Code-compliant steel framing addresses “ghosting”

Ghosting refers to faint marks or outlines that can sometimes appear on internal linings, typically following the shape of the framing behind them. These marks occur when cooler surface areas attract airborne particles like dust or soot, which settle more readily on those spots. 

Since 2006, the National Construction Code has required thermal bridging mitigation measures when fixing lightweight external claddings to steel frames. Techniques such as battening-out cladding, using reflective insulation wraps and installing thermal breaks have significantly reduced the risk of aesthetic issues like patterned staining, also known as “ghosting”.

This significantly reduced risk has been confirmed by physical testing¹, which measured the temperature variation of plasterboard on a variety of steel framed, lightweight clad walls.

Even in older homes with direct fixed cladding, ghosting has become less common due to changes in modern living – such as a reduced use of gas heating, open fires, and indoor smoking, along with the widespread use of exhaust fans in bathrooms and kitchens.

In higher risk environments, such as in very cold climates (i.e. alpine regions), external insulation can be added to help maintain warmer internal plasterboard temperatures and avoid any potential issues with mould, condensation or patterned staining.

It’s also worth noting that ghosting can occur in any home - including those with timber framing – if insulation is poorly installed. Gaps in insulation can create cold spots that attract dust, as shown in this timber-framed ceiling (Figure 1). Ensuring insulation is correctly installed without gaps is the best way to avoid this.

Figure 1