Engineered to withstand extreme weather conditions, coastal storms, and hydrostatic pressure through multi-chamber thermal profiles and dual EPDM sealing systems.
Established in 2014, Grandex Door Solutions Co., Ltd. is a premier entry door manufacturer operating from a modern 35,000 m² facility. With 16 years of industry expertise and 8 years of dedicated export experience, the company generates an annual export revenue of USD 28 million.
Grounded in strong OEM and ODM trade backgrounds, our products primarily serve North America and Western Europe, supported by a network of over 1,200 supply chain partners. We cater to leading building material distributors, real estate developers, and commercial contractors.
Quality is integral to our operations: supported by strict ISO 9001 certified internal testing and third-party laboratory verification, our 45-member QA team ensures rigorous quality control throughout production. Driven by an active R&D division with 85 specialized engineers, we introduced 120 new door designs last year and offer full custom solutions spanning custom dimensions, security locks, surface finishes, and decorative glass panels.
Water ingress in modern architecture causes structural degradation, mold proliferation, and internal finish damage. Our waterproof aluminum doors solve moisture penetration at a molecular and structural level.
Traditional sliding and hinged doors fail during wind-driven rain because wind pressure forces water past threshold barriers. Our proprietary profile geometries incorporate pressure-equalized inner chambers. By balancing internal sash pressure with external ambient wind velocity, surface tension breaks, directing water outwards through hidden dynamic weep slots.
We eliminate water infiltration along perimeter joinery using continuous Vulcanized EPDM (Ethylene Propylene Diene Monomer) synthetic rubber gaskets. Resisting UV degradation, thermal cycling (-40°C to +120°C), and elastic compression fatigue, our triple-gasket system ensures watertight integrity rated up to 1000 Pa under hydrostatic spray tests.
Condensation is an invisible source of water damage. By embedding 24mm to 34mm fiberglass-reinforced Polyamide (PA66GF25) thermal strips between inner and outer extruded aluminum profiles, we break thermal bridges. This drastically reduces dew-point condensation inside high-humidity luxury installations.
| Performance Metric | Standard Commercial Grade | Grandex Waterproof Aluminum Systems | International Compliance Standard |
|---|---|---|---|
| Water Tightness | 300 Pa - 450 Pa | 750 Pa - 1050 Pa (Class E1050) | ASTM E331 / EN 12208 / AS2047 |
| Wind Load Resistance | 2.0 kPa - 3.0 kPa | 5.0 kPa (DP100 Hurricane Standard) | TAS 201/202/203 (Florida NOA) |
| Air Infiltration Rate | 1.5 m³/m²·h | < 0.1 m³/m²·h (Airtight Grade 4) | AAMA 501 / EN 12207 |
| Thermal Insulation (U-Factor) | 2.8 - 3.5 W/m²K | 0.8 - 1.4 W/m²K (NFRC Certified) | Energy Star / NFRC 100 |
| Acoustic Isolation | 28 dB - 32 dB | 42 dB - 48 dB (Double/Triple Laminated) | ISO 140-3 / ASTM E90 |
China dominates global architectural aluminum production through unmatched vertical integration, advanced metallurgical expertise, and extreme manufacturing efficiency.
China accounts for over 50% of the world's primary aluminum output. Sourcing directly from Chinese manufacturers ensures immediate access to high-purity 6063-T5 and 6063-T6 architectural grade aluminum alloys. These alloys provide superior tensile strength, exceptional structural elasticity under storm stress, and optimal surface reactivity for protective anodizing or fluorocarbon powder coating.
With Grandex operating a 35,000 m² automated manufacturing facility, procurement costs are lowered by 30% to 45% compared to Western European or North American domestic fabricators. B2B buyers benefit from bulk pricing on premium imported hardware (such as German Siegenia, Hoppe, or GU) combined with automated Chinese assembly precision.
Our 85-member R&D engineering department allows real estate developers and general contractors to customize structural dimensions, mullion reinforcements, thermal break gaps, and finish coatings (AkzoNobel powder coating, fluorocarbon PVDF, or wood grain transference) to exact regional building codes.
Every waterproof aluminum door leaves our ISO 9001 factory floor following rigorous multi-stage CNC precision machining and performance testing.
Raw materials
Sawing
Milling
CNC Milling
CNC Drilling
CNC Center
Cutting
Intelligent Sorting
Checking and Packing
Sawing Machine
Milling Machine
CNC Milling Machine
CNC Drilling Machine
CNC Center Machine
Double Head Cutting Saw
Intelligent Sorting Line
Semi-finished products inspection
Performance tester
Custom engineering tailored to diverse geopolitical climates, architectural designs, and functional building requirements.
For high-rise condos and waterfront estates in Florida, the Caribbean, and Australia. Integrated with PVB/SGP laminated impact glass and heavy-duty multi-point stainless steel locking hooks (Grade 304/316) that withstand Miami-Dade Florida NOA wind loads and continuous saltwater spray without corroding.
Flush-threshold lift-and-slide systems engineered for seamless indoor-outdoor transition. Featuring heavy-duty bottom tracks with concealed subterranean drainage channels that handle extreme downpours while maintaining ADA-compliant barrier-free entry.
Basements and semi-subterranean walkouts face severe surface water run-off and thermal bridge ice build-up. Thermal break tilt-and-turn windows and outward-opening hinged entrance doors provide double moisture barriers and thermal conservation.
Navigating global import requirements requires absolute certification alignment. Grandex doors are pre-tested to meet major Western building standards.
For importers and commercial builders in North America, thermal efficiency and fenestration integrity are paramount. Our products undergo rigorous testing by accredited NFRC (National Fenestration Rating Council) laboratories, delivering verifiable U-factor ratings down to 0.22 BTU/h·ft²·°F and SHGC (Solar Heat Gain Coefficient) optimized for northern cold zones or southern warm zones. Furthermore, structural strength meets AAMA/WDMA/CSA 101/I.S.2/A440 rating standards.
Exporting to Australia requires strict compliance with AS2047 (Windows and External Glazed Doors in Buildings) and AS1288 glass selection codes. Grandex products undergo severe deflection, air infiltration, water penetration (up to Class 450Pa/600Pa), and ultimate strength tests. For the European market, full CE marking and EN 14351-1 compliance guarantee compliance with rigorous thermal, acoustic, and environmental directives.
Explore our full line of commercial entry doors, panoramic floor-to-ceiling fixed windows, and heavy-duty bi-folding door systems.
How next-generation materials and architectural trends are shaping the future of waterproof aluminum fenestration.
Modern luxury architecture demands maximum daylight and expanded glass area. Emerging manufacturing techniques use high-tensile 6063-T6 aluminum alloys to shrink sash frames to ultra-narrow profile widths (as slim as 18mm) while retaining DP100 hurricane impact ratings and water resistance.
Waterproof doors are increasingly integrating smart building management systems (BMS). Automatic rain sensors automatically close bi-folding and sliding doors at the first drop of precipitation, while motorized multi-point locks integrate seamlessly with biometric access control.
With global ESG mandates, global buyers prioritize suppliers using recycled aluminum billets and low-VOC PVDF surface treatments. Grandex leverages energy-efficient electric melting furnaces and closed-loop water filtration to minimize carbon footprints.
Expert technical insights regarding sourcing, structural performance, custom OEM capabilities, and international logistics.
Grandex Door