Aluminium Curtain Wall Profiles: Design, Standards & Complete Guide

Aluminium curtain wall profiles form the skeleton of every modern high-rise facade — they hold glass panels in place, channel rainwater away, and transfer wind loads to the building structure. Getting the profile design right means the difference between a facade that performs for 50 years and one that leaks, corrodes, or cracks within a decade. At NA-VIEW, we have extruded curtain wall profiles for projects across 30+ countries, including thermal break mullions, pressure plate caps, and unitised system components.

Stick-Built vs Unitised Curtain Wall Systems

Curtain wall construction falls into two broad categories, each with different profile requirements:

Stick-Built Systems

In stick-built construction, vertical mullions and horizontal transoms are delivered as individual extruded lengths and assembled piece by piece on the building site. This method requires simpler profiles and lower upfront material investment, but demands more site labour and quality control. Stick-built systems dominate mid-rise projects (under 30 storeys) and regions with lower labour costs.

The key extruded components in a stick-built system include: main mullions (typically 50–250 mm deep), transoms, pressure plates, cover caps, gasket channels, and thermal break profiles. Each profile must maintain precise dimensional tolerances since field assembly leaves no room for adjustment.

Unitised Systems

Unitised curtain wall panels are pre-assembled in a factory — glazing, gaskets, insulation, and spandrel panels are all installed into an aluminium frame before shipping to site. This approach requires more complex interlocking profiles with integrated drainage channels, but dramatically reduces site labour and improves quality consistency. Unitised systems are the standard for high-rise towers (30+ storeys) in developed markets.

NA-VIEW supplies extrusion profiles for both stick-built and unitised systems, with in-house capability to produce the tight-tolerance interlocking features required for unitised panel assembly.

For a full design methodology, see our curtain wall aluminium profile design guide.

Key Profile Design Requirements

Structural Performance

Curtain wall mullions must resist wind loads that increase exponentially with building height. A 50-storey tower in a typhoon-prone region like Southeast Asia can experience design wind pressures exceeding 3.5 kPa. Profile design optimises the moment of inertia (I-value) relative to aluminium weight — deeper sections with internal ribbing provide higher stiffness per kilogram of material. NA-VIEW’s engineering team works from project-specific structural calculations to recommend profile geometries that meet deflection limits (typically L/175 for mullion spans).

Thermal Break Technology

Aluminium conducts heat approximately 1,600 times faster than air — without thermal breaks, a curtain wall would be a thermal sieve. Modern thermal break profiles insert a polyamide strip (PA66 GF25) between the interior and exterior aluminium sections, creating a continuous insulation barrier. The strip width (typically 14.5–42 mm) determines the profile’s U-value — wider strips provide better insulation. NA-VIEW extrudes both the interior and exterior aluminium halves of thermal break profiles, with integrated strip-retention geometries that ensure mechanical interlock after the roll-crimping process.

For detailed cost-performance analysis, read our thermal break aluminium window cost guide.

Drainage and Weather Sealing

Curtain wall profiles must incorporate a pressure-equalised drainage system — a network of internal chambers and weep holes that equalises air pressure between the outside and the internal glazing pocket. This prevents rainwater from being driven into the building by wind pressure differential. The profile design must include: a rain screen chamber (outer), a pressure equalisation chamber (middle), and an air seal chamber (inner). Each chamber requires specific profile features — drainage slots, gasket grooves, and condensation collection channels — that are most cost-effectively produced through extrusion rather than post-machining.

Standards and Compliance

Curtain wall profiles must comply with regional standards that govern structural, thermal, and durability requirements:

• EN 13830 (Europe): Product standard for curtain walling, covering wind resistance, water tightness, air permeability, and impact resistance.
• AAMA 501 (North America): Test methods for metal curtain walls, including dynamic water penetration and structural performance.
• AS 4284 (Australia): Testing of building facades for weather tightness and structural adequacy.
• GB/T 21086 (China): Curtain wall performance classification and testing methods.

NA-VIEW’s aluminium extrusion profiles are tested to EN 755 mechanical property standards as a baseline, with project-specific compliance documentation provided for each regional standard. All shipments include mill test certificates showing chemical composition and mechanical properties.

Aluminium Alloy Selection for Curtain Wall Profiles

Surface Finishing for Curtain Wall Profiles

Curtain wall profiles are always surface-finished for both aesthetics and corrosion protection. The most common finish for high-rise facades is PVDF (polyvinylidene fluoride) coating — a 30–40 μm fluoropolymer layer that resists UV degradation, chalking, and colour fade for 20+ years. Anodising (AA15–AA25 grade) is also widely used, particularly for natural metallic and bronze finishes. Powder coating (Qualicoat Class 2) is an option for interior-facing components and lower-budget projects.

Our aluminium surface treatment comparison covers all finishing technologies in detail.

Procurement from NA-VIEW

When you source curtain wall aluminium profiles from NA-VIEW, here is what to expect:

• Die design review within 7 working days: Our engineers evaluate your profile drawing for extrusion feasibility, suggest geometry optimisations, and provide a fixed die cost quotation.
• Sample production within 3 working days: Three free samples for your dimensional and surface quality verification.
• ±0.5 mm tolerance on all critical dimensions, with tighter tolerances negotiable for interlocking features.
• 25–35 day production lead time after sample approval, with ISO 9001 quality documentation throughout.
• FOB, CIF, or DDP shipping — we export to ports worldwide in seaworthy wooden crates with interleaving protection.
• Payment by T/T, L/C at sight, or PayPal for sample and small-batch orders.

Frequently Asked Questions

What is the standard length of curtain wall aluminium profiles?

Standard production lengths are 5,800–6,500 mm, determined by press run-out capacity and container loading efficiency. Custom lengths can be cut to project specifications — cutting tolerance is ±2 mm.

Can NA-VIEW produce thermal break profiles?

Yes. We extrude both interior and exterior halves of thermal break profiles, including the polyamide strip retention grooves. The thermal break assembly (roll-crimping) is typically performed by the curtain wall system fabricator; we can also arrange this through partner facilities if needed.

What surface finishes are available for curtain wall profiles?

PVDF coating (30–40 μm, AAMA 2605 compliant), anodising (AA15–AA25), and powder coating (Qualicoat Class 1 or 2). Colour matching to RAL, Pantone, or custom standards is available.

What are your payment and shipping terms?

T/T (30% deposit, 70% against B/L copy), L/C at sight, PayPal for orders under $2,000. FOB Shenzhen, CIF, or DDP terms available. Standard production lead time is 25–35 working days.