How do I raise a constructional hearth by 1/2"

[toomuchworknotenoughtime]

Apologies if this has been dealt with elsewhere. I've searched and found nothing else on point.

Suspended timber ground floor. Concrete constructional hearth present in front of newly opened up fireplace. Originally (and I can see this in another room) hearth tiles would have been present flush with the timber floor.

Real solid fuel fire to be installed.

I intend to re-lay hearth tiles (and in fact have some bought some Stovax glazed hearth tiles). However for aesthetic reasons I want to lay the tiles slightly wider than the constructional hearth. To cut back the existing floorboards is not really an option as the constructional hearth is bounded by the last joist and the boards would then fall short.

What I want to do is bring the constructional hearth up flush with the floorboards and overlap the floorboards with the last tile all round. This would give a slight lip but I plan to put a fender around the edge. Question 1) will this work - I'm a bit worried about cracking around the boundary between tiles on timber and tiles on concrete. Question 2) what material should I use to bring the concrete up level. Heat resistent screed or sand/cement mix? I've never done any cementing - is it easy to lay say 1/2" to get it up level. Do I need to roughen up the existing surface and/or PVA it?

Thanks

 

[noseall]

Double tile it with some cheapo seconds beneath.