Steel Structure Inspection

Per CSA S16 Clause 5 and CSA G40.20/G40.21, all structural steel must meet the specified grade (e.g., 300W, 350W, 350WT for low-temperature applications). Mill test certificates must accompany all steel deliveries and must report chemical composition, yield strength, tensile strength, and elongation. Steel for seismic applications must meet CSA S16 Clause 27 supplementary requirements.

1. Verify mill test certificates are provided for all structural steel members and confirm grade matches design drawings (e.g., CSA G40.21 350W)

2. Check that yield and tensile strength values on mill certificates meet minimum requirements for the specified grade

3. Confirm heat numbers on steel members correspond to mill test certificates for traceability

4. Verify Charpy V-notch (CVN) impact test results are provided for steel designated as notch-tough (WT grades) per CSA G40.21

5. Check that steel plates and sections are free of visible defects such as laminations, seams, or excessive mill scale

- Mill certificates missing or not matched to delivered steel members

- Incorrect steel grade delivered (e.g., 300W instead of specified 350W)

- CVN impact test results not provided for WT-grade steel required in low-temperature applications

- Surface defects in steel not identified before fabrication

Per CSA S16 Clause 28, fabrication must conform to approved shop drawings and meet dimensional tolerances specified in CISC/AISC Code of Standard Practice. Members must be fabricated to correct length, camber, and profile. Bolt holes must be drilled or punched to the correct diameter per CSA S16 Clause 22. Cutting must produce clean, smooth edges free of notches.

1. Verify shop drawings are stamped approved by the engineer of record before fabrication proceeds

2. Check member lengths, depths, and profiles against shop drawings within CSA S16 fabrication tolerances

3. Confirm bolt hole diameters match specified bolt size plus the standard oversize per CSA S16 Clause 22.3 (typically 2 mm oversize)

4. Verify specified camber is built into beams and trusses per shop drawing requirements

5. Check that all cut edges are clean, free of notches, and comply with surface roughness requirements

- Fabrication proceeding on unapproved or superseded shop drawings

- Bolt holes punched oversize or out of position preventing proper fit-up

- Required camber not built into long-span beams leading to visible sag

- Flame-cut edges with gouges or notches creating stress concentrations

Per CSA W59 and CSA W47.1, all welding must be performed by certified welders employed by a CSA W47.1 certified company. Weld procedures must be pre-qualified or qualified per CSA W59 Clause 5. Fillet welds must meet minimum size per CSA S16 Table 4 and CSA W59 requirements. Complete and partial joint penetration groove welds must meet the acceptance criteria in CSA W59 Clause 12.

1. Verify the fabricator holds current CSA W47.1 certification and all welders have valid CWB qualifications for the weld positions and processes used

2. Confirm welding procedure specifications (WPS) are available on site and match CSA W59 pre-qualified or qualified procedures

3. Inspect fillet weld size using a fillet weld gauge and confirm minimum leg size per CSA S16 Table 4

4. Check for visible weld defects: undercut, porosity, incomplete fusion, cracks, and excessive reinforcement per CSA W59 Clause 12

5. Verify non-destructive testing (NDT) has been performed per the inspection plan (UT, MPI, or RT as specified)

- Welders without valid CWB certification for the required weld position or process

- Fillet welds undersized or with excessive convexity reducing effective throat

- Undercut exceeding CSA W59 limits at critical connections

- NDT not performed on specified percentage of welds before members are concealed

Per CSA S16 Clause 23, high-strength bolts (ASTM A325M or A490M) must be installed to the required pretension using turn-of-nut, calibrated wrench, twist-off bolt, or direct tension indicator methods. Slip-critical connections require faying surfaces to meet specified slip resistance classification per CSA S16 Clause 23.4. Snug-tight connections must have all plies in firm contact.

