Appearance is everything



A potential bugbear for plastering contractors, builders, interior designers and architects alike is the appearance in a finished building of surface imperfections on walls and ceilings. Most customers have an expectation of a perfectly flat, blemish-free plasterboard surface finish. In practice, however, this is impossible to achieve and all that can be realistically expected is the perception of flatness.

Unwanted effects include visible jointing of plasterboards even after painting, over-lit or glaring expanses of wall, and unwanted shadowing at certain times of the day.


Planning to avoid issues with the appearance of walls and ceilings is much easier than fixing problems at a late stage. If you want to create a particular effect, there are a number of factors to consider. Light-filled rooms with large windows or use of glossy paints may call for a higher level of finishing of plasterboard walls and ceilings. The choice and positioning of lighting is critical.

Managing customer perceptions is also critical, to avoid disappointment. Point out that a richly-shaded sheen paint may reveal unexpected textures in a north-facing family room overlooking a pool. Similarly, they will need guidance when selecting different types of lighting – and ideally before the method of plasterboard finishing is determined.

For the technical requirements, there are two principal standards to refer to: AS/NZS 2589 ‘Gypsum linings: Application and finishing’ and AS/NZS 2311 ‘Guide to the painting of buildings’.

However, even when plasterboard installation has been carried out strictly in accordance with AS/NZS 2589, a major cause of dissatisfaction with plasterboard surfaces is from unfavourable lighting from internal or external sources.


Because issues with the appearance of plasterboard walls and ceilings after painting can arise, we developed an illustrated guide some years ago, endorsed by Master Builders and the Association of Wall & Ceiling Industries. Our Lighting & Decorating Plasterboard Design & Application Guide has just been updated and reissued.

It covers potential issues with both natural and artificial light, as well as the sometimes unexpected effects of glare. It also describes two levels of finishing plasterboard – Level 4 and Level 5 – which can help overcome the appearance of ‘seams’ in plasterboard walls and ceilings under certain conditions or decorating materials.

It also includes a number of recommendations for the types and positioning of lighting, discussing potential effects on both walls and ceilings.

If you’d like a copy of the Lighting & Decorating Plasterboard Design & Application Guide, click here or visit your local USG Boral trade store