Patching up old fireplace holes

[daveaspy]

I've just removed our old fire and fireplace surround and this is what I was greeted with

clearly damp plaster on either side and the base is really rather damp to the touch. It looks like the installer just dumped a load of plaster in the bottom to level it up and bridged the cavity. I've cleaned it all out and am left with...

so the inner wall is breezeblock, not sure what that lump is on the base but it is tied to the outer wall? So whats my plan with this then? (I'm not concerned with the hole in the outer wall at the moment, I will get around to removing the fan unit and sort that out later). Do I need to chop out the damp plaster or will that be fine once its dry? Remove some more plaster far enough to see the edges of the breezeblocks so they can be removed and whole new ones mortared in?

Eventually this will have a bioethanol fire (no need for discussion on this, the mrs has already bought it ) mounted over the hole so it will need to be a solid wall.

 

[lostinthelight]

Eventually this will have a bioethanol fire (no need for discussion on this, the mrs has already bought it ) mounted over the hole so it will need to be a solid wall.

74 pence per kwh to run?

 

[dontbelieveawordofit]

cheaper if you put petrol in it.

joke. don’t put petrol in it!

 

[daveaspy]

74 pence per kwh to run?

Well I won't be buying the fuel, if she wants it on she'll have to buy the fuel!

We do have gas central heating in the room so it's more a thing to look at than actually hear the room

 

[daveaspy]

So been a bit busy to sort this but should get something done soon as the wallpaper has now arrived Can anybody advise me on the best course of action for filling this hole? I've worked out the underlying concrete block pattern (please forgive the graphic work)

I'm thinking completely replace 1, 2, 4 and 5. Filling in the gaps between 3/4 and 5/6 with a cut block?

 

[Alastairreid]

You will need a vent as well.

 

[daveaspy]

You will need a vent as well.

why do I need a vent? It is not a chimney, just an external wall that used to have a flue through it?