What is a rodding eye?

A rodding eye (also called a rodding point or access plug) is a capped access fitting fitted to a drain or soil pipe that allows drain rods to be inserted to clear a blockage. It consists of a short branch pipe fitted with a screw or push-fit cap at ground or wall level. Rodding eyes are smaller and cheaper than inspection chambers but provide more limited access - they allow rodding in one direction only and cannot be used for CCTV surveys or visual inspection.

When can a rodding eye be used instead of an inspection chamber?

Approved Document H permits rodding eyes in place of inspection chambers in limited situations: at the head of a drain run (where the drain starts at the building), and on straight runs where an inspection chamber exists within the maximum rodding distance. They may not be used at junctions, bends, or changes of gradient, where a full inspection chamber is always required. On domestic projects, rodding eyes are commonly fitted at the base of soil stacks and at the entry of drains to the first inspection chamber.

How does a rodding eye work?

A rodding eye is installed as a T or Y branch from the main drain pipe, brought up to just above ground or floor level and sealed with a removable cap. When a blockage occurs, the cap is removed and flexible drain rods (screwed together in sections) are fed into the pipe and pushed along to break up and dislodge the blockage. Rodding eyes must be oriented to allow rodding in the direction of the drain flow toward the blockage - a facing-upstream rodding eye is ineffective.

Drainage & Utilities noun

Rodding Eye

/ ˈrɒdɪŋ aɪ /

Also known as: rodding point, access plug, drain access eye, RE

Definition

A rodding eye is a capped access fitting installed on a drain or soil pipe that allows drain rods to be inserted to clear a blockage without digging or opening an inspection chamber. It is smaller and simpler than an inspection chamber - it provides a single rodding access point in one direction but cannot be used to inspect the drain or access it visually. Approved Document H permits rodding eyes at drain heads and on straight runs, but not at junctions or bends.

In practice

Rodding eyes are commonly fitted at the base of soil stacks (where the stack connects to the underground drain), at the entry point of a drain under a building, and at the head of short branch drains serving gullies or rainwater pipes. They consist of a 100mm or 150mm swept T-junction branch brought up to a point just above finished floor or ground level, sealed with a screwed or push-fit access cap.

On drainage drawings, rodding eyes are abbreviated as RE with a reference number. When drain rods are inserted, they are pushed in the downstream direction to dislodge blockages. Care must be taken not to unscrew the rod sections inside the pipe - a lost rod section in a drain is difficult to recover and may itself cause a blockage. On plastic drain systems the cap must be replaced carefully to avoid cross-threading.

Building Regulations

Relevant PartPart H - Drainage and waste disposal

Permitted positionsHead of drain, straight runs within rodding distance

Not permitted atJunctions, bends, or changes of gradient

Approved Document H Table 5 sets out where access points are required and which type is acceptable. Rodding eyes are permitted at the head of a drain run (where the drain begins) and on straight runs where full inspection chamber access exists within the maximum rodding distance (22m for 100mm pipes, one end). They do not satisfy the requirement for access at junctions or bends, where a full inspection chamber is always needed.

Full Building Regulations guidance

Rodding Eye

Just so you know...