Interior Heritage
Export Portfolio
High-Performance Architectural Crittall French Door Assemblies
Engineered to deliver classic industrial heritage aesthetics alongside superior air-water tightness, advanced safety tempering, and strict European standard structural reliability.
Thermal Break
NFRC Tested
EN 14351-1
Acoustic Partition
Architectural Grade
Minimalist Iron Art
Luxury Pivot / Swing
Engineering Baseline
Material Science: High-Tensile Aluminium vs. Traditional Carbon Steel Crittall
Architects and structural engineers specify aluminium Crittall-style assemblies to overcome the thermal bridging and corrosion vulnerabilities intrinsic to early 20th-century hot-rolled carbon steel profiles.
| Performance Characteristic | Architectural Grade T6 Aluminium (DERCHI System) | Legacy Hot-Rolled Carbon Steel | Compliance Test Benchmark |
|---|---|---|---|
| Thermal Conductivity (U-Value) | 1.1 – 1.6 W/(m²·K) via Polyamide PA66 Thermal Struts | > 3.8 W/(m²·K) — High Thermal Bridging Risk | EN ISO 10077-2 / NFRC Certified |
| Atmospheric Corrosion Resistance | Native passivating oxide film + 60–80μm fluorocarbon/powder coat | Vulnerable to galvanic rust and oxidation at welded joints | ISO 9227 Neutral Salt Spray (> 3000 Hours) |
| Structural Weight Ratio | Approx. 2.7 g/cm³ — Minimizes subframe dead load & hinge fatigue | Approx. 7.85 g/cm³ — Heavy load, demanding structural lintels | ASTM E330 Structural Performance |
| Glazing Pocket Capacity | Accommodates 24mm–38mm Low-E Argon-filled double/triple glazing | Typically restricted to single monolithic or narrow 16mm IGU | EN 1279 Insulating Glass Units Standards |
| Acoustic Attenuation (Rw) | Up to 42 dB with multi-chamber EPDM co-extruded gaskets | Averages 28 – 32 dB due to rigid metal-to-metal rebate contact | ISO 140-3 Sound Reduction Index |
Procurement Trends
The Global Shift: How Commercial Specifiers Are Sourcing Crittall Doors
Strategic purchasing managers across Europe, North America, and Australasia are transitioning to advanced extruded aluminium assemblies driven by strict building codes and ESG mandates.
Thermal Barrier Decoupling
Global net-zero mandates, including the EU Energy Performance of Buildings Directive (EPBD) and ASHRAE 90.1, now reject non-thermally broken metal frames. Advanced technoform polyamide multi-cavity thermal struts are mandatory to eliminate interior condensation and prevent mold growth in premium projects.
Consolidated Container Procurement
Developers increasingly move away from fragmented single-system sourcing. They prefer consolidated direct-factory packaging that pairs Crittall French doors with entrance pivot systems, acoustic interior partitions, and hurricane-rated sliders, optimizing shipping container cube utilization by up to 28%.
Precision True-Divided & Applied Muntins
To reduce long-term maintenance costs without sacrificing vintage aesthetics, architects prioritize dual-applied architectural grid profiles featuring internal duplex shadow spacers. This delivers the look of traditional multi-pane steel glazing while preserving single-unit insulating glass performance.
Procurement FAQ
Frequently Asked Questions by Commercial Specifiers & Importers
Essential guidance covering international certification verification, thermal break structural integrity, hardware compatibility, and intercontinental freight operations.
How does CE Certification EN 14351-1 apply to aluminium Crittall style doors?
Under the EU Construction Products Regulation (CPR), external pedestrian doorsets must satisfy the harmonized European standard EN 14351-1. This mandates third-party laboratory verification for wind load resistance (EN 12211/12210), water tightness under static pressure (EN 1027/12208), air permeability (EN 1026/12207), and overall thermal transmittance (EN ISO 10077). DERCHI provides full Declaration of Performance (DoP) documentation and CE marking with each batch, ensuring clear compliance for local council sign-offs and building certifiers across all EU member states.
Can extruded aluminium match the ultra-slim sightlines of classic Crittall steel?
Yes. By engineering high-yield 6063-T6 aluminum alloys with strategically thicker internal web walls (1.8mm–2.5mm), DERCHI achieves sash sightlines down to 28mm–35mm. This matches the minimalist look of industrial rolled-steel frames while accommodating modern insulated glass units (IGUs) up to 32mm thick, delivering true period aesthetics without sacrificing energy efficiency.
What surface treatments protect coastal installations from sea salt corrosion?
For marine environments (within 5 km of coastlines), we specify Qualicoat Seaside-class architectural powder coating or fluorocarbon (PVDF) 3-coat spray finishes. These coatings withstand over 3,000 hours of Neutral Salt Spray testing (ISO 9227) without blistering, pitting, or chalking, making them superior to treated carbon steel which remains susceptible to seam rust.
How do you construct muntin bars to maintain glass thermal performance?
We primarily use Simulated Divided Lites (SDL). Extruded low-profile aluminum muntin profiles are mechanically interlocked and bonded to the outer glass faces with 3M VHB structural tape, paired with internal duplex spacer bars within the sealed double glazing unit. This replicates the visual appearance of individual panes while avoiding thermal bridging, air leaks, and weak seals typical of older True Divided Lites (TDL).
What locking hardware options are available for exterior security compliance?
Our exterior swing doors incorporate European standard multi-point locking gear (featuring top and bottom shootbolts plus center deadbolts) supplied by certified partners like Siegenia, Hoppe, or Sobinco. These systems meet PAS 24 / RC2 intruder resistance benchmarks and support integrations with smart smart-lock cylinders and building access controls.
How does DERCHI manage shop drawing engineering and export logistics?
Our in-house project team provides full BIM and 2D CAD production drawings to verify rough opening sizes, threshold drainage weep pathways, swing clearances, and wall interfaces prior to fabrication. For export, all products are packed in moisture-sealed shrink wrap, cushioned with corner edge guards, and crated in fumigation-free wooden crates for direct transport to your job site or warehouse.