Chimney removed to below roof - does it still need venting?

[Niscars]

Hi, the house we are buying has already had the central chimney lowered below the roof tiles and the top of it is now in the loft. Inside the house there are vent grills cut in plywood used to cover up the fire places.
I am going to make a better job of sealing up the fireplaces with either stud work or bricks prior to skimming but do I actually still need to have an air vent if the top of the chimney is not exposed to the elements?

Thanks,
Niscars

 

[^woody^]

There is always a risk of internal condensation and associated tar leeching, more so if the flue is on an external wall, less so if on a internal one - one which you may want to take if that is the case and avoid vent grills in the rooms.

 

[Niscars]

Thanks for the reply. It is the central one, so internal walls only.

Ta,
Niscars