Safety Critical · 12 checks

Scaffolding Inspection
QA inspection checklist

Scaffolding inspection quality audit.

Every check below carries what good looks like, when it passes, the standard it comes from and the defects that usually fail it. That guidance is what turns a tick-box into an inspection.

Foundations & Standards

  1. 1.
    Base plates on firm, level ground
    What to look forEach standard rests on a base plate (with adjustable jack if needed) on firm, level ground. No standards on soft ground without sole board. Base plate properly seated — not propped up on rubble. Slope corrected with adjustable jack, not with packers.
    Acceptable whenPer TG20:21 / NASC SG4: base plate on firm bearing surface; sole board (timber 220 × 35 mm minimum) under base plate on soft ground; standards plumb on level base.
    StandardNASC TG20:21 — Tube and fitting scaffolds. NASC SG4:22 — Preventing falls in scaffolding operations. BS EN 12811-1 (performance requirements).
    Common defectsBase plate on uncompacted soil — sinks under loadStandards on packers / wood blocks — unstableNo sole boards on soft groundAdjustable jack at maximum — unstableBase plate at edge of slab / formation
  2. 2.
    Standards plumb
    What to look forStandards plumb in two directions checked with spirit level. Variation < 25 mm in 3 m. No leaning columns. Adjustable jacks set to even out building / ground variation.
    Acceptable whenPer TG20:21 / NASC SG4: standards plumb within ±25 mm in 3 m. No "leaning" assemblies — significant out-of-plumb requires re-erection.
    StandardNASC TG20:21. NASC SG4:22. BS EN 12811-1.
    Common defectsStandards leaning — load not vertical, instabilityOut of plumb visible from groundAdjustable jacks not used to correct ground irregularityCompound from multiple lifts magnifies leanNo plumb check at completion
  3. 3.
    Sole boards where required
    What to look forSole boards (timber 220 × 35 mm minimum) under base plates on soft ground (clay, fill, gravel). Boards span at least two standards. Boards in good condition — no rot, splits, or missing.
    Acceptable whenPer TG20:21 / NASC SG4: sole board minimum 220 × 35 mm timber on softer than concrete substrate; spans 2 standards or 600 mm minimum each side.
    StandardNASC TG20:21. NASC SG4:22.
    Common defectsNo sole board on soft groundSole board too narrow / shortRotted timber soleSole board off-line under base plateSpans only one standard
  4. 4.
    Ties at correct positions per design
    What to look forTies to building at design centres (typically every 4 m vertical, every other lift; horizontal centres per design). Tie type per design (through-tie, box-tie, lip-tie, anchor-tie). Anchors load-tested at random points.
    Acceptable whenPer TG20:21 / NASC SG28: tie pattern per design (typically 4 m centres vertical, 6 m horizontal); pull-out tests on 3 + 1 in 20 anchor ties; standard records in Section 5 of the design.
    StandardNASC TG20:21. NASC SG28:22 — Anchorages. BS EN 12811-1.
    Common defectsTie missing where design requiresAnchor pull-out test not doneWrong tie type (lip-tie used where load demands box-tie)Tie removed by trade and not reinstatedCompound deviation from design — instability

Platforms & Access

  1. 5.
    Full boarding — no gaps > 25mm
    What to look forWorking platform fully boarded — typically 5-board access platform (1.0 m wide), 4-board for narrow scaffolds. Boards sound, no splits or rot. Gaps between boards ≤ 25 mm. Boards not over-hanging > 4× thickness.
    Acceptable whenPer TG20:21 / NASC SG4 / Working at Height Regulations 2005: gap between boards ≤ 25 mm; gap to building ≤ 300 mm; full board width per work activity (5-board for masonry, 4-board minimum for inspection).
    StandardNASC TG20:21. NASC SG4:22. Work at Height Regulations 2005.
    Common defectsGap > 25 mm between boards — falling object riskGap > 300 mm to building — fall riskSingle board missing — fall throughCracked / split boardOver-hang > 4× thickness — see-saw
  2. 6.
    Double guardrails and toe boards in place
    What to look forTop guardrail at 950-1100 mm above platform; intermediate guardrail mid-height. Toe board ≥ 150 mm. All sides of working platform unless against the building. End-loops or stop-ends at platform ends.
    Acceptable whenPer Working at Height Regulations 2005 Schedule 2 / TG20:21: top guardrail 950-1100 mm; toe board ≥ 150 mm; gap between top and intermediate ≤ 470 mm. End closure where loading bay / drop.
    StandardWork at Height Regulations 2005 Schedule 2. NASC TG20:21.
    Common defectsTop guardrail < 950 mm — fall hazardNo intermediate rail — gap > 470 mmToe board missing — falling toolsEnd of platform openBuilding gap > 300 mm without inboard rail
  3. 7.
    Ladder access secured and extends 1m above platform
    What to look forLadder secured top and bottom (tied or stable foot). Extends 1 m above platform for hand-hold. Angle 75° (1:4 rise / run). Boards / rungs sound.
    Acceptable whenPer TG20:21 / Work at Height Regulations 2005: ladder angle 75° (1:4 rise:run); extends ≥ 1 m above platform; tied or footed; rungs sound; ladder beyond 9 m needs intermediate landing.
    StandardWork at Height Regulations 2005 Schedule 2. NASC TG20:21. BS EN 131 (ladders).
    Common defectsLadder not extended above — no hand-holdLadder unsecured — slips at topWrong angle (too steep / shallow)Ladder over 9 m without intermediate landingDamaged rungs
  4. 8.
    Loading bay gates operational
    What to look forLoading bay gates close fully, latch in place. No gaps when closed. Sized for material (typically pallet width 1.2 m). Gate above floor with toe board / kick rail. Material protected from falling.
    Acceptable whenPer TG20:21: loading bay gates self-closing or fitted with positive latch; opening width per use; safe boundaries above and below.
    StandardNASC TG20:21. Work at Height Regulations 2005.
    Common defectsGate does not close fullyNo latch — wind blows openGate width too narrow for palletToe board missing under gateMaterial above stacked higher than gate

