Almost 1.7 million potholes were repaired in England and Wales during the last tax year alone, a chunk of which were due to failures involving manhole covers or ironwork. Discover the tried, tested and independently approved materials for manhole reinstatements, together with the finer details for upskilling your landscaping or civils team to repair them.
The costs of repairing failed ironwork
Failed manhole covers, or ironwork as they’re often called in the industry, is a growing issue in the UK. In fact, it has been revealed that 50% of ironwork repairs now fail within a jaw-dropping 12 months of installation. This is such a problem that in some locations the lifespan of manhole installations are now being measured in months rather than years.
According to WRc research back in 2011, over 70,000 manhole covers are replaced in the UK each year at a cost of £40 million to the water industry alone. Their study also highlighed that up to 85% of manholes on heavily trafficked routes had failed in some way.
Fast forward to today and it’s estimated that overall £250 million is spent in the UK each year on repairing ironwork failures, with local highways authorities and utility companies footing these bills.
Why do manhole covers fail?
There are many reasons why ironwork or manhole covers fail on our roads, including:
- Poor road design
- Carriageway chamber failure
- Ironwork frame failure
- Insufficient materials used for manhole reinstatements
- Poor workmanship degrading the road
- Budget cuts
However, Dave Youell, an ironwork and bitumen repair expert from Instarmac’s Ultracrete team, says: “The list of causes to ironwork failure is in fact endless.”
Ironwork frame failures
Ironwork cover failure is one of the reasons why manhole reinstatements deteriorate. Dave explains how this can happen.
“The ironwork cover can sometimes sink within the frame. This can either be due to wear of the seating, or if the handscape contractor installed the incorrect class of manhole cover for that type of road.”
We touch on the different classes of manhole covers and choosing the right one for your road repair job later on.
First, let’s cover the tried and trusted materials for manhole reinstatements.
Always use HAPAS certified materials
When it comes to repairing ironwork, it’s essential to apply a tried and trusted method and always use approved materials for manhole reinstatements.
As a contractor, you want to provide professional reinstatements that remain in place for years to come. Besides, a solid track record of long-lasting repairs will be sure to land you repeat business from utilities companies or property and maintenance teams.
Wondering which manhole reinstatement system to use? We strongly advise to always choose materials that are HAPAS certified, which in layman’s terms stands for the Highway Authorities Product Approval Scheme.
The HAPAS product certification scheme for the highways sector offers your business the reassurance that the products are independently reviewed to provide evidence of their performance and lifespan.
Ultracrete's Ironwork Reinstatement System
The team at Instarmac’s Ultracrete have brought together a range of specialist products for ironwork or manhole reinstatements for permanent repair solutions.
Independently tested by a third party laboratory accredited by UKAS (The UK Accreditation Body), the Ultracrete system for manhole repairs has been approved for use by the British Board of Agrément (BBA).
BBA is one of the country’s leading organisations that offers testing, approval and certification services to manufacturers supplying the construction industry.
Dave advises, “I would always recommend our BBA HAPAS Ironwork Reinstatement System. Approved HAPAS products go through a rigorous assessment process involving lab and field testing.”
Just in the field itself, these tests can take up to two years. Regular site inspections and performance trials follow too.
Once a certificate has been issued, the manufacturer is then audited every six months to ensure they are maintaining their assessment criteria. Following that, they are reassessed every three years.
“Any product that has HAPAS approval offers confidence and long-term proven durability,” shares Dave. “Here at Ultracrete, we’re proud to have had the HAPAS certification since 2005.”
HAPAS approved materials for manhole cover repairs
Let’s take a look at what Ultracrete’s HAPAS approved system includes for durable manhole reinstatements. Many of the independently tested products listed below have been approved for use on the London Underground and Overground.
Bedding mortars for manhole reinstatements
First off, the new ironwork frame for the manhole reinstatement must be bedded onto a solid, sound chamber with a bed depth of between 15mm and 50mm. Bedding materials must be free of any voids on the underside of the frame.
Which bedding mortar you use depends on the size of the new ironwork frame and the category of the road.
