Show the points where movement catches as well as the full track. Local damage may have a different repair option from extensive wear. Photographs help describe the problem but cannot establish that the track, rather than the rollers or frame, is the only cause.
Loose or damaged fixings can affect the running surface. Accessible fixing points need sound support for ordinary work to proceed. Deterioration beneath the rail may require a different assessment; covering it with a new section does not restore an unsound base.
The agreed repair is checked with the accepted panel and its hardware. Catching at one point can differ from resistance along the entire run. Any roller or alignment work should be listed separately so a track-only quote does not imply every movement problem will disappear.
Repair an accepted accessible rail or fit a compatible running insert or replacement section without changing the building envelope. Scope limits: Accessible non-structural running rails only. No threshold waterproofing alterations, drainage-system redesign, structural changes, major glazing or powered operators.