separately.

Related literature

The following content references this product:

Standard product features


Iron which has been cast in sand moulds and bonded with resin.

Plate thickness:

10 mm.



- Q155:

Weight: 1 kg. Drain hole area: 4000 mm².

- Q300:

Weight: 2 kg. Drain hole area: 8000 mm².

- Q440:

Weight: 2.5 kg. Drain hole area: 12 000 mm².

- Q580:

Weight: 3 kg. Drain hole area: 17 000 mm².

- Q720:

Weight: 3.5 kg. Drain hole area: 22 000 mm².

- Q855:

Weight: 4 kg. Drain hole area: 27 000 mm².

- Q1000:

Weight: 5 kg. Drain hole area: 32 000 mm².


- Painted (black):

Uses a three-part epoxy primer, followed by two-part epoxy black gloss top coat which is extremely hard wearing.

- Standard (bare):

Will rust to leave a natural brown coating of iron oxide, which will protect the grille from further corrosion.

Accessories/ Other requirements:

- Junction box (4 x 4", 108 x 108 mm):

Clips into the channel grating to allow for smooth drain water flow around corners. Weight: 0.5 kg. Drain hole area: 3000 mm².

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-20-80/305 Footway gratings

NBS Specification

NBS Buliding logo
This product is associated with the following NBS clauses:

Product specification

An important note about specifying



Cast Iron Air Brick Company


+44 (0)1598 711999

Product reference

Channel Drainage Gratings


6 x 4" (148 x 108 mm).
12 x 4" (289 x 108 mm).
17 x 4" (431 x 108 mm).
23 x 4" (572 x 108 mm).
28 x 4" (711 x 108 mm).
33 x 4" (851 x 108 mm).
39 x 4" (995 x 108 mm).


[Painted (black)]
Insert RAL code.
[Standard (bare)]

Accessories/ Other requirements

[Not required]
[Accessory pack]
Includes two end caps to terminate the length of the channel grating and a leaf trap.
[Junction box (4 x 4", 108 x 108 mm)]
To Provide X, L and T shaped junctions.

Manufacturer details

Down Farm,
Devon, EX32 7QQ
Tel +44 (0)1598 711999
Fax +44 (0)1598 711999
NBS Plus