Building a swimming pool in concrete or containing concrete necessarily requires formwork. Here's a look at the two types of formwork available: reusable formwork and permanent or disposable formwork.
Recoverable formwork
Used in masonry, reusable formwork is a mold into which concrete is poured. Once the concrete has dried, the mold is removed. Pools built with reusable formwork are more expensive because their construction requires significant labor. Regardless of the formwork, the installation principle is the same: pouring the bottom with reinforcement and installing the formwork for pouring the pool structures .
• Wooden formwork
It is the oldest of the recoverable masonry formworks. This type of formwork is no longer used today because it is bulky and difficult to install.
• Formwork
These formworks use the same technique as wooden formwork but are made of plastic or steel. They are easier to install, lightweight, and allow for rounded shapes.
Permanent/lost formwork
It is a formwork that is made up of modular panels (resin, PVC or polypropylene), or formwork blocks made of concrete or polyester. Once assembled together, the formwork is reinforced before receiving the concrete.
It is impossible to separate the concrete from the formwork, which is an integral part of the structure. This is why this formwork is called permanent formwork.
• Modular panels
Based on a patent filed by the Piscines Desjoyaux group in 1978, this permanent formwork is made of modular injected polypropylene panels. Pre-assembled in the factory and assembled directly on site, the panels are then reinforced before pouring the concrete. The bottom and walls are poured in a single operation to obtain a monolithic and self-supporting structure.
• Formwork blocks
Their shape is identical to that of concrete blocks. Hollow and bottomless, once assembled together on a concrete slab, they form the pool wall. The concrete is poured into the formwork blocks as soon as the reinforcement is completed. Unlike the modular pool, the concrete slab and the pouring of the formwork blocks cannot be done in a single operation since the formwork blocks are installed on the concrete slab.
