Steelwork
QA inspection checklist

Fabrication & Delivery

1. 1.

   Steel delivered matches approved fabrication drawings
   What to look forEach piece carries a unique mark cross-referenced to the GA and erection drawings. Section sizes, lengths, and hole patterns match the latest revision. Delivery note matches the loading list.
   Acceptable whenAll members must match the latest IFC fabrication drawings — no superseded revisions accepted. Length tolerance ±2 mm up to 10 m, ±3 mm over 10 m per BS EN 1090-2 EXC2.
   StandardBS EN 1090-2:2018 — Execution of steel structures, EXC2 (typical) or EXC3 (heavily loaded). NSSS 7th Edition — National Structural Steelwork Specification.
   Common defectsOld drawing revision used for fabrication — pieces no longer fitMember marks rubbed off or unreadable — cannot be cross-referencedWrong section size delivered (e.g. UB 305x102 instead of 305x127)Holes drilled in wrong position or to wrong diameterCamber missing on long-span beams where specified
2. 2.

   Mill certificates and CE/UKCA marking available
   What to look forEN 10204 type 3.1 inspection certificates traceable to heat number on each piece. CE/UKCA marking on the Declaration of Performance shows the fabricator's execution class. Certificates cover the actual cast/heat used, not just the grade.
   Acceptable whenAll structural steel must be supplied with EN 10204 3.1 certs. Fabricator must hold BS EN 1090-1 factory production control certificate. Execution class on DoP must match design (typically EXC2).
   StandardBS EN 1090-1:2009+A1:2011 — Conformity assessment requirements. BS EN 10204:2004 — Inspection documents. Construction Products Regulation (UK CPR).
   Common defectsType 2.2 certificates supplied where 3.1 specified — not traceable to castNo CE/UKCA mark — fabricator not 1090-1 certifiedCertificates cover wrong heat number — not the steel actually deliveredExecution class on DoP lower than design requires (EXC1 instead of EXC2)
3. 3.

   No visible damage, distortion, or defects
   What to look forSections straight on visual sighting. Flanges and webs without dents, gouges, or laminations. No twist along length. Edges of plates clean — no notches > 1 mm. No transit damage from chains or strops.
   Acceptable whenStraightness deviation ≤ L/1000 or 5 mm (whichever greater). No notches, gouges, or arc strikes deeper than 0.5 mm. No surface laminations exposed.
   StandardBS EN 1090-2:2018 Section 6 — Geometrical tolerances. BS EN 10034 — Structural section dimensional tolerances.
   Common defectsBowed beams from poor stillage during transitTwist in long members — most visible when sat on flat groundChain or strop damage to flanges — gouges or paint lossArc strikes from temporary tacking left in placeLamination on plate edges — sign of poor parent material
4. 4.

   Protective coating / primer intact
   What to look forEven coating colour with no rust bloom showing through. DFT readings consistent across the member. Edges and corners covered (often the failure point). No mechanical damage from handling.
   Acceptable whenDFT must meet specification per coat — typical shop primer 75 μm, intermediate 100 μm, topcoat 50 μm. Edges within 90% of nominal DFT. Surface free of rust to Sa 2½ before coating per ISO 8501-1.
   StandardBS EN ISO 12944-5:2018 — Protective paint systems. BS EN ISO 8501-1 — Surface preparation grades. BS EN ISO 19840 — DFT measurement.
   Common defectsRust bloom showing through primer — substrate was not Sa 2½Thin DFT on edges and corners — applicator missed first stripe coatSolvent boiling / pinholes in coating from over-thick applicationCoating damage from chains, slings, or stillage contactMill scale not removed before priming — coating will delaminate
5. 5.

   Member identification marks match drawing references
   What to look forHard stamp or paint mark visible on each piece, located where it remains visible after erection. Marks match the erection drawing piece list exactly. Mark format consistent (e.g. B1/01, C2/03).
   Acceptable whenEvery member must carry a unique mark per BS EN 1090-2 cl.6.2. Mark must remain legible after coating and erection. Marking location should not coincide with welded zones unless permitted.
   StandardBS EN 1090-2:2018 cl.6.2 — Identification, inspection and traceability. NSSS Section 5.5.
   Common defectsHard stamp obliterated by intumescent or topcoatTwo pieces with the same mark on siteMark on the wrong face — invisible after erectionMark does not match piece (admin error at fabrication)

Erection & Alignment

1. 6.

