Aluminium or Polypropylene for Terrace Furniture? A Guide for Hospitality Professionals
When a restaurateur or hotelier orders furniture for a terrace, the question of material comes up sooner or later. Aluminium and polypropylene are by far the most common materials for professional outdoor use today — yet they differ in properties, suitability and cost logic more than first appearances suggest.
This guide is not an advertisement for either. It is a comparison that helps you understand which material is right for your specific context.
Why Material Is Not a Trivial Decision
Furniture for a hospitality terrace is not merely a visual choice. It is a logistical, maintenance and financial decision you will live with for the next 8 to 15 years. A material that is ideal for a hotel pool terrace in a Mediterranean climate is not necessarily optimal for a restaurant with mixed indoor and outdoor use in a continental climate.
Both materials — aluminium and polypropylene — are represented today among certified professional furniture for the HoReCa sector. Furniture for public use must, under standard EN 581-2 (Class 2 / Contract), pass considerably stricter tests than its domestic equivalent: the static seat load for the professional class is 150 kg without permanent deformation, compared to only 90 kg for the domestic class. This difference in requirements is reflected both in structural dimensioning and in material selection — and it applies to both materials discussed here.
Aluminium: Lightness, Long Service Life, Premium Positioning
Material Properties
Professional outdoor aluminium furniture is most commonly made from powder-coated aluminium profile with a wall thickness of 2.0–2.5 mm or more. Thinner profiles (1.0–1.5 mm) appear in cheaper furniture for domestic use — they are not suitable for professional HoReCa applications.
Aluminium is:
- Exceptionally corrosion-resistant — it does not rust, which is particularly relevant for coastal locations, pool terraces and humid climates
- Dimensionally stable at high temperatures — an aluminium frame does not deform in the heat, a significant advantage over plastic
- Long-lasting — quality powder-coated aluminium furniture lasts 10–20 years without major intervention
- Highly recyclable — according to the European Aluminium Environmental Profile Report (2024), aluminium recycling rates in Europe are among the highest of any material; recycled aluminium requires only around 5% of the energy needed for primary production
- Visually neutral and premium — aluminium is associated with a higher price class and integrates well into contemporary hotel and restaurant concepts
You will find aluminium chair and table models for professional use in our range of garden chairs and garden table bases and tables. Two typical examples of aluminium construction in our range are the Victory ZRN, with an aluminium frame and a techno-rattan seat with double UV protection, and the Teak Alu ZRN, which combines an aluminium frame with a teak wood seat — both certified to SIST EN 581-1 and 581-2.
Weaknesses of Aluminium
It heats up. Aluminium conducts heat better than plastic — furniture in direct sunlight becomes hot to the touch, which is unpleasant for guests at the pool. The solutions are shading, textile seats (Batyline, Textilene) or furniture with mesh seats, which reduce skin contact with the surface. On sun loungers for pool terraces, the combination of an aluminium frame and a textile sling is the industry standard for precisely this reason.
Higher purchase price. A professional aluminium chair is on average more expensive than an equivalent polypropylene model. The difference depends on the model and supplier, but it is noticeable when comparing equivalent classes.
Coating durability: Research published in the journal Metals (MDPI), comparing the corrosion resistance of powder-coated 6060 aluminium alloy, showed that a properly applied coating provides high barrier protection — but only as long as it remains undamaged. Mechanical damage (scratches, impacts) is the point where moisture begins to penetrate beneath the coating. Coating systems that include pre-anodising demonstrated significantly better resistance under prolonged exposure to moisture and salt. Reputable suppliers offer coating touch-ups as part of their maintenance programme.
Powder coating is not used on aluminium alone — an example of a quality powder-coated metal construction for professional outdoor use is the Philia Mesh by the Italian manufacturer Pedrali, where the tubular steel frame is protected with a powder coating designed for outdoor conditions.
Polypropylene: Practicality, Colour Options, Economy
Material Properties
Polypropylene (PP) is a thermoplastic that appears in professional furniture in two versions: pure polypropylene and glass-fibre-reinforced polypropylene (GFR PP). For professional HoReCa use, the reinforced version is recommended — its rigidity and resistance to deformation at high temperatures are significantly better.
Quality polypropylene for outdoor use:
- Contains UV stabilisers mixed into the mass — not merely applied to the surface. The colour runs through the entire material, not just the surface. When the surface wears over time, the colour does not disappear.
