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A layer membrane is installed very quickly in the roofing industry. The reasons for this rapid increase are: cheap installation, resistance to atmospheric conditions has long term and protection against water structures. The market share of the membranes with one layer 25-30 years ago was uncertain but today one layer membranes are most used segments of the roofing industry. Changing the membrane paved with one layer has created a revolution in the market. Several manufacturers have participated in the market of the membrane with a layer and tried to increase their sales and annual profits. Were the factors able to follow the rapid increase in PVC and a layer membrane? Why PVC membranes have become a term known by all architects, building owners and entrepreneurs of the rooftops? The answer is several advantages provided by one layer membranes. Installation cost can be compared with that of bitumen membranes and it is even less. Not only had the resistance against atmospheric conditions of long-term supported with guarantees and the quality to be a material of roof suitable for the building movements, but also problems emerged with the use of asphalt membranes are among the main reasons for the success of the membranes with a layer.  One layer membranes are developed further, formulated and combined; product dimensions and sizes by manufacturers.  They have been provided to the market in Europe in general as 1.20, 1.50 and 1.80-2.00 mm and 1.14-1.52 mm to the United States. PVC membranes which occur more among the membranes with a layer due to its advanced features are also flexible that they are able to adapt to the thermal and structural constraints and their being multifunctional let them be used in various different domains. Despite its advanced features, one layer membranes cannot respond to every problem of roofs. Each roof has its own characteristic. Despite the fact that one layer membranes were capable of solving several problems of roofs, the membrane paved will continue to keep their market share.


Historical Perspective

The popularity of the PVC and the other a layer membranes come not just advanced performance. Other economic and technological factors are also effective for the creation of one layer membranes. One layer membranes have become alternatives to rooftop instruments that progressed for various reasons in the 1970s. During the embargo of the Arabs for oil in 1973 being the main material of bitumen membranes caused refineries to prefer the small masts to gain high as a heating oil, ethylene and propylene as sub products. Asphalt is a sub product that appeared with the increase in the price of oil. The availability of the asphalt has decreased and its price increased. As a result, bituminized products have become much more expensive and the use of membranes with a layer that is not dependent on oil has become more frequent and one layer membranes have become much more economical. Asphalt is not the only product whose price has increased. The owners of the buildings began to reflect more deeply on the costs of warming and cooling. The factors affecting the roofing industry: low price, the need for insulation with an R-value advanced materials *. Although the polyester (expanded or extruded polystyrene) in accordance with these criteria, this is not compliance with bitumen. The need to increase the price of labor, decrease in costs of materials forced manufacturers of materials testing to alleviate the system applied with two layers. However, the inadequate performance of the system with two layers prevented manufacturers to have good results. As the price of bituminized products increases, a layer membranes decreased and they have become more competitive in the market.  At the end of the 1980 s and beginning of the 1990s, bituminized commodity prices and that a layer membranes almost equalized. From this period, one layer membranes beat sales five years records. The architects, contractors of roofs and owners of buildings began to pay more attention to one layer membranes. 


It is the layer membrane manufacturers that give '10 years' guarantee for the first time in the industry. Layer membranes manufacturers have developed in a very short duration requirements of the program of guarantee as give license, education, supervision of work and technical consultation. Contractor license program and surveillance of the roofs, we, the manufacturers can provide and guarantee the impermeability.  Even the costs of right cases presented for insulation reasons are reasons enough for the owners of buildings and architects prefer a system of roofs guaranteed by the related companies. Even if the cost of the roof is less than 5% of the cost of the entire building, this may be calculated nearly 30% or 50% in the trial. Single layer membrane system is reliable.  If there is a problem despite this reliability, this is usually made by the errors during installation. For this reason; we doing surveillance for roof very carefully protect the owner as well as ourselves against potential problems and organize some programs of perfect application. 



There are several membranes impermeability applied as a layer with their own advantages and disadvantages. Despite their structures chemical very different, it is possible to classify them in three main groups: elastomers, thermoplastics and bitumen modified.



Even though they are known as thermosets improved; elastomers take their names instead of chemical procedures during manufacture which are called the improvement or vulcanization. Their chains of molecules are of cross-links or vulcanize to create a permanent chain. They are not to train, reform or weld with temperature. These materials are combined only with special or with technical vulcanization (high pressure and high temperature) welding solutions. Elastomeric membranes are Butil, EPDM, Neoprene and other polymers.




Thermoplastics are separated from elastomers due to prevent the creation of cross-links and vulcanization of molecules. Materials are combined with temperature or special weld because of the chemical structure of thermoplastics. PVC dominates the market of membranes with a layer with a large percentage.  PVC owes its popularity in the industry has the advanced performance of membranes, PVC and very often quality checks by manufacturers