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Building components · Drainage Elements

Rodding Eye

Explains rodding access as separable from chamber access, and what is gained and given up by providing one rather than the other.

Form:Conveyance elementRoles:DrainageTermination

Educational reference entry. What this element has to do, and whether any particular arrangement of it is adequate, depends on the whole assembly, the loading, the exposure, local requirements, the manufacturer's instructions and qualified professional design.

Overview

What a rodding eye is

A rodding eye is a short capped branch brought up from a drainage run to a surface, so that rods or clearing equipment can be introduced into the run from above. It gives access to the pipework without the excavation, the chamber and the cover that an inspection chamber requires.

What it provides is access along the run, in the directions its branch allows, from a single point. It does not let the flow be seen, it does not give somewhere to reach into, and it does not give access to a junction from more than one side — which is precisely the trade being made when one is provided instead of a chamber.

Boundaries

How it differs from nearby elements

The distinctions that keep this entry from being a restatement of its neighbours.

  • It is not an inspection chamber. A chamber lets the run be seen and reached into and commonly serves several directions at a junction; a rodding eye admits rods along the run and does nothing else.
  • It is not a gully. A gully admits surface water into the system; a rodding eye is normally sealed and admits nothing but the rods used to clear a blockage.
  • It is not an outfall. An outfall is where the system as a whole discharges; a rodding eye is an access point on a run that continues past it.

Terminology

Common names and aliases

These names describe the same element. The library keeps one entry per component so that a trade term or a regional name never becomes a second, thinner page.

  • cleaning eye
  • access eye
  • rodding cap

Dependencies

What it depends on

What has to be right elsewhere for this element to do its job.

  • Where it sits relative to the run, since rodding reaches only in the directions the branch allows.
  • Its cover remaining findable and liftable, because an eye that has been paved or planted over is no longer access.
  • Remaining sealed in normal use, since an opening into a drainage run is otherwise a route for water in and for drain air out.
  • There being a record of the run, because an access point whose direction and extent are unknown is of limited use at the moment it is needed.

Considerations

Topics that genuinely apply here

Subjects worth discussing about this element. These are discussion topics, never measured values, ratings or performance claims.

Maintenance & access

A rodding eye concentrates the clearing provision at one place and along one route, which is useful where a chamber cannot be positioned and limiting where a chamber could have been.

Documentation

An access point that appears on no record is commonly found only by excavation, which defeats the reason it was provided.

Moisture

A cap that is loose or damaged lets surface water into the run and lets drain air out of it, commonly at a point close to a building.

Buildability

Rodding eyes are small and are finished flush, which makes them among the easiest things to lose under later paving or landscaping.

Materials

Commonly incorporates

Materials this element commonly contains as a distinct constituent part, rather than being made of.

Materials LibraryReady-mixed concrete →A concrete surround is commonly cast around the fitting to hold it and to carry the cover.Materials LibraryEngineering brick →Brick surrounds are met where an eye is brought up in older drainage or in repair work.Materials LibraryGalvanised steel →Coated steel covers and frames are used where an eye is finished into a trafficked surface.Materials LibraryStainless steel →Used where the cover must remain removable after long periods without use.

Assemblies

Building systems this element is met in

The role this component fills inside each assembly. A role describes what the element does there — it is not a statement that this component suits that system in any particular building.

Service zoneBuried Drainage Network →Provides rodding access to a length of the buried network where no chamber is placed.Service zoneSurface Water Collection →Allows a surface water run to be rodded from a point on its length.Service zoneLand Drainage →Gives access to a collector run that is otherwise entirely buried.Service zoneWall Base Drainage →Allows the drain at the base of a retained structure to be rodded without excavating against it.

Clarifications

Commonly misunderstood

  • That a rodding eye is a small inspection chamber. It performs one of the chamber's jobs and none of the others.
  • That providing rodding access removes the need for chambers. Where a run has to be seen, or reached at a junction from more than one direction, an eye cannot do it.

Conversations

Questions for qualified professionals

Questions worth asking someone with the project in front of them. This page cannot answer them.

  • Which lengths of the run can be rodded from this eye, and in which direction?
  • Is the position of the eye recorded, and does it appear on the drainage plan?
  • Is the cap sealed, and how would a failed seal be noticed?
  • Where a chamber was not provided, what was the reasoning, and what is not accessible as a result?

Go deeper

Related Build Design Hub guides

Planning guidance behind the decisions this element involves.

Preparation

Related planning checklists

Owner-side preparation before the conversation where this element comes up.

What this entry does not do

  • This entry describes a position. It states no size, spacing, depth or cover arrangement, and none can be inferred from it.
  • Below-ground drainage access provision is a regulated matter and part of qualified drainage design.

Drainage & Rainwater Elements

The gutters, outlets, downpipes, channels, chambers and traps that collect water, carry it and let it be inspected.

Browse all drainage elements entries →