Why is there a 30mm gap between the panes of glass?
We get asked why we design a 30 millimeter gap between the panes of glass. So the glass panes don’t touch.
There are four main reasons:
Expansion and contraction can cause cracking
The first is so the glass sheets don’t touch. In summer and winter glass expands and contracts, and if the panes were touching, the expansion could cause them to chip, or crack, or even explode.
Prevent a finger trap
The second reason for the 30 mill gap is so there isn’t a finger trap. Any less space, and a child or an adult could trap their fingers in the gap.
Easy handling and installation
The third reason relates to practicality and ease of installation. When installing, the panes need to be lifted and positioned into place, and the gap makes it very simple to do this by hand.
Tolerances and good looks
The surface that the bottom rail gets fixed to is not always perfectly level. This may cause the gap between the panes to not be exactly the same all the way up. If the panes were very close, a small variation of one or two millimeters would be very obvious, and the glass could look crooked. With a wider spacing between panes, this difference is not noticeable.