   Erected to correct sequence per method statement
   What to look forErection sequence matches the temporary works design. Bracing follows immediately behind erected frames. No more than the designed unbraced bays open at any time. Lifting plan reflects current site conditions.
   Acceptable whenSequence as agreed in approved temporary works design. No member to be released from crane until permanent or temporary bracing has been fitted in accordance with the erection method statement.
   StandardBS EN 1090-2:2018 cl.9 — Erection. BS 5975:2019 — Temporary works. SCI P391 — Structural steel erection.
   Common defectsBracing skipped to chase programme — frame unstableCrane lift sequence creates unbraced bays beyond designWind speed exceeds method statement limits — work continues regardlessErection mark sequence misread — pieces fitted out of order
2. 7.

   Column plumb check within tolerance

   Record: Deviation (mm)
   What to look forPlumb checked with theodolite or laser plumb in two orthogonal directions, near the top of column before next lift. Holding-down bolts not over-stressed by alignment shimming. Lean is consistent and not concentrated at one floor.
   Acceptable whenColumn verticality per BS EN 1090-2 Annex D.2.20: max(h/500, 5 mm) per storey, and max(h/1000, 50 mm) for full building height. NSSS allows ±10 mm at column splices over a single storey of typical 4 m.
   StandardBS EN 1090-2:2018 Annex D.2.20. NSSS 7th Edition cl.9.6 — Erection tolerances.
   Common defectsOut-of-plumb in one direction across multiple columns — base setting-out errorColumn leans because base shims not tight before groutingPlumb measured before bolt-up complete — connection slip changes alignmentCumulative lean over 4+ storeys exceeds h/1000
3. 8.

   Beam level check within tolerance

   Record: Deviation (mm)
   What to look forTop of steel level checked with rotary laser or precise level at both ends and mid-span. Camber accounted for if specified — beam will appear high in the middle when first set. Levels checked after self-weight only, before composite loading.
   Acceptable whenLevel of beam ends ±10 mm from theoretical position per NSSS. Difference in level across paired beams ±5 mm. Camber tolerance ±10 mm or L/500 for spans > 5 m.
   StandardBS EN 1090-2:2018 Annex D.2.19. NSSS 7th Edition cl.9.6.
   Common defectsBeam set high or low because column splice shim depth incorrectCamber lost — beam fabricated straight when camber was specifiedLevels checked too early, before all dead load appliedDifferential settlement of crane mats during erection
4. 9.

   Temporary bracing installed as per design
   What to look forTemporary bracing matches the temporary works engineer's drawings. Connections to structure are bolted (not just clamped). Bracing follows the erection sequence — never trailing more than designed.
   Acceptable whenTemporary bracing must remain in place until permanent bracing, slabs, or shear connections provide stability. Removal only with written permit from temporary works coordinator (TWC).
   StandardBS 5975:2019 — Temporary works procedural control. SCI P391. CDM Regulations 2015.
   Common defectsTemporary bracing removed before permanent stability achievedBracing tied off with chains/wire instead of bolted connectionsBracing capacity inadequate for wind load on partial frameTWC permit-to-remove process not followed
5. 10.

   Base plates level and grouted correctly
   What to look forBase plate sat on shims or levelling nuts, grout poured underneath with no voids. Grout flows out around full perimeter. Air vents in larger plates show grout has reached centre. Holding-down bolts torqued only after grout has cured.
   Acceptable whenBase plate level ±3 mm to design level per NSSS. Non-shrink grout to BS EN 1504-6 with strength ≥ 60 N/mm² unless specified higher. Minimum grout thickness typically 25 mm. Grout must reach minimum strength before column is loaded.
   StandardBS EN 1504-6:2006 — Anchoring of reinforcing steel bar. NSSS cl.9.7. SCI P398 — Joints in steel construction: simple joints to Eurocode 3.
   Common defectsVoids under base plate — grout dropped from one side and did not flow throughWrong grout used — general mortar instead of non-shrink cementitiousHolding-down bolts torqued before grout cured — bolt damageBase plate not level — shims used instead of levelling nuts on heavy columnsNo vent hole on large base plates — air pocket in centre

Connections

1. 11.

