Glanced Light – Wall and Ceiling Imperfections

In certain conditions you can easily see very slight surface imperfections

This is known as ‘Glanced Light’ . . . .  so what does is mean?

Well when light strikes a surface at a flat angle like in this first sketch its said to be a glancing angle.

Because of the angle any imperfections in the surface cause shadows that make the defect more obvious.

The most obvious point where you may notice glanced light is at the joints between plasterboard panels.

Its not uncommon in the joints showing up as bands of a different shade.

In full light like the second sketch these sort of imperfections are less likely to show up.

What’s Acceptable

For the typical project home any imperfection that shows in full light is unacceptable.

In glanced light you should not see screw of nail fixings although joints will most likely be faintly visible.

If you are uncertain go to your builders display house and look at how their ceiling looks.

How To Minimise Glanced Light Issues

  • Specification – In the old days all plasterboard had a skim coat of plaster applied over the whole surface rather than just the joints. Although you can ask for this it will be at a substantially added cost.
  • Workmanship – If the plasterboards are fixed with the joints running towards the windows any joint imperfections will be minimised. A skilled tradesman should then be able to make the joints and fixings holes fairly smooth.
  • Lighting – Pendant light fittings are better than fittings that are closer to the ceiling as they give full light. Avoid windows that go up to ceiling level.
  • Decoration – Matt paints are better than silk finishes. Roller applied paint is better than spray applied.  Alternatively a textured finish to the ceiling will mean the texture covers the joints.


To find out more about inspecting your new house see

anewhouse PCI Guide


1 Comment

  1. Cleusa

    I had never heard about something like this. Its useful to know

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