It’s the neat way of fixing boards to a timber subfloor – nails go through the tongue at an angle so they’re hidden once the next board is fitted. Just don’t skimp on nail spacing: too far apart and the floor won’t be properly secured.

Q: Can I just float my floor on underlay? A: You can – but it’s the least solid option. Floating floors never feel quite as robust as glued or nailed ones and they’re notorious for that annoying “tick-tack” noise when you walk on them. They also demand a perfectly flat subfloor. Any dips or bumps mean the joints are constantly flexing, and once those joints fail, repairs are awkward at best. And despite the myths: click floors do still need glue in the joints if floated. Ignore that and you’re asking for trouble.

Q: How long should I let boards acclimatise? A: Trick question. It’s the building that should be acclimatised to normal living conditions, not the other way round. New builds and refurb jobs are soaking wet environments. Letting your boards sit in that will just load them with moisture – then they’ll shrink later and leave gaps. Dry the building properly first.