Fibreboard under carpet underlay query

[Clevergirl]

Hello DIY World.

Quick question, I want to reduce noise and better insulate a bedroom.
Would it work if I put 11mm fibreboard down on the floorboard and then lay Carpet underlay on top of it then carpet?

In theory that would work but would the fibreboard break off and crumble as the weight wont be evenly distributed?

What is everyone's thoughts on it?

Floorboard/Fibreboard/Underlay/carpet

Thanks in advance

 

[alan333]

I have concrete floor + layer of polythene + 8mm laminate fibreboard + carpet underlay + carpet. It's been laid for 4 years now in our lounge and there's only one bit where you can slightly see one board edge in the carpet pile. Tape the fibreboard joints with some strong and wide duct tape or something before laying the carpet underlay and it'll probably be ok.

BTW I did mine cos the skirting had already been raised to suit the outgoing laminate.