What is aluminium in construction?
Aluminium is a lightweight, corrosion-resistant metal widely used in construction for window frames, curtain walls, roofing, cladding and structural elements. With a density roughly one-third that of steel, aluminium offers an excellent strength-to-weight ratio, making it a popular choice in both residential and commercial building projects.
Key properties
| Property | Value / Description |
|---|---|
| Density | ~2,700 kg/m3 (about 1/3 of steel) |
| Melting point | ~660 degrees C |
| Corrosion resistance | Naturally forms a protective oxide layer |
| Thermal conductivity | High (~205 W/mK) — requires thermal breaks in frames |
| Recyclability | 100% recyclable without loss of quality |
| Strength | Moderate; increased through alloying (e.g. 6060, 6063 alloys) |
Common applications
Window and door frames
Aluminium frames are slender, strong and virtually maintenance-free. Modern aluminium frames include a thermal break (a plastic or polyamide strip between the inner and outer profiles) to reduce heat transfer and meet insulation requirements.
Curtain walls and facades
Large commercial buildings often use aluminium curtain wall systems:
- Lightweight framework supports glass panels
- Allows large, uninterrupted glazed surfaces
- Withstands wind loads without excessive weight on the structure
Roofing and cladding
- Standing seam roofing — aluminium sheets joined with interlocking seams
- Composite panels — aluminium skins bonded to an insulating core (ACM panels)
- Rainscreen cladding — ventilated aluminium panels on a subframe
Structural elements
- Pergola and conservatory frames
- Balustrades and handrails
- Lightweight beams and columns in secondary structures
Advantages and disadvantages
| Advantages | Disadvantages |
|---|---|
| Lightweight — easy to handle and transport | Higher material cost than steel |
| Corrosion-resistant — no painting needed | High thermal conductivity (needs thermal breaks) |
| Long lifespan (50+ years) | Lower strength than steel (larger profiles needed) |
| 100% recyclable | Can suffer galvanic corrosion when in contact with dissimilar metals |
| Available in many finishes (anodised, powder-coated) | Energy-intensive primary production |
Surface finishes
- Anodised — electrochemical process that thickens the natural oxide layer; available in silver, bronze, black and other colours
- Powder-coated — a durable paint finish applied electrostatically and baked; virtually unlimited colour options
- Mill finish — untreated aluminium; acceptable for concealed or industrial use
Tips for DIY use
- Always use stainless steel or aluminium fasteners to avoid galvanic corrosion
- Pre-drill holes to prevent cracking or distortion
- Use a thermal break or insulating strip when aluminium meets a heated interior space
- Cut aluminium with a fine-toothed blade (carbide-tipped) on a mitre saw or circular saw
Related terms
- Curtain wall
- Thermal break
- Cladding
- Anodising
- Glazing
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