Smell coming from 6 month old flat roof.

Phil4432

I had a flat roof installed last October, since the weather has warmed there's a slight smell coming from it into the front room.  There is a minor crack where the wall meets the ceiling, that's been on my never ending DIY list to sort out.  So I think the smell is coming in via that.

I'll seal it up with filler soon, just wondering if the smell is anything to be alarmed about.  Thereis a void between the plywood roof board and plasterboard, I remember seeing some bricks in there when the roofers took up the old roof, and replaced one of the boards that had rotted through by a small leak. 

Hard to describe the smell, at first I thought it was organic.  Pretty sure its not organic though, doesn't smell mouldy or musty as such.  The roof seems to be fully watertight.

Anything to be concerned about?

Thanks.