Open fire surround and fireback installation

[James247]

Hi I'm new to the forum, I'm in the process of installing a cast iron fireplace for an open fire. I will need to increase the height to just under the existing lintel to fit the concrete fireback into the opening.

I've highlighted the approx height of the lintel in red overlayed onto the fire surround.

Would this opening be too low? As the surround has a front hood that I would imagine would direct smoke/heat up behind the surround and up the front door the wall. Or would the hood be sealed into the wall?


Also I don't have a fireback lintel to direct the smoke up so was hoping to utilise the existing square lintel already installed

Thanks