HEPWORTH CLAY & TERRACOTTA
Suppliers of: Clay Drainage Pipes, Clay drain pipe, Clay drainage systems, inspection chambers, Terracotta ridge tiles, chimney pots, air bricks, fireplace lintels, ventilation terminals
Hepworth Clay drainage systems from Wavin are manufactured from natural materials to produce durable, high strength, quality products. This enables sustainable installation on site using recycled aggregates, and rigorous maintenance regimes in service. These market leading clay drainage systems are accepted within the built environment for residential, adoptable, commercial and industrial applications.
Fired to perfection in a unique production process, vitrified clay is a well-established material for use in below-ground drainage systems. Hepworth from Wavin is the No. 1 clay drainage brand in the UK, with a reputation for product quality, technical ability and customer service.
Hepworth Clay pipes and fittings can be used for the majority of drainage installations. Whether it’s domestic, adoptable, commercial or industrial drainage you are installing. Clay’s main benefits are its durability and longevity, plus it has a good environmental profile from a raw material through manufacturing, installation, in-use to end of life.
- Clay’s high intrinsic strength means less granular bedding is required
- Can be used with recycled aggregates – reducing costs and environmental impact during construction
- Locally sourced and manufactured in the UK – 100% sustainable and recyclable
- Quality assured kitemarked to BS EN 295-1 and BS 65
- Lifetime jetting guarantee – jetproof to 7,500 psi (at a flow rate not exceeding 20 gals/min held static for 5 minutes)
- Especially suitable for brownfield sites – vitrified clay is resistant to almost all chemical attack
- Ideal for sites with a high water table, removing the risk of floatation
- Life expectancy of over 100 years
The Hepworth Clay Range
- SuperSleve DN100 - 300 clay pipes fitting & gullies for use in housing, adoptable, commercial, industrial, and road drainage
- Channels for use in constructed manholes
- HepLine - perforated land drainage system
- Inspection Chambers
- New Hepworth Clay Product, Design and Installation Guide with a comprehensive design section including Hydraulic and Structural, first look at the new BS 9295 standard & specification examples. Also full product details and installation guidance. Order a hardcopy or download from guide.hepworthclay.co.uk
- Online training module: myportal.wavin.co.uk
- ‘How to videos’ & Clay overview video:www.hepworthclay.co.uk or youtube
Terracotta is an extraordinary material that is naturally resistant to the effects of acid corrosion, extremes in temperature, weathering and other environmental factors. Hepworth represents over a century of expertise in harnessing those properties in the manufacture of superior heating, ventilation and roofing solutions.
Hepworth Terracotta offers a comprehensive range of products for the construction and ventilation of domestic flue and chimney systems including a range of chimney pots, ventilation terminals, ridge tiles, and air bricks.
- Ventilation terminals
- Gas terminals
- Chimney pots
- Flue liners
- Fireplace lintels and components
- Ridge tiles
- Airbricks and cavity liners
View the Wavin Ranges on BPi:
- Wavin Group Entry
- Osma Above & Below Ground Drainage
- Hep2O Push-fit Plumbing
- Hep2O Underfloor Heating & Cooling
- Warmafloor Underfloor Heating
Further Technical information is available to download from the BPi Download Library
Hepworth - How to install a clay drainage system
How to install a clay drainage system
When installing a clay drainage system, there are best practices that will help to ensure a safe and effective installation. In this blog post, Paul Wydell, Product Manager for Hepworth Clay explains how health and safety considerations should be considered when planning, excavating and preparing the trench for the installation of the pipeline.
Depending upon whether the new pipeline to be installed is to be a drain (serving a single property) or a sewer (serving two or more properties) will dictate which authority, regulation and guidance that should be followed with respect to its design and installation. In general terms, private drainage should follow the Building Regulations Approved Document H. Where England, Wales, Scotland and Northern Ireland each have a local version of their regulations required for building. Conveniently, covering similar geographical areas sewer installation guidance should follow that of Sewers for Adoption in England, Welsh Ministers Standards in Wales, Sewers for Scotland in Scotland and Northern Ireland Water for Northern Ireland.
System design utilises the documents mentioned above plus additional guidance in the form of BS EN 752, Drains and sewer systems outside buildings to create a topographical design layout and hydraulic design. Where structural design is led by BS EN 1295 Structural design of buried pipelines under various conditions of loading and BS 9295 Guide to the structural design of buried pipelines these documents will help form the basis of a workable and self-maintaining drainage system for many years to come.
One of the many benefits of clay drainage is its long asset life derived in the main from its durability originating in product strength. Vitrified clay pipes are load bearing structural components, who’s intrinsically high strength is determined by material properties and unique manufacturing process. This strength is verified in the factory by continual testing and is delivered to site for incorporation into the permanent works.
Before beginning excavation, all underground services should be located and uncovered with extreme care, not simply limiting the search to the usual suspects of gas, electricity and water.
The trench should be adequately supported during excavation, according to the depth and width of trench being dug and diameter of pipeline being installed. This can take the form of simple trench sheets with manually adjustable trench props all the way up to trench boxes with hydraulic rams to hold the trench walls upright and stable. Providing substantial protection for the ground workers.
