Straightening out Chimney Breast arch

[Retired Spread]

I wouldn't dab in that fireplace pal, adhesive is gypsum based more suction on it than Kelly Brook sucking a golf ball through a hose pipe, you've got soot on bricks which will bleed through dabs and into the board and also fireplaces are notorious for damp

 

[Cockney]

Like this head acheView attachment 50486. Check the bayView attachment 50486

What filthy animal has been treading all over them boards?

 

[John j]

What filthy animal has been treading all over them boards?

Your second person to say that lol

 

[DIYDerek]

I wouldn't dab in that fireplace pal, adhesive is gypsum based more suction on it than Kelly Brook sucking a golf ball through a hose pipe, you've got soot on bricks which will bleed through dabs and into the board and also fireplaces are notorious for damp

Thanks for the advice. Would you just bond the gaps then finish it?

Not sure how I would "straighten" the arch without a board? I'm not keen on doing anything structural like removing it and adding a lintel.