I have knocked the plaster off around my fire in readiness for fitting a new fire. I have gone back to the brick as ther plaster was loose. It looks like some of the bricks above the fire could be loose as there are small gaps between the bricks and mortar in places. Also the bricks sound a bit less solid than the surrounding bricks when tapped. I assume this is due to heat over the years. Should I get these seen to before it all gets re-plastered. I am getting other brickwork done to the hole to accomodate a hole in the wall fire anyway.