The "MaterialWaste%" column is used to estimate how much material is wasted on SqFt based jobs. The wasted material is then displayed in the Area Module and in reports that calculate cost and margin. This does not impact Revenue (amount charged to client).
For example:
The calculation will take the SqFt cost that is set in the SKU items administration page and add a Waste %.
Cost of the SKU Item= $5/SqFt
MaterialWaste% = 20%
Reported Cost = $5 * 1.2 = $6/SqFt