[lee_dewing]

[lee_dewing]

Cleaned glass roof
White powder mark not outside

Tried wiping off mark inside
Won’t come off

In between pane ?
White powdery mark

Is it condensation but sun turns white ?

Rest off glass is clear / normal

Thanks lee

[Splash & dash]

Cleaned glass roof
White powder mark not outside

Tried wiping off mark inside
Won’t come off

In between pane ?


 Not sure what it is but seen this a few times as the seals on the pains break down it looks like a white corrosion powder nothing you can do about it the pain needs replacing , I think it’s ti do with normal air getting in and the nitrogen coming out ? Seam to remember a glazier saying something about it years ago .
White powdery mark

Is it condensation but sun turns white ?

Rest off glass is clear / normal

Thanks lee

[lee_dewing]

Thanks Slap Dash 👍

Looked up on internet
Will post

Thanks lee

[lee_dewing]

https://www.nachi.org/condensation-double-paned-windows.htm

[lee_dewing]

This one ☝️ me think 🤔

silica haze.  Once the silica gel has been saturated, it will be eroded by passing air currents and accumulate as white “snowflakes” on the window surface. It is believed that if this damage is present, the window must be replaced.