I have thinking about insulating between the floor joists on the groundfloor. Which would be the best insulation to use. I dont know whether to use expanded polystyrene sheets or Kingspan tf70. Can the normal Kingspan phelonic insulation sheets be used to insulate between floor joists.? I ask this because the tf70 boards have a urethane core.
I dont know the differences between the two and hope someone could shed a little light on the subject.
In terms of thicknesses i was thinking of either 200mm of polystyrene or 100mm of kingspan.
Thanks in advance for any info.