1. Verify bolt grade (A325M or A490M) matches specification and bolts are marked with correct identification

2. Confirm pretensioning method is being used per CSA S16 Clause 23.7 and daily calibration of equipment is documented

3. Check that washers are installed in the correct position per CSA S16 requirements (hardened washer under turned element)

4. Verify slip-critical connection faying surfaces are clean, free of paint (unless approved), and meet the specified slip coefficient

5. Inspect for full bolt engagement with a minimum of one full thread visible beyond the nut

- Bolts not pretensioned in slip-critical connections, installed only snug-tight

- Faying surfaces contaminated with paint, oil, or dirt reducing slip resistance

- Incorrect bolt grade installed (A325M used where A490M is specified)

- Turn-of-nut rotation insufficient or not verified with a calibrated wrench

Per CSA S16 Clause 28.7, erected steel must be plumb, level, and aligned within the tolerances specified in CSA S16 and the CISC Code of Standard Practice. Column plumbness must not deviate more than 1:500 of the storey height. Beam and girder elevations must be within specified tolerances. Temporary bracing must be maintained until permanent bracing or floor diaphragms are in place.

1. Verify column plumbness using a transit or total station and confirm deviation does not exceed 1:500 of storey height per CSA S16

2. Check beam elevations and bearing seats against design levels within specified tolerances

3. Confirm all temporary bracing and guy wires are in place per the erection plan until permanent lateral bracing is installed

4. Verify anchor bolt locations, projection, and nut tightening against base plate details on shop drawings

5. Check that column base plate grout is placed and cured per specification before removal of erection loads from shims

- Columns out of plumb beyond tolerance due to anchor bolt misalignment

- Temporary bracing removed prematurely before permanent bracing or diaphragm is in place

- Base plate grout not placed leading to point loading on levelling shims

- Beam-to-column connections not fully bolted during erection creating instability

Per CSA S16 Clause 25, steel surfaces must be prepared and coated per the contract documents. Surface preparation must conform to SSPC/NACE standards (e.g., SSPC-SP6 commercial blast or SSPC-SP10 near-white blast). Coating systems must achieve specified dry film thickness (DFT). Galvanizing, when specified, must conform to CAN/CSA-G164 (Hot Dip Galvanizing of Irregularly Shaped Articles) or CSA G189 (Sprayed Metal Coatings).

1. Verify surface preparation grade meets specification (SSPC-SP6, SP10, or SP5) using visual comparators

2. Measure dry film thickness of each coat using a calibrated magnetic or eddy current gauge

3. Check for holidays, pinholes, runs, and sags in the coating system using holiday detection equipment where specified

4. Verify touch-up of field connections, damaged areas, and bolt heads is completed with compatible coating

5. Confirm galvanized surfaces (where specified) meet minimum coating thickness per CAN/CSA-G164

- Surface preparation inadequate leading to premature coating failure and corrosion

- Dry film thickness below minimum specification on complex profiles and edges

- Field welds and bolted connections not touched up leaving unprotected steel

- Coating applied outside acceptable temperature and humidity ranges per manufacturer's data

Per NBC Part 3 (Fire Protection, Occupant Safety and Accessibility) and NBC 3.2.2, structural steel members must be protected to achieve the fire resistance rating specified for the building. Sprayed fire-resistive materials (SFRM) must be applied to the required thickness per ULC listings. Intumescent coatings must be applied per manufacturer's certification. Fire protection must not be penetrated or damaged by subsequent trades.

1. Verify the fire resistance rating required for each structural member per NBC Part 3 and the building's fire safety design

2. Measure SFRM thickness using a depth gauge at multiple points per the ULC-listed assembly and confirm minimum and average thickness requirements

3. Check SFRM adhesion by applying moderate hand pressure to verify bonding to steel substrate

4. Verify intumescent coating dry film thickness where used and confirm product is listed for the application

5. Confirm fireproofing is continuous with no gaps, missing coverage, or damage from mechanical, electrical, or other trades

- SFRM thickness below ULC-listed minimum due to insufficient application or over-trimming

- Fireproofing damaged or removed by subsequent trades and not repaired

- SFRM applied to contaminated or oily steel surfaces resulting in poor adhesion

- Gaps in fireproofing at connections, hangers, and penetrations through steel members