Floor Wastes in Bathrooms – When Are They Required? The provision of floor wastes in bathrooms and when they are required is one of the more contentious issues in relation to bathroom construction. There is much anecdotal evidence out there in relation to this, but what are the facts? There are two primary documents in relation to wet areas construction: the Building Code of Australia (BCA) AS 3740 – 2010 Waterproofing of domestic wet areas   Class 2, 3 or Class 4 part of a building So starting with Volume 1 requirements: For apartment buildings (Class 2 buildings), hotels, motels