Renovation Of The Roof With Suction Drainage Systems

When rehabilitating a light deck-type roof, you should consider a few factors. The height of the baseboards, the geometry of the benches, openings, channels, are some of the elements that you should consider. Also, consider storm-water runoff points.

Most storm-water runoff points are resolved through evacuation systems by:

Gravity: When the bottom tube is connected to the waterproofing through a compatible prefabricated accessory, called a vertical water outlet.


Induced vacuum: Commonly known as a suction system, in these cases the downpipes are connected to a single network, sucks in rainwater due to the absence of air in the network. These systems work with a complete tube, so sizing the different diameters of the network is essential for correct operation.

How to Rehabilitate a Roof with a Suction Drainage System?

When we have to rehabilitate a roof where evacuations are produced by vacuum or suction systems, the application of new waterproofing with the existing water outlet becomes more relevant and becomes a critical point in the process. For any roofing job, consult with us at

Most of these special water outlets are made of laminated steel sheet on which a vulcanized TPO or PVC coating is applied to subsequently receive the waterproofing membrane by heat sealing. If the renovation of the roof requires a waterproofing system different from the existing one, special care must be taken in this process, as compatibility between the vulcanization leaving water and the new sheet may not be possible. It is in these cases that we must locate, together with the manufacturer of the water outlet, the special piece or collar that adapts the existing water outlet to the new waterproofing sheet.

In other cases, the water outlets have a metal pressure ring which, with the help of a rubber ring, seals the connection between the water outlet and the new blade through pressure.