Divide the wall area by the coverage of one bag, and round up to a whole bag. For 1,000 sq ft at 13 mm you need 38 bags of SIG-MR or 50 bags of PlastoPlus.
| Wall area at 13 mm | SIG-MR, 25 kg bags | PlastoPlus, 20 kg bags |
|---|---|---|
| 100 sq ft | 4 bags | 5 bags |
| 500 sq ft | 19 bags | 25 bags |
| 1,000 sq ft | 38 bags | 50 bags |
| 2,000 sq ft | 75 bags | 100 bags |
For another area or thickness, use the calculator on the SIG-MR page or the PlastoPlus page. You can also enter the coverage of another plaster and compare the number of bags.