ASTM · EN Standards · Application Methods · Testing Protocols · Labor Training · Quantity Formulas · Deglazing Log
All applicable international standards governing structural silicone glazing design, materials, testing, and installation.
| Standard | Body | Title / Scope | Application | Key Requirement | Reference |
|---|---|---|---|---|---|
| ASTM C1184 | ASTM | Specification for Structural Silicone Sealants | 1-Part & 2-Part SSG | Tensile strength ≥ 345 kPa; Shore A hardness 20–60 | FacadeMart |
| ASTM C794 | ASTM | Adhesion-in-Peel of Elastomeric Joint Sealants | Peel adhesion testing | ≥ 9 N/25mm width after 7/14/21 day cure | FacadeMart |
| ASTM C1401 | ASTM | Guide for Structural Sealant Glazing | Design & Installation Guide | SSG bite size, dead load support, edge clearance | FacadeMart |
| ASTM C719 | ASTM | Adhesion & Cohesion of Elastomeric Joint Sealants Under Cyclic Movement | Movement capability ±25% / ±50% | No failure after 10 cycles extension/compression | FacadeMart |
| ASTM C1087 | ASTM | Determining Compatibility of Liquid-Applied Sealants with Accessories | Compatibility testing | No discoloration, adhesion loss, or migration | FacadeMart |
| ASTM C1382 | ASTM | Determining Tensile Adhesion Properties of Sealants | Tensile pull-off testing | Cohesive failure mode preferred; >75% cohesive | FacadeMart |
| ASTM E330 | ASTM | Structural Performance of Windows under Uniform Static Air Pressure | Wind load resistance testing | No failure at 1.5× design pressure | FacadeMart |
| ASTM C920 | ASTM | Specification for Elastomeric Joint Sealants | General sealant classification | Type S (single) or M (multi), Class 25/50, Grade NS/P | FacadeMart |
| ASTM C1521 | ASTM | Evaluating Adhesion of Installed Weatherproofing Sealant Joints | Field pull test / inspection | Cohesive failure mode; field tab pull test | FacadeMart |
| EN 13022-1 | EN | Glass in Building — Structural Sealant Glazing Part 1: Glass Products | European SSG glass requirements | Glass edge quality, tempering, heat soak test | FacadeMart |
| EN 13022-2 | EN | Glass in Building — SSG Part 2: Assembly Rules | European SSG assembly | Bond thickness, width calculation, substrate prep | FacadeMart |
| EN 15434 | EN | Glass for Architecture — Product Standard for Structural / Unframed Silicone Glazing Sealants | Sealant product approval in Europe | 10 year durability testing, UV aging, tensile | FacadeMart |
| ETAG 002 | EOTA | European Technical Approval Guideline for Structural Sealant Glazing Kits | ETA product approval | Durability, UV, water immersion, thermal cycling | FacadeMart |
| ISO 11431 | ISO | Adhesion / Cohesion Properties After Immersion in Water | Water immersion adhesion | Adhesion maintained after 7 day water soak | FacadeMart |
| ISO 8339 | ISO | Determination of Tensile Properties | Tensile dumbbell test | Elongation at break >150%; modulus reporting | FacadeMart |
Moisture-cure single-component structural sealants. Simplest to apply; requires ambient humidity for crosslinking.
Moisture-cure (acetoxy or oxime). Atmospheric humidity crosslinks the polymer from outside in. Deep sections cure slowly — maximum recommended bite: 6mm depth for 1-part.
Temperature: 5°C – 40°C. Relative humidity: 30–75% RH. Below 5°C or <20% RH: cure rate drops dramatically. Above 75% RH: surface skin forms too fast (slump risk).
Pneumatic or battery cartridge gun (300ml or 600ml). Backer rod in place first. Nozzle cut at 45°. Single continuous bead. Tool within 5–7 minutes of application.
Clean all bonding surfaces with isopropyl alcohol (IPA) ≥ 70%. Wipe in one direction; discard cloth after each pass. Allow 5 minutes flash-off before priming. Check for contamination, coatings, or dust. Mask adjacent surfaces.
Apply manufacturer-specified primer (e.g., Dow P5200N, GE SS4155) on porous substrates. Thin coat; allow 20–40 min open time before sealing. Never apply sealant on wet primer.
Size: 25–33% wider than joint. Push flush. Closed-cell polyethylene rod only. Prevents 3-sided adhesion and controls joint depth (depth = 50–100% of width).
Cut nozzle to match joint width. Apply in one continuous pass without stopping. Maintain constant speed. Fill joint completely — no voids, no entrapped air. Apply at 45° angle pushing bead, not pulling.
