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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 is our highest quality range of access covers and gully grates with over 500,000 installations and zero reported failures. Available with a 10 year warranty*, Unite is engineered for a long life and has been in service on highways for over 20 years, providing substantial savings on both installation costs along with unnecessary road disruption.

Unite manhole cover installed at Birmingham Town Hall

Superior quality and conformance

Using the very latest tools and software, the Unite range of manhole covers and gully gratings has been engineered for an extremely long life.

Key to Unite’s longevity is minimising seat wear between covers/gratings and frames. The range has the stiffest cover/grating structure in its class and on top of this, seating which is less vulnerable to any movement caused by covers and gratings flexing. In fact we're so confident in Unite's performance, it's available with a 10 year warranty*.

Unite has also been design to work sympathetically with bedding mortars, reducing stresses on the frame foundation – identified by WRC as a major cause of manhole cover failure. To increase surface contact with bedding materials the underside of the Unite frame features an engineered tread pattern, and to inhibit crack initiation all contours of the Unite frame, where it engages with the bedding materials, are fully rounded.

BS EN 124, CD 534 v0.1.0, Kitemark

Engineered for a sustainable future

  • Available with a 10 year warranty*
  • In service on highways for over 20 years
  • Over 500,000 installations with zero reported failures
  • Cover and grating designs substantially reduce seat wear
  • Frame features are sympathetic to bedding materials
  • Retrofittable sealing plate available
  • Exceeds BS EN 124
  • Complies with DMRB, CD 534 v0.1.0 and Series 500
  • Kitemarked by BSI
  • 100% recyclable product
Unite manhole cover installed in Piccadilly Circus
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

Unite in numbers

Unite is a proven range, in service for over 20 years and offers significant benefits to asset owners, contractors and end users.

available on Unite range

10 year warranty

units installed


average lifetime saving


proven lifespan

Over 15years
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.

Meeting the needs of National Highways CD 534 v0.1.0 with Unite

National Highways has updated CD 534, a significant set of its requirements for manhole covers and gully grates installed on their road network. First released in February 2020 and updated to version 0.1.0 as of May 2022.

Frame flange area

CD 534 v0.1.0 now sets a minimum flange area of 190,000mm² for D400 and 285,000mm² for E600 covers, this equates to 2.1N/mm² as in HA 104/09.

Frame depth and weight

A 150mm frame depth is now required on motorways and all purpose trunk roads. A lower limit frame weight is also specified to ensure frames are stiff enough.

Skid resistance

The WRc test mehod is now the only accepted test method for calculating skid resistance on raised chequer. This test measures a small tyre’s resistance to sideways slip caused by the cover surface.

D400 or E600

E600 manhole covers are to be installed in place of D400 covers where the Annual Average Daily Traffic (AADT) of light goods vehicles travelled on a road is greater than 1,500 in each direction.

Check road traffic statistics for AADT
Unite manhole cover being installed

How much can I save?

Ironwork replacement typically takes around 3 hours*. Studies show the 2,000 users per hour of A-roads are delayed by an average of 4 minutes in roadworks**. This loss of earnings and productivity equates to over £3,000 per hour. The saving to society of not having a 3-hour long unnecessary manhole replacement is at least £9,000 and cuts the associated noise, dust and waste.

  Unite Typical MHC
Approximate cost £225 £110
Installation frequency 1 2+
Installation cost £600 £1,200
Total cost £825 £2,620
Total Savings £1,795
Sustainable saving Social cost £9,000

*Based on independent analysis commissioned by a major water utility.
**Statistics collated from Department for Transport & The National Traffic Survey 2014
***Based on a 600 x 600mm clear opening

Traffic on a busy London road

> 1,500 Annual Average Daily Traffic (AADT)?

With the introduction of CD 534 there were several key changes. This includes the requirement for E600 manhole covers to be installed in place of D400 covers where the Annual Average Daily Traffic (AADT) of light goods vehicles travelled on a road is greater than 1,500 in each direction.

As a "rule of thumb", most A roads will have an annual average daily traffic number over 1,500 light goods vehicles. Full traffic data can be found for many locations around the UK on the Government website.

Unite D400 manhole cover installed at Piccadilly Circus

More than 100,000 units supplied to Thames Water

Thames Water

As a key supplier to Thames Water, whose adoptable assets are installed in some of the most high profile and heavily trafficked roads in the UK, we've managed to reduce their manhole cover failures to 0 through the use of Unite. We have now supplied more than 100,000 Unite units to Thames Water without one recorded failure over a 20-year period. We’re incredibly proud of our Unite series and how its pioneering design has been underlined by its fantastic performance.

Retrofittable identification bolt being installed in a Unite access cover
Only with Wrekin

Retrofittable badging and antenna options

Unite* and Highway access covers are the only ranges on the UK market to include provisions for communications equipment, such as antennas, to be installed within the cover.

Antenna in cover linked to hardware in chamber

The ID bolt provision can be used for antennas, allowing communications equipment, such as water meter monitoring, to be installed within a chamber beneath a cover whilevproviding a strong signal above ground without the need to dig or adjust the surrounding road surface. Saving significant time, effort and money while minimising disruption.

* references ending /KUE

Unite in action

Related case studies

Related case study

Junction 9 improvements for the M27

Wrekin secured the exciting opportunity to supply Unite manhole covers and ironwork installation systems to the county’s most significant infrastructure project in recent history. Hampshire County Council and Highways England have committed to funding a £23m infrastructure project, which will improve the M27 and benefit motorists for years to come.

MJ Church
MJ Church
Read more
Related case study

Unite(d) at Sunderland City Council

Sunderland City Council is responsible for the maintenance and repair of most roads and bridges in Sunderland. Like so many highway authorities, it had been receiving complaints from residents about noisy manhole covers. They immediately suggested Wrekin Products’ Unite manhole covers, which in addition to eliminating displacement under heavy traffic, as J T Dove explained, offer a range of other benefits.

Sunderland City Council
Sunderland City Council
Read more
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.