Coatings & Finishes Print E-mail
Coatings & Finishes
Once placed in service timber should be coated to enhance the appearance and/or the durability of the material.

Interior timber surfaces are easily and satisfactorily coated with a wide range of products such as paints, stains or oils as the timber is normally seasoned and free of surface impurities which hamper the coating process.

Exterior timber surfaces on the other hand are exposed to the elements of ultraviolet light, heat, cold, water and airborne contaminates before and during coating and therefore create difficulties for the painter. The purpose of an exterior coating is firstly to provide a protective coating against weathering and secondly to provide an appealing overall finish to the structure.

The selection of the correct coating product is essential to maintain visual appeal and also for the ongoing performance of the timber. Each timber species has particular characteristics that could effect the application of certain products and it is important to know a little about the timber being coated and make reference to the various manufacturers' product literature for specific recommendations.

When any timber (treated or untreated) is exposed to the weather, the timber will take up and lose moisture from or to the atmosphere as the environment around the timber changes on daily or seasonal basis. The timber will expand or contract when it takes up or loses moisture.

As a result of taking up and losing moisture, the timber will develop surface checking. The severity of the checking will depend on the timber species, the rate at which the moisture content of the timber changes and how long that moisture content is maintained before it changes again.

The application of a protective coating to the timber surface will minimise the effects of weathering of any timber (treated or untreated) in an exposed situation. The protective coating slows down the rate at which the timber will take up or lose moisture. By slowing that rate down, the severity of any checking is considerably reduced.

Protective coatings include products which penetrate the surface of the timber and products which provide a film or coating to the surface of the timber.

Protective coated pine is widely available on the Australian market in a broad range of accurately sized and milled products for a variety of external, above ground applications. (See: Protective Coated Pine)