Bituminous (roll-on/sheet) materials are ideal for underground works, foundations, and flat roofs because they are highly durable and withstand groundwater pressure. On the other hand, cementitious (two-component) elastic waterproofing is best for wet rooms, balconies, and swimming pools because tiles can be laid directly onto it using tile adhesive.

Yes, it is possible using specialized materials designed for negative water pressure, such as penetrative (penetrating) waterproofing. This material penetrates deep into the concrete pores, reacts with water, and blocks capillaries from the inside. However, for ideal results, it is always better to wrap the foundation from the outside during the initial construction phase.