Envirobed CD534 Bedding Mortar
Envirobed CD534 (which is the same HAPAS-approved formula as Envirobed HA104) is a high-performance, two-part bedding mortar developed for major utility companies to provide exceptional performance for manhole reinstatements. As a cementitious alternative to resin it can still be used during wet weather to neatly and consistently fill the voids and provide excellent lateral stability.
Both CD534 and HA104 are suitable for use with all ironwork frame sizes on Type 0, Type 1 and Type 2 category roads.
For a formula that is significantly easier to apply, choose Envirobed HA104 Flowable (now CD534 Flowable). This flowable bedding mortar is also HAPAS approved.
United Utilities, the UK’s largest water company, used Ultracrete’s flowable bedding system to reinstate manhole covers and frames across its network in North West England. Increasing traffic volumes are severely impacting the road infrastructure as well as causing damage to the ductile ironwork within the roads themselves.
Sammy Nelson from United Utilities reports, “UltraCrete’s Envirobed Flowable system has reduced defects on our network by 98%. Its simplistic application has also saved us time on site, improved productivity and reduced reinstatement costs.”
M60 Rapid-Strength Bedding Mortar
M60 bedding mortar is the market-leading, rapid-strength mortar to bed and level all types of ironwork reinstatements and access covers.
Along with being HAPAS approved since 2005, M60 also conforms to HD27/15. It can also be used for bonding bedding kerbs, granite setts and paving flags.
Choose M60 when you are installing frames of less than 675mm x 675mm x 100mm in size for Type 3 and Type 4 category roads. M60 can also be used for B125 category cycle paths and footpaths.
M60F Fibre-Reinforced Mortar
Much like M60, M60F bedding mortar is another popular rapid-strength mortar and comes with added fibres for superior strength. Again, it’s HAPAS approved and conforms to HD27/15.
M60F is also the ideal choice when installing smaller ironwork frames (outlined above for M60) for Type 3 and Type 4 roads, plus footpaths and cycle paths.
PY4 Polyester Resin System
An alternative to cementitious bedding mortars is the PY4 Polyester Resin System. This two-part product is a polyester, resin-based mortar used to bed and level ironwork within roads, junctions and turning areas that receive lots of heavy traffic.
PY4 provides a stiff supporting mortar and is highly recommended for ductile ironwork. The mortar boasts a rapid strength gain and when used the area can be opened to traffic in 40 minutes.
Much like Envirobed, PY4 can be used for all ironwork frame sizes on Type 0, Type 1 and Type 2 category roads.
Ironwork backfilling and concrete surfaces
Use a high-strength material for ironwork backfilling and for manhole covers set within concrete surfaces.
When backfilling, add one of the approved concrete materials listed below at least 25mm above the flange of the ironwork frame, no greater than 100mm from the road surface and within 350mm of the edge of the access chamber’s new frame.
Please note: if you are using a flowable bedding mortar such as Envirobed, use the same material for ironwork backfilling.
QC10 Rapid Strength Concrete
HAPAS approved, QC10 is a rapid-strength concrete that has been designed specially for thick section repairs, haunching reinstatements and ironwork backfilling.
QC10F Flowable Concrete
A fibre-modified concrete option that is also HAPAS approved. QC10F Flowable Concrete is also rapid-setting and has been designed for backfilling around manhole frames and gullies.
What’s the difference between QC10 and QC10F?
“It’s really down to contractor choice at the end of the day, but also what has been approved in the spec of the road repair,” explains Cleo Canning from The Paving Experts.
“QC10 is a stiffer mortar, and therefore more buildable. Whereas QC10F is a runny, flowable mortar which can be poured easily.
“But one of the main differences between these two concrete materials is that QC10 can only go to a 250mm depth, while QC10F can go to 500mm.
“Setting time is another key distinction between the two,” adds Cleo. “Any contractor who needs a faster setting concrete with strength, they’d go for QC10F. As a flowable concrete, QC10F gets to 20N/mm² in just 90 mins, meaning it can be open to traffic much quicker. In fact, 30 minutes faster than QC10.”
