1.2 Statement of Special Inspections, Continuous vs. Periodic Inspection
Key Takeaways
Where required, the permit applicant submits a Statement of Special Inspections (SSI) under IBC Section 1704.2.3. The registered design professional in responsible charge usually prepares it under Section 1704.3.
Continuous special inspection requires the inspector to be present continuously when and where the specific work is performed, precluding simultaneous observation of multiple remote operations.
Under IBC Table 1705.3, standard reinforcing steel placement prior to concrete placement is a periodic inspection, whereas concrete placement itself requires continuous inspection.
Use the adopted code and the approved SSI together. An approved project requirement for continuous inspection still applies when the code table calls for periodic inspection.
1.2 Statement of Special Inspections, Continuous vs. Periodic Inspection
The Statement of Special Inspections (SSI) identifies the work, tests and inspection frequencies for the project. Use it with the approved drawings and specifications to schedule the required inspections before work is concealed.
A central competency tested on the ICC Reinforced Concrete Special Inspector exam is distinguishing between Continuous Special Inspection and Periodic Special Inspection, understanding their exact definitions under the International Building Code (IBC), and applying the mandated inspection frequencies in IBC Table 1705.3.
The Statement of Special Inspections (SSI): Mandate and Contents
Under IBC Sections 1704.2.3 and 1704.3, the permit applicant normally submits a Statement of Special Inspections prepared by the registered design professional in responsible charge. For construction without a registered design professional, the building official can approve a qualified person to prepare it. The requirement applies to projects and portions of work subject to special inspection, with the exceptions in the applicable code.
What to find in the statement
- Work covered. Locate the materials, systems, components and work that require special inspection or testing. On a concrete job, separate structural slabs, foundations and embedded anchors where their requirements differ.
- Type and extent of inspection and testing. Identify what the agency will inspect and what tests are required. Use the approved specifications and referenced standards for test methods, sampling and acceptance details.
- Frequency. Determine whether each inspection is continuous, periodic or follows a notation in the referenced standard. Plan the staffing around the required frequency.
- Wind and seismic requirements. Identify the additional work and the designated systems or components subject to special inspection or testing under the applicable IBC provisions.
IBC Section 1704.6 addresses structural observation separately. Section 1704.2.2 requires work to stay accessible and exposed until required special inspections or tests are complete. If a concrete pour will cover reinforcing steel at noon, arrange to verify the required reinforcement first. If the work has already been concealed, document the missed inspection and refer it for resolution.
Continuous vs. Periodic Inspection: Code Definitions
IBC Chapter 2 (Definitions, Section 202) provides the legal definitions that govern field inspection scheduling:
Continuous Special Inspection
A special inspector stays present wherever the activity requiring continuous inspection is taking place, for the time that activity is performed.
Operational Application:
- The inspector must be physically positioned at the active work zone for the entire duration of the specified operation.
- For concrete placement under Table 1705.3, remain present during the placement operation and verify the application and consolidation techniques.
- Spatial Rule: An inspector assigned to continuous inspection cannot observe two separate concrete pours occurring simultaneously at different locations on the site. If Pour A is on the 5th floor suspended slab and Pour B is on the basement retaining wall, schedule qualified inspectors to cover both locations or sequence the pours so one inspector can stay with each operation.
Periodic Special Inspection
A special inspector visits intermittently while the work is underway or after it has been performed, at times when the required features can be verified.
Operational Application:
- The inspector reviews the work at predetermined milestones: before, during, or after completion of an operation.
- For reinforcing steel, periodic inspection means thoroughly inspecting the rebar cage layout, bar sizes, spacing, lap splices, clearances, and supports after the ironworkers complete tying and before concrete placement commences.
- The inspector does not need to watch every tie wire being twisted or every bar chair being set, but must inspect the completed assembly before it is encapsulated.
IBC Table 1705.3: Required Special Inspections of Concrete Construction
Use the activity in the adopted table to determine the frequency. Rows 1, 3–10 and 13–14 below give examples with the same frequency in the 2021 and 2024 model IBC. Check exceptions under Sections 1704.2 and 1705.3 and any project-specific requirements.
