Insulating an already boarded out loft

[t121anf]

When we moved in I needed to store some stuff up in our loft.

at the time the loft had approx 150mm of insulation in and I boarded over this with boards screwed direct to the beams

I've taken advantage of nPowers insulation offer and now have 30 rolls of insulation waiting to be fitted to take me up to at least 270mm of insulation.

However, I mentioned this to my father in law (a joiner by trade) who said the chipboard boarding is a good insulator in it's own right.

so, do I,

a) remove boarding where I don't need it, 3/4s of the loft and lay insulation as if the loft wasn't boarded

b) lay the new insulation on top of the boards (got no use for them if I take them up)

c) don't waste my time as the boards are doing a good job

d) ***add your suggestions here***

i think my preference is still A, but want some pro's opinions

 

[mointainwalker]

Your chipboard is not doing a particularly good insulation job:

the R value of 22 mm chipboard is 0.17
.............................. glass-wool is 0.55

So for equal thickness your glass-wool ( assumin that's what you have ) is 200% better at keeping those expensive therms/KwH in the house.


As far as your choices

a) Worse than totally useless. You create all the work of removing and disposing of boards to achieve .... what exactly ? You have diminished your insulation by the R value of the now absent chipboard in order to spread dirt throughout the house and chip the paintwork !! FORGET IT.

b) It's a bit unusual, but the only one that makes sense..

 

[t121anf]

so insulation on top of the board it is.