Timber Treatments

Regardless of species, in an external environment, the appearance of all timber will change over time through exposure to UV light, rainwater and natural water soluble tannins leaching out from the timber.

Timber species with ‘Class 1 Very Durable’ classification can be successfully used in outdoor settings without the support of preservative treatments. But where the original colouration of the timber is the preferred appearance over a longer period of time, the application of a supplementary treatment will help to retain the colour for longer. Without additional treatment, over time the timber will naturally develop a weathered silver-grey colour.

For the majority of products containing timber, we use Iroko hardwood as standard. Defined as ‘very durable’, untreated Iroko will show signs of fading within 3 months – and after 12 months the natural colouration will have disappeared in most situations. If the original colouration is preferred to be retained over a longer period of time we recommend that pre-treatment measures are undertaken at the outset.

timber slats on the Railroad bench at Vauxhall one

Treatment options

There are 2 types treatments

Film-forming coatings
Film forming coatings sit on top of the timber surface essentially like a paint, and will break down over time due to UV and/or mechanical wear (such as people sitting on them) and flake to expose the bare timber beneath. So do not recommend using film-forming coatings on our products.

Penetrative finishes
Penetrative finishes permeate into the grain to retain the natural colour of the timber for longer than untreated timber, whist also protecting against warping, splitting and cracking.

As standard our Iroko comes ‘smooth planed’ but we also offer supplementary treatments. Our most popular being a UV protective finish in a tinted ‘teak’ colour that complements the natural hue of Iroko, which protects against fading and supplements colouration. Other finish colours are available – just ask our team.

Steel and timber Acra litter bin in quaker friars

Finish application

Iroko is rich in natural oils, which may keep supplementary treatments from penetrating freshly machined timber and can sit on the surface as an unattractive deposit that may not properly dry. In an ideal situation, Iroko would be allowed to naturally weather outdoors for around 3 months before application of a finish. This way the grain opens up and naturally occuring extractives are allowed to leach out and treatments cant penetrate more effectively.

This isn’t practical in most applications though, especially on products that have many timber parts fitted to steelwork frames for example. In these situations we sand the surface to open up the grain and cleanse with thinners prior to applying a 2-coat finish treatment.

AKRI planter with integrated timber seating in Newington- Green

Ongoing maintenance

Re-treat twice a year for optimum use

Applying a UV protective finish to Iroko will give a richer colouration over a longer time compared with untreated timber. In our experience, Iroko typically benefits from re-treatment on a bi-annual basis. The amount of work involved in restoring the timbers depends on their condition at the time, and the desired appearance to be achieved.

As a minimum, a thorough clean and/or light sand is recommended. For a deeper clean, specialist restorative treatments can be used. Due to the many factors that can affect the appearance of timber placed in the outdoors, (including its natural colouration at the outset and the degree of exposure to the elements)-we strongly recommend that maintenance coats are tested on a discrete area of a product to ensure the desired effect is achieved prior to the work being undertaken on the whole product.

Freshly machined

Untreated timber

Iroko can range from a yellow to golden or even medium brown, sometimes all evident in a single board. It has a medium to coarse texture, with open pores and generally machines well to a smooth finish, except where interlocked grain may cause localised tearout.

UV protective finish

Our UV protective finish gives a matt-sheen finish, which darkens and enhances the natural beauty of the wood. We offer this in a number of colour applications, teak being our most popular. Ask our sales team about other desired applications.

Untreated vs UV treated Freshly machined Iroko timber

2-3 Months

Untreated timber

After exposure to the elements, and in particular UV light from the sun, the natural colouration in iroko will soon begin to desaturate.

UV protective finish

A treated surface may begin to dull slightly, but will retain far more colouration than untreated timber.

Untreated vs UV treated Freshly machined Iroko timberUntreated vs UV treated Iroko timber after 2 to 3 months

6 Months

Untreated timber

Depending on the degree of UV exposure, the colouration in any natural timber can be almost entirely lost within 6 months, meaning it may have little resemblance to the original freshly machined material.

UV protective finish

UV protective finished surfaces continue to show good colouration.

Untreated vs UV treated Freshly machined Iroko timberUntreated vs UV treated Iroko timber after 6 months

12 Months

Untreated timber

Most timber in most situations will fade to a silver-grey within 12 months. Restoring natural colouration in weathered timber requires either exhaustive sanding down or the use of specialist restorative cleaners.