Insulation under suspended floors

[carryoncamping]

The Shell of my extension is now up, and am about to tackle the inside.

I have a suspended wooden floor and was wondering what insulation to use between the joists i.e. Fibreglass wool on netting, or Rigid eg. Kingspan Thermafloor?

What are the pros/cons to each?

Thanks,

 

[Deluks]

A question of price/performance. Rigid more expensive but better performance for the depth. You'll get away with polystyrene/jablite. Will probably need a bit more than the recommended 80mm of kingspan. Or see if xtratherm have a supplier near to you, it's like kingspan but slightly cheaper.

 

[carryoncamping]

With regards to rigid insulation, should the insulation be level with the top of the floor joists. i.e. no airgap between the floorboards and insulation.

Is the fibreglass type just bog-std loft insulation, or is it specific to floors?

Thanks