Does Squid cause HR++(+) glass to break due to thermal stress?

Thermal glass break is a direct consequence of tensions caused by a temperature difference between two adjoining areas in the same sheet of glass. The issue of thermal breaks is a complex one with lots of aspects at play: the cutting and installation of the glass, the building design, the positioning of objects outside the window or in the room next to the glass, and all the various types of sun awnings, blinds, foils and other window decorations.

It is true however that you need to be more careful with HR++(+) glass than with (normal) double glazing.

What is Squid like compared to window foil?
Window foil forms a seal and ensures that heat accumulates. If there's too much heat absorption, a thermal break can occur.
Squid on the other hand is an open (breathable) weave that absorbs a lot of the energy so heating up is limited.
Our tests have shown that with the 5 lightest colours Squid never exceeds the limit for a thermal break (35°C), even on the most sensitive windows.  
Chalk, Bone, Oak, Ash and Rock are therefore safe to use on super insulating glass or HR++(+) glass.
Conclusion: in contrast to window foil, Squid on a window can never be the cause of a thermal break. There is an increased likelihood of a thermal break only in combination with a number of other factors (poor installation, extra heat or partial lighting of the window).

We therefore provide a few tips to reduce the risk of thermal break.

> Rather, opt for a light colour, which also blocks more solar energy.
> Make sure that no part of your window can heat up in a particular place on the inside; don't position any heat sources right next to the window and avoid placing large darker objects (curtains, chairs, frames, etc.) too close.
> Also avoid placing large objects outside the window that put it partially in the shade.

You can find more information about this issue online.