Expansion gap cover between old brick and engineered wood

[paro]

Hi All - Wondering if anyone has any suggestions for an expansion gap between an engineered wooden floor and old brick floor. I've finished laying the boards now and managed to get the levels I was after. I want to use something as inconspicious as possible for the transtion to the old cottage, so no wooden strips or similar if it can be helped. The best I've been able to come up with as possibly being suitable is burnt sand mastic but not am guessing it's probably not got sufficient stretch. The rest of the floor has a huge 40mm gap but would like to minimise what goes here if possible.

 

Someone suggested leaving it as a shadow gap but I am not sure that will work from a cleanliness perspective as it will just pick up all the muck over time. 

 

Thanks, Paul

 

[markc]

That looks neat, I would fill with a coloured flexible filler / silicon etc. anything on top will be more obvious and as your levels look right, a cover strip would be more of a trip.

[Russell griffiths]

Aluminium profile 2mm thick, powder coated to your choice of colour. 
stuck down