Flooring & tile

Screeds and self-levelling underlayment; carpet by roll and by tile, with seams and cushion; vinyl, laminate, terrazzo and epoxy; tile with its grout, spacers and edge profiles; access and raised floors with pedestals, stringers and cutouts; underfloor heating mats and cable spacing; transitions, cove base and skirting; and the setting-out that decides waste — pattern, diagonal, bullnose.

Whether the floor is laid, poured or built. A laid floor is a setting-out problem and its waste comes from the pattern and the room shape, not from a flat percentage. A poured floor is a volume and a coverage rate. A raised floor is a counting problem — panels, pedestals, stringers — whose awkward part is the cutouts rather than the field.

The slab itself, which is concrete, and the floor's structural deflection or vibration, which is framing or structural steel.