What scaling looks like on camera
Instead of a smooth wall you see a rough, rusted, layered surface that catches everything passing through it. The pipe is still structurally there, but its usable diameter is gone and every flush drags against it.
Cabling versus descaling
A cable slides right over scale and changes nothing. Descaling with a chain knocker removes the buildup and returns the pipe to something close to its original bore.
When cast iron is genuinely done
If the bottom of the pipe has rusted through into the soil, cleaning is no longer the answer and we will show you that on the footage rather than sell another cleaning.

