Lighting is an important element when it comes to construction design and can affect the overall atmosphere and ambiance of an area. Before the start of a construction project, it is crucial to consider how the overall appearance may be affected by ‘Glancing Light’ issues and thus the required Level of Finish for walls and ceilings.
What is Glancing Light?
The term “Glancing Light” generally refers to a critical or unfavourable lighting in which surface irregularities are accentuated and emphasised when light is shone directly across the surface of a wall or ceiling. This can include natural as well as artificial lighting such as:
- Spotlights close to walls
- Large uncurtained windows or skylights
- Unshaded light bulbs
- Outdoor reflective surfaces
- Gloss or sheen paint finishes
- Ceiling mounted fluorescent lights
Preventing Glancing Light Issues
In reality, plasterboard surfaces can never be perfectly flat and every surface contains a certain amount of variations. However, there are positive design options and considerations when it comes to achieving the perception of flatness and a consistent finish by minimising glancing light issues on wall and ceiling finishes. These include:
- Selection & positioning of internal lighting
- Installation of blinds, shades or curtains
- Painting application and techniques to impart soft and uniform textured finish (see Painting Preparations below)
- Selection of paint colour and sheen level
- Specifying and installing a Level 5 Finish where darker colours or gloss paints are used (this must be specified at the design stage)
Painting Preparations
To achieve quality results on new plasterboard surface, the AS/NZS2311: “Guide to the Painting of Buildings” recommends that ‘a sealer undercoat followed by two coats topcoat should be applied as a minimum.’ Sealer undercoat should be lightly sanded prior to subsequent coats. Some minor but numerous irregularities can also be minimised by skim coating surfaces with plasterboard primer / precoat followed by fine sanding before the application of sealer undercoat and topcoats.
In the case of spray-painting application, it is recommended that all paint coats are back-rolled and allowed to dry thoroughly before applying the subsequent coats to create a textured background. However, backrolling must be carried out over wet paint to achieve the texture required. Of course, all surfaces should also be cleaned and dust free prior to painting.
PGP Plastering are specialists in achieving a consistent finish while considering the issues of glancing light. Our highly experienced team of commercial plasterers can assist with determining the best way to achieve a desirable flawless finish on your ceilings and walls in conjunction with the lighting conditions of your fit-out project.
Please click here to view our Gallery showcasing projects that PGP Plastering has completed. We are commercial plasterers of Brisbane, Melbourne, Gold Coast, and Sunshine Coast. We use the latest innovative commercial plastering techniques to ensure each fit-out is completed to the highest standard of finish, specific to each project brief.
Get in touch for an obligation free quote today! Ph. 1300 633 403 or send us a message via our website.
References:
- AS/NZS 2589:2017 ‘Gypsum linings – Application and finishing
- AS/NZS2311: “Guide to the Painting of Buildings”
- https://www.usgboral.com/content/dam/USGBoral/Australia/Website/Documents/English/lighting-guide/Lighting%20and_Decoration%20Guide.pdf
- https://www.dulux.com.au/applicator/technical-advice/preparation/glancing-light
