A post-installed adhesive anchor in a curtain-wall load path is a safety-critical structural connection—not a generic “chemical bolt” chosen or installed from a rule of thumb. Its substrate, actions, geometry, product qualification, installation procedure, inspection and records must form one project-approved system.
This guide is a coordination and quality-assurance framework for facade consultants, structural engineers, contractors, inspectors and owners. It provides no anchor size, hole size or depth, spacing, edge distance, torque, cleaning sequence, cure time, temperature limit or allowable load. Those values must come from the responsible engineer’s design and the current approval and instructions for the exact anchor system.
1. Confirm the connection strategy and responsibilities
Coordinate cast-in plates, channels or other planned supports before concrete placement wherever the project design uses them. A post-installed anchor may be considered for a missed or misaligned embed, refurbishment, retrofit or a deliberately engineered connection, but it is not an automatic correction and it does not by itself make a facade connection compliant.
Facade engineer
Defines the curtain-wall reactions, bracket and rail behaviour, movements, tolerances, interfaces and the load path from cladding to the primary structure.
Structural engineer
Confirms the substrate and designs the anchorage, plate and supporting concrete for the applicable actions, failure modes, code and project conditions.
Anchor supplier and installer
Provide the current scoped assessment, instructions, system components, training and a controlled method that exactly matches the approved design.
Inspector and contractor
Establish hold points, verify work against approved documents, retain traceability, identify nonconformance and prevent concealed or loaded work from bypassing acceptance.
2. Survey the substrate before design or drilling
Start with drawings, construction records and a site survey, then resolve uncertainty through an investigation planned by the project team. Record whether the base is normal-weight concrete or another material, its verified strength and age, cracked or uncracked design condition, member thickness, surface condition, previous repairs, moisture or water exposure, temperature range and any chemical, coastal or fire exposure. Masonry, hollow units, screeds, toppings and unidentified repair materials are not equivalent to concrete.
Use an approved scanning and setting-out method to map reinforcement, post-tensioning, services, cast-in items, edges, openings and accessible opposite faces. The survey must also establish the actual room for the bracket, plate, washers, nuts, tools and inspection. If the proposed location conflicts with reinforcement, an edge, damaged concrete or another concealed item, stop and return the connection to the designers; moving the hole can change group action, eccentricity, edge effects and the facade geometry.
3. Design the complete anchorage, not one isolated rod
| Design topic | Project questions | Controlling evidence |
|---|---|---|
| Actions and movements | Dead, wind, seismic and construction actions; sustained tension; thermal and building movement; eccentricity, prying, fatigue or impact where relevant. | Approved facade reactions, load combinations and structural anchorage calculations for the applicable code. |
| Concrete and geometry | Cracked condition, strength, thickness, edges, spacing, anchor group, reinforcement, plate stiffness and installation tolerances. | Verified survey/as-builts, engineer’s drawings and the exact product’s current qualified range. |
| Failure and robustness | Steel, bond, pullout, concrete breakout, splitting, pry-out and shear; interaction, group effects, deformation, redundancy and consequences of failure. | Engineer’s limit-state checks and a defined load path through plate, bracket, facade and primary structure. |
| Exposure and service | Concrete and ambient temperature, dry/damp/water-filled holes, chemicals, freeze/thaw, corrosion, fire and required working/service conditions. | Current ETA, ICC-ES report or other locally accepted evaluation whose scope matches every claimed condition. |
| Element and system | Threaded rod, insert or approved reinforcing-bar application; material grade, coating, washers/nuts, adhesive, dispenser, mixer and accessories. | One identified, compatible system plus approved specifications, evaluation report and manufacturer’s current installation instructions. |
The structural engineer must select the design resistance and check the supporting member. A supplier table, software output, field pull result or old photograph cannot replace those checks. The plate, welds or bolts, slot orientation, shims or grout, bracket, rails and primary structure also require design; anchor capacity is not the capacity of the complete facade connection.
4. Match the product assessment to the jurisdiction and use
Build a code-and-evidence matrix for the project location. In United States work, the adopted edition of ACI CODE-318 addresses anchoring to concrete in Chapter 17; qualification may reference ACI CODE-355.4 and a current product-specific ICC-ES report evaluated under the applicable AC308 criteria. The locally adopted code edition, report status and report conditions govern—not the newest edition merely because it exists.