| Table 1705.3 item | Inspection or testing task | Frequency | What to check |
|---|---|---|---|
| 1 | Reinforcement, including tendon placement where applicable | Periodic | Check layout, size, spacing, cover and details before concealment. |
| 3 | Anchors cast in concrete | Periodic | Compare size, location and embedment to approved drawings. |
| 4a | Horizontal or upwardly inclined adhesive anchors resisting sustained tension | Continuous | Observe the applicable product installation steps. |
| 4b | Mechanical anchors and other adhesive anchors | Periodic | Check the product’s approved evaluation report for specific requirements. |
| 5 | Use of the required concrete mix | Periodic | Match delivery records to the approved mixture. |
| 6 | Fabricating strength specimens and testing fresh concrete before placement | Continuous | Observe or perform the required tests when they occur. Determine how often to sample from the applicable test frequency requirements. |
| 7 | Placement of concrete or shotcrete | Continuous | Verify conveying, depositing and consolidation where applicable. |
| 8 | Specified curing temperature and techniques | Periodic | Verify the specified protection and record conditions. |
| 9 | Application of prestressing force and grouting of bonded tendons | Continuous | Observe the applicable operation. |
| 10 | Precast erection | Periodic | Check erection against approved details. Separate rows address certain diaphragm connections. |
| 13 | In-place strength before post-tensioning or before removing shores and forms from beams or structural slabs | Periodic | Verify the strength evidence required for the operation. |
| 14 | Formwork shape, location and dimensions | Periodic | Check the formed geometry against approved documents. |
Item 2 depends on the IBC edition
- 2021 IBC. Verify weldability of bars other than ASTM A706 periodically. Inspect single-pass fillet welds up to 5/16 in. periodically and other welds continuously under the model table.
- 2024 IBC. Verify weldability of bars other than ASTM A706 periodically. Inspect welded reinforcement splices and welding of primary tension reinforcement in corbels continuously. Continuous inspection also applies to reinforcement welding for special moment frames, special structural wall boundary elements and coupling beams. The remaining single-pass fillet welds up to 5/16 in. and other remaining welds are periodic in the model table. Check applicable ACI 318 and AWS D1.4 provisions.
In a typical pre-pour scenario, a periodic rebar check verifies the exposed cage before the pour. Continuous concrete placement inspection begins with the specified placement activity. Continuous observation of a test under item 6 and the number of samples required for a pour are separate decisions.
Post-Installed Adhesive Anchors: The Life-Safety Continuous Rule
IBC Table 1705.3 item 4a requires continuous special inspection for adhesive anchors installed horizontally or upwardly inclined to resist sustained tension. Both the installation orientation and the load condition matter. Mechanical anchors and adhesive anchors outside item 4a are periodic under item 4b. Check the approved product evaluation report for installation and inspection requirements.
ACI 318-19 Section 26.7.2(e) also requires a qualified, certified installer for the sustained-tension applications described in item 4a. Confirm the specified installer qualification and use the approved instructions to check the actual drilling and cleaning methods, adhesive and anchor installation. Different systems can call for different tools and cleaning sequences.
Project Specifications vs. Building Code Minimums
Identify the applicable code minimum and read the approved statement and project requirements. For example, the IBC table classifies ordinary reinforcement placement as periodic. If the approved SSI requires continuous inspection during placement of beam-column joint reinforcement on this project, staff that operation for continuous inspection.
Concrete test frequency works the same way. If the project requires a strength sample at least once per 50 cubic yards, plan for that limit and check the applicable requirements for placement days and floor or wall area as well. A volume threshold alone may give too few samples. If the approved documents appear to reduce a code-required inspection frequency, seek clarification from the responsible design professional and building official before the work is covered.
What distinguishes continuous special inspection under IBC Section 202?
Special inspection where the inspector visits the job site for at least two hours during each phase of work
The inspector stays present throughout the work requiring continuous inspection at the location where it is performed
Special inspection conducted remotely using real-time high-definition video feeds and sensor logging
Special inspection where the inspector reviews completed structural assemblies immediately prior to concrete discharge
According to IBC Table 1705.3, what are the respective required inspection frequencies for: (1) inspecting reinforcing steel placement prior to concrete placement, and (2) inspecting the concrete placement and consolidation operation?
(1) Periodic; (2) Continuous
(1) Continuous; (2) Periodic
(1) Periodic; (2) Periodic
(1) Continuous; (2) Continuous
Under IBC Section 1705.3, which specific post-installed anchor installation condition legally mandates Continuous Special Inspection rather than Periodic Special Inspection?
Mechanical expansion anchors installed vertically downward into a foundation footing to resist column uplift
Screw anchors installed horizontally into exterior tilt-up concrete panels to secure temporary architectural cladding
Adhesive anchors installed horizontally or upwardly inclined (overhead) to support sustained tension loads
Cast-in-place headed anchor bolts secured in grade beams prior to concrete placement
Sections you finish are checked off in the contents.