European and British manufacturing standards should only ever act as a starting point for a specification. To maximise whole life costs you need to consider far more Paul Thompson, Product and Marketing Manager for Saint-Gobain PAM UK argues.
Standards are vital in that they verify that a product or system has met a baseline level of performance. They help prevent the specification of poor quality products, so they are a useful place to start on a specification.
Manufacturers will comply with system standards such as ISO 9001 for quality systems, ISO14001 for environmental management systems plus others for raw materials and health and safety. In addition, their manufactured products might comply with product standards, such as EN124 for access covers and gratings.
A quality mark can confirm compliance to a standard, which shows that a third party has independently verified the system or product.
BS EN 124, for example, covers gully tops and man hole tops for vehicular and pedestrian areas. Depending on the application you may then also need to consider a further British Standard – BS7903 covering the ‘selection and use of manhole covers and gully tops for installation within the highway’.
Part 1 of EN124 defines the scope of the standard and classifies what the products are used for, its materials, the design and performance requirements and the testing regime to ensure that they perform to a minimum level.
Parts 2-6 are specific to the different types of material used to manufacture access covers and gratings, with part 2 detailing the requirements of products made of cast iron and contains the specific tests relevant to this material.
Such testing is important to ensure that the products are fit for purpose. The problem is that they don’t always reflect what happens to the product in service.
For example, BS EN 124 requires a static load bearing test where the test load is applied to the cover and held for 30 seconds. The condition of the cover top is then recorded and a report prepared.
Unfortunately static load failures do not happen in real life; access covers and gratings installations tend to fail as a result of dynamic or transitional loading exerted by different traffic conditions.
This is why such standards should only form the base requirements for a specification, to which other industry specific and client requirements are overlaid.
Within the highways industry you will also find the guidance note HA104/09 Chamber Tops and Gully Tops for Road Drainage and Services: Installation and Maintenance. This is seen by many as an example of best practice and makes performance-based recommendations that supplement EN124 for a client.
To quote directly from this guidance: ‘The premature failure of chamber top and gully top installations has been shown to be a major contributory factor to the annual maintenance budget of UK roads.
‘These failures are not usually of the frame and cover itself but of the supporting system and the pavement surface, generally flexible, immediately adjacent to the installation. Rocking of the frame and cover in failed installations can occur under traffic, causing noise pollution and potential hazard to vehicles.’
The guidance note details requirements for each critical element of different applications covering gully tops, chamber tops, bedding materials, new work installations and reinstatement works.
When it comes to specifying ironworks, it is important to be aware of the standards and guidance notes, but not to rely on them if you want to achieve the best whole-life costs for the installation.
There are multiple factors to consider for a specification. What is the installation’s environment and location, will it be heavily trafficked? Is it important to secure the cover against theft or prevent access and what about safe access for authorised users? For safety is it worth considering anti-skid surfaces?
Finally, it is worth noting that such installations are a complete system. The best results come from specifying suitable products which includes not just the ironwork, but also the materials used to install them. More often than not failures are due to poor installation practice and it is incumbent on the whole supply chain to both train personnel and to check that best practice is followed.
Standards are vital, but on their own they are not enough. They should be there to help but are not a crutch that a specifier can rely on if they want to minimise the life cycle costs of ironwork.
Saint Gobain-PAM UK has developed an hour long CPD accredited training course called Access Covers and Gratings – Standards and Specification Overview and Guidance.