TR-1 Structural Steel Erecting and Bolting
1704.3.2 Details. The special inspector shall perform an inspection of the steel frame to verify compliance with the details shown on the approved construction documents, such as bracing, stiffening, member locations and proper application of joint details at each connection, including connections designed for seismic effects.
1704.3.3 High-strength bolts. Installation of high-strength bolts shall be inspected in accordance with this section.
1704.3.3.1 General. While the work is in progress, the special inspector shall determine that the requirements for bolts, nuts, washers and paint; bolted parts and installation and tightening in such standards are met. For bolts requiring pretensioning, the special inspector shall observe the preinstallation testing and calibration procedures when such procedures are required by the installation method or by project plans or specifications; determine that all plies of connected materials have been drawn together and properly snugged and monitor the installation of bolts to verify that the selected procedure for installation is properly used to tighten bolts. For joints required to be tightened only to the snug-tight condition, the special inspector need only verify that the connected materials have been drawn together and properly snugged.
1704.3.3.2 Periodic monitoring. Monitoring of bolt installation for pretensioning is permitted to be performed on a periodic basis when using the turn-of-nut method with matchmarking techniques, the direct tension indicator method or the alternate design fastener (twist-off bolt) method. Joints designated as snug tight need be inspected only on a periodic basis.
1704.3.3.3 Continuous monitoring. Monitoring of bolt installation for pretensioning using the calibrated wrench method or the turn-of-nut method without matchmarking shall be performed on a continuous basis.
Details
SIGN-ON / Inspect / SIGN-OFF (package)What Structural Steel Special Inspection Looks
On a busy New York City high-rise construction site, structural steel erection can advance several floors per week. EZTR1's certified special inspectors are on the steel deck alongside the ironworkers — verifying each bolted connection as it is assembled, before the work is covered by the next floor or fireproofing is applied.
Typical NYC projects that require this inspection:
- High-rise residential towers in Manhattan, Long Island City, and Downtown Brooklyn — where moment frames, braced frames, and composite floor systems require continuous or periodic bolt monitoring
- Mixed-use commercial/residential buildings (5–40+ stories) subject to NYC BC Chapter 17 special inspection requirements from the first structural steel connection
- Additions and structural steel transfers in existing buildings — including cantilever additions and steel moment frame insertions in landmarked buildings
Why it matters: An improperly pretensioned high-strength bolt can slip under wind or seismic load, potentially causing a joint to lose its designed stiffness. NYC's seismic design requirements mean that many steel connections must be verified as fully pretensioned — not just snug-tight — before the structure is loaded.
EZTR1's Inspector Qualifications
EZTR1's structural steel special inspectors hold ICC Special Inspector certifications for structural steel and are registered with the NYC Department of Buildings as qualified special inspection agencies under 1 RCNY § 101-06. Every inspection report is prepared, signed, and submitted directly to the DOB.
Ready to schedule your structural steel special
inspection? Contact EZTR1 to confirm availability for your project's erection schedule.