Gas pipe sleeving and sealing through ceilings?

[Guitarmaan]

Hi all, I'm new to this forum. Maybe someone can answer these simple questions. . . . .

I know gas pipes need sleeving through walls, but is the same true for going through ceilings?

Also, pipes need to be sealed at least at one end. When a meter is in a cupboard or compartment and the pipe is not sealed going through a wall (or ceiling), is that classed as At Risk or just Cause For Concern?

thanks!