The Quatrefoil cast iron gratings are exclusive to the Cast Iron Air Brick and although they can be used vertically for ventilation they are more often used as Drainage gratings in conjunction with the Manthorpe plastic channel.
These are often specified to create elegant drainage and landscaping along paths and pavements of feature gardens and around fountains and pools.
This design is an authentic reproduction of quatrefoil symbol found in many gothic churches across Europe and in Paris and Florence. It is therefore fitting that it was chosen to drain surface water along the steps of the entrance to the Italian garden in Hyde Park, London. This has been part of the Royal parks renovation scheme and is Grade2 listed by Historic England.