13.3 Batten Material and Finishes for Street Furniture

Draffin Technical Note 13.3

The vast majority of street furniture utilises a frame and batten style design (eg. cast aluminium frame set with timber battens). Most street furniture suppliers have an array of options in this regard, with each option having its own advantages and disadvantages. These fall into the following categories:

  • Durability
  • Strength
  • Aesthetic Value (subjective/personal)
  • Cost
  • Environmental Impact/Sustainability
  • Availability
  • Maintenance Requirements

In this Tech Note, we will hopefully be able to share some of our experience to make it easier for you to choose the best material and finish for your project.

Timber Battens for Street Furniture

Kwila aka, Johnstone River teak, scrub mahogany (Nth Qld), merbau (Malaysia), vesi (Fiji)

Typically imported from Indonesia, Kwila has many excellent properties for outdoor furniture. The dense, consistent grain makes it very strong and free from imperfections, and the natural oils give a range of benefits for durability, including natural termite protection. Although the Indonesian Government has banned the export of timber that is not verified as sustainable, conservationists allege that much of it is exported illegally, which is becoming a major factor when choosing materials.

Pros

  • Very few imperfections, straight, consistent colour and grain
  • Great Colour
  • Highly Durable for outdoor applications
  • Strong, long spans between supports
  • Readily Available

Cons

  • Sustainability is questionable
  • Requires periodic sanding/oiling to keep colour, stop from cracking

//www.daff.qld.gov.au/forestry/using-wood-and-its-benefits/wood-properties-of-timber-trees/kwila

Blackbutt

Generally grown in sustainable plantations in Australia, Blackbutt is a very dense timber that is becoming quite popular among municipalities due to its sustainability and durability. Its major pro is also its major con, which is its variety of colour and grain. Some users love the character, others don’t. Like a lot of eucalypt species, it can be prone to twisting, cracking and gum vein.

Pros

  • Sustainably Produced
  • Very Dense
  • Character
  • Highly Durable for outdoor applications
  • Strong, long spans between supports
  • Readily Available

Cons

  • Prone to Splitting and Cracking
  • Inconsistent Colour and Grain
  • Prone to Gum Vein

//www.daff.qld.gov.au/forestry/using-wood-and-its-benefits/wood-properties-of-timber-trees/blackbutt

Spotted Gum

Generally grown in sustainable plantations in Australia, Spotted Gum is another Eucalypt similar in characteristics to Blackbutt. Its defining feature is variety of colour and grain, which adds huge character when shown off, but is not favoured for some applications.

Pros

  • Sustainably Produced
  • Very Dense
  • Character
  • Highly Durable for outdoor applications
  • Strong, long spans between supports
  • Readily Available

Cons

  • Prone to Splitting and Cracking
  • Inconsistent Colour and Grain
  • Prone to Gum Vein

//www.daff.qld.gov.au/forestry/using-wood-and-its-benefits/wood-properties-of-timber-trees/blackbutt

Treated Pine

Pros

  • Sustainably Produced
  • Consistent Colour
  • Cheap
  • Readily Available
  • Easy to Machine

Cons

  • Soft
  • Needs Treating to make it suitable for outdoor use

Sustainability of Timber

Contrary to a lot of popular opinion, timber is a very sustainable material to use, if it is sourced from a sustainable plantation. The act of using timber creates a static store of carbon, as long the tree is replaced when harvested then more carbon is now in solid form rather than C02 in our atmosphere. There is also opinion that the production process of growing and harvesting timber produces less C02 than other materials, ie Aluminium, Composites.

Timber Finishes

No Finish

Durable hardwoods can be left untreated and can do quite well in open spaces. The timber will tend to go grey within 12 months, and may crack and splinter more than if coated, but will generally last a long time in this state. Among councils there is an increasing trend towards leaving timber uncoated. This frees them of the need to maintain the finish (which may not have been done anyway). It has also become vouge in some applications, particularly in conjunction within Stainless Steel.

Quantum/Cutek Style Stains

Water soluble, non toxic, non flammable, deep penetrating commercial timber finishes. Generally tinted and can be re-coated/repaired on site with brush.

Pros

  • Cost Effective
  • Natural Look
  • Easy Application
  • Low Environmental Impact

Cons

  • Requires recoat min 12 monthly

2 Pak/Polyurethane/Marine Clears

By using a hard clear coating that sits on the surface of timber like glass, you can achieve a look that is stunning. However, the number one downside is that they tend not to stand up in areas where you find street furniture. Because they are clear, they are prone to be broken down by UV, and because they are hard, they will crack and become opaque as timber moves with temperature/humidity. There are different systems that work to varying degrees, but in general it is wise to steer clear of any clear coating on timber that dries hard on the surface for outdoor use.

Pro’s

  • Beautiful Finish
  • Hard Wearing
  • Protects Timber

Cons

  • Breaks Down in environment
  • Expensive Process
  • Generally not environmentally friendly
  • Difficult to apply
  • Toxic chemicals

 

Timber Alternatives

Composite Battens for Street Furniture

There are now a variety of different composite battens available, offering a wide range of textures and colours to replace the use of timber. Most of these products use a mixture of recycled plastic and recycled timber waste, bonded together with some virgin materials and glues. Marketed mainly for its environmental benefits, there is some who would argue that the production process, shipping, power, virgin materials and chemicals make it no more environmentally friendly than sustainable timber. However composites do have other advantages, such as no ongoing maintenance, and uniform finish.

Recycled Plastic

Made from almost 100% recycled plastic, the main benefits are the sustainability and the lack of maintenance required. A large variety of batten sizes are available, and the product is reasonably priced. However, size for size the product is far weaker than timber, so either much larger sections need to be used, or more supports. This makes it impractical for some designs.

Pros

  • Sustainability
  • Variety of Colours available
  • Zero Maintenance
  • When large sections used very hardy

Cons

  • Weak, needs more support than same sized timber
  • Can sag in sun
  • Can add cost to furniture if more supports are required than timber

Anodised Aluminium

Light, strong, low maintenance, economical; aluminium is a great material for many applications. Finish and section properties are always constant and free from imperfections. Aluminium profiles can span large distances making it possible to work with less framing which reduces cost. The big downside of aluminium is the environmental impact, both in the extremely high use of electricity to manufacture, and the release of perfluorcarbons

Pros

  • Consistent
  • Economical
  • Durable
  • Maintenance Free
  • Large Spans

Cons

  • Environmental Impact
  • Clinical look that doesn’t suit all applications

 

Draffin Street Furniture and Battens

Draffin Street Furniture has vast experience with all of the above batten options. We have no prejudice towards any of above, other than ensuring that what we recommend fits the needs of the customer and the environment in which they are to be used. Each customer has a different set of priorities and our own is to meet these needs. If you have and questions or need advice when specifying a batten material please contact one of our friendly engineers. We love to put our experience and resources to work helping solve our customer’s problems.

Sources

1. //www.daff.qld.gov.au/forestry/using-wood-and-its-benefits/wood-properties-of-timber-trees

2. //www.csiro.au/Outcomes/Climate/Reducing-GHG/Measuring-the-environmental-impact-of-aluminium-production.aspx.