Dusty / Dirty loft needs insulation

[sawm24]

i have just moved into a 30's semi and had a fist look at the loft this weekend.

The place is covered in black dust / dirt, with a very thin layer of insulation underneath.

I dont intend to use the loft for anything, i just need to remove some junk the previous owners left benind and after that the only time anyone will be up there will be for maintenance etc.

If i were to have new insulation put over the top of the old stuff without getting all the dirt hoovered up would it cause any problems?

I am dreading having to rent an industrial cleaner and crawl about trying to hoover it all up

 

[big-all]

if theres nothing inflamable[straw brought in by birds ect]
and nothing to decompose if your only talking black dusty sooty deposits a further layer up to the present 10 inch 250mm wont make much difference

its a bit lazy as old insulation can deteriorate and become fairly useless but fairly harmless but its your choice
but dont restrict air flow in the eaves
the loft space must carry on being draughty and dusty to air the woodwork