Anyone who wants a glass sliding wall runs into the same question sooner or later: how wide do those panes actually come out, and how much space is lost because they slide past one another? The answer is simpler than it looks, and you need no more than a tape measure and a one-line sum.
Measure the opening width, not the outer dimension
The opening width is the distance between the posts or walls the wall goes between. So it is not the outer dimension of your veranda. Measure at three heights — bottom, middle and top — and take the smallest. Walls and posts are rarely true, and a wall that fits at the top but binds at the bottom cannot be corrected afterwards.
Then measure the height, from the floor to the underside of the profile the top track fixes to. If your terrace slopes, measure at the lowest point. Pass that difference on as well: we allow for it, so the panes run just as smoothly everywhere.
The overlap: allow ten centimetres per joint
Sliding panes run past one another. At every joint two panes overlap, and that overlap is what makes the wall wind- and rainproof. Allow about 10 centimetres per joint.
The number of joints is always one less than the number of panes. On a 4-track wall that is three joints, or about 30 centimetres of extra glass.
The formula
Total glass width = opening width + (number of panes − 1) × 10 cm.
Width per pane = total glass width ÷ number of panes.
A worked example
Say you have an opening of 360 centimetres. That is a 4-track version. The sum then becomes: 360 + 3 × 10 = 390 centimetres of glass, divided over four panes. That is about 97.5 centimetres per pane.
Why is that figure interesting? Because it determines how comfortably you walk through when you slide one pane aside. Below 80 centimetres it gets tight with a tray in your hands; above 110 centimetres a pane becomes heavy to slide. Between those two lies the comfortable zone, and that is where the standard versions land by themselves.
Which version goes with which size?
Roughly: up to 200 centimetres a 2-track, up to 300 a 3-track, up to 400 a 4-track, up to 500 a 5-track and up to 600 a 6-track. If you land exactly on a boundary, choose the version with more panes: they come out narrower, and narrower panes are lighter and easier to handle.
If you want wider than six metres, we do it in two parts with a post in between. That is not a workaround but simply how it works: a single eight-metre track will not stay flat.
What people misjudge
- The walkway. Even with all the panes pushed aside you keep one stack of panes standing on one side. Allow for that if you have a door or a path there.
- A sloping terrace. Two centimetres’ difference over four metres is normal, but you need to know before the track is made.
- Existing verandas. Sliding walls usually fit a canopy that is not ours as well. Along with the measurements, send a photo of the profile the top track fixes to.
Or have it worked out
Our glass sliding walls page has a measuring aid: you enter your opening width and see straight away which version goes with it, how wide your panes come out and what the from-price is. In the configurator you then work with your exact measurements.
If you cannot work it out, send a photo of your situation with your measurements via WhatsApp. We will look with you, and it costs you nothing.