Tool within 5 minutes using a dry, smooth spatula or finger (gloved). Wet tooling (soap/water) is not recommended for structural silicone — it inhibits cure at surface. Concave profile. Remove masking tape immediately.
Do not disturb joint for 24 hours. Full structural cure: 14–21 days. Protect from rain for first 24 hrs. Temperature log the glazed area. Inspect at 7 days for surface cure and adhesion.
Two-component condensation or addition cure systems. Required for factory glazing (shop application), large SSG bites, and quality-controlled structural bonding.
Addition-cure (platinum catalysed) or condensation cure. Base (Part A) + curing agent (Part B). Ratio typically 10:1 or 1:1 by volume. Full cure independent of humidity.
Meter-mix pump (dual cartridge or drum pump) with static mixer nozzle. Ratio-verified by butterfly test every batch / cartridge. No manual mixing allowed for structural grade.
Factory / shop glazing preferred. Can be field applied with approved meter-mix equipment. Deep bites (up to 12–15mm) achievable. Faster cure than 1-part for full section.
Before each cartridge or each work shift, dispense approx. 50mm of sealant from the nozzle onto a non-porous surface. Fold the bead onto itself to form a "butterfly." Observe colour consistency throughout the cross-section. If the colour is uniform (no streaks), the mix ratio is correct and application may proceed. Streaky or marbled appearance = incorrect ratio = STOP and purge nozzle / replace cartridge. Log the result.
Install dual cartridge / drums. Prime pump — discard first 30 seconds of output (purge). Attach static mixer. Perform butterfly test on a card. Verify uniform colour before proceeding to substrate.
IPA wipe, flash-off, primer if required. 2-part silicones often have better adhesion to clean substrates without primer — verify with adhesion test coupons per ASTM C794.
Position glass on setting blocks per ASTM C1401. Apply masking tape. Ensure gap dimensions (bite width × depth) match design calculations. Spacers / shims in place.
Fill from bottom, work upward (for horizontal joints) or from one corner. Inject from one side to push air out. Maintain continuous flow, no stop-start air pockets. Keep mixer nozzle submerged in fresh sealant during application.
Tool immediately — open time is 15–30 min (check TDS). Verify full contact with both substrates. No air voids. Take a witness bead sample (butterfly snap test at 1 hr).
Shore A hardness at 24 hrs (snap cure coupon). Peel test coupon at 7 days (ASTM C794 ≥ 9 N/25mm). Tensile coupon at 14 days (ASTM C1382). Log all results in panel logbook.
All mandatory and recommended tests for structural silicone glazing projects. Applicable to both 1-part and 2-part systems.
The most critical pre-application quality check for 2-part silicone. Tests mix ratio visually. Must be performed before each shift and each cartridge change.
Verifies that 2-part sealant is curing correctly. Performed on a witness bead sample taken during application.
Measures adhesion-in-peel of cured sealant to substrate. Most common QC test used for site verification and approval of substrate/sealant combination.
Measures tensile adhesion strength. Crucial for structural strength verification. Often done on mock-up panels in the factory.
Tests that spacers, gaskets, sealants, films, or coatings don't inhibit curing or adhesion of the structural silicone.
Non-destructive / semi-destructive field test performed directly on installed sealant beads at random sampling intervals.
| Test | Standard | When | 1-Part | 2-Part | Pass Criterion | Failure Mode |
|---|---|---|---|---|---|---|
| Butterfly Test | Manufacturer requirement | Before each shift / cartridge | — | Required | Uniform colour, no streaks | Marbled = wrong ratio |
| Snap Test | Internal QC | 1–3 hrs post-apply | Optional | Required | Clean cohesive snap | Sticky = cure inhibition |
| Shore A Hardness | ASTM D2240 | 24–48 hrs | Yes | Required | Target 30–50 Shore A | Too soft = under-cure |
| Peel Adhesion | ASTM C794 | 7 days cure | Yes | Yes | ≥ 9 N/25mm; >75% cohesive | Adhesive = substrate issue |
| Tensile Adhesion | ASTM C1382 | 14–21 days | Yes | Yes | ≥ 0.14 N/mm² (140 kPa) | Adhesive pull = reprimer |
| Compatibility | ASTM C1087 | Pre-project (once) | Yes | Yes | No inhibition, bleed, or discolor | Inhibition = change spacer |
| Field Tab Pull | ASTM C1521 | During & after install | Yes | Yes | Cohesive failure | Adhesive = remove & reglaze |
| Movement Capability | ASTM C719 | Pre-project (once) | Yes | Yes | No failure ±25% movement | Tear = wrong sealant spec |
Key formulas for SSG bite size, sealant volume, and structural capacity as referenced in ASTM C1401 and manufacturer design guides. Full Calculator at FacadeMart.com
Per ASTM C1401 the allowable design stress for SSG is 0.14 N/mm² (140 kPa) in tensile and shear. Manufacturer values are higher (0.17–0.20 N/mm²) but 0.14 is the code-allowable.
