I need urgent advice re. Loft Insulation!

[SeamusG]

Hello, in the eaves of our loft we have non-insulated joists with thin board over them. We got someone in to put in loft insulation put they just laid horizontal strips of it on top of the existing board. My questions are
(1) Was this a waste of time? (I assumed the insulation would go between the joists but when they told me they would not lift the existing floor I still thought the insulation would have some covering (they told me it was fibre glass so I assumed a covering/containing layer - rather than just the fibres)
(2) If it was (a waste of time and money) , what level of "comeback" have we - can we refuse to pay them or can we insist they lift the boards (we would pay them more for this but we just want to get it right).

We feel we have got the worst of both worlds here as we are not convinced what they have done will provide any insulation benefit and also our space is no longer useful for storage as we dont want to lay even light items directly on to the fibres.

Any quick advice on this would be really welcome. Thanks!

 

[freddiemercurystwin]

I don't quite understand this bit specifically (they told me it was fibre glass so I assumed a covering/containing layer - rather than just the fibres)

(I assumed the insulation would go between the joists but when they told me they would not lift the existing floor I still thought the insulation would have some covering (they told me it was fibre glass so I assumed a covering/containing layer - rather than just the fibres)

It won't make a lot of difference that there is a void.

The standard upgrade for loft insulation is 3 layers of insulation cross laid. If you want to retain storage the existing boards need to be lifted, one layer of insulation goes between the existing ceiling joists, then new joists go down at right angles to your existing and your next 2 years of insulation go between those new joists. Then board on top of the new joists. Obviously that is a whole lot more work than just adding some insulation.

 

[AronSearle]

It depends if the floorboards are installed in an "airtight" manor (unlikely)

If it is just boards over layered onto rafters, at cross angles to the joists, then air from the eaves will be able to blow up and under the boards, and likely there are gaps around truss rafter connections, making the insulation layer over the top 80% useless.

You could put noggins at junctions under the boards to "box in" the floorboard area, frankly however this is probably just as difficult to do as to just lift them, you could as a make do solution squeeze some insulation in rather than noggins.

 

[SeamusG]

Thanks for your speedy replies and advice. The boards we have down do seem pretty airtight. What I meant about fibre glass is that it is the material (it looks rough and whispy rather than the images of insulation I see on the web) but when he told me "the top would be glass fibre" I thought that meant there would be a smooth "finish" to it rather than just rough tufts of fibre). If it is potentially 80% useless should the installer not have alerted me to that prospect or am I just naiive to think that?

 

[mointainwalker]

If they were so useless as to lay the insulation on top of the floor instead of between the joists, then yes you are being naive to expect them to do anything correctly..