Choosing underlay - based on what's going on top or what is underneath?

[cjmj]

Hi everyone, I'm going to be laying laminate flooring in my new house. Will be removing the current carpet. The underfloor is fibreboard suspended on wooden beams (these wooden beams are suspended on metal beams).
I picked laminate flooring and want to choose "Volden Aquastop 3mm" underlay since it has good reviews (making the room warmer and being somewhat water resistant).

My question is, does it matter that the underfloor is fibreboard, does that influence the type of underlay in some way?

Bonus question: Do I remove the carpet gripper strip? I'm assuming yes, but thought I'd ask.

Many many thanks.

Picture of current situation: Fibreboard with some kind of foam underlay and carpet.

 

[crazydaze]

You don't need a water membrane underlay over a wood substrate, these are designed for concrete substrates to protect the flooring you are laying.

Best Underlay for laminate/engineered wood is Duralay Multitex, it's the wood substrate version of Duralay Timbermate XL.

 

[cjmj]

You don't need a water membrane underlay over a wood substrate, these are designed for concrete substrates to protect the flooring you are laying.

Best Underlay for laminate/engineered wood is Duralay Multitex, it's the wood substrate version of Duralay Timbermate XL.

Thanks so much! Yeah that makes sense.. I'll see if I can get the one you recommend!