- Is lighter than aluminium alternatives — an advantage for folding and stacking furniture that is moved frequently
- Offers a wider range of colours — mass colouring allows a rich colour spectrum without coating limitations
- Is easier to clean — a smooth surface without coating layers means there are no points where dirt can work its way beneath the surface
- Is more affordable — at equivalent strength classes, polypropylene is often cheaper than aluminium
You will find polypropylene and other plastic models for intensive hospitality use among our garden chairs and banquet chairs. A textbook example of properly formulated GFR polypropylene is the Trill ZRN by the Italian manufacturer Nardi — glass-fibre-reinforced polypropylene with additional UV protection, a 200 kg load capacity, CATAS certified to UNI EN 581-1 and 581-2, at a weight of just 3.7 kg and stackable up to 6 pieces.
Weaknesses of Polypropylene
Thermal deformation. Polypropylene is a thermoplastic material — at high temperatures (55–70 °C on the furniture surface in full sun) it softens slightly. In quality reinforced PP this effect is minimal and reversible; in unreinforced or blended PP, permanent seat deformation appears after seasons of intensive use.
Embrittlement with age. UV degradation of polypropylene proceeds via photo-oxidation — UV rays break down the polymer chains, progressively reducing the material's tensile strength and elongation. A study published in Photochemical & Photobiological Sciences (Springer Nature, 2023) showed that inadequately stabilised polymers lose a large share of their mechanical properties after prolonged sun exposure — the material becomes brittle and cracks under load instead of flexing. The key difference between quality and cheaper products lies precisely in the formulation: UV stabilisers mixed into the mass work throughout the material's entire service life, while surface coatings break down within the first seasons. A separate study (ResearchGate, 2025) measured changes in the tensile strength of PP at various durations of UV exposure and confirmed that degradation in unstabilised PP is noticeable after just 500 hours — which, on a terrace with intensive sun exposure, means less than a single season. An EN 581 certificate for professional use is one indicator that the material is properly formulated; details are in our guide to certificates for HoReCa furniture.
Visual class. Polypropylene is often perceived as more functional and less prestigious than aluminium — a relevant limitation for certain hospitality concepts (high-category hotels, fine dining).
Direct Comparison by Key Parameters
| Parameter | Aluminium | Polypropylene (GFR) |
|---|---|---|
| Corrosion resistance | Excellent | Excellent (no metal) |
| UV resistance | Excellent (coating) | Excellent (stabiliser in mass) |
| Dimensional stability in heat | Excellent | Good (in reinforced version) |
| Weight | Medium | Low |
| Purchase price | Higher | Lower |
| Service life (professional use) | 10–20 years | 7–15 years |
| Colour options | Limited (coating) | Wide (colour in mass) |
| Maintenance | Minimal | Minimal |
| Replaceable parts (seat, mesh) | Yes (modular models) | Rarely |
| Visual class | Premium | Functional |
When Aluminium Is the Better Choice
Aluminium is the optimal solution for:
- Hotel pool terraces, where furniture is in constant sun exposure and in contact with moisture and chlorine — see our range of sun loungers
- Coastal and Mediterranean locations, where salty air accelerates steel corrosion and plastic degradation
- Lounge and wellness terraces, where visual class is part of the product and a premium appearance is expected
- Long-term investments, where total cost per year of use matters more than purchase price
- Locations with intense sun and no shading, where plastic heats up and deforms more — combined with parasols, the load on the furniture is further reduced
When Polypropylene Is the Better Choice
Polypropylene is the optimal solution for:
- Restaurants and cafés with mixed indoor and outdoor use, where furniture is frequently moved between spaces
- Event and congress configurations, where fast folding and transport are key operational parameters — see folding tables and banquet chairs
- Schools, cultural institutions and municipal facilities, where purchase price is a limiting factor and the furniture is not exposed to extreme conditions
- Shaded locations (pergolas, canopies), where the furniture temperature stays lower
- Seasonal installations, where furniture is not used over winter and is stored indoors
What About HDPE?
High-density polyethylene (HDPE) is the third plastic alternative, found in professional furniture in certain premium lines — among them ZOWN New Classic, where HDPE is the material of the seats and tabletops. Compared to standard polypropylene, HDPE has better dimensional stability under prolonged static load and is somewhat more resistant to high temperatures.
An experimental analysis published in npj Materials Degradation (Nature, 2025) examined how different ageing conditions — thermal ageing, moisture and UV exposure — affect the mechanical properties of HDPE. The results showed that HDPE retains a significantly higher share of its initial tensile strength and toughness compared to standard PP under the same ageing conditions, confirming its advantage in intensive outdoor use.
In practice, HDPE positions itself between standard polypropylene furniture and aluminium — higher plastic quality, lower price than aluminium, longer service life than standard PP. We have covered the ZOWN collection in more detail in our ZOWN New Classic overview.
