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Plinth Filling Verification Checklist

Essential Checklist+

Complete these critical checks before approving the work or proceeding to the next construction stage.

✓12 Inspection Points
✓5 Verification Categories
✓Footprint & Formation Verification+
  • Plinth footprint length and width used match the architectural/foundation drawing, not assumed round numbers.
  • Formation level (base of fill) is cleared of organic matter, debris, and standing water before fill placement begins.
  • Foundation trenches and plinth beam are fully cured and backfilled at the sides before internal plinth filling starts, so the fill has lateral support.
✓Fill Material & Compaction+
  • Fill material matches what's specified/available on site (soil, murram, sand, or hardcore), not just whichever default was left selected.
  • Fill is placed and compacted in thin layers (commonly 150-250 mm loose per lift), not dumped and compacted in one thick layer.
  • Fill material is free of large debris, construction waste, or oversized boulders that would leave voids under the PCC bed.
✓PCC Bed+
  • PCC mix ratio and thickness match the project specification.
  • PCC is placed only after the fill below has been tested/confirmed as adequately compacted, not poured on a freshly dumped, unconsolidated layer.
✓DPM Installation+
  • DPM gauge/thickness meets the project specification (commonly 300 micron / 1200 gauge minimum).
  • Sheets are lapped by at least the specified minimum (commonly 150mm) at every joint, and joints are sealed.
  • DPM turns up at the perimeter walls to link with the wall damp-proof course, not left flat and stopping short at the wall face.
✓Final Check+
  • No settlement, soft spots, or hollow sound is detected when walking the compacted fill surface before the PCC bed is poured over it.
Full QC Checklist+

Verify footprint/formation, fill material and compaction, PCC bed, DPM installation, and final check.

✓24 Inspection Points
✓5 Verification Categories
✓Footprint & Formation Verification+
  • Plinth footprint length and width used match the architectural/foundation drawing, not assumed round numbers.
  • Formation level (base of fill) is cleared of organic matter, debris, and standing water before fill placement begins.
  • Fill depth used matches the actual difference between formation level and the underside of the planned PCC bed.
  • Foundation trenches and plinth beam are fully cured and backfilled at the sides before internal plinth filling starts, so the fill has lateral support.
  • Termite/soil poison treatment is applied to the formation level before fill placement, where specified, since it can't be added once fill covers it.
✓Fill Material & Compaction+
  • Fill material matches what's specified/available on site (soil, murram, sand, or hardcore), not just whichever default was left selected.
  • Fill is placed and compacted in thin layers (commonly 150-250 mm loose per lift), not dumped and compacted in one thick layer.
  • Each layer is compacted to a firm, non-yielding surface (tested by walking over it or with a plate compactor pass) before the next layer is placed.
  • Fill is watered to near-optimum moisture content before compaction, since both bone-dry and waterlogged fill compact poorly.
  • Fill material is free of large debris, construction waste, or oversized boulders that would leave voids under the PCC bed.
  • Compaction near the plinth beam and column stubs is done with hand tampers, not heavy plate compactors, to avoid damaging or displacing them.
✓PCC Bed+
  • PCC mix ratio and thickness match the project specification.
  • PCC surface is level and reasonably smooth, since the DPM needs to lie on it without sharp projections that could puncture it.
  • PCC is placed only after the fill below has been tested/confirmed as adequately compacted, not poured on a freshly dumped, unconsolidated layer.
  • PCC bed is cured for the applicable minimum period before the DPM and floor slab load is placed on it.
✓DPM Installation+
  • DPM gauge/thickness meets the project specification (commonly 300 micron / 1200 gauge minimum).
  • Sheets are lapped by at least the specified minimum (commonly 150mm) at every joint, and joints are sealed.
  • DPM is free of tears or punctures before the floor slab/screed is poured over it.
  • DPM turns up at the perimeter walls to link with the wall damp-proof course, not left flat and stopping short at the wall face.
  • DPM is protected from damage by reinforcement fixing, foot traffic, or material stacking between installation and the floor slab pour.
✓Final Check+
  • Finished floor level (after slab/screed/flooring) lines up correctly with the plinth beam, door thresholds, and external ground level.
  • Total fill, PCC, and DPM material used is reconciled against this calculator's estimate before closing out the item in records.
  • No settlement, soft spots, or hollow sound is detected when walking the compacted fill surface before the PCC bed is poured over it.
  • Site is photographed at each stage (compacted fill, PCC bed, DPM laid) before it's covered by the next layer, for future reference.
Inspection Notes+
Use the latest approved drawings, specifications, and site measurements.
Complete all critical checks before proceeding to the next work stage.
Record deviations and confirm rectification where required.

Related Calculators & Guides

Plinth Filling CalculatorOpen the related calculator and verify the current project inputs.

FAQ

Use it after collecting the project inputs and again before approving or closing the relevant work stage.
No. It supports verification but does not replace approved drawings, specifications, codes, manufacturer requirements, or professional inspection.