Internal window board fitting

[Jimmy3]

I'm refurbing our bedroom and have removed the old window board/window cill.
The bottom of the window is basically back to brick work and needs to be raised up around 1 - 2 inches (including the window board thickness) to make the existing window look neat.
Should i try and level the exposed brickwork with mortar or plaster before laying my board on top?
I have seen a previous post which says screw some plyboard into the brick and gripfix the new board onto the ply which makes sense. But i'm not sure how to finish the brick work prior to fixing the ply board down.
Would the new window board stick straight on to mortar?

 

[Mw Roofline]

I'd just mortar it and no nails the cill to the mortar.

 

[Jimmy3]

Thanks. I'll try that then.
The wood won't bond to the mortar direct then? As this would make it easier as i could just level the new board straight onto the wet mortar.

 

[gregers]

i wouldnt bed on to wet mortar/pug,i would allow to dry then bed down using gripfil.that way you can get it level with the adhesive.

 

[Jimmy3]

OK Thanks.
That's a good idea.