Cast iron was prized for strength and quiet operation, and remains common in older commercial buildings and units. Its enemy is corrosion: the internal bore rusts and scales, roughening and narrowing until flow suffers, while walls thin from the inside out.
Descaling can restore the bore, and relining then protects the remaining wall — often the only practical fix for cast iron buried in concrete slabs.
The historical standard for in-building and in-slab sanitary drainage.
Pre-1970s houses, apartment stacks and commercial buildings, often within slabs.
A CCTV drain inspection is the standard way to confirm whether this is what's happening in your pipes: the camera shows the condition on screen, a locator pinpoints the exact position and depth, and you get a recorded report before any repair decisions are made.
A CCTV drain inspection shows exactly what's happening inside your pipes — no guesswork.