Blocking first floor fireplace.

diysos101

I’ve removed a gas fire from a bedroom!! I’ve had the chimney capped (with air gap) and now looking to close the hole and add adequate ventilation. Do I need the air vent at bedroom level or would the loft level be sufficient to draw air flow? Would prefer to avoid the cold draught where bed head will be! 

Maybe I could add vent at loft level and fill the bedroom hole with bricks to reduce the depth of the chimney void? 

If it remains a void at bedroom level then which is best to close - with bricks or plasterboard? and do I insulate behind? I would have thought thin plasterboard would be cold?
sorry lots of questions! Hoping for your advice on best way forward.  

stuart45

I always brick them up. You can use a hit and miss vent if you want to close it occasionally. The vent needs to be low down to get the air flow through the whole flue.

FreeBear

stuart45 said: The vent needs to be low down to get the air flow through the whole flue.

The hole for the vent need not be large - A couple of 25mm diameter holes should be enough. I have two fireplaces bricked up here without any vents at the bottom. Never experienced damp problems - Do have a solid fuel stove which puts quite a bit of heat into the chimney, so that will certainly be helping to keep damp at bay.

Brick up with aerated cement (breeze/thermalite) blocks.

stuart45

Not sure if customers would be too happy with a couple of holes drilled into the wall. I've always fitted a hit and miss, which they can open and close to suit their needs. Holes do allow spiders etc. to enter the room.

FreeBear

Drill the holes, cover with some fine mesh, and then fix a hit'n'miss vent over the top. Keeps it neat to look at, and there shouldn't be any howling cold draughts in the winter months.

stuart45

When building in I leave the hole in so no need for the drill. I prefer a bit more ventilation, as it can be controlled or cut off with the vent. Some chimneys suffer from damp more than others.