Manholes: Inspection Chambers, Frames and Access Covers

Every drainage network needs points where it can be inspected, rodded and cleared. In buildings and around them, those points are manholes and inspection chambers, closed at the surface by a frame and cover that must carry traffic, keep odours in and, often, blend with the floor finish.

Jawdah includes manholes in its sanitary ware and drainage family, with two named items. Their detailed specifications have not been published yet, so this page explains how manholes are put together and specified, and what to confirm with the Jawdah team before ordering.

On drawings, the word manhole can describe two different things: the inspection chamber itself, a pit or shaft that gives access to pipes and junctions, and the frame-and-cover assembly that closes that chamber at floor or ground level. Procurement documents should make clear which one is meant.

Inside buildings, manhole covers are found over drainage access points in basements, plant rooms, kitchens and car parks. Outside, they sit in paving, landscaping and roads. In each case the cover must suit the load, the floor finish and the need to keep gases and odours inside the system.

Jawdah lists two items under Manholes: Manholes 50 mm and Manholes 70 mm. No descriptive text, material, clear opening, overall size, load rating or sealing detail has been published for either item, and the product data does not state what dimension the 50 mm and 70 mm figures describe.

All of these values are confirmed per project by the Jawdah team. The general guidance on this page helps you prepare the questions and information they will need.

A typical access point combines a chamber, a frame and a cover. The chamber may be built in masonry or concrete, or supplied as a preformed unit. The frame is bedded on top of the chamber and set level with the finished surface. The cover sits in the frame and can be lifted with keys for inspection.

• Chamber: gives working access to pipes, bends and junctions.
• Frame: transfers loads to the chamber and holds the cover at floor level.
• Cover: solid top or recessed tray that takes the floor finish.
• Seal: a gasket or grease seal that limits odour and gas escape indoors.
• Lifting keys or points: allow safe removal of the cover.

Solid-top covers present a plain or patterned metal face, commonly with an anti-slip texture. They are simple and robust, and suit plant rooms, service yards and roads.

Recessed covers, also called infill or tile-in covers, have a tray that is filled with screed, tiles, stone or paving so the cover almost disappears into the floor. They are favoured in lobbies, kitchens, retail floors and landscaped areas. The depth of the tray must suit the thickness of the finish placed in it, which is why recessed covers are often described by a depth figure in millimetres.

Manhole covers are needed wherever a drainage line must remain accessible.

• Basements, plant rooms and pump rooms.
• Commercial kitchens and back-of-house corridors.
• Shopping malls, lobbies and finished interior floors.
• Car parks, service yards and loading areas.
• External paving, courtyards and landscaped areas.

Four decisions drive the specification. First, the load: a pedestrian floor, a car park and a loading bay need very different covers, so state the traffic type. Second, the clear opening needed for maintenance access. Third, the surface: solid top or recessed, and if recessed, the finish and its thickness. Fourth, sealing: indoor covers over foul drainage normally need a sealed design to keep odours in.

Add the material requirement, for example stainless steel in hygienic areas, and any restrictions on lifting weight for maintenance staff.

Bed the frame fully on the chamber with a suitable mortar so it cannot rock, and set its top level with the finished floor. For recessed covers, fill the tray carefully so the finish is flush with the surrounding floor and does not bond the cover to the frame.

Keep the seating faces clean, check that the cover lifts and closes properly, and grease or fit seals where the design requires it.

Because the meaning of the 50 mm and 70 mm figures is not defined in Jawdah's product data, the first step is to ask the Jawdah team what each figure describes, for example a recess depth, a frame height or another dimension. Once that is confirmed, compare it with your floor build-up and finish thickness.

Each item has its own page with an RFQ checklist. Use the 50 mm page and the 70 mm page to prepare your enquiry, and send floor sections showing the finish at each access point.

• Jawdah lists two manhole items: Manholes 50 mm and Manholes 70 mm.
• Jawdah has not published material, size, load rating or sealing data for its manholes.
• Jawdah's product data does not define what the 50 mm and 70 mm figures describe.
• A manhole access point consists of a chamber, a frame and a removable cover.
• Recessed manhole covers take the floor finish in a tray so they blend with the floor.
• Indoor covers over foul drainage are normally specified as sealed.

• Item: Manholes 50 mm or Manholes 70 mm, and what the figure must represent.
• Location and traffic type (pedestrian, car park, loading area).
• Clear opening required for maintenance access.
• Cover type: solid top or recessed infill.
• Floor finish and its thickness at each cover.
• Sealing requirement (indoor foul drainage).
• Material requirement, for example stainless steel.
• Number of access points, layout drawings and site address for delivery.

• Manholes 50 mm
• Manholes 70 mm
• Trench Drain
• Floor Drains
• Sanitary Ware & Drainage