Bricking up a fireplace

[boymum59]

We're looking at blocking up a fire place, bricking it, plasterboard and then plastering it. Do we need to put a vent in somewhere? I know we need to put some kind of insulation up the chimney, any recommendations what to use?

You don't need to brick it, plasterboard will be fine. If you put insulation up then you need to leave a gap so that air can still flow up the chimney otherwise you can get issues with damp. This is also why you need a small vent in the bottom where the fire would have been. About the size of a brick is about right.

Might be worth putting some insulation onto the back of the plasterboard?