Steve Jones wrote:
Hi,

I need to get some insulation into the void under a flat roof.

The roof is 12x12ft and I can get access between the joists from one
end.

I'm hopping that I can push loose-fill insulation in from the
end using a home made tool of some sort.


You can, using a sweeping brush, but you won't get it 12 feet, maybe if you
took a section of ceiling down at the opposite side you might have a chance.

Can anyone tell me if the approach stands reasonable chance of
working or is the loose-fill likely to clog up before I manage to
push it to the far end of the roof?

Also which insulation product is the most pushable?

fibreglass.
Rockwool is heavier but it's also more brittle because the strands are
shorter and thicker than glass.
polystyrene is a fire hazzard.
Celotex type stuff is possible if you cut it into squares the width of the
joists and push each one along until each run is filled but this is
expensive