   Bolted connections complete — correct grade and size
   What to look forBolt head markings show grade (8.8 or 10.9) and manufacturer. Length protrudes 1-3 threads beyond nut. Washers used both sides for HSFG. Connection square — no taper between plies.
   Acceptable whenBolts to BS EN 14399 (HSFG) or BS EN 15048 (non-preloaded). Minimum protrusion: 1 full thread beyond nut. Washer under turned element. Connection plies in tight contact — gap < 2 mm allowed only with packs.
   StandardBS EN 14399-3/4/6 — High-strength preloaded bolting. BS EN 15048-1 — Non-preloaded bolting. SCI P358 — Joints in steel construction.
   Common defectsGrade 8.8 used where 10.9 specified — visible from head markingBolt too short — no threads showing past nutBolt too long — fouls adjacent steelwork or excessive protrusionMissing washers under HSFG turned elementHoles drifted oversize because misalignment — ream not permitted
2. 12.

   Bolts torqued / preloaded to specification

   Record: Torque (Nm)
   What to look forCalibrated torque wrench used (calibration cert in date). Bolt and nut marked with paint pen after torquing to show completion. Witness marks remain aligned. Connection square — no gaps between plies.
   Acceptable whenPretension to BS EN 14399-3: M16 grade 10.9 = 91 kN minimum, M20 = 142 kN, M24 = 205 kN, M30 = 326 kN. Torque values per manufacturer K-factor; typical M16: 200-275 Nm, M20: 400-550 Nm, M24: 700-950 Nm. Combined method (torque + part-turn) is the typical UK practice.
   StandardBS EN 1090-2:2018 cl.8.5 — Tightening of preloaded bolts. BS EN 14399-3:2015. SCI P358.
   Common defectsNo paint witness mark — bolt may not have been torquedWitness marks rotated relative to nut — bolt has slipped, retorque requiredVisible gap between connected plies — re-torque or re-fit requiredWrong bolt grade or length used — typically too short on slip-resistant connectionsCalibration of torque wrench expired — readings unreliableLubrication on threads inconsistent with K-factor used
3. 13.

   Welded connections comply with approved WPS
   What to look forWelder qualification covers the process, position, and material thickness in use. WPS displayed at workstation. Run-on/run-off plates used on full-strength butt welds. Preheat applied where specified — temperature crayon evidence.
   Acceptable whenWelder qualified to BS EN ISO 9606-1 for material and position. WPS qualified by PQR per BS EN ISO 15614-1. Preheat per material thickness and grade — typically 50-100°C for thicker S355.
   StandardBS EN ISO 9606-1:2017 — Welder qualification. BS EN ISO 15614-1:2017 — WPS qualification. BS EN 1090-2:2018 cl.7 — Welding.
   Common defectsWelder qualification expired or wrong position (e.g. 1G qualified, doing 3G work)No preheat applied to thick S355 — risk of HAZ crackingWrong consumable used — basic vs rutile mismatch with WPSWPS nowhere on site — welder working from memory
4. 14.

   Weld visual inspection — no cracks, porosity, undercut
   What to look forWeld profile smooth and consistent — no overlap on toes. No visible cracks (transverse, longitudinal, or crater). No undercut at fusion line. Spatter cleaned. Weld size matches WPS — gauge measurement of fillets.
   Acceptable whenBS EN ISO 5817 quality level B (EXC3) or C (EXC2) — typical UK building. Undercut max 0.5 mm (level B) or 1.0 mm (level C). No cracks of any size permitted. Porosity max 4% projected area.
   StandardBS EN ISO 5817:2014 — Quality levels for welded joints. BS EN ISO 17637 — Visual inspection. BS EN 1090-2:2018 Table 17.
   Common defectsSurface cracking — visible with magnifier or dye penetrantUndercut at fillet weld toe — stress raiser, often near beam-column connectionsExcessive convexity on fillets — poor fusion at rootCrater cracks at run-stops — weld terminated without ramp-downLack of penetration on full-strength butt weldsSpatter not removed — masks underlying defects
5. 15.