The excavated material should be placed an appropriate distance away from the trench wall. The point of influence of excavated material loading on the trench wall usually starts at a horizontal distance approximately equal to the depth of the trench. In other words, within the 45 – 90 degree angle from the base of the trench.
Where possible, trenches should be prevented from filling with water and protected from disturbance caused by footfall which will reduce the amount of support provide by the trench base. The only solution being to dig deeper and reinstate with hardcore and pipe bedding material. Adding time and cost to the project.
For a subsoil that can be trimmed manually, then a class D natural trimmed trench bottom can be created without any granular fill. The trench should be trimmed along its length with recesses to accommodate the jointing couplings and to ensure that the pipe is full supported. Whilst this method of installation takes the most time, it is also the most efficient both financially and environmentally. Where the excavated material can be adequately compacted it can be returned as backfill to the trench for maximum environmental benefit and cost saving.
Alternatively, the pipe can be surrounded by recycled aggregate to BS EN 13242 creating a class S bedding. The structural suitability of the aggregate can be determined by a compaction fraction test to determine the ability of the aggregate to provide additional structural support to the pipeline. The lower the fraction the better the aggregate. Compaction fractions lower than 0.15 (even though it’s a decimal!) are best.
Primary aggregate from quarries and dredging should only be used with clay drainage where recycled aggregate is not available.
The strength of clay pipes means that pipe bedding surround is not normally there to augment the pipes strength but to protect it from the surrounding ground from subsequent movement and improve the speed of installation.
Starting at the downstream end, lay the first pipe in the trench providing temporary bracing to resist the jointing action of subsequent pipes.
In order to create an effective pipe joint, you should first check for any damage on the components to be used and ensure that the seal inside the coupling and the outside of the pipe spigot is clean. The pipe end chamfer (but not the coupling seal) should be lubricated to the required insertion depth. The lubricated pipe spigot should be offered up to the coupling with the pipe offset slightly horizontally. The pipe should then be pushed firmly whilst centralising in one action until the joint is pushed home, this should be heard and felt with a satisfying clunk.
When installing pipe at manhole positions as rocker pipes or to adjust the pipeline length at manhole or junction positions, installation time can be minimised by using standard short lengths of 300mm, 600mm and 1000mm. When non-standard pipe lengths are required, Hepworth SuperSleve pipes of 100mm and 150mm can be cut on site using a lever action chain cutter for 225mm and 300mm pipes a powered masonry saw is required. Operators should always be trained to safely operate the saw and select the correct blade. PPE including googles, gloves and an appropriate dust mask should be worn. Ideally the saw should also have a water feed to help supress the dust.
An air test should be conducted on Hepworth clay installations in accordance with Approved Document H and BS EN 1610:2015. This should be conducted on every three pipes before any backfilling takes place. This will highlight any incorrectly made joints before backfilling takes place making any remediation quick and easy.
Backfilling should include compacting material by hand in layers not exceeding 100mm, evenly on either side of the pipe until a minimum coverage of 150mm over the pipe is reached. Additional backfill should then be added in layers of less than 300mm, compacting each layer in turn. The first layers will need to be compacted manually. Once there is at least 450mm of compacted material above the pipe crown, mechanical compaction equipment can be used.
Following best practices when laying clay pipe and taking time to ensure that the trench is fully prepared will ensure that the pipe is fully functional with a life expectancy of beyond 100 years. In the long run this will help to save material, money and the environment. Delivering a clay drainage system with a low whole life cost and a high whole life value.
More information on Hepworth Clay and instructional videos can be found on the Hepworth Clay YouTube playlist.
Hepworth Clay plays a part in new £200 million training ground
Built on an 80 acre industrial site in Manchester, a new £200 million state-of-the-art football academy and training ground is set to benefit from a durable underground clay drainage solution from Hepworth Clay which will offer low lifetime cost and a long service life.
Designed by Rafael Vinoly Architects, the football academy is home to 450 players training each week and features a 7,000 capacity stadium, a team building with changing rooms, a gym, a refectory and injury and rehab centre, staff offices, media centre, on site accommodation and 16.5 football pitches.
Ensuring this impressive new facility will stand the test of the time, groundworks contractor Murraywood Construction specified the Hepworth SuperSleve clay drainage system for the building facilities to guarantee chemical resistance, longevity, strength and a trouble free future.
Available in 100mm, 150mm, 225mm and 300mm diameters and used in commercial or industrial construction, adoptable sewers, highways and general building works, the Hepworth SuperSleve system consists of plain ended pipe and fittings with additional push fit flexible couplings.
With the team’s training facilities built on polluted ground, it was vitally important that clay drainage was specified due to the risk of chemicals. Hepworth SuperSleve clay pipes not only offer the required resistance in these aggressive ground conditions but have proven durability, which for the client means they have a drainage system that will stand the test of time.
Peter Mason , Murraywood Construction.
“Clay drainage pipes also allow specifiers to reduce installation costs as well as environmental impact by minimising the volume of primary aggregate needed from quarries. Clay pipes have tremendous compressive strength which allows their installation with reduced amounts of granular bed and surround, recycled material or even reused as-dug material if suitable." said Paul Wydell, Product Manager at Hepworth,
“With the new clay drainage system offering the client an unmatched service life, market leader Hepworth Clay has played a part in ensuring this new state-of-the-art facility is built to last and there will be no disruption to the footballing activities of this Premier League club.”