Manholes (SANS 1294): Components (750-2000)

Cover slabs and reducer slabs are supplied to match the full 1,000 mm to 2,000 mm nominal chamber range, stepping the chamber diameter down to a standard access opening for the frame and cover. Covers and frames are available as a Type 2A assembly (640 mm cover, 860 mm frame), with a matching Round Spacer and an Extra Heavy Duty frame option, plus 750 mm and 1,000 mm valve boxes to Type 11A.

Concrete lids share a common 640 mm outside diameter and 125 mm thickness across the range, and are supplied in Medium Duty, Heavy Duty, Extra Heavy Duty and Lockable options — the difference between them is manufacturing specification for duty rating rather than size. A Six Way Base is also available for multi-pipe junction chambers.

Unit mass increases with size, from around 65-85 kg for lids, frames and spacers up to roughly 1,750 kg for the largest 2,000 mm cover slab, so confirm lifting capacity on site before delivery of the larger components. Masses shown in the tables above are approximate and subject to manufacturing tolerances.

Manhole components are installed at the top of an assembled chamber shaft: a cover slab or reducer slab seats onto the uppermost chamber section to close the shaft and reduce the opening to the standard access diameter, and the frame and cover are then bedded in place flush with the finished surface level.

Reducer slabs are used where the chamber diameter is larger than the standard access opening; cover slabs are used where no reduction is needed. Frame and cover sizes are matched by Type — confirm the frame and lid you're specifying belong to the same Type before ordering.

1. What is a reducer slab used for?

A reducer slab caps a manhole chamber and steps the opening down to the standard access diameter for the frame and cover. Reducer slabs are supplied for nominal chamber sizes from 1 000 mm to 2 000 mm.

2. What is the difference between Medium, Heavy and Extra Heavy Duty lids?

All three share the same 640 mm outside diameter and 125 mm thickness. The difference is the duty rating they are manufactured to, not their size; confirm the rating needed for the application with our sales team.

3. Do you supply manhole components in KwaZulu-Natal?

Yes. Global Precast Coastal supplies manhole components from its factory in Port Edward to contractors, municipalities and consulting engineers across KwaZulu-Natal, with a sales office at 71 Old Main Road, Hillcrest for enquiries closer to Durban. Send your site location with your enquiry to confirm transport arrangements and lead times.

4. What is the largest cover slab available?

The 2 000 mm cover slab, at 2 180 mm outside diameter and approximately 1 750 kg. Confirm lifting capacity on site before delivery.