Good day to you Young Ed,
When I mentioned additional problems with masking, I was thinking of a cleaner I know who did this a few years ago.
He thought that the plasic sheet was no good if the water could run underneath, so he taped it down.
When he removed it he found that the adhesive had reacted withthe floor coating and some came up with the tape
This would not happen with Woodmans' sugestion, but then not every CC would refit the carpet to the required standard.
Regards,
John.