Pipe Cover Checker

Cover over a buried pipe from surface and invert levels, checked against a minimum.

Inputs

Results

Surface RL	m Finished surface level over the pipe
Invert RL	m Inside bottom (invert) of the pipe
Pipe size given as
Outside diameter (OD)	mm
Internal diameter (ID)	mm
Wall thickness	mm OD = ID + 2 × wall
Minimum cover required	m Indicative only — use your authority's value

Obvert (top of pipe) RL	—
Cover	—
Check vs minimum	—

How cover is worked out

Obvert RL = Invert RL + OD · Cover = Surface RL − Obvert RL. Cover is measured to the outside top (obvert) of the pipe, so pipe wall thickness matters — enter the outside diameter, or an internal diameter plus wall thickness (OD = ID + 2 × wall). A negative cover means the pipe obvert sits above the surface — check your levels.

Situation (indicative)	Typical minimum cover
Not subject to vehicle loading	~0.45–0.60 m
Under roads / trafficable areas	~0.60–0.75 m

Important: Minimum cover depends on pipe class, material, bedding, loading and the relevant authority — SEQ Water Supply & Sewerage Design and Construction Code (SEQ D&C Code), QUDM, council standards and the pipe manufacturer all govern. The preset values above are a rough guide, not a compliance figure. For reference and checking only — verify with a qualified engineer.

References

Cover = ground level − obvert level is standard drainage/utility practice (e.g. QUDM; SEQ Design and Construction Code). Minimum-cover figures vary by authority and loading case — confirm against the current SEQ D&C Code, the relevant council standard drawings, and the pipe manufacturer's installation limits for the specific pipe class.