Standard covers safe access

28 October 2011

Peter Jennings discusses the role of FACTA in driving important on-going developments in standards for access covers that will enable specifiers to make the right choice when selecting products.

Fabricated access covers – consisting of a frame and cover – fulfil a huge variety of applicationsfor internal and external building applications. With such diverse use, access covers are constructed from a variety of materials and offer flexibility in design and size, depending on the access requirement to the underground utility.

Gaps in the ratings
Back in 1994, BS 497was replaced by BS EN 124 Gully Tops and Manhole Tops for Vehicular and Pedestrian areas. However, the scope of the publication failed to fully address access cover specifications and was published primarily for brittle cast iron materials, taking little account of the elastic material characteristics of the increasingly popular steel and aluminium covers. Additionally, the standard’s load classes from A15, B125 up to F900 are not comprehensive enough. With covers having to withstand a wide range of applications, the wide gulf between A15 (0.6tonneslows moving wheel load) and B125 (5 tonnes slow moving wheel load) is not practical, potentially leading to uneconomic selection as there are many applications that naturally occur somewhere between the two load classes. Another shortfall of BS EN 124is the general guide to product stability that relates to brittle cast iron materials and sets out test load parameters for the various classes of products in terms of static load tests that are not applicable to elastic materials.

FACTA fills load class niche
To address these anomalies in BS EN 124, the industry formed a new trade association comprising leading UK manufacturers and suppliers of access covers and manhole covers to the construction industry.

Since the formation of the Fabricated Access Cover Trade Association (FACTA) in the early 90s, the Association has made significant progress by producing its own FACTA Specification to fill the niche for cost effective fabricated covers used in applications where wheel loads are not as high as demanded by the B125 load class. Through participation and co-operation with other manufacturers, the research and technical development of fabricated access covers led to a uniform standard of grading in accordance with the loading requirements for specific locations. The FACTA Specification contains two additional load classes, AA and AAA, to sensibly bridge the wide gulf between A15 and B125 set out in BS EN 124, providing reliable and economic solutions for these applications.

Confidence in selection for specifiers
Significantly, the FACTA Specification and additional load rating criteria have enabled engineers and designers to specify more suitable products with industry recognised load class rating, confidently knowing that dimensional stability will not be compromised under loads experienced during service life. The addition of the two extra load classes now bridges the gap and provides specifiers better defined option criteria. For example, a class FACTA AA-rated access cover has been assessed to bear a 1.5 tonne per wheel load is suitable for private car transit areas and driveways, while the next, FACTA AAA-rated is capable of withstanding a load of 2.5 tonnes per wheel and will meet the demands of light industrial areas where trolleys and light pallet trucks operate.

A list of specifications produced by FACTA now provides specifiers with comprehensive guidance and, with such rigorous technical requirements, sets the bar high in ensuring only well engineered fabricated access covers meet its stringent pass grade criteria. In addition, FACTA has also published and promoted its Guide to Performance Classes, which enables specifiers and a wider audience to understand the FACTA Specification guide and draw some simple comparisons to BS497 and BSEN124.

More recently, with industry backing and support, FACTA has also played a pivotal role in the generation of BS 9124Specification for steel and aluminium access cover systems with over 1metreclear opening and also BS 5834 Surface boxes, guards and underground chambers for the purpose of utilities.

One such product covered by FACTA’s Specification process is ACO’s Alucover range of access covers. The covers are suitable for a range of internal and external public areas such as retail or transport terminals and provide an unobtrusive visual finish. In line with FACTA Specification, all of the Alucover range is graded by load class, ranging from A to B, to deliver long and effective service life.

Benefiting construction
One of the many projects to benefit from FACTA-rated Alucover access covers is the recently opened Welsh Government offices in Llandudno. The Llandudno Junction Office is one of three Welsh Assembly government administrative hubs sited in Wales and covers 8000 square metres, accommodating up to 650 staff. The environmental design considerations of the building include locally sourced materials, such as the famous slate from Penrhyn Quarry in Bethesda. In fact, the building has won several Green accreditations such as a BREEAM ‘Excellent’ assessment rating and has, uniquely in Wales, an Energy Performance Certificate ‘A’ rating becoming the most energy efficient government building in the region.

This prestigious project has paid particular attention to every detail and the architects and contractors have specified access covers meeting industry recognised FACTA specification to provide the performance and appearance they were looking for.

New Developments on the horizon
The revision of BSEN124 has already begun in order to achieve European harmonisation under the direction of CEN, the European standards body. One of the mandated requirements for the revision was for the inclusion of other materials including steels and aluminium, concrete, plastics and composite materials along with existing grey and ductile iron materials. The revised standard will not only cover load bearing capacity, but also key issues such as child safety, skid resistance and reaction to fire as part of the essential characteristics for the standard.

FACTA continues to play an active role on the BSI standards development committee revising BSEN124 and remain committed to contribute the production of a standard that is fair and appropriate for industry needs.

Performing a vital role
With no clear indication of when the revised standard will be issued, the current BS EN 124 offers little or no guidance on selection of products other than cast iron. Until such time, the FACTA Specification will remain at the forefront in addressing this issue, providing specifiers, designers, architects and contractors with guidance in making the appropriate choice for product specification across a wider range of materials for the necessary load application. Furthermore, FACTA is now revising this specification to account for changing trends and needs of the market place.

Negotiating the successful introduction of its specification for access covers in pedestrian and vehicular areas in the revised BSEN 124 is only one many FACTA’s future objectives. As well as having a general role in promotion, education and the forming of alliances across Europe in the construction industry, the Association’s presence looks assured as it tackles more specific issues.

As such an inconspicuous component, access covers will continue to go completely unnoticed to all but construction professionals. However, just like many other unobtrusive items surrounding us daily, these products perform a vital function to ensure our continued safety.

Peter Jennings is Technical Director for ACO Building Drainage