blocking chimney

[gnasher]

Just moved into a mid terraced 1920's house. If we light a fire downstairs, smoke escapes from behind a built-in wardrobe upstairs. For some reason the upstairs fire place was not covered over. How do we block the upstairs chimney? Is it a big job or can we do it ourselves?
Previous threads I've seen do not deal with blocking the chimney.
Thanks for any advice

 

[Carpenter]

I think you really need to have a competent person (builder/ surveyor/ architect/ engineer) to see the situation on the ground- especially before you go blocking up any fireplaces as doing so can lead to a build up of condensation within the flue unless adequate measures are taken to provide ventilation. What you describe doesn't sound good anyway.