Category: Plumbing

Sewerage demolition

Sewerage demolition is not just “cut out the old pipe”. The work is often tied to odours, residual wastewater, shared risers, neighbours, slabs and the risk of damaging active branches. Safe demolition is needed before riser replacement, bathroom reconfiguration, villa reconstruction and external-line replacement.

When demolition is performed

  • Before full replacement of an old line.
  • During a major bathroom renovation.
  • Before riser replacement or branch reconstruction.
  • During yard and external-drainage reconstruction.
  • When the old network must be decommissioned before a new layout is installed.

What has to be done correctly

  • Stop use of the branch. Otherwise someone may discharge water during the works.
  • Install plugs. To stop odours and accidental spillage.
  • Understand what is private and what is common. In a shared building this is critical.
  • Avoid damaging adjacent active lines.
  • Plan waste removal immediately. Cast iron and old plastics take space and create a lot of mess.

Where demolition is hardest

  • Risers in multi-unit buildings.
  • Pipes buried in screed under tile.
  • External lines under paving.
  • Old cast iron. Heavy, brittle, noisy and dusty to cut.

What it costs

  • Local removal of one branch — 300–1,200 ILS
  • Demolition of sewerage in one bathroom — 800–2,500 ILS
  • Demolition of a cast-iron riser or complex section — quoted separately
  • Waste removal and disposal — often priced separately

FAQ

Can the old sewer line be removed and the openings left exposed until the next stage?

Only for a short time and only with reliable plugs. An open riser or outlet quickly fills the space with odour and creates spill risk if somebody uses plumbing higher up the system.

Do neighbours need to be warned when a riser is being demolished?

Yes, absolutely. If the works involve a shared vertical stack, all residents on that stack need to know the shutdown window and must not use the drains during the works.

Which is more expensive — demolition or installation of the new system?

Usually the installation is more expensive. But on difficult jobs, demolition can consume a substantial part of the budget, especially with cast iron, screed or yard concrete.