I'm currently calculating approx 3m x 3m of ply give or take. Then enough compound to cover 6 square meters at up to 18mm depth (though I'd have some left over because of the variation in height in the concrete).
But that's to apply ply to the existing boards. Your suggestion is for the same amount of ply, just replacing the boards, then enough compound to cover 15 square metres at a depth of up to 30mm?
I'm currently calculating approx 3m x 3m of ply give or take. Then enough compound to cover 6 square meters at up to 18mm depth (though I'd have some left over because of the variation in height in the concrete).
But that's to apply ply to the existing boards. Your suggestion is for the same amount of ply, just replacing the boards, then enough compound to cover 15 square metres at a depth of up to 30mm?