Why Do Old Drains Collapse?

Old drains collapse because of a combination of age-related material degradation, environmental stresses, and the inherent weaknesses of historic pipe materials and installation methods. Understanding why old drains fail helps you assess your own property's risk and take preventative action before a collapse causes expensive damage.

What to Look For

• Clay pipes: mortar joints crack and separate, allowing soil and root entry
• Concrete pipes: acidic sewage gradually erodes the pipe wall from inside
• Cast iron pipes: corrosion thins the pipe walls over decades
• Pitch fibre pipes (1950s–70s): deform and collapse as the material softens
• All old pipes: ground movement, traffic loading and frost cause cumulative damage
• Victorian engineering: shallow installation, poor bedding, inadequate gradient

How We Diagnose the Problem

CCTV surveys reveal the current condition of old drainage — showing wall erosion, joint displacement, deformation, cracks, and early-stage collapses. Our condition ratings help you understand which pipes need immediate attention and which can be monitored.

How We Fix It

Drain relining is ideal for old pipes — the new liner seals all joints, covers cracks, and creates a smooth new bore inside the deteriorating old pipe. For sections that have already fully collapsed, targeted excavation replaces just the failed area.