Do we need a lintel below this brick curve?

[StephenStephen]

....so we found another fireplace this morning, which we now plan to open up and have a woodburner installed.

I'm concerned because that brick arch seems very flat, and also there's very little wall on the right hand side to stop it pushing outwards once we've taken the bricking up out of the middle.

Should we put a lintel below the brick arch, and if so, is it best to go for steel or concrete?

Thank you for your help, Stephen

 

[StephenStephen]

Update: we've just found a curved piece of metal under the brick arch, so assuming it's sound all the way across, I reckon we're sorted.