The tunnel discs are designed to fix firstly the diffuser felting to the tunnel wall. Once the discs are fixed to the wall, the adhesion of the PVC waterproof sheet to the discs themselves may be carried out with a suitable hot air blower.
The discs are fixed with a special gun with an explosive charge. They are spaced at about 70-80 cm from disc to disc.
The whole surface of the ribbed discs must be glued to the PVC sheet so that the best possible adhesion is obtained to resist pressure from buildups of water.
The disc is ribbed to make it more rigid and improve the adhesion of the PVC sheet even on very uneven surfaces. The disc is also shaped with an central inset to take a washer for the fixing nail.
The flat disc is available with or without steel washer incorporated.
The pre-inserted washer has a diameter of 21,75 mm with a central hole of 5 or 6,4 mm.
The flat disc is available also with knock-out system.
Flat disc with knock-out system has to be glued only externally to the holes of the system.
They have a high flexibility even at low temperatures. They have excellent long term physical and mechanical properties and are compatible with PVC synthetic waterproofing.