Underlay does most of the comfort work over a slab, so specify that properly and the floor above it will feel warmer than the price suggests.
The underlay does most of the comfort work when laminate goes over a slab, and Southampton has a great many slabs: the post-war centre, the estates of Millbrook and Coxford, the ground floors of Bitterne. A moisture-barrier underlay to the concrete, the AC-rated boards clicked together above it with a gap at every wall, and the floor feels warmer than a slab has any right to. For a Portswood student let the board is chosen because it survives a year of furniture and is replaced cheaply.
In a pre-war terrace the suspended timber is levelled before the underlay goes down, or the click joints ride the joists. The laminate’s abrasion standard is written for dry rooms, so the kitchen, the shower room and a waterfront flat’s hall go to the BML rigid vinyl. At Houndwell Place the screed is heated, and the boards are listed as compatible with the heating.
Flats are 42% of the homes in Southampton, and laminate in a flat is a question of sound before anything else: a hard click floor over a bare slab carries footfall into the flat below. Approved Document E sets the impact-sound limits and the lease usually adds a clause, and the answer is the underlay, chosen on a tested impact-sound figure under EN 16354 rather than a claim on the pack. Check the lease first.
Private renting is 29% of households in Southampton, and laminate is the landlord's floor in Southampton for the plain reason that it is the quickest to replace between tenancies and the least costly to replace. An AC4 rating carries domestic wear; the rooms that suffer are the ones with water, and there the rigid-vinyl range takes over.