Our house has about 4" original loft insulation between the joists
(some yellow fibre glass stuff) and about 6-8" top-up insulation laid
perpendicular to the original. The extra stuff is the Pink Panther
white fibre glass (?) inside a perforated pink plastic bag.

The problem is that condensation is building up inside the plastic
sheeting and saturating the white insulation, there doesn't appear to
be any dampness underneath. The loft appears to be reasonably
ventilated, certainly I can see daylight all around the eaves.

Short of debagging the Pink Panther stuff which is probably a nasty
job, is there anything else I should consider?

Thanks!

Jonathan