Is 50mm Kingspan between floor beams enough?

[phatboy]

We have a bungalow with suspended wooden floors. The void below is ventilated, so draught comes up through the old floors.

When refitting with ply boards, is 50mm Kingspan insulation underneath sufficient, when foamed and taped in?

Down here the temperature generally never gets below 2 degrees.

The maths of kw/m2 etc has me a little lost!

Thanks
Tim

 

[tony1851]

is 50mm Kingspan insulation underneath sufficient,

How long is a piece of string?

Floor insulation is difficult to calculate because much depends on the plan-shape and perimeter of the house.

Generally 75-100 kingspan is used nowadays to comply with Building Regs, but any thickness will give you increased comfort,
even if it doesn't comply.

Make sure that all joints are taped - a lot of heat is lost through uncontrolled ventilation.

 

[John D v2.0]

Yes as Tony says the important thing is stopping the uncontrolled ventilation aka draughts. We went for 100mm in our floor just because the price difference wasn't much. It is harder to cut though.

I never got the whole perimeter to area thing for suspended floors, I understand for solid floor but surely there's a designed in thermal bypass going in all the time in suspended floors?