Foundations Inspection Checklist

Check trench dimensions match structural engineer drawings (depth, width, steps)

Confirm formation level is clean, firm and free of loose material or standing water

Verify steel reinforcement placement, laps, cover and spacer positions

Check concrete specification (mix, slump, sulphate class) matches design requirements

Inspect step positions, depths and overlap against NHBC Chapter 4.4 guidance

Confirm radon barrier / DPM installed correctly with sealed laps and no punctures

Verify drainage pipes passing through foundations are correctly sleeved with flexible joints

Check foundation bolts / starter bars / holding-down straps positioned per design

Confirm trench fill concrete level is within 150mm of finished ground level (or as designed)

Verify cavity tray / DPC at base of cavity is correctly positioned and lapped

Check piling mat or raft slab reinforcement layout matches engineer specification

Inspect ground beam dimensions, reinforcement and bearing onto pile caps

Confirm any retaining wall design and waterproofing matches structural engineer details

Verify service entries (gas, electric, water) are sleeved and sealed through foundation walls

Check substructure blockwork mortar joints are full, perpends filled and coursing level

Confirm weep holes are present at base of external leaf above DPC

Verify ground levels and falls away from the building for surface water drainage

Check any engineered fill or compaction test certificates are available on site

Inspect DPM overlaps are correctly taped and dressed up inner leaf to meet floor DPC

Confirm building control / warranty provider sign-off of excavation before concrete pour