Ductile Iron Covers

For a standard residential driveway, a Class B rated grate or cover is sufficient, as Class B loading is suitable for slow-moving domestic traffic.

For commercial driveways or areas with truck traffic, a heavy-duty Class D grate or ductile iron cover is required for safety and compliance.

The clear opening refers to the size of the open space or void beneath a cover or grate, and typically matches the internal size of the pit chamber below. It is the most critical dimension when ordering pit covers.

Access covers and grates are usually larger than the clear opening size in order to sufficiently cover the pit beneath. It is important to note that any dimensions in the product descriptions typically refer to the nominal clear opening, not the external dimensions of the cover or grate itself. For specific product dimensions, SVC can provide technical datasheets or product drawings for accuracy.

Yes. To function correctly, a 'raw' ductile iron cover is designed to be infilled with concrete and cast into a structural reinforced concrete surround. This footing transfers the traffic load safely to the underlying pit and pavement structure, and produces a neat-looking installation.

SVC also offers ductile iron access covers that are pre-encased and infilled with concrete, meaning that it is delivered to site as a complete unit that can be easily installed over the pit by simply lifting the encased unit into place. This saves contractors time and labour during installation, as the need to build formwork and pour concrete on-site is eliminated.

Absolutely! SVC can supply ductile iron access covers and multi-part covers rated to Class D, E, and G, which are specifically designed, tested, and approved to withstand the loading requirements of highway and main road traffic. While we also supply ductile iron access covers with a Class B load rating, these are not compatible for road installation and should only be used in driveways or behind-kerb applications where they are suitable for slow-moving domestic traffic.

Ductile iron is significantly stronger and less brittle than traditional cast iron. This allows for more efficient designs with higher load ratings and a far greater resistance to cracking under repetitive traffic loads, increasing the durability and longevity of these heavy-duty access covers in the built environment.