General

  1. 9.
    Scaffold tag system current — green tag displayed
    What to look forScaffold tag (Scaftag or similar) at access point. Green tag = safe to use; signed by competent inspector. Inspection date within 7 days. No yellow / red tags. If tag missing, scaffold should not be used.
    Acceptable whenPer Work at Height Regulations 2005 reg 12 / NASC SG4: weekly inspection by competent person (CISRS Advanced Scaffolder Supervisor or equivalent); tag updated. After-event inspection (storm, alteration) before use.
    StandardWork at Height Regulations 2005 reg 12. NASC SG4:22. CISRS Card scheme.
    Common defectsTag overdue — > 7 days since last inspectionNo tag — scaffold cannot be usedTag signed by non-competent personYellow tag (incomplete) but in use anywayAfter-storm inspection not made
  2. 10.
    No damaged or bent tubes, fittings, or boards
    What to look forVisual inspection of every tube, coupler, and board. No bent / dented tubes. No corroded fittings — bright zinc or recent paint visible. No painted-over damage. Boards sound, no splits across grain.
    Acceptable whenPer TG20:21 / NASC SG6 (good practice): tubes straight, no kinks; couplers operate freely with full thread engagement; boards meet BS 2482 visual grade.
    StandardNASC TG20:21. NASC SG6:22 — Stripping and storing of scaffold materials. BS 2482:2009 (scaffold boards).
    Common defectsBent tube in compression — buckling under loadCoupler stripped thread — slipsPainted-over damage hiddenCracked board across grainRusted fittings — strength reduced
  3. 11.
    Sheeting/netting secure (if fitted)
    What to look forDebris netting / weather sheeting secured at all edges. Wind-loading per TG20 calculation. Tied to scaffold standards / ledgers — not to boards or guardrails. Eyelets in good condition. No tears > 100 mm.
    Acceptable whenPer TG20:21 / NASC SG18 (sheeted scaffolds): sheeting designed in for wind load; ties at ≤ 600 mm centres along edges; eyelet tears < 100 mm; sheeted scaffold has additional ties to building.
    StandardNASC TG20:21. NASC SG18:22 — Sheeted scaffolds.
    Common defectsSheeting partially torn — flaps in windTied to guardrail — load misdirectedNo additional ties — wind loads exceed standard tie designEyelets pulled throughSheet at gable end not stop-corded
  4. 12.
    Erected by CISRS-carded scaffolders
    What to look forErection team holds CISRS cards (Trainee, Scaffolder, or Advanced Scaffolder) appropriate to the scaffold type and complexity. Supervisor on site is CISRS Advanced + Supervisor card. Card details cross-checked.
    Acceptable whenPer CISRS scheme: Trainee can assist; Scaffolder can erect basic scaffolds; Advanced Scaffolder can erect complex / system scaffolds; Supervisor for sites > 5 scaffolders. Card valid date.
    StandardCISRS — Construction Industry Scaffolders Record Scheme. NASC SG4:22.
    Common defectsTrainee working unsupervisedCard expiredWrong card grade for complex scaffoldNo supervisor on siteSub-contractor cards not verified

Questions people ask

What is a scaffolding inspection QA inspection for?

To record that the work was checked against the specification before it was covered up or handed over: a pass or fail against each item, a measurement where one matters, and a photo where it failed. It is the evidence a client's quantity surveyor or clerk of works asks for, and the thing that settles the argument at final account.

What standards does this checklist check against?

Each item names its reference. On this checklist that includes NASC TG20:21, NASC TG20:21. NASC SG4:22. BS EN 12811-1., NASC TG20:21. NASC SG4:22., NASC TG20:21. NASC SG28:22, NASC TG20:21. NASC SG4:22. Work at Height Regulations 2005., Work at Height Regulations 2005 Schedule 2. NASC TG20:21.. The contract specification and the approved drawings always take precedence over a general standard; where they say something stricter, inspect to that.

Who signs a QA inspection off?

The person who carried out the check, named and dated, and where the contract calls for it the client's representative as a witness. The signature records that the check was done and what was found. It is not a warranty of the work.

How many items are on it, and do I have to use them all?

12 checks across 3 sections. Delete what does not apply to the job and add anything the specification asks for that is not here. A checklist that has plainly been thought about carries more weight than a long one nobody read.

Is this useful for a subcontractor as well as a main contractor?

More so. The subcontractor is the one who gets asked to come back and open something up. A signed inspection sheet with photos at the time is the cheapest insurance on a construction site.

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The same 12 checks, with the guidance a tap away, photos against each fail, measurements recorded, an NCR raised automatically and a branded PDF at the end. Signed on site. 14 days free.

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