(Also see Liquid Waterproofing Membranes)
The main purpose of waterproofing is to prevent the intrusion of water and moisture in unwanted areas. All shower floors must have waterproofing.
Waterproofing is also an important step in installations, such as second-story bathrooms and laundry rooms, where excess water and moisture may occur.
MAPEI recommends MAPEI’s Mapelastic AquaDefense for most areas where waterproofing is required.