Transitions.

Transitions are the details where the finish meets another material — a doorway, a floor-covering junction, a level change, a lift threshold. They are the highest-visibility details on a floor and the most common source of visual complaints.

Transitions perform two functions: they conceal the perimeter expansion gap between finishes, and they resolve any level difference between abutting surfaces. Both should be designed at specification stage, not resolved on site.

Standard details include flush aluminium T-sections, capped ramps for level differences up to 10 mm, and recessed metal channels for high-traffic thresholds. The specification should nominate profile, finish and fixing at the same time as the primary product.