I've used Darfen twice now. Im always impressed with their work and on the last installation it was freezing and raining and you still showed up!
Carl Hayes, City Technology College- Birmingham

Inter-Block Site Safety System

The Inter-Block, innovative boundary solution installed by Darfen, for construction sites where space and stability are an issue.

The Inter-Block is the latest demarcation solution and the only blocker to fit a standard Heras panel achieving a height of 2metres. Designed to minimise any trip hazard and maximise the inner working area of construction sites as the width of the space saving Inter-Block is less than a standard fence foot. It is a robust and versatile block that easily accommodates angles or corners without compromising on strength.

The block is water filled, two water filled blocks provide a weight of 320kg, each interlock and are ready for the Heras fence panel to simply fit into the channel.

Inter-Block has a small footprint for inner city projects and is tested to 57mph by Mira.

For temporary security solutions Darfen can discuss your requirements and recommend the best solution for your specific site. We understand that each site is different and the customers’ requirements will vary. There are a number of factors that need to be taken into account, from deciding which panel, fixings and feet are most suitable to considering non trip materials for pedestrian walkways and security solutions. Darfen can also offer a Wind Loading calculation service* and if necessary our additional Stormguard support can be installed to help against high winds. No matter what your site requirement is, Darfen have the answer.



2000mm (H) x 3500mm (W) panels available.

Standard square Anti-climb – vertical tubes 38.1mm and horizontal tubes 25.4mm.

Heavy duty square Anti-climb – vertical and horizontal tubing at 38.1mm all round frame

Heavy duty tube frame (38.1mm) provide strength and versatility.

1750mm long.

600mm high (highest point).

380mm wide.

Weighs 14kg when empty (per unit).

Weighs 160kg when full (per unit).

50mm draining point for easy empty.



Corporate colours available. Branding and mould graphics available.

1250mm x 150mm reflective strips can be added for visibility.

Lights can be added for increased visibility.


Wind Loading

Inter-Block has a small footprint for inner city projects and is tested to 57mph by Mira.

Inter-Block and heras panel