The invert is the internal bottom of a pipe or channel. When drainers set out a new drain, they calculate invert levels at each end to guarantee the pipe falls continuously towards its outlet.
Council drainage plans record invert depths at connection points, which is how a drainer knows how deep to dig before a new connection is made.
Provides the reference level for setting pipe gradients and connection depths.
Used on drainage plans, in trenches during installation, and when comparing pipe depths.
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.