Wood
For street furniture, in public spaces, the choice of wood is critical, as it determines the product’s longevity, maintenance requirements, and aesthetic ageing.
Metalfabrik offers two types of wood for street furniture; all are sustainably sourced and carry the FSC certificate.
- Softwood: Pine and Spruce
Pine is one of the most common materials for outdoor furniture due to its availability and initial low cost. It has a light, yellowish colour with grain patterns and knots. Because it is a softwood, it is naturally susceptible to decay, shrinking, and swelling. For street furniture, it must be treated with preservatives to ensure it withstands the natural elements, including humidity and UV radiation.
- FSC Tropical Wood: Iroko
Often referred to as African Teak, Iroko is a tough, dense wood with a rich, reddish-brown colour. It contains high oil content, which acts as a natural preservative against the weather. It is durable and naturally resistant to rot, decay, and insect attacks without the need for regular coating and maintenance. It is very stable and handles the wear and tear of public use exceptionally well.
Summary
- Pine has a nice and natural look and is cost-effective, but requires regular treatment to prevent rot and warping.
- Iroko is a choice for longevity, offering natural resistance to decay and high durability in public spaces. Although it is sourced from tropical climate zones, the maintenance-free service may pay off both in ecological and financial aspects.
Wood treatment
For Softwood:
- OrganoWood stain
OrganoWood is an innovative, eco-friendly wood protection system from Sweden that encapsulates the wood fibres with silicon minerals, creating a physical barrier that protects the wood from rot and fire.
Initially, the wood retains its natural colour, but over time and with exposure to the elements, it develops a uniform silver-grey patina.
It reduces the risk of cracking, is cool to the touch on sunny days, and requires low maintenance compared to traditional wood treatments.
OrganoWood ageing
- Remmers stain
Remmers is a premium German-engineered wood stain. Water-based “Aqua” range is a sustainable alternative to solvent-based stains, offering deep colour penetration while remaining breathable and moisture-regulating.
For Tropical Wood:
Tropical wood for street furniture can be coated with modified oil or left untreated.
Non-Treated (natural) tropical wood turns in a silvery-grey patina over time due to UV exposure. It requires almost no maintenance beyond basic cleaning, as the wood’s natural density protects it from rot and insects for decades. Oiled wood maintains the original deep brown/reddish colour. However, it requires regular re-oiling to prevent it from greying.
Untreated v.s oiled tropical wood
Metal
For urban furniture, commonly used metals are carbon steel, stainless steel, aluminium and cast iron. Each metal has its own properties that determine its applications. Here are the most common uses for each metal.
- Carbon Steel
Carbon (or mild) steel gives sturdiness to the structure. Thanks to this quality, the furniture is durable and long-lasting. At the same time, we can have comparatively thin frame lines, thus delivering a ‘clean’ and minimalistic look.
- Stainless Steel
Stainless steel has a natural quality to remain semi-shiny and radiant over time, which gives a contemporary appeal. A more rust-resistant grade, AISI316 is selected on demand for close to marine and chemically aggressive environments.
- Aluminium
Aluminium has excellent corrosion resistance when treated with our coating system, including surface pretreatment and 2-layer powder coating.
Besides, aluminium has an outstanding quality to maintain its shape and dimensions when welded. Therefore, it is used in large-sized planters where the surface plane should be even and free from any distortions.
- Iron
Iron is used in some of our classic-style pieces of furniture, where only the casting method can be used to obtain the ornamental components. Cast iron elements give a unique look that couldn’t be achieved otherwise.
5. Corten steel (aka weathering steel)
Commonly used in contemporary-style planters and tree grilles, Corten steel is chosen for its unusual reddish-brown colour, durability and low maintenance requirements.
Metal Coatings & Finishes
Metal surfaces can be treated by various methods, each of them delivering different visual effects and longevity results.
1. Hot dip galvanisation (HDG)
HDG gives maximum protection against rust in the open air. A layer of zinc is melted onto the carbon steel, giving a decades-long life cycle to the outdoor furniture. It is maintenance-free and is regarded as one of the most efficient anti-corrosion solutions.
2. Powder coating
This finish is applied as a top coat, usually to the galvanised and pre-treated surface. Powder coat delivers a uniform coating with excellent adhesion characteristics, abrasion and chemical resistance. It contains no solvents and doesn’t emit volatile organic compounds (VOCs) into the atmosphere.
We offer three colour palettes to suit various occasions. The specific RAL colour is possible on demand.
3. Blasting + powder priming & coating
This surface protection system has largely replaced HDG for the reasons of delivering better paint adhesion, better appearance, less material distortion, shorter production time and smaller ecological footprint. This coating system is used for all sheet material except closed profiles and tubes, as well as for iron.
4. Brushedsurface for stainless steel
This surface finish delivers a smooth and unidirectional finish. We use G300 coarse grain for grinding, giving the surface a semi-shiny appearance.
5. Bead-blasted surface for stainless steel
Another finish for stainless steel used to obtain a more matte effect than the brushed surface. Microscopic glass beads under high pressure are applied (blasted) on the surface to acquire an opaque and smooth look. The bead-blasted finish protects against oxidation of the stainless steel surface, and it doesn’t fade over time.
Low-maintenance Materials
These four optional selections of materials ensure the demanding levels of resistance and aesthetics:
- Stainless steel
Normally, painted surfaces tend to lose lustre over time, especially bike racks that may acquire scratches. It will require repainting and a range of additional upkeep tasks. Anyone who decides on stainless steel will find there is minimal maintenance for the street furniture to retain its original attractive look. Please consult us on choosing the steel grade and finish for the best results.
- Hot-dip galvanised steell
HDG ensures a decades-long life cycle even in harsh urban, industrial and next-to-marine environments.
- Corten steel (aka weathering steel)
Corten steel has a long service life with minimal maintenance. It performs best where the surface can dry naturally after rain. To support the rust patina, gently clean exterior surfaces at least once a year with a soft nylon brush, warm water, and mild soap. - FSC Iroko tropical wood
Iroko requires no maintenance to retain its mechanical properties. For an eye-catching visual appearance, we advise little maintenance by removing dirt and re-oiling it once it loses its initial look.
Follow the instructions on https://metalfabrik.eu/maintenance/.