Home DIY

Drafty chimney woes continued: I've managed to reduce the drafts getting from the boarded up chimney behind the stud wall, so now the draft is only coming out of the fireplace hit and miss vent, and strongly. I've realised there's no cowl on the top of the chimney stack but we can't get there without scaffolding so it's likely to only happen next year when we get the roof renovated. In the meantime, which is the least worst option in terms of causing damp?

1. Install a chimney sheep or chimney balloon and leave the hit and miss vent at the fireplace open
   
2. Don't install a chimney sheep but close the hit and miss vent when it's particularly cold (which is likely to be quite a lot of the winter)
   
3. A.N.Other (maybe install a chimney sheep but trap a bit of tube/conduit down the side of it to allow a little bit of airflow?