For European work, a product-specific European Technical Assessment may be based on EAD 330499-02-0601, with design under the applicable EN 1992-4 and national provisions. Other jurisdictions may require different evaluations, certification, tests, inspection and installer competence. Confirm current versions, holder, manufacturing site, anchor element, substrate, drilling and cleaning method, embedment range, cracked/uncracked and seismic scope, installation direction, sustained-load, temperature/moisture, corrosion and fire conditions before approval.
5. Convert the approved design into installation hold points
The contractor’s method statement should translate the engineer’s drawings and the exact evaluated system into checkable steps without changing them. At each stage, record acceptance before the work becomes concealed.
| Hold point | Verify before release |
|---|---|
| Setting out | Approved revision, anchor ID, substrate survey, scan record, access, edge/member geometry, reinforcement avoidance and protection of facade, fire and water-control interfaces. |
| Hole formation | The specified drill and bit type, hole diameter and depth, orientation, equipment condition and any permitted wet/dry method exactly match the engineer’s design and current product document. |
| Hole preparation | The approved cleaning tools, sequence, repetition and hole condition are followed and witnessed as required. Never assume all systems prohibit water or permit the same brush, air or vacuum method. |
| Adhesive and element | Correct system and element, lot/batch, expiry, storage, cartridge and material temperature, dispenser, mixer/nozzle, initial purge, fill and insertion method, embedment mark and orientation. |
| Cure and protection | Work/gel and full-cure conditions are taken from the current instructions for actual base-material and adhesive temperatures; the anchor remains protected from movement, disturbance and load until released. |
| Plate and connection | Plate bearing/flatness, approved packing or grout, washer/nut, thread engagement, tightening or torque where specified, bracket geometry, corrosion protection and final inspection meet the drawings. |
Use installers with the competence required by the adopted code, specification and product system. Where U.S. provisions apply, check whether the installation direction and sustained-tension condition trigger certified-adhesive-anchor-installer requirements; ACI publishes sample specification language. Special inspection, witness frequency and concealed-work release must be defined before installation starts.
6. Plan representative site testing without turning it into design data
Site pull testing may be required to investigate an existing substrate, validate a proposed installation method, verify workmanship or proof-test installed anchors. It is not automatically required at one universal frequency or load. The structural engineer must issue the plan: purpose, representative substrate and locations, anchor state, installation control, test equipment and calibration, load direction, test rate and hold, acceptance criteria, damage limits, reporting and disposition.
A successful test does not establish an unqualified product’s design resistance, prove every installed anchor, or validate a substrate and condition outside the evaluation report. A failed or anomalous result is a nonconformance requiring investigation of material, substrate, drilling, cleaning, installation, cure, test setup and population; do not simply move the hole or repeat at a convenient location.
7. Control nonconformance and retain traceability
Stop and identify any location with an unscanned obstruction; reinforcement or service contact; damaged, cracked, shallow, deep, oversized or misplaced hole; unexpected moisture; uncertain cleaning; wrong, expired or poorly stored component; incomplete fill; lost embedment; movement during cure; temperature or time outside the approved range; plate misfit; unapproved tightening; or failed test. Quarantine affected anchors and adjacent work. The engineer’s written disposition may require investigation, removal, engineered abandonment, repair or redesign; it must not be guessed on site.
- building, elevation, grid, plate/bracket and unique anchor ID;
- approved drawing, calculation, specification, evaluation and instruction revisions;
- substrate information, scan and setting-out record, hole-forming equipment and installer;
- product, anchor element, accessories, lot/batch, expiry, storage and temperature records;
- installation date/time, hole and cleaning verification, embedment mark and cure release;
- inspector, photographs, test equipment/calibration and field-test results where specified;
- nonconformance, engineer/manufacturer disposition, corrective work and reinspection; and
- final as-built location, concealed-work release and O&M/inspection handover.
Adhesive surrounding a rod is not universal corrosion protection. Specify the rod, nuts, washers, plate, welds/coatings and dissimilar-metal interfaces for the actual exposure and service life. Likewise, an anchor approval does not establish curtain-wall fire resistance, water tightness, drainage, air control or thermal performance. Coordinate penetrations and repairs with the structural, facade, waterproofing and fire teams responsible for the complete assembly.
For facade context, review the Terracotta Rainscreen page and dated reference files in Catalogues & Downloads. These resources do not replace the anchor engineer’s project-specific design or the current anchor-system approval.
Coordinate the facade information package
Send the project location, facade drawings, wall build-up, bracket/rail concept, proposed substrate, survey information, design criteria and applicable code. LOPO can provide relevant terracotta-system information; the project’s qualified facade and structural professionals remain responsible for the load path, anchor specification, testing, installation control and acceptance.