1960/70 built property with an outside chimney (Walls on inside are flush) with a 10" (guess) tin lining. There was a Baxi installed but prior was a 'proper' fireplace.
i need to brick this up as its not wanted but is it adequate to drill a few good sized holes from the outside and place a vent over the opening?
Do I need to remove the concrete chimney insert or is it OK just to break through so air to liner unobstructed?