The sheet was to stop the screed drying before it had cured, it was just
laid on top of the screed.

I guess self leveling stuff is the way to go.

Thanks,
Jon...
Michael Mcneil wrote:
"jon" wrote in message



I screeded (75mm) a floor about 10 days ago and removed the plastic
sheeting today. There are some areas that are crumbly and once the loose
material is removed a small crater is left behind, say 30-40mm diameter
and about 3 or 4 mm deep. The screed surrounding this appears sound.


What was the plastic sheet for?

Not the damp proof was it?

The "pit" sounds like the puddle that would form (especially if the
water given off is trapped at the surface.) A puddle would form at the
lowest point and a layer of cement would separate from the mix forming a
crust. A little self leveler or a mix of pva and cement will patch it.