   NDT reports available where required
   What to look forNDT scope matches the spec — typically a percentage of full-strength butt welds and critical fillet welds. Reports show technique, equipment, operator (PCN level 2 minimum), and accept/reject criteria. Defects cross-referenced to weld map.
   Acceptable whenNDT extent per BS EN 1090-2 Table 24: EXC2 typically 10-20% of butt welds depending on stress utilisation; EXC3 typically 100%. Operators certified to BS EN ISO 9712 (PCN). Acceptance to ISO 5817 quality level matching execution class.
   StandardBS EN 1090-2:2018 Table 24 — NDT scope. BS EN ISO 17635 — NDT general rules. BS EN ISO 9712 — Operator certification.
   Common defectsNDT scope below specified percentage — cherry-picking weldsOperator certification expired or wrong sector (e.g. casting not welding)Reports lack reference to weld map — cannot trace defect to locationDefects above reject criteria left unrepairedWrong technique used (UT instead of RT for crack-sensitive locations)

Finishing & Handover

1. 16.

   Fire protection applied to specification
   What to look forIntumescent DFT measured at multiple points per member, recorded on a thickness map. Application has no orange-peel, blistering, or cracking. Top coat (where required) applied within overcoating window. Edges fully covered.
   Acceptable whenDFT to manufacturer's loading table for required fire rating (typically 30, 60, 90 minutes) at the member section factor (Hp/A). Tolerance 80% nominal at any single reading; mean ≥ 100%. Surface temperature within product's application window.
   StandardBS 476-21/22 or BS EN 13381-8 — Fire test methods for protection of steel. ASFP Yellow Book. Manufacturer's data sheet and assessment report.
   Common defectsDFT below 80% minimum on flange edges or web junctionWrong fire rating applied — 60 min product on 90 min memberSection factor (Hp/A) miscalculated — DFT inadequateNo top seal coat where exposed to weather or wet areasCracking after curing — substrate temperature too high during application
2. 17.

   Touch-up paint applied to site welds and damage
   What to look forSite welds and damaged areas wire-brushed to St3 minimum, primed and topcoated to system spec. Patches feathered into surrounding paint — no hard edges. DFT comparable to factory coating.
   Acceptable whenSurface preparation to ISO 8501-1 St2/St3 (power tool cleaned). Repair coating system matches original specification. DFT within 80% of factory build-up. Overlap onto sound paint by minimum 50 mm.
   StandardBS EN ISO 12944-5:2018. ISO 8501-2 — Preparation grades for previously painted surfaces.
   Common defectsTouch-up paint applied over loose mill scale or rust — early failureWrong paint product used — incompatible with factory coatingPatches too thin — colour mismatch and inadequate film buildSite welds left untreated — first failure point in 5 years
3. 18.

   Snag list items addressed
   What to look forSnag register cross-referenced to drawings and member marks. Each item signed off with date, person, and remedial action. Re-inspection record available. No items left "open" without target close-out date.
   Acceptable whenAll snags categorised (cosmetic / structural / safety). Structural and safety items closed before handover. Cosmetic items may have agreed close-out programme.
   StandardBS EN 1090-2:2018 cl.12 — Inspection and corrective action. Project-specific QA plan.
   Common defectsSnags closed without re-inspectionItems moved to "next phase" indefinitelyNo photographic evidence of remediationStructural snags reclassified as cosmetic to permit handover
4. 19.

   As-built survey completed
   What to look forSurvey covers column positions, levels at each floor, plumb of risers, and key setting-out points for follow-on trades. Carried out by independent surveyor. Results compared to design tolerances and signed off.
   Acceptable whenSurvey to confirm all geometry within BS EN 1090-2 Annex D tolerances. Reported deviations annotated on as-built drawings. Where exceeded, agreed remedial action with designer.
   StandardBS EN 1090-2:2018 Annex D — Geometrical tolerances. RICS surveying guidance.
   Common defectsSurvey limited to grid lines — does not cover floor levels or risersSurveyor used setting-out grid that drifted from original controlOut-of-tolerance items not flagged on as-builtNo record of base setting-out for follow-on slab/cladding works
5. 20.

   Handover documentation complete
   What to look forPack includes: mill certs, weld procedure & welder quals, NDT reports, bolt torque records, fire protection thickness records, paint DFT records, as-built drawings, snag close-out, declaration of performance.
   Acceptable whenHandover dossier per CDM 2015 Health & Safety File requirements. Steelwork-specific contents per BS EN 1090-2 cl.12 inspection records. Fire protection records per ASFP guidance and Building Regulations.
   StandardCDM Regulations 2015 — Health and Safety File. BS EN 1090-2:2018 cl.12. ASFP Yellow Book.
   Common defectsMill certs missing for late-replacement piecesWelder qualifications expired during the worksNo fire protection thickness records — only product certificateAs-built drawings not updated to reflect site changes

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