3-pane sliding patio door, made to measure

Where the 2-pane sliding patio door has one fixed and one sliding pane, this door adds a second fixed pane: fixed on the left, sliding in the middle, fixed on the right. That gives a symmetrical look with glass at both ends, and a wider door overall — though the centre pane still slides behind only one of the two fixed panes, not both.

The standard size is 4,200 × 2,300 mm. If you want wider still, or two sliding panes instead of one, the 4-pane sliding patio door is the layout that provides for that.

Two fixed panes mean less track and hardware than on the 4-pane sliding patio door, and that is exactly why this door is the usual choice for many living rooms: a wide view with glass on both sides of the opening, and the sliding pane only where you really need it. For maintenance, less movement also means less track and hardware to keep clean and adjust.

This layout sits between the 2-pane and 4-pane sliding patio doors: wider than the 2-pane door, with symmetrical glass at both ends, but with less track and hardware than the 4-pane one. If you are torn between the three, look first at the width of your opening — 3,000, 4,200 or 5,400 mm — and only then at how many panes you want to move.

For this door, measure the threshold height and the floor build-up on both sides as well as the width and height; at 4,200 mm wide the track carries more weight than on the 2-pane door, so a flat, solid base matters even more here. Have your installer confirm how it meets the floor before you order.

You choose colour and finish freely for the whole door — the two fixed panes and the sliding pane are almost always the same colour, for a continuous look. Maintenance is mainly in the track under the sliding pane: keep it clear of sand and dirt, because that is what hinders the lifting mechanism most over time. The two fixed panes either side need only the normal care of glass and frame.

When renovating a living-room wall, this is often the replacement chosen for an older patio door or a set of French doors, giving more glass and a more symmetrical look. In a new build, this width is often set as the standard living-room opening, with the architect choosing this symmetrical look over the larger way through a 4-pane door would give.

For security, the sliding centre pane is the point to watch; the two fixed panes either side need no lock. Ask about extra locking points on the sliding pane if you want to put more weight on this.

The weight of the sliding centre pane decides how heavy the lifting mechanism has to be; the two fixed panes carry no hardware load. The configurator checks whether the glass you choose suits the profile and the size.

Still not sure? Use the comparison with the other layouts in this group, above, to see which arrangement suits your situation best.