Bitumen surfacing materials
For manhole covers set in bitumen, use an approved hot lay or cold-lay tarmac filler.
Enviro Mastic Hot Lay Tarmac
Use Enviro Mastic hot-lay tarmac for a structurally sound surface course for a manhole reinstatement without the use of mechanical compaction. This hot-applied, rubber-modified mastic asphalt has been approved for use in all types of road categories plus B125 footpaths and cycle lanes.
When applying Enviro Mastic, use the layer-on-layer method with no more than 50mm-deep layers.
Enviro Mastic is fully certified for ironworks, utility reinstatements and pothole repairs through Product Assessment Certification through Pavement Testing Services (PTS) Ltd.
Instant Road Repair
Ultracrete’s Instant Road Repair 10mm (available in bags and tubs) has been HAPAS approved by BBA since 2002 as a surfacing material for general repairs on Type 3 and Type 4 roads.
When using a cold-lay tarmac such as Instant Road Repair (IRR) or Tough Patch (listed below), you must provide a greater trimback to allow for compaction tools. Apply the material in no more than 45mm layers compacted to 30mm. The depth of this surface course should be no less 60mm within the carriageway.
IRR 6mm can be used for surfacing manhole repairs on footpaths and cycle lanes.
Tough Patch
Also certified for use on Type 3 and 4 category roads is Tough Patch 10mm, which comes with a higher skid resistance value. This is another option for permanent cold-lay surfacing material (PCSM) on Type 3 and Type 4 category roads. See the specific instructions for using cold-lay tarmac under Instant Road Repair above.
Surfacing specialists opt for Tough Patch when repairing surfaces that require more skid resistance. For example, if the manhole reinstatement is on a lorry carpark, a turning circle at a cross-roads or an area that is more prone to surface water and potential skid risks.
Tough Patch 10mm is made to order. Contact The Paving Experts on 0330 122 1025 to order or email orders@thepavingexperts.co.uk
Tough Patch 6mm can be used for manhole reinstatements in footpaths and cycle lanes.
Bitumen adhesive and sealants
A tack spray and edge sealant is strongly recommended to secure the reinstatement in place and prevent water ingress.
SCJ Seal and Tack Coat Spray
Apply SCJ cold joint spray to the surface base and all inside vertical edges when applying each layer of asphalt. As an extremely strong adhesive and sealant, SCJ improves the bond of the bitumen surface material and helps to prevent water ingress.
SCJ spray has been HAPAS approved since 2005.
Instaband ECO Overbanding Tape
Made from thermoplastic, Instaband ECO Overbanding Tape is specially designed to apply to asphalt roads to prevent water ingress and progressive fretting.
HAPAS approved since 2012, it prevents water ingress immediately to prolong the life of your manhole cover repair.
Become a registered professional
Many different contractors and organisations carry out repairs on our roads. With varying standards and quality of work, Ultracrete has introduced a UCARS approved accreditation scheme to promote best practice in the highways industry.
As a member, you become a recognised professional. Once you’ve attended an initial training session (currently held online via a webinar), you will receive continued support to ensure your full understanding of working to the right specs for the road network.
Upcoming events for the Accredited Reinstatement Specification are all listed in the Ultracrete Training Academy calendar. The Training Academy also contains regular webinars on installing recess access covers and weighing up whether to repair reinstatements with a cement or resin bed.
Call our experts for tailored advice
The Paving Experts have been working with local civils and landscaping contractors for over a decade and have a wealth of experience in the tarmac and road repair trade. Great deals are also available when buying a pallet or part-pallet of materials with us.
Should you have any questions about ironwork reinstatement materials, cold lay tarmac, backfill mortars or the range of bitumen surfacing materials and sealants, drop our team of experts a line and find out more about the recommended ironwork installation materials available.
Our team is on hand weekdays from 8.30am to 5.30pm on 0330 122 1025.
Please note: this article should not be considered as advice for installing ironworks. We strongly advise visiting the Ultracrete Training Academy for specific advice on the accredited manhole reinstatement system and specific materials to use.
