LOAD BEARING LOFT INSULATION BOARDS - ANY GOOD???

[RichyBee]

Thank you for looking at my post!

I have a house built in 1926 with very poor/thin loft insulation. I wish to add to my loft insulation but wish to use it for general box/christmas decoration etc. storage.

I know that filling between joists with standard loft insulation then laying down wooden loft boards will only give me approximately 100mm of the recommended 270mm of loft insulation

Would anyone advise laying 270mm of standard insulation rolls around the sides while laying load bearing insulation boards in the centre for storage above the 100mm of insulation between the joists??? I know that laying wooden boards on 100mm of insulation is a waste of time, especially in a 80 year old house with no cavity wall insulation.

I would rather not spend the time & money installing 2" x 4" joists at right angles to the existing joists to help raise the existing loft joists closer to the required 270mm of insulation.

r.s.v.p. - thanks...

RichyBee

 

[JohnD]

I know that laying wooden boards on 100mm of insulation is a waste of time

No it isn't

If you haven't already got 100mm of insulation, hurry up and fit it.

the first 100mm of insulation saves you a lot more money than the second 100mm of insulation does.

This is because (I haven't got the figures to hand so these are for ilustration) 100m saves you (say) 60% of ceiling heat loss. So it will reduce £100 of loss through the ceilings to £40. A saving of £60

The second 100mm will save you 60% of remaining losss. But the remaining loss is now only £40. So it saves you 60% of £40 which is a saving of only £24.

The third 100mm will save even less money.