Among the materials used in the waterproofing of this type of hydraulic works – Lagoons , the membranes with modified bitumen have advantages for this type of use.
The APP ( atatic polypropylene) modified bitumen composite guarantees a better waterproofing and a longer duration compared to other materials.
In addition, the fact that the membrane is reinforced with 150 gm2 polyester reinforcement gives this type of material excellent mechanical resistance.
This membrane has a mass of 4 kgm2 , upper and lower finished in polyethylene, is available in rolls of 1×10 m and its commercial name is POLYSTER 40 .
It is possible to introduce in the manufacturing process an anti-root additive allowing roots to be simply repelled, thus preventing their penetration into the membrane and their consequent degradation – POLYSTER 40 ( Garden ).
In this type of hydraulic works, the application of a bituminous membrane with the same characteristics as the previous one, but with a surface finish higher than mineral grain, can also be considered.
The use of this mineralized membrane increases its mechanical resistance to the action of puncturing elements that may exist on the membrane (e.g. stones for embellishment).
This membrane has a mass of 5.0 kgm2 , upper finish in mineral grain (slate grain) and lower finish in polyethylene , is available in rolls of 1x8m and its commercial name is POLYXIS R 50 (Garden).
We are dealing with materials tested by LNEC – Laboratório Nacional de Engenharia Civil – for which this body has issued an approval document.

The main advantages of these materials are:

– Resistance to the effect of roots and other vegetation.
– Absence of physical and mechanical degradation due to atmospheric agents
– Resistance to temperature variations and ultraviolet rays.
– The mass of at least 4.0 kgm2 allows for application on the soil, with good mechanical resistance to the stresses to which it will be subjected.
– Any damage can be easily repaired by simply applying a piece of the same material to the area to be repaired using a torch flame.
– This type of material can be placed directly on the soil without the need for concrete structures.