Harrowden supplies North Sea cobbles in sizes ranging from 20 to 40mm in 25kg bags.

The naturally rounded cobble stones are a blend of subtle greys and browns giving an aesthetically-pleasing finish.

Recommended for use on green roof installations as a fire break and to provide free-draining areas, as well as for habitat creation on biodiverse roofs.

Installation

In accordance with the GRO code garden cobbles should be installed 300mm wide around all perimeters, including rooflights and rain outlets.

They should also be installed 500mm wide where there are building openings like doors, windows or opening roof lights.

Finally, cobbles should also be installed to a depth of 50mm or at least to the same depth as the substrate / plant layer.

To ensure there is no substrate in the fire break Harrowden advises the use of an edging product to provide separation.

Features

20-40mm (stone width)
Rounded
Easy to handle

Applications

Fire break on living roof installations
Creation of dry free-draining areas
Habitat creation on biodiverse roofs
Decorative landscaping for pathways etc
Pond creation and rock pools

The company cannot guarantee that all pebbles are rounded and smooth. Sizes may vary due to this being a naturally-quarried product.