Total Cost per Year of Use: The Key Calculation
Purchase price is the wrong criterion for comparing furniture materials in professional use. The right criterion is total cost per year of use — purchase price divided by years of use, plus maintenance.
An example for a restaurant chair:
| Aluminium (premium) | Polypropylene (professional) | |
|---|---|---|
| Purchase price (indicative) | €180 | €80 |
| Expected service life | 15 years | 10 years |
| Annual cost excluding maintenance | €12 | €8 |
| Maintenance (annual, average) | €1–2 | €0.5–1 |
| Total annual cost | ~€13–14 | ~€8.5–9 |
The difference in annual cost is smaller than the purchase price suggests. For hotels and complexes ordering 200 or more pieces, this difference totals €800–1,000 per year — relevant, but not decisive if aluminium offers a better guest experience.
Practical Advice for the Decision
Before ordering, answer three questions:
1. What is the location's exposure? Direct Mediterranean or coastal conditions, constant sun exposure and moisture — choose aluminium or HDPE. A shaded terrace in a continental climate — polypropylene is sufficient.
2. What is the visual standard of the concept? Boutique hotel, fine dining, wellness — aluminium. A restaurant focused on functionality and fast guest turnover — polypropylene.
3. How often is the furniture moved? Event use, stacking, transport between venues — polypropylene or HDPE (lighter). Fixed or semi-fixed installation — aluminium.
For larger hotel projects, it is also worth looking at our dedicated hotel equipment page, which brings together models suitable for public use.
Conclusion
There is no universally better material. Aluminium wins on durability, visual class and resistance to extreme conditions; polypropylene on price, weight and colour options. For most hospitality terraces, both materials — given a correctly chosen model and a certificate for professional use — are sound long-term solutions.
The mistake hospitality operators make most often is not choosing wrongly between aluminium and polypropylene furniture — it is buying domestic-class furniture for professional use. The difference between Class 1 and Class 2 under EN 581 is, at that point, more decisive than the choice between materials.
Looking for aluminium or polypropylene furniture for your terrace? Contact us — we advise on material, model and certification for your specific location and use.
Autor članka: Jan Češnjevar
Sources and References
- EN 581-2 (mechanical strength requirements for outdoor seating, Classes 1 and 2): CEN — European Committee for Standardization
- EN ISO 105-B02 (colour fastness of textiles to light): ISO — International Organization for Standardization
- REACH Regulation (EC) No 1907/2006 — chemical safety of materials: EUR-Lex
- Effect of UV stabilisers on polypropylene in outdoor exposure: Effects of UV Stabilizers on Polypropylene Outdoors — PubMed Central / PMC. The study documents the mechanisms of UV degradation of PP and the effectiveness of different stabiliser types.
- Effect of UV exposure duration on polypropylene properties: Study of the Effect of Ultraviolet Exposure Duration on Polypropylene Properties — ResearchGate. Measures changes in the mechanical properties of PP at various durations of UV exposure.
- Effects of UV radiation on natural and synthetic materials: Effects of UV radiation on natural and synthetic materials — Photochemical & Photobiological Sciences / Springer Nature. A comparative study of the degradation of various polymers under solar and artificial UV exposure.
- Mechanical properties of HDPE under various ageing conditions: Experimental and numerical investigation on mechanical properties change of HDPE in various aging conditions — npj Materials Degradation / Nature. An experimental analysis of how ageing conditions (heat, moisture, UV) affect the strength parameters of HDPE.
- Corrosion resistance of powder-coated aluminium — comparison of coating systems: Investigation of Corrosion Resistance in Powder-Coated 6060 Aluminum Alloy — Metals / MDPI. Compares the resistance of anodised and powder-coated aluminium under corrosive conditions.
- FIRA International — testing and certification of contract seating (EN 581): FIRA International Seating Testing — a UKAS-accredited laboratory for furniture testing to European standards, including EN 581.
- European Aluminium — Environmental Profile Report 2024: Environmental profile of the European aluminium industry — Data on the recyclability, carbon footprint and sustainability characteristics of aluminium in Europe.
- PlasticsEurope — The Circular Economy for Plastics (2024): The Circular Economy for Plastics — A European Analysis — Data on the recyclability of PP and HDPE and the environmental characteristics of polymer materials.
- Certificates for HoReCa furniture — vebo.si guide: Certificates for HoReCa Furniture: What a Professional Chair, Table or Lounger Must Have
- ZOWN New Classic — collection overview: ZOWN New Classic: Professional Folding Furniture