drylining adhesive

[vonspritz]

The instructions for the knauff drylining adhesive I'm using for dot & dab advise using one 25 kilo bag for one and a half 8x4 plasterboards.
This seems excessive, It seems like I'd have to coat the whole board rather than dot it to use that much. Can anyone advise:
1) how much to use per board?
2) how thick to apply?
3) how much gap between wall & board once fixed?
Thanks
Vonspritz

[welsh brickie]

mix to a clotted cream consistency the drywall adhesive goes on the wall not the board you want the blobs to be about 60mm thick 4 across a 1200mm board and every 500 to 600mm you will need a straight edge like a 4x2 timber to knock the plasterboard into position it should stand off the wall about 20mm, remember to pack it off the floor so use a off cut of plasterboard to rest the board on they can be removed later once the stuff has set.

[vonspritz]

Thanks for your prompt reply.
what is the reason for the 20mm gap between wall & board? why not five or ten mm? presumably the boards will still stick to the wall & its easier to get it flat. And any reason for blobs on wall not board? Its easier to do with the board flat on the floor.
Vonspritz

[welsh brickie]

20mm gives room for any discrepancy in the wall,in can be tighter if you wish, the reason the wall is applied with the adhesive, is because its easier to manage the board and it doesn't bent under the weight