Interviews / 7/3/2025

Waterproofing: the secret behind the durability of swimming pools

Mapei solutions for durability, efficiency and comfort

Interviewee

Dino Vasquez

Corporate product manager, waterproofing line, Mapei

Waterproofing is a crucial and technically demanding step in building long-lasting swimming pools. Mapei provides a range of waterproofing solutions—including Mapelastic membranes, Planiseal 288, and Purtop Easy DW—adapted to different substrates and environments. Long-term performance also depends on proper maintenance with high quality products, which ensures safety, hygiene, energy efficiency, compliance, and aesthetic value while minimizing costs and structural risks.

Waterproofing is one of the most important and delicate operations when building a swimming pool. What are the main aspects and critical points that need to be considered?

The aspect most attention is usually dedicated to is aesthetics, but when you decide to build a hydraulic structure, the most delicate aspect is its actual design. Errors and oversights in this phase lead to really unpleasant consequences in terms of watertightness and the durability of the structure over time. There are various fundamental points that need to be taken into consideration: from correct mix design to sealing cold joints and components for the recirculation, filter and lighting systems, from preparing and waterproofing inside the pools, right up to choosing appropriate materials to finish off surfaces. However, there are also certain other critical areas that require attention, such as corners and edges between walls, skimmers, inlets, pump systems and the geometry of the structure; all elements that need the right level of attention during the design phase. Then you also have to include verifying the substrate in the case of existing structures. In fact, the presence of cracks may be a sign of a structure settling which is why, before proceeding with waterproofing work, it is a good idea to look carefully into these situations.

Renovation work was carried out on the public outdoor pools in Gubbio (Italy) by using Mapei products.

Which Mapei products are the most suitable for waterproofing a swimming pool?

Mapei offers specific solutions for waterproofing swimming pools that guarantee long-lasting, high performance. Amongst the products most often used are cementitious membranes from the Mapelastic range which differ according to their fluidity and application method adopted. Their use presumes that covering material will be applied afterwards using adhesives and grouts suitable for contact with chlorinated water. As an alternative, it is possible to use cementitious products that are left exposed, such as Planiseal 288, or polyurethane products such as Purtop Easy DW with a coloured finish. Which product to use is determined by the type of substrate (new or existing) and the position of the pool (sunken, with a roof, indoors or outdoors) and the products used to clean the pool.

The public swimming pool in Brno (Czech Republic) was completed with Mapei solution, including waterproofing materials applied on the substrates.

How important is maintenance work on a swimming pool?

It is essential that a swimming pool is maintained to guarantee five conditions:

safety and hygiene, to keep the water clean and safe, reducing the risk of bacteria and preventing accidents due to structural damage;
durability and efficiency, to protect structures and improve the energy efficiency of filter systems;
cost savings, because preventive maintenance reduces the risk of serious damage and repair costs are minimised, increasing the service life of the pool;
compliance with standards;
aesthetics and comfort, for a more beautiful and comfortable swimming pool.