Level 5 finish: when you actually need it (and when you don't)

A Level 4 finish — three coats over tape and fasteners, sanded — is right for most walls painted in a flat or matte colour with normal lighting.

You want Level 5, a full skim coat over the whole surface, when light rakes across the wall: floor-to-ceiling glass, pot lights close to a wall, gloss or deep-tone paint, or a long uninterrupted hallway.

We check finishes with a work light held flat against the surface before we call a room done. It shows every seam the naked eye misses at midday.

Ask for it at estimate time — skimming after the fact means re-protecting the whole room, and that costs more than doing it in sequence.