Curtain Wall Glass Setting Blocks and Edge Clearances Inspection

The checklist

Documentation & Conditions

1. 1Open approved shop drawings and glazing specs; confirm block type, dimensions, hardness, and edge clearance requirements; attach current revisions to the checklist as evidence.
2. 2Verify frame plumb, level, and square using a spirit level and diagonal measurements; record readings and photos; proceed only if within project tolerances.
3. 3Confirm environmental conditions suitable for glazing (temperature, wind, precipitation); record ambient temperature (°C) and wind speed (m/s) with a handheld meter.
4. 4Check that required approvals for glass type and setting block material are issued; upload approvals and manufacturer datasheets to the record.

Tools & Materials Verification

1. 5Calibrate calipers, durometer (Shore A), and feeler gauges before use; photograph calibration labels and note dates on the checklist.
2. 6Inspect setting block packaging for manufacturer, batch, and expiry; photograph labels; confirm block hardness matches specification (record durometer reading ±1 Shore A).
3. 7Measure block length, width, and thickness with calipers; confirm dimensions per drawings (record to 0.5 mm) and capture photos against a scale.
4. 8Verify chemical compatibility of blocks and edge spacers with sealants/gaskets using approved compatibility reports; upload report references and acceptance letters.

Setting Blocks Installation

1. 9Place two setting blocks at quarter points along the sill per unit width; mark measured locations with a non-permanent marker and photograph.
2. 10Confirm blocks bear fully on the frame substrate (no rocking); use a 0.05 mm feeler gauge to check for gaps; shim or reset if gaps exceed gauge.
3. 11Check block adhesion or mechanical retention (if specified) using manufacturer’s method; document adhesive type, lot number, and curing status with photos.
4. 12Verify block thickness achieves specified glass edge clearance at sill; measure with calipers; record achieved clearance to 0.5 mm.
5. 13Ensure blocks are free of debris and burrs; wipe with lint-free cloth and approved cleaner; photograph clean bearing surfaces before setting glass.
6. 14Confirm block compressive load capacity suits glass weight; record glass dimensions, type, and calculated mass; note manufacturer allowable load and safety factor.

Edge Clearances & Centering

1. 15After setting the lite, measure edge clearances at four sides using feeler gauges; record each side’s minimum and maximum values to 0.5 mm.
2. 16Verify glass is centered in the pocket; measure opposing clearances; confirm difference within drawing tolerance; record delta and photo with gauge in place.
3. 17Confirm specified glass bite (edge cover) is maintained; measure visible bite with a depth gauge or template; record reading and acceptance per drawings.
4. 18Check that temporary spacers or location blocks used during setting are removed or retained only if specified; photograph condition after removal.
5. 19For IGUs, confirm the edge spacer is not in contact with frame; use a borescope or mirror to visually verify; capture close-up images.

Movement, Contact & Protection

1. 20Verify no glass-to-metal or glass-to-fixings contact at any edge; sweep a 0.1 mm feeler gauge; if contact found, re-center and re-measure.
2. 21Confirm designed movement allowance for thermal/sway is available (sum of clearances per side); record calculation and compare with specification.
3. 22Inspect gaskets or tapes adjacent to edges for correct seating without twisting; photograph continuous seating and record any splices or joints.
4. 23Apply protective edge guards or temporary retainers if required; verify they do not reduce clearance; photograph installation and note removal plan.

Records & Sign-off

1. 24Attach marked-up photos showing block positions, measured clearances, and glass ID; include unit number and elevation grid reference.
2. 25Log installer and inspector names, date/time, and instrument IDs; capture digital signatures within the checklist platform for traceability.
3. 26Confirm compliance “per approved project specifications and authority requirements”; mark status (Accepted/Rejected), note punch items, and issue the QR-linked report.

Preview the printable checklist

Preview page one below. Open the image or download the PDF for all pages.

At a glance

• Ensure setting blocks match approved material, hardness, and dimensions, and sit at correct quarter-point locations to carry dead load without inducing stress. Record measurements and photographs for traceability, preventing premature edge damage and warranty challenges.
• Measure and document uniform edge clearances around the lite using feeler gauges and calipers. Consistent clearances preserve specified bite and prevent frame contact, reducing fracture risks from thermal movement, building sway, and live-load deflection.
• Verify compatibility among glass, setting blocks, spacers, sealants, and gaskets. Proper materials and movement allowance prevent chemical attack, migration, or stress concentration, supporting long-term performance and watertightness per approved project specifications and authority requirements.
• Interactive online checklist with tick, comment, and export features secured by QR code.

