Best way to fit trim around fireplace to allow for expansion / contraction?

[boilerhater]

Hi, I recently had to add expansion gaps to my living room perimeter as my numpty contractor failed to do so, and it was causing my solid wood floorboards to cup in the summer months. I used a multitool to cut off the edges after removing skirting & fireplace trim - all good so far.

However, now I'm at the point of installing new trim / beading around the fireplace hearth to hide the gap. I was going to use 'no more nails' glue, but I've noticed that it sets rock solid. And obviously the expansion gap is there to allow movement of the boards. So I'm worried that the trim might end up cracking the granite hearth when the boards expand during the summer?

Can anyone recommend a glue that will be suitably flexible, allowing the boards to move? I know nails are an option but if I can get away with an adhesive I'd prefer that!

EDIT Just saw that 'Sticks like sh*t' says it allows 15% movement... anyone recommend that? https://bit.ly/2yVoDZZ

 

[dazlight]

You want to use a wood end bar which you fit to the sub floor

like this


https://www.amazon.co.uk/Lacquered-Flooring-Profile-Threshold-Suitable/dp/B00FK2DYGK