Outdoor Aluminium Solutions

Why aluminium for outdoor structures?

Outdoor structures live in the harshest conditions a building product faces: full sun, rain, coastal salt, temperature swings, wind and, in some regions, snow. Timber needs regular treatment and eventually rots; steel rusts the moment its coating is damaged; PVC softens and yellows under strong UV. Aluminium forms its own protective oxide film, keeps its strength across the outdoor temperature range and can be coated to last for decades.

Extrusion is the other reason aluminium dominates outdoor living. A single profile can combine a structural beam, a hidden gutter, a cable channel for lighting, a screw port for end caps and a track for screens. That integration gives clean, modern lines with no visible downpipes or wiring, and makes systems quick to assemble from pre-cut kits.

Weight matters too. Aluminium has about one third the density of steel (2.70 g/cm³ against 7.85 g/cm³), so a 4 × 4 m pergola frame can be carried and erected by a small crew without lifting equipment, footings are smaller, and shipping costs per unit are lower. For roof terraces and balconies, where every kilogram loads the building structure, that difference often decides the material.

Outdoor aluminium systems at a glance

Pergolas and gazebos

Pergolas and gazebos form the largest group of outdoor aluminium systems. Both provide shade; the differences lie in the roof and in how the structure is supported.

Residential gazebos and pergolas are commonly sold in footprints from about 3 × 3 m (10 × 10 ft) to 5 × 5 m (16 × 16 ft). Popular intermediate sizes are 3 × 3.6 m (10 × 12 ft), 3.6 × 3.6 m (12 × 12 ft) and 3.6 × 4.9 m (12 × 16 ft). Post sections typically range from about 80 × 80 mm to 120 × 120 mm for residential units and 150 × 150 mm and larger for commercial structures and multi-bay canopies.

Sunrooms, solariums and screen rooms

When the aim is to use outdoor space through more of the year, the structure gains walls. How far to enclose it depends on climate, budget and how the room will be used.

A sunroom performs only as well as its weakest component. For year-round rooms, specify thermally broken profiles, insulated glass with solar control, an insulated roof, cross-ventilation (opening vents low and high) and drainage that copes with heavy rain on a large glazed roof. In hot climates, shading and ventilation are more important than U-value; in cold climates, the reverse. Screen rooms usually use fibreglass mesh around 18 × 16 strands per inch, or finer 20 × 20 mesh where small biting insects are a problem; aluminium mesh resists pets and damage better.

Carports, sheds, greenhouses and screens

Boundary fences, pool fences and balcony railings use the same profile families. They are covered in detail on our fence and railing systems, slat fencing and privacy fence and gate pages.

Common alloys and tempers for outdoor systems

Nearly all outdoor profiles are 6xxx-series Al-Mg-Si alloys, which extrude well, take coatings evenly and are age-hardened to useful strength. The choice between them depends on the load a member carries and the surface finish required. Values below are EN 755-2 minimums for thin-walled profiles.

Minimum properties fall slightly for thicker walls. North American projects specify ASTM B221, where 6063-T5 is 152 MPa tensile and 110 MPa yield minimum and 6061-T6 is 260 MPa and 240 MPa.

As a rule of thumb, 6063-T5 covers the majority of outdoor members; move to 6063-T6 or 6005A-T6 when spans grow, and reserve 6061-T6 for parts where strength matters more than surface finish. Roof sheet, fascias and shed panels are usually coated 3003, 3105 or 5005 sheet; see our 5005 sheet and colour-coated sheet pages.

Colours and surface finishes

The finish decides how an outdoor structure looks after ten years. Select it by exposure: UV intensity, distance from the sea, industrial pollution and how often the structure will be cleaned.

Within about 1 km of the sea or near swimming pools, specify a marine-grade pretreatment (for example Qualicoat Seaside), a durable coating class and A4 (316) stainless steel fasteners. Dark colours absorb more heat and expand more; allow for movement at long runs of fence and pergola beams.

Design, hardware and installation considerations

• Loads: design to local codes, for example EN 1991 (Eurocode 1) in Europe, ASCE 7 in the United States, IS 875 in India and AS/NZS 1170 in Australia; check the aluminium members to EN 1999 or the Aluminum Design Manual.
• Wind on enclosures: adding glass, screens or solid privacy panels greatly increases wind load on posts and anchors compared with an open frame.
• Snow: in snowy regions, state the design snow load at the outset; louvre blades, polycarbonate and long spans are the usual limits.
• Drainage: concealed gutters in beams and downpipes in posts need outlets sized for local rainfall and directed away from paths and footings.
• Fixings and contact: use stainless fasteners, isolate aluminium from copper, bare steel and treated timber, and avoid trapping water at post bases.
• Foundations: concrete pads or slabs with anchors sized for uplift; on timber decks, fix to the structural frame, not the boards.
• Hardware: hinges, locks, rollers and motors should be rated for outdoor use and for the panel weights involved; preferred hardware brands can be matched on request.

How to choose the right outdoor aluminium product

1. Define the useShade and airflow points to a pergola or gazebo; seasonal or year-round living to a screen room or sunroom; growing, parking or storage to a greenhouse, carport or shed.
2. Check the siteFreestanding or against a wall, ground or roof terrace, available footings, and access for installation.
3. Set the climate requirementsWind and snow loads, rainfall, UV, coastal exposure and whether heating or cooling will be used inside.
4. Choose featuresManual or motorised roof, lighting, side screens, glass walls, insect mesh, privacy panels, heaters.
5. Confirm finish and documentsColour and coating class, packing and labelling, and any certificates or test reports needed in the target market.

Export orders are packed with profiles protected by film and wrapping, small parts bagged and labelled by part number, and pallets or wooden crates suited to sea freight. Mixed containers combining profiles for several systems are common.

Explore outdoor and building systems

Outdoor aluminium (aluminum) structures: FAQ