Quick questions about Dot & Dab

[carryoncamping]

How many 8’x4’ boards should a 25kg bag of adhesive realistically stick, assuming the wall is plum and a gap of no more than 20mm between wall and board?

My local Buildbase sells 9.5mm and 12.5mm for exactly the same price of £5.66. I’ve used 12.5mm on ceiling and am tempted to use 12.5mm for the walls, (extra weight is NOT a problem) but a smooth non-warped finish is, is it OK to use 12.5mm with Dot and Dab?

Thanks

 

[clout stench]

ONLY use 12.5 when dot and dabbing in my opinion.

1 bag should fix two to three 8x4 PB's.

 

[carryoncamping]

Thanks, that's about what I thought.