"Dave Page" wrote in message
...
Doctor Drivel wrote:

As he is removing the old insulation, it is best seal up the holes where
cable and pipes penetrate with silicon, then lat a poly vapour barrier on
the plasterboard/joist. Pin it with a staple gun to side of the joists
and tape the joins with big overlaps. Then lay the insulation and lay
the new joists. Then make sure the hatch
is sealed and insulated too.

Is that just to stop drafts, or for any other reason? The ceiling appears
to be chipboard rather than plasterboard here.

About 42% of heat loss in UK homes is via air-leakages. Preventing water
vapour from entering the cold loft prevents condensation on the timbers,
hence the sealed loft hatch.