Roof Insulation

I have to create a slop on aroof (area 4500n/sq) (1,5% slop)
i want to spry it with polyuerithne foam (averge of 30c'm)
1)how much material needed for 1m/sq
2)what is the weight of material 1m/s'q
3) " " " cost per 1 kg(f,o,b) 4)equipment ?