Chimney stack removal

[sunbeam37]

We are planning to have a chimney stack removed as we no longer use it and it's leaning. Will this make lots of sooty dust in the roof space, especially when the last few layers of bricks are removed to get the stack below the roof tiles?
Also afterwards the top of the chimney will be open into the roof space and it is quite draughty up there. Is soot in chimneys only dislodged with a bit of force or will soot blow around in the roof space whenever there is a draught, and if so can the top of the chimney be sealed somehow to stop it?
Thanks for any advice.

 

[catlad]

Shove some loft insulation down the shaft.

 

[Alastairreid]

The vents can be sealed off once inside the attic, but if it is an external stack it will need a couple of air bricks installed.

 

[Doggit]

Get the chimney swept before you remove it, then stuff the insulation in afterwards