Expanding foam around perimeter?

[rhysjc]

Hi all, in need of some advice!

I’ve taken up the old carpet and will be laying LVT after I’ve overboarded with some ply. My question is around what I should be doing around the edges of the floorboards where there’s a gap to the wall? When I removed the old skirting there was some sort of black fibre stuffed in the gap. I assume the idea is to stop drafts though this is upstairs so above a heated room, and maybe also to block some noise?

Should I be replacing this, and if so with what? I was thinking expanding foam but concerned that may stop the boards expanding?

 

[Wayners]

Foam is soft. Won't stop movement of boards

 

[rhysjc]

It does set pretty hard, maybe it’s soft enough to allow expansion still?