Viscous oil residue after evaporation, bitumen has been used in architecture for millennia. Present in Babylon or on the roof terraces of the mediterranean rim, its sealing qualities are known for a long time. However, used alone, it remains a fragile material and very sensitive to heat.
The invention of stabilization products derived from styrene (discovered in 1835 by a Berlin pharmacist) and that of butadiene (developed by two German engineers, W. Bock and E. Tschunkur in 1930) provide a powerful solution to overcome the flaws bitumen...
In the 1940s, the first so-called multilayer waterproofing are applied (among others) on warships. They combine the resistance of synthetic menbranes with the qualities of bitumen stabilized by chemical additives.
From the 1950s, progress accelerated and solutions in asphalt bilayer appeared.
The French company SMAC filed in 1969 the patent B3A (Bitumen, Armed, Aluminim, Asphalt) present on many works of art.
The process is gradually abandoned in favor of polymer bitumen membranes, such as the SBS (polystyrene-butadiene-styrene)...
This type of waterproofing, however, remains a product whose handling and hot laying is still very often the preserve of professionals.