How thick are your cabinet boards, and what about the back panel?

Carcass panels are 18 mm as standard, with 16 mm available where budget is tight. Back panels are the detail that separates a durable cabinet from a weak one: 5 mm backs flex and crack against the wall, so we recommend 9 mm as a minimum and 18 mm where the cabinet is load-bearing or wall-hung. Always confirm back panel thickness in writing — it is a common silent downgrade.