Worktops are particularly subject to steam and heat exposure near dishwashers and ovens.
It is necessary to protect the underside of the worktop by structural means. Self-adhesive aluminium foils generally provide reliable water vapour protection and are easy to handle.
Appliance manufacturers supply aluminium repellent strips or protective cover plates, which you must use. This moisture-repellent strip or cover plate deflects and repels steam and heat.
The mounting of the aluminium foil on the underside of the panel differs between postformed and square edge worktops. For postformed worktop the aluminium foil should overlap the laminate infeed by about 2 mm. For the square edge worktop the aluminium foil should be mounted so that it overlaps the ABS edge by about 1 mm.