| Panel Width (m) | Panel Height (m) | Wind Load (kPa) | Min Bite Width (mm) | Recommended Bite (mm) | Notes |
|---|---|---|---|---|---|
| 0.6 | 1.2 | 1.0 | 13 | 18 | Light façade, low zone |
| 0.9 | 1.5 | 1.5 | 20 | 25 | Standard office façade |
| 1.2 | 2.4 | 2.0 | 34 | 40 | Medium panel, high wind |
| 1.5 | 3.0 | 2.5 | 54 | 60 | Large panel — requires 2-part |
| 2.0 | 3.6 | 3.0 | 77 | 80 | Unitised system, structural silicone + mechanical back-up |
Values based on Fs = 0.14 N/mm² per ASTM C1401. Verify with project engineer for actual design. Full Tables at FacadeMart
Dow, Momentive (GE Sealants), Elkem, and Wacker are the four primary global structural silicone manufacturers. All products below are ASTM C1184 / EN 15434 approved grades.
| Brand | Product | Type | Tensile Strength (N/mm²) | Elongation at Break | Shore A | Design Stress (N/mm²) | Standard |
|---|---|---|---|---|---|---|---|
| Dow | DOWSIL 993 | 1-Part | 0.69 | 250% | 45 | 0.17 | ASTM C1184 |
| Dow | DOWSIL 983 | 2-Part | 0.86 | 200% | 40 | 0.21 | ASTM C1184 / EN 15434 |
| GE / Momentive | SCS2000 | 1-Part | 0.55 | 300% | 35 | 0.14 | ASTM C1184 |
| GE / Momentive | SCS2700 | 2-Part | 0.80 | 220% | 42 | 0.20 | ASTM C1184 / EN 15434 |
| Elkem | GLASS-GRIP 100 | 1-Part | 0.60 | 280% | 38 | 0.15 | EN 15434 |
| Wacker | ELASTOSIL N569 | 1-Part | 0.65 | 270% | 40 | 0.14 | EN 15434 / ETAG 002 |
| Wacker | ELASTOSIL SG-20 | 2-Part | 0.90 | 180% | 48 | 0.20 | EN 15434 / ETAG 002 |
Values from manufacturer TDS; verify current TDS before design. Design stress per ASTM C1401 = 0.14 N/mm² regardless of product data. Compare Products — FacadeMart
A compact field-ready training guide for glazing applicators and supervisors. Laminate and post at the workstation.
Nitrile gloves (not latex), safety glasses, steel-toe boots. If using solvent cleaner (MEK, IPA, Xylene): ensure ventilation, no sparks. Structural silicone sealant is non-toxic once cured but uncured material is a skin sensitiser — minimise contact. SDS must be available at workstation.
| Defect | Cause | Remedy |
|---|---|---|
| Adhesive failure (peels off substrate) | Dirty surface, no primer, or wrong primer | Remove sealant, re-prep, re-prime, reapply |
| Air bubbles / voids | Gun stopped, incorrect angle, fast cure | Cut out void zone, clean, refill, re-tool |
| Soft / tacky after 48 hrs (2-part) | Wrong mix ratio, cure inhibition, old material | Remove all uncured sealant, identify cause, replace cartridge |
| Discolouration / staining | Incompatible gasket or primer bleeding | Review compatibility test; replace incompatible component |
| Sealant shrinkage / pulling away | Joint too wide for sealant modulus, or under-filled | Review bite design; ensure full fill; re-check with tensile coupon |
| Poor tooling / rough surface | Tooled too late, wrong tool | Cosmetic only if structural bond intact; test adhesion |
Removal of structurally bonded glass panels. Requires careful planning — never cut structural silicone without a safe glass retention plan in place.
Structural silicone is the sole dead-load support in many SSG systems. Never cut or remove structural silicone without temporary glass retention equipment (suction cups, glass clamps, scaffolding, or telehandler support) in place first. Glass panels can weigh 50–400 kg. Always have at least 2 trained operatives. Work at height requires RAMS (Risk Assessment & Method Statement).
