Help with loft floor

[j0hnny11]

Hi

Would someone please advise me on my floor.

I wish to lay a floor in my loft. At present the insulation is laid running with the joists then overlayed across the joists.

Once I have secured the wires, how do I lay the panels, directly ontop of the insulation that is running across the joists or does it needs cutting so it lays across ways but is in between each joist. IE so I can see the joists

Thanks in advance

John

 

[mac391]

You need to see the joists !!
Your excess insulation might sit inbetween on top of whats's already there but dont pack it too tight.

 

[big-all]

what your planning tends to be called a light storage area

flooring involves 8x2" timbers fixed indipendently

 

[notexpert]

You need to see the joists !!
Your excess insulation might sit inbetween on top of whats's already there but dont pack it too tight.

I thought Jonny was talking about laying the boards (rather than the insulation) between the joists which seemed mad. your answer showing he was talking about the insulation only makes more sense.

 

[ajrobb]

Loft joists are typically 4" or 100 mm. Current insulation is 250 mm (I think), so 100 mm mineral wool is laid between joists and another 150 mm laid across them. Your loft sounds like this.

To lay a light storage area, I'd be concerned about lack of ventilation and condensation within mineral wool. Maybe take up all the mineral wool where the flooring will be and fill the gaps between the joist under the flooring with something like Celotex GA3075 (75 mm) laid against the plaster and leaving a 25 mm ventilated gap between the insulation and the flooring.

Maybe I'm just an old worry guts.