Posted on: 4 December 2018Share
Access covers for water supply and sewage are important for covering and protecting against dirt and water whilst remaining stable under heavy traffic without budging or rocking. The best covers allow easy and convenient access to underground services without compromising on decorative style and finishing. Access covers come in a range of shapes, sizes and materials which are selected according to the site area in which they will be installed. Australian standards and guidelines have particular requirements for access covers and must comply with specific Australian guidelines. These guidelines address the following things:
- frame dimensions
- keyhole dimensions
- sufficient gas and water tightness
- sufficient load-bearing capabilities
These guidelines are dependent on the class of the site area in question. Classes range from very light duty (Class A) to very heavy duty (Class G). Here is a summary of the classes and their recommended site areas, from most light-duty to most heavy-duty:
- Class A: Places (including pathways) that are accessible only to pedestrians and cyclists and closed to other traffic
- Class B: Areas that are accessible to vehicles (except for commercial vehicles)
- Class C: Shopping centres and those areas exposed to slow-moving vehicles
- Class D: Areas open to heavy-duty vehicles
- Class E: Docks and aircraft pavements exposed to high wheel loads
- Class F: Docks and aircraft pavements exposed to very high wheel loads
Unfortunately, numerous cases of non-compliance have resulted in people being seriously injured. In many industrial, residential and commercial building projects, the load-bearing requirement is completely disregarded and choice of access cover is based mostly on price. Companies are willing to compromise on quality for a much cheaper access cover.
What materials are access covers available in?
Selection of the material will be based upon the class of the site area where the access cover is to be installed. There are a huge range of companies offering high-quality access covers in cast iron, galvanised steel and composite materials. Galvanised steel access covers are mostly used for areas intended for light wheel loads, whereas ductile iron covers are used for both light- and heavy-duty applications.
How the final selection should be made
The final selection of the access cover should first and foremost comply with the Australian standards and guidelines. This will be determined through a thorough analysis of the site area considering factors such as speed, frequency and type of traffic. This will then lead to the final decision of which type of cover will be most suited to the area.