I jave just had a gas fire disconnected and removed from my living room. It had a flue, meaning that there is now a hole in the living room wall. There is some kind of ducting going up from this inside the wall and, I assume, out via the roof somewhere. The wall is plaster board over breeze block. I don't think the flue itsef can be more than 10 x 20 cm, but can only feel from the bottom.
Can I just stick a new bit of plasterboard over the hole and leave it that or do I need to leave a hole for ventilation?? Do I need to do anything at the other end of the flue (outside the house I mean) or can it just stay open?
I'm not worried about the draught, I just don't want to cause any kind of damp problem.