What Are Pull Tests in NYC Construction?
A pull test—also called a proof load test or tension test—is a field procedure that applies a measured tension force to a post-installed anchor to verify it can safely carry its design load. In New York City, pull testing is a required quality assurance measure for numerous anchor applications, mandated by the NYC Building Code and DOB directives to protect workers, pedestrians, and building occupants.
The test is performed using calibrated hydraulic equipment. A jack positioned over the anchor applies an axial tensile load to a specified level, and the anchor must sustain that load without pulling out, fracturing, or causing distress in the surrounding substrate. A Licensed Professional Engineer oversees the testing and certifies whether each anchor passes or fails.
Why NYC Requires Pull Testing
Post-installed anchors—mechanical expansion anchors, adhesive anchors, undercut anchors, and threaded rod installations drilled into hardened concrete or masonry—behave differently from anchors cast in place. Their performance depends on:
- Substrate quality: Concrete or masonry that is cracked, honeycombed, or weaker than specified may not develop full anchor capacity
- Hole preparation: Inadequate cleaning of adhesive anchor holes is a leading cause of anchor failure
- Installation technique: Torque application, embedment depth, and edge distances directly affect performance
- Environmental conditions: Temperature affects adhesive anchor cure; sustained load affects creep
Because these variables cannot be fully captured through inspection alone, physical testing provides the most reliable confirmation that anchors will perform as designed.
When Pull Tests Are Required in NYC
Scaffold and Sidewalk Bridge Anchors — DOB Bulletin 2016-005
One of the most common pull testing requirements in NYC comes from DOB Bulletin 2016-005, which requires periodic load testing of scaffold tie anchors and sidewalk bridge anchors during installation and at regular intervals throughout the scaffold's service life.
Every active construction site with exterior scaffolding in New York City is subject to this requirement. The bulletin specifies:
- Test sampling rates for new anchor installations
- Load requirements based on the scaffold design
- Documentation and certification by a Licensed PE
- Periodic retesting during extended scaffold service
Non-compliance with Bulletin 2016-005 can result in Stop Work Orders from the DOB and creates significant liability exposure.
Facade and Curtain Wall Anchors
Post-installed anchors securing facade elements—cladding panels, curtain wall frames, stone veneer, brick ties, and architectural metals—must often be pull tested as part of the installation verification program. Facade anchor failures can cause panels or cladding to detach and fall, creating public safety hazards.
The testing program for facade anchors is typically specified by the facade designer or engineer of record and may reference ASTM E488 or project-specific acceptance criteria.
Parapet Anchors and Tie-Backs
Parapets that have been remedially anchored to the building structure—using through-bolts, chemical anchors, or mechanical anchors drilled into the roof deck or structural frame—should be pull tested to verify the repair's adequacy. This is particularly relevant following Local Law 126 parapet assessments that identify anchorage deficiencies.
Mechanical and Structural Equipment Anchors
HVAC rooftop units, generators, elevator machinery, and structural steel connections made with post-installed anchors are candidates for pull testing when the engineer of record specifies load verification or when the substrate conditions are uncertain.
NYC Building Code BC 1704.32
The governing code provision for post-installed anchor special inspections is NYC Building Code BC 1704.32. This section requires special inspection of post-installed mechanical and adhesive anchors, which includes both visual inspection of installation and proof load testing when specified by the engineer of record.
The Pull Test Procedure — Step by Step
Pre-Test Engineering Review
Before any testing begins, the Licensed PE reviews the project documents to establish:
- The design load for each anchor type and installation condition
- The test load — typically expressed as a percentage of the design load. Common values range from 1.0x to 2.0x the design load depending on the application
- The number of anchors to be tested (sampling rate)
- The required hold time — how long the anchor must sustain the test load, typically 1–5 minutes
- Acceptance criteria — what constitutes a pass
Equipment Calibration
Testing equipment consists of a calibrated hydraulic jack, a reaction frame, and a pressure gauge or load cell. The equipment must be calibrated by an accredited metrology laboratory, and calibration records must be current. Uncalibrated equipment produces unreliable results that lack legal defensibility.
Anchor Identification and Documentation
Each anchor to be tested is identified and its location recorded. Pre-test documentation includes:
- Anchor manufacturer and model
- Nominal diameter and specified embedment depth
- Substrate material (concrete or masonry) and compressive strength, if known
- Installation date and installer
- Any notable installation conditions
Load Application
The jack is positioned coaxially over the anchor and the load is applied gradually, typically in increments. The PE observes:
- Displacement: Any movement of the anchor or surrounding substrate
- Cracking: Radial or circumferential cracking in the substrate
- Gauge behavior: Whether load holds steadily or drops, indicating slippage
If the anchor sustains the full test load for the specified hold time with displacement within allowable limits, it passes.
Pass/Fail Criteria
A pull test passes when:
- The anchor sustains the specified test load for the required hold time
- Measured displacement (if recorded) is within the acceptable range specified by the engineer
- No visible distress (cracking, concrete cone formation) is observed
A pull test fails when:
- The anchor pulls out of the substrate before reaching the test load
- The anchor sustains the load but with displacement exceeding allowable limits
- Substrate cone failure occurs
- load drops significantly during the hold period
Reporting and Certification
After testing is complete, the PE produces a certified test report for each anchor including:
- Anchor identification and location
- Applied test load and hold duration
- Observed displacement (if measured)
- Pass/fail determination
- The PE's seal and signature
What Happens When an Anchor Fails?
A failed anchor requires investigation and corrective action before the installation can be accepted. The PE evaluates:
Possible causes:
- Inadequate embedment depth (anchor too shallow)
- Incorrect hole preparation (debris, moisture in adhesive anchor holes)
- Compromised substrate (cracked, delaminated, or low-strength concrete)
- Wrong anchor type for the application
- Incorrect installation procedure
Corrective options:
- Remove and replace the anchor at the same location after remediation
- Relocate the anchor to an area with adequate substrate
- Add supplemental anchors to compensate for reduced capacity
- Redesign the anchor group with revised edge distances or embedment
The corrective approach must be reviewed and approved by the engineer of record before implementation. The replaced or relocated anchors are then retested.
Selecting a Pull Testing Engineer
For pull tests in New York City, work with a firm that:
- Holds a current Professional Engineer (PE) license in New York State
- Has specific, documented experience with ASTM E488 and DOB Bulletin 2016-005 protocols
- Owns or regularly uses calibrated hydraulic testing equipment with current calibration records
- Can provide detailed, PE-certified reports acceptable to the DOB
- Understands the full scope of NYC Building Code Chapter 17 requirements
Frequently Asked Questions
How long does a pull test take?
Individual anchor tests typically take 10–20 minutes inclusive of setup, loading, hold time, and documentation. A testing program covering many anchors may span a full day depending on quantity and site access.
What percentage of anchors need to be tested?
Sampling rates vary by application. DOB Bulletin 2016-005 specifies rates for scaffold anchors. For other applications, the engineer of record determines the sampling program. Common rates range from 10% to 100%.
Can we pull test adhesive anchors immediately after installation?
No. Adhesive anchors must cure to full strength before testing. The required cure time depends on the adhesive product, temperature, and substrate conditions — the manufacturer's published cure schedule governs. Testing before full cure will produce unreliable results.
Does a passing pull test guarantee long-term anchor performance?
A passing pull test confirms the anchor develops the required capacity at the time of testing. It does not guarantee performance over the entire service life. Anchors in aggressive environments, subject to sustained loads, or exposed to chemical attack should be evaluated periodically.
Who pays for pull testing on a construction project?
Responsibility for testing costs is typically defined in the project contracts. In most NYC projects, the building owner or general contractor retains the testing engineer directly or through the special inspection agency.