How to Use This Interactive Curtain Wall Glazing Checklist

1. Preparation: stage calibrated calipers, feeler gauges, durometer (Shore A), spirit level, borescope/mirror, lint-free cloths, approved cleaners, PPE (gloves, eye protection), access equipment, and current shop drawings/specifications.
2. Create a new inspection in the app, select elevation and unit IDs, and preload manufacturer datasheets, compatibility reports, and environmental limits relevant to the glazing scope.
3. Using Interactive Mode: tick each item as you measure, attach photos with scales, enter readings to the nearest 0.5 mm/Shore A, and log batch numbers. Add comments and assign corrective tasks if deviations appear.
4. Coordinate fixes: re-center glass, replace blocks, or clean seats as required. Re-measure affected points, update evidence, and close tasks with responsible party, due date, and verification photos.
5. Export and share: generate a commentable report and export as PDF/Excel including photos, readings, and drawings. Enable QR on the cover page for field retrieval and verification.
6. Sign-Off: capture installer and inspector digital signatures, confirm compliance per approved project specifications and authority requirements, archive the QR-authenticated record, and distribute to stakeholders.

Why setting blocks matter and how to place them

Setting blocks transfer the glass dead load into the curtain wall frame while protecting the vulnerable lower edge from contact and stress. Proper hardness prevents creep or point loading; correct thickness and width deliver the specified edge clearance and bite. Place two blocks at quarter points to avoid cantilevering and distribute load. Blocks must sit flat on clean, stable substrates, secured per manufacturer guidance. Dimensional checks with calipers and durometer readings confirm conformance before the lite is set. For IGUs, compatibility with sealants and edge spacers is critical to avoid chemical attack or migration. Photographs, batch labels, and measurement logs create a defensible record that supports warranty and handover. If the frame is not plumb or level, rework before glazing to avoid compensating with blocks, which can mask misalignment but cause uneven clearances and long-term problems.

• Two blocks at quarter points distribute dead load evenly.
• Hardness and dimensions must match approved drawings.
• Blocks must sit flat; no rocking or gaps under load.
• Compatibility with sealants and IGU spacers is essential.
• Record photos, labels, and measurements for traceability.

Measuring edge clearances and preserving uniform bite

Uniform edge clearances prevent glass-to-frame contact during thermal movement, building sway, and live-load deflection. After placing the lite on blocks, measure clearances at multiple positions on each side using feeler gauges and record minimum and maximum values. Centering is checked by comparing opposing sides; large deltas indicate misplacement or frame issues. Maintaining the specified bite protects the edge and supports weather seals. Use templates or depth gauges for repeatable bite checks, and verify that temporary spacers are removed if not part of the design. Any point contact, snagging gaskets, or twisted tapes must be corrected immediately. IGUs require special care to avoid compressing the edge spacer. Final documentation should tie readings to unit IDs and elevation references to make future audits simple and defensible.

• Measure each side’s minimum and maximum clearance.
• Confirm centering by comparing opposing side values.
• Maintain specified edge bite using repeatable gauges.
• Eliminate any glass-to-frame point contact immediately.
• Link measurements to unit and elevation IDs.

Movement allowance, compatibility, and field evidence

Curtain walls experience thermal changes, interstorey drift, and live-load deflection, so gaps must provide the movement allowance detailed in the design. Sum the edge clearances and confirm they meet or exceed the specified requirement. Check that gaskets are seated without twist and that compatible materials are used throughout the glazing pocket. Rubber hardness, sealant chemistry, and IGU edge constructions must align with vendor approvals to prevent staining, embrittlement, or delamination. Evidence capture is more than photos: include durometer readings, caliper logs, tool calibration dates, and material batch numbers. Finally, secure digital sign-offs and a QR-authenticated export to close the loop, enabling quick retrieval during commissioning, maintenance, or incident reviews. This disciplined approach reduces disputes and accelerates approvals.

• Verify movement allowance from summed clearances.
• Seat gaskets evenly; avoid twists and pinches.
• Use materials with documented compatibility approvals.
• Capture readings, calibrations, and batch data.
• Finalize with QR-authenticated digital sign-off.