My Wrekin
Understand the link between poor ironwork installations and pothole creation. Our new whitepaper Potholes - More than a surface issue is now available.  Get your copy

A quality above the rest

Unite™ D400 Gully Grates

Our premium Unite D400 gully grates combine new technology with proven features to deliver a super long-life and the lowest whole-life cost of any D400 gully grate on the market.

Unite D400 Gully Grate Render

Simply the best-performing gully grates available, Unite has been installed more than 500,000 times to date – with no reported failures. Made from extremely durable and 100% recyclable ductile iron, Unite is packed full of unique design features to ensure an unrivalled lifespan.

Unite brings thousands of pounds worth of savings across the lifetime the grating, while preventing unnecessary road disruption and lowering carbon emissions by reducing the number of replacements or repairs.

Serving on highways for more than 20 years, the key to Unites success is how it minimises seat wear between the frames and the gratings, reducing failures. Unite has the stiffest grating structure in its class, making the seating less vulnerable to any movement caused by flexing during trafficking.

BS EN 124, CD 534 v0.1.0, Kitemark

Unite D400 gully grates reduce whole life cost thanks to:

  • A three-way hinge means they can be easily installed and reversed in any orientation to match traffic flow.
  • Enhanced pedestrian and cycle safety, a lower secondary grid disrupts surface water flow increasing surface water run off.
  • Safety-stop hinges prevent covers falling once opened.
  • Enlarged frame corners help to dissipate loads onto the foundation, increasing reliability.
  • Mechanical lifting points for easier handling.

Gully grates

Stock code Range Clear opening
Base opening
Overall frame
Frame depth
Waterway area
Options My Wrekin
DGHT0D4/4545/KU Unite 450 x 450 475 x 475 670 x 580 100 1,440
DGHT0D6/4545/KU Unite 450 x 450 475 x 475 670 x 580 150 1,440

Available options and accessories


Unite 10 year warranty

Unite 10 year warranty

When installed with either our Unipak polymer resin bedding mortar, or Instarmac Envirobed® CD534 flowable bedding mortar, the Unite range is available with a 10-year product warranty*.

Due to its unique design and overwhelming success in the local authority and utilities sector, Unite is the proven choice for durability and longevity for highway ironwork installations.

View further warranty information

* Subject to terms and conditions

Packed full of features

  • The covers feature a universal beam (also known as an I beam) providing significant improvements to rigidity, reducing seat wear for an enhanced service life.

    Universal beam icon
  • Both covers of the double triangular grating feature I beams that interlock to provide high rigidity while still allowing the grating to hinge as one unit.

    Beam in beam design
  • The high seating position ensures that forces are transmitted more directly downwards, meaning conversion of traffic loads into mortar-compatible compression forces.

    Cover support geometry
  • The enlarged frame corners help to dissipate loads onto the foundation, providing a longer service life and increased reliability.

    Enlarged frame corners
  • Hinged in three directions to allow the product to fit in any required orientation.

    Hinged in 3 directions
  • Mechanical lifting points are provided.

    Mechanical lifting point
  • Reversible hinge allows the grating to hinge with the direction of the traffic flow, improving safety.

    Reversible hinge
  • Safety-stop hinges prevent covers from falling once opened.

    Safety stop hinges
  • Reduced apertures provides increased safety for pedestrians and bicycles, over standard gratings.

    Pedestrian safe
  • Unite is available with a 10 year warranty (subject to terms).

    Unite 10 year warranty
  • Meets the requirements of CD 534 v0.1.0 (formerly HA 104/09).

    CD534 v0.1.0
Road breaking up around gully grate installation creating a pothole


Helping to find solutions to the UK's pothole problem

Potholes across the UK’s road and highway network are a real problem. But did you know ironwork specification and selection can affect and even increase the likelihood of a pothole forming?

Our new report explores;

  • Some of the ways in which potholes are caused; including identified links to ironwork
  • What features of ironwork can increase the likelihood of pothole formation 
  • Suggests solutions you should be looking for when specifying ironwork
  • and much more.
Unite gully grate hinging in 3 directions
Rapid reversal

Hinged in 3 directions

Gully gratings should always be hinged with the direction of traffic flow. However, if traffic is reversed on a street, gully gratings could potentially be hinging in the wrong direction. Typically gully grates would need to be dug up and reset, or even replaced entirely if the hinging direction isn't reversible.

Unite gully grates accommodate 3 directions of hinging within the frame. This means the frame doesn't need to be dug up, the grating can simply be reversed within the frame.

Unite gully grate textured flange underside
Fit and forget

Textured flange underside

The underside of the frame flange has a textured surface. This surface increases adhesion to bedding materials by allowing the grating to use both the adhesive and mechanical properties of the bedding mortar.

Holes are also in the frame allowing mortar to pass from the underside to the topside of the frame. This creates an interlock, securing the frame in place. These features, and more combine, to give Unite installations the lowest whole life cost of any ironwork available. In fact, we're so confident in Unite's longevity it's available with a 10 year warranty*.

*Subject to terms

Unite gully grating enlarged frame corners and rounded flange edges
Help to dissipate the load

Enlarged frame corners

Heavily trafficked ironwork needs to be able to with stand extreme loads for a long time. Key to this is a solid foundation. The enlarged frame corners featured on Unite gully gratings are critical. During the development stages of Unite we analysed where forces are distributed within the frame. We found that the corners take most of the stress. To combat this we increased the surface area of the corners and added rounded frame edges to the circumference of the frame. The means loads and stresses are minimised and any vibrations are safely dissipated, as the smooth edges are more sympathetic to the bedding mortar.

Related case studies

Related case study

M60 - M62 Smart Motorway

The M60 – M62 smart motorway forms an important part of the main east-west transport corridor, linking Merseyside and Greater Manchester with Yorkshire and the Humber. Wrekin Products worked closely with Manchester Smart Motorway JV, offering technical advice and adapting the specification of the product to ensure it would provide the optimum solution. 
Manchester Smart Motorway JV
Read more

Knowledge base articles

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Contact us

Contact us

Whether you are looking for live project support, or are in the initial stages of specification, we are always on hand and happy to help.