Photograph panel from inside and outside. Identify all silicone joint locations (typically 4 sides). Check if any mechanical safety clips/retainers are present — these must be removed last. Log panel code in deglazing record.
Attach minimum 2 (preferably 4) vacuum/suction cups rated for the panel weight plus 3× safety factor. Or use external scaffolding glass carrier. Verify suction with vacuum gauge before proceeding.
Use sharp triangular oscillating blade or structural silicone knife. Cut along the bond line — silicone to glass interface. Insert knife flat (parallel to glass face). Work around all 4 sides. Do not use power angle grinder near glass.
With suction cups held and operative(s) stabilising the panel, push gently from inside to break the remaining bond. Slide panel outward. Lower panel on suction frame to a glazing trolley or flat surface.
Use plastic scraper + IPA or Dow OS-2 silicone remover. Never use metal scrapers on aluminium frames or glass. Remove all traces of cured silicone. Sand or abrade if needed. Confirm all residue removed before re-glazing.
Record in the panel log: panel ID, date deglazing occurred, reason for removal (damage, defect, inspection), condition of sealant on removal (cohesive vs adhesive failure), and operative names. This data is critical for warranty & facility management.
Required data fields for the structural silicone glazing log. Maintain one row per panel. Archive for minimum 10 years.
ASTM C1401 and ETAG 002 require full traceability of all structural silicone bonds. The logbook provides the evidence trail for warranty claims, inspection audits, insurance, and post-occupancy investigations. It must accompany the building's O&M manual.
| # | Column Name | Data Type | Example Entry | Notes |
|---|---|---|---|---|
| A | Panel Code | Text | F3-B-012 | Floor-Bay-Panel sequential |
| B | Date Glazed | Date | 14/03/2024 | Actual date sealant applied |
| C | Shift / Time | Text | AM / 08:30 | Morning / Afternoon / Night |
| D | Operator Name | Text | Ahmed R. | Certified applicator only |
| E | Supervisor Sign-off | Text | J. Malik | QC supervisor initials |
| F | Sealant Product | Text | DOWSIL 993 | From approved product list |
| G | Batch / Lot Number | Text | LOT-2402-A | From cartridge label |
| H | Expiry Date | Date | 31/08/2024 | Must be future at time of use |
| I | Ambient Temperature (°C) | Number | 24 | Measured at workstation |
| J | Relative Humidity (%) | Number | 55 | At time of application |
| K | Butterfly Test (2-part) | Pass/Fail | Pass | N/A for 1-part |
| L | Snap Test Time & Result | Text | 10:30 / Pass | 2-part only |
| M | Shore A (24hr coupon) | Number | 42 | Target 30–50 |
| N | Peel Test (7-day) | Number + mode | 14 N / Cohesive | ASTM C794 ≥9N/25mm |
| O | Tensile Test (14-day) | Number + mode | 0.38 N/mm² / Coh. | ASTM C1382 ≥0.14 N/mm² |
| P | Panel Status | Dropdown | Passed / Rework / Failed | Conditional formatting: green/amber/red |
| Q | Rework Notes | Text | Adhesive fail top edge — re-primed and resealed 16/03 | Free text |
| R | Deglazed? | Yes/No | No | Link to Deglazing Log tab |
| Column | Field | Formula / Notes |
|---|---|---|
| A | Date | Date of QC record |
| B | Panels Glazed Today | =COUNTIFS(Glazing_Log[Date Glazed],A2) — auto count |
| C | Pass Rate (%) | =COUNTIFS(…[Status],"Passed",…[Date],A2)/B2 — >95% target |
| D | Avg Shore A | =AVERAGEIFS(…[Shore A],…[Date],A2) |
| E | Avg Peel Force | =AVERAGEIFS(…[Peel],…[Date],A2) |
| F | Any failures? | =COUNTIFS(…[Status],"Failed",…[Date],A2) — conditional format red if >0 |
| G | Supervisor Sign | Manual entry |
| Column | Field | Notes |
|---|---|---|
| A | Panel Code | Cross-reference to Glazing Log |
| B | Original Glaze Date | Auto-lookup from Glazing Log |
| C | Deglaze Date | Actual date of removal |
| D | Years in Service | =(C2-B2)/365 |
| E | Reason for Removal | Dropdown: Damage / Defect / Inspection / Renovation |
| F | Failure Mode on Removal | Cohesive / Adhesive / Mixed |
| G | Condition of Frame / Glass | Free text — record corrosion, coating failure, etc. |
| H | Re-glazed? | Yes/No / Replacement date |
| I | Operative | Name + certification number |
| J | Supervisor Sign-off | Signature required |