The problem - just had an extension built that had to include a
manhole cover in the main corridor. It's a proper job sealing cover,
so no worries with smells etc. I'm currently tiling and grouting the
floor area but am at a bit of a loss over what to do around the
manhole. I've cut the tiles to fit and still allow the man hole to
lift - but what can I use to fill the gaps that won't cause me
trouble in the future? I've thought of candle wax or similar just to
fill the gaps?

Any idea's gratefully appreciated.