British Products Made in British Foundries

Channel grating cut into concrete pavement
Quatrefoil SystemQuatrefoil cast Iron Gratings - Italian garden Hyde Park LondonIMG_2955Bare metal Quatrefoil allowed to rust for a natural authentic finishQuatrafoil Channel GratingInterconnecting mechanismEnd of Quatrefoil grating with channelNBS Plus Endorsement Stamp Purple 256rps_369_rgbQuatrefoil Channel GratingInstallationIMG_2950quatrefoil hyde park 3

Quatrefoil Grating

From: £180

Quatrefoil Grating

Londoners Please Note – To see an example of the Quatrefoil grating in situ please visit the grade 1 listed “Italian Garden in Hyde Park” where several metres are installed at the top of the steps at the pump room end.

At last, an elegant and simply stunning cast iron channel grille combined with a modern interlocking channel system. The Quatrefoil linear drainage channel, also known as channel gratings or French drainage channels are specifically suitable for removing surface water in domestic period properties and pedestrian areas in conservation areas. The system can be installed for light vehicular use on driveways, patios and paths with block and flag stone paving or tarmac or concrete.

See examples of our own installation on our blog Part One  and Part two 

The Quatrefoil grilles are 108mm wide and 10mm thick and are available in a variety of lengths up to 1000mm long with a choice of bare metal or painted black finish. The bare metal finish will rust to leave a natural brown coating of iron oxide which will protect the grille from further corrosion. For those wishing to create their own channel or use an existing channel or indeed use the Quatrefoil grille as a vent or internal floor grille they are available with or without the plastic channel.

Quatrefoil grilles purchased with the channel will be supplied fully assembled with screws.

We chose this design, not only for its large free draining holes, which are unlikely to block, but also because we wanted our grille to appeal to conservationists and period property restorers alike to enhance walkways and driveways in the simplest home or grandest mansion. The Quatrefoil design can still be seen today in windows of Norman churches in England and throughout many Gothic London properties and of course, in Europe in Paris at Notre Dame and Florence, Italy. It is fitting that it was chosen to drain surface water along the steps of the entrance to the Italian garden in Hyde Park, London.

A standard length is 1 metre long (995mm) although it is possible to have shorter lengths to allow the channel to fit almost any situation. Shorter lengths available are 155mm, 292mm, 431mm, 572mm, 711mm and 851mm. Whilst the 1 metre long version has four screw holes ( a pair at each end as per photo), all shortened versions of the Quatrefoil grille are supplied with only two holes at one end.

Sizes are castings and ends require grinding to finish so exact dimensions in mm maybe + or - 1 or 2mm different to dimensions shown here.

The Quatrefoil channel gratings can be used with the Quatrefoil Junction Box to form L-shaped,  T-Shaped and Cross Over Junctions

Channel is also available with accessory pack complete with end caps and leaf trap as an optional extra.

Links to product data sheets showing installation instructions for the plastic channel system can be found below:-

Spec sheet for installation of plastic channel grating

Spec sheet for plastic channel

Please note we cannot accept returns on shorter lengths less than 1metre long as we cut them to order and we cannot accept bare metal returns that have started to rust.

Clear selection

Specification PDF for Cast Iron Quatrefoil Drainage Channel ciabQ1


Item Nom. Size (Inch) Size (mm) Weight (kg) Nom. Area of Drain Holes (mm2) Plate Thickness (mm)
Q1000 39 x 4 995 x 108 5 32000 10
Q855 33 x 4 851 x 108 4 27000 10
Q720 28 x 4 711 x 108 3.5 22000 10
Q580 23 x 4 572 x 108 3 17000 10
Q440 17 x 4 431 x 108 2.5 12000 10
Q300 12 x 4 289 x 108 2 8000 10
Q155 6 x 4 148 x 108 1 4000 10

Additional Information

Size in mm

995, 851, 711, 572, 431, 289, 148


Bare Metal, Painted Black

Channel Grating

Supplied with Channel, Supplied without Channel