The Furniture Industry Research Association

The centre of knowledge for the furniture industry

Technical Information Article

​Timber treatments and finishes: An introduction

Download PDF

Timber can be physically altered and chemically engineered through the application of various treatments and finishes to meet demanding performance requirements. Covers preservation, treatments to improve performance in fire and various finishing treatments.

Timber is one of the world’s most versatile materials. It has a remarkably diverse range of uses from fuel to a structural and/or decorative material in buildings bridges and boats. It is now recognised as environmentally friendly and provides a natural warmth and beauty unmatched by other products.

Although we think of timber as one material, in reality it is a whole range of materials and products. Timber species vary in density, strength and durability from balsa (density around 100kg/m3) to greenheart, used for building bridges, wharves and jetties (ten times denser at about 1050 kg/m3). In addition there is an increasing number of wood products from board materials, such as plywood, particleboards and fibreboards, to engineered structural components, such as glued laminated timber, timber frame panels and I- beams.

Just as timber can be physically altered and ‘engineered’ to meet our needs so it can also be chemically ‘engineered’ through the application of various treatments and finishes to meet demanding performance requirements.Finishing and preservation treatments can transform the performance and appearance of timber used externally.

These broadly fall into three categories:

  • preservative treatments to prevent biological attack – by fungi, insects and marine borers
  • treatments to improve behaviour in fire
  • finishing treatments to protect from weather or wear and to provide decoration
Preservation treatments

Timbers vary in their susceptibility to attack by biological agents with some being naturally extremely durable. Others are less durable but it is important to note that all timber which is kept dry (ie below a moisture content of 25%) will not sustain fungal attack.

There are three main types of wood preservative: tar oils, waterborne and organic solvent-borne. Waterborne and organic solvent types are the most widely used for the protection of building timbers. Their primary function is to penetrate and be retained usually in a ‘shell’ of the outer few millimetres of timber to guard against stain, decay, mould growth and insect attack.

Most water-borne preservatives are applied by vacuum/pressure impregnation. After impregnation, the copper-chromium-arsenic (CCA) types most frequently encountered become fixed and insoluble in the wood, giving high durability to the timber. Other types of water-borne preservatives may require the protection of a finish to prevent long-term leaching in exposed situations. Timber treated with water-borne preservatives must be dried to an appropriate moisture content before use.

Organic solvent preservatives can be applied by dip, double-vacuum or vacuum/pressure impregnation treatments. Some form of finish is essential for satisfactory exterior performance. They have the advantage that the timber is not wetted during treatment so the moisture content is not altered. The treatment should always be allowed to dry before a finish is applied.

Contact: BM TRADA
E-mail: enquiries@bmtrada.com

You may be interested in
entries related to...

Testing,
Finishes
13 Entries

  • FIRA International expands flammability testing laboratory

    FIRA International expands flammability testing laboratory

    News November 2018

    FIRA International has opened a newly expanded flammability laboratory.

  • Fire safety of furniture and furnishings in the contract and non-domestic sectors

    Knowledge Hub

    The fire safety of upholstered furniture supplied into the non-domestic market is more complex. It is heavily influenced...

  • The Furniture Retail Quality Group best practice guide - flammability testing

    Knowledge Hub
  • ​Childcare product classification

    Knowledge Hub

    Within the furniture and childcare product industries there is confusion surrounding the classification of childcare pro...

  • ​Edge sealants for wood-based boards

    Knowledge Hub

    Protecting board edges is a vital part of board performance in humid conditions. This wood information sheet gives guida...

  • Electrically actuated furniture for the domestic market - a guide to the UK Regulations

    Knowledge Hub

    This document is a guide to the application of the Machinery Directive to motorised furniture. It does not replace any l...

  • Electrically powered office furniture - a guide to the UK Regulations

    Knowledge Hub

    This document is a guide to the application of the Machinery Directive to electrically powered office furniture. It does...

  • Guide to Health and safety management for the woodworking and furniture industries

    Knowledge Hub
  • ​Performance of furniture finishes and surfaces

    Knowledge Hub

    The performance of furniture finishes and surfaces is defined in FIRA Standard 6250, which has its origins in British St...

  • ​Reduce upholstery fabric complaints through testing

    Knowledge Hub

    Upholstery fabrics are required to be of satisfactory quality and fit for purpose.This means they are expected to be fre...

  • What do I need to know to sell highchairs in the UK?

    Knowledge Hub

    Summary of highchair testing and specification requirements taking account of the current standards and possible introdu...

  • Standards applicable to the sale of childcare (furniture) products in the UK

    Knowledge Hub

    A summary of some of the products and standards relating to the manufacture, specification and sale of furniture and rel...

  • BFC Proposal for updating FFFSR - June 2017

    Knowledge Hub