600 × 600 or 1200 × 600: which ceiling tile size should you use?

Why is 600 × 600 the standard?

Almost every lay-in LED panel, diffuser and access tile is made for a 600 × 600 opening, and replacement tiles are stocked everywhere. A single tile is light and easy for one person to lift, which matters for maintenance.

When does 1200 × 600 make sense?

In long corridors, where the long side runs along the corridor and makes it look longer and calmer. In large, simple areas, where fewer cross tees mean less labour. And where a design calls for a rectangular rhythm.

The drawbacks are bigger, floppier tiles that can bow more in damp conditions, and fittings that may need a cross tee added to sit in a 600 × 600 opening.

Can I change tile size without a new grid?

Often yes. A 1200 × 600 grid becomes 600 × 600 by adding cross tees in the middle of each opening. Going the other way means removing tees, which leaves the grid with spare slots and is rarely worth it.

What about tile thickness and edges?

Most UK tiles are 15–20mm thick. Square-edge tiles are the cheapest, tegular edges give a shadow line that hides small grid wander, and microlook edges with a 15mm grid look the finest. The edge choice changes the look far more than the tile size.