Brand new laminate floor with some creaks

tallac

My house has had a loft conversion, so the wooden subfloor is brand new. Good quality Quick-Step underlay has been used and an interlocking laminate flooring has been laid on top. When I walk on the laminate I can feel very minor differences in height. It doesn't feel like there is something small caught under the flooring but more like gentle rises and crests in the subfloor. In some areas there are some very tiny creaking as well. There is a decent expansion gap all the way around (at least 1.5cm) and none of the skirting boards have been installed yet.

My questions are:

1. Should a properly installed sub-floor and laminate flooring be completely and perfectly creak free?
2. The very small rises and crests in the subfloor, how should they have been resolved by the works people?
3. Does it require some levelling compound to be used on top of the subfloor but below the underlay?
4. Is it worthwhile for me to buy a very long spirit level to check that the flooring has been levelled sufficiently? (if yes, is 1m long enough)?

Thanks for the help

Jeepers_Creepers

1. Yes.

2. They shouldn't exist at all. It should be nigh-on perfectly flat on construction.

3. If the subfloor's (chipboard?) unevenness is the cause, then something needs to be done. I guess lifting it up, levelling the joists with spacer strips and relaying is too big a task, so a levelling compound could well be ideal.

4. Might be. I'd suggest as long as possible, and a 'straight edge' will do instead of a spirit level; it's not the 'level' you are looking at, but unevenness. I dunno - something like  https://www.screwfix.com/p/forge-steel-feather-edge-72-/52912?tc=IC4 but probably cheaper ones available.

Of course it's impossible to tell from this side of the screen what the cause is - perhaps it's creaky laminate?