Drain pipe materials and repair library

Material

Cast iron

Possible locations

Soil stacks and drainage runs

Separate assessments

Deposits inside the pipe and remaining structural condition

Useful records

Route, joints, supports and access

• Buried drain or above-ground stack
• Leaks, restriction and survey records
• Branches and available access
• Known corrosion or previous repairs

Approved Document H: drainage and waste disposal

Material

Concrete

Typical application

Gravity drainage and sewer infrastructure

Important distinctions

Pipe surface, cracks, joints and movement

Repair evidence

Survey, dimensions and service conditions

• Survey with defect locations
• Pipe diameter and route
• Industrial discharge information
• Access and capacity constraints

Approved Document H: drainage and waste disposal

Material identification

Confirm from records and competent inspection

Inspect closely

Deformation, internal condition and remaining passage

Possible decisions

Specialist preparation, lining or replacement

Key limitation

A liner does not automatically correct the pipe route

• Full survey and inaccessible lengths
• Extent of deformation
• Pipe route and branch locations
• Previous cleaning or repair attempts

Material

Unplasticised PVC (PVC-U)

Typical system

Gravity foul and surface-water drainage

Inspect closely

Shape, support, joints and branch connections

Avoid assuming

That every plastic drain is suitable for lining

• Pipe dimensions and markings if known
• Survey and deformation findings
• Drain use and discharge type
• Access and connection locations

Material

Vitrified clay

Typical system

Underground gravity drainage

Inspect closely

Joints, fractures, alignment and connections

First evidence

CCTV survey with defect location and dimensions

• Survey footage and written findings
• Pipe diameter and route
• Defect position and branch locations
• Previous repairs or root problems

• Crack extent: whether the crack is localised or recorded at several positions.
• CCTV evidence: recording, defect description and measured distance from the access point.
• Access: chamber locations, pipe route and restrictions around buildings or occupied areas.

• Chamber depth and opening: confirm the installed access arrangement.
• Investigation access: identify what can be inspected without assuming personnel entry.

• Bend position: measured distance from the access point and the change of direction.
• Passage through the bend: bore condition and any restriction shown on CCTV.

• Branch position: measured survey location and the connected run.
• Connection geometry: branch layout and the condition of the surrounding pipework.

• Connection position: where the drain enters the chamber and any defect at the transition.
• Chamber condition: damage or access restrictions that affect the connection.

• CCTV finding: pipe shape, alignment and measured defect position.
• External support: record where bedding or surrounding fill remains unknown.

• Access type: identify the fitting or chamber used for inspection or testing.
• Repair area: note which part of the drain can be reached from that access.

• Route: measured position of the drain beneath the building and available access points.
• Restrictions: bends, branches and any section that could not be reached or surveyed.

• Coupling position: measured location and the defect recorded on CCTV.
• Connection details: pipe materials, sizes and geometry on both sides of the coupling.

• Affected route: identify the foul drain section and its connected branches.
• CCTV finding: defect description and measured position from the access point.

• Channel finding: defect position within the chamber.
• Connected pipework: inlet and outlet positions and any separate pipe defect.

• Branch connection: the affected branch, junction geometry and its position in the survey.
• CCTV evidence: recording, defect description and measured distance from the access point.
• Access: chamber locations, pipe route and restrictions around buildings or occupied areas.

• Joint condition: the reported gap and the condition of the adjacent pipework.
• CCTV evidence: recording, defect description and measured distance from the access point.
• Access: chamber locations, pipe route and restrictions around buildings or occupied areas.

• Size change: both pipe diameters and the measured position of the transition.
• Transition geometry: survey view of the change and nearby connections.

• System identification: confirm push-fit waste pipework and pipe size.
• Access: joint locations, branches and the section affected.

• Route: confirm where the rainwater connection runs and its intended destination.
• Repair position: measured location and any affected junctions or bends.

• Product identification: record the pipe type, size and any visible markings.
• CCTV finding: internal bore condition, connections and measured defect position.

• Joint finding: leakage, movement or obstruction, with its measured CCTV position.
• Adjacent pipework: pipe size, branch positions and any nearby bend.

• Access point: location and the section of drain it can reach.
• Drain route: bends, branches and distance to the reported defect.