uPVC sliding windows.

A sliding panel has to move, so it cannot be clamped onto a gasket the way a hinged sash can. It seals along its running edges instead, against brush or gasket sections built into the track and the interlock. That is a good seal when the geometry is right and the panels are true, but it is a different mechanism from compression.

If noise or dust is the main complaint about an existing window, say so early. A casement may be the better answer even where a slider looks like the obvious fit, and it is worth comparing the two before the order is placed.

The number of tracks decides how much of the opening can actually be open at once. A two-track, two-panel window opens to half its width. Three tracks give more. The panel count and the track count together also decide how heavy each panel is, which feeds back into reinforcement and hardware.

None of this is chosen from a catalogue page. Send the opening width and height, the floor, and how many panels you want, and the technical team will confirm what the system can carry.

The two things that stop a slider running well are grit in the track and blocked drainage. Both are maintenance, not manufacture. Keep the track clear and check the drainage slots stay open, particularly after a monsoon.

Rollers and locks are fitted by the fabricator from hardware chosen for the panel weight. Ask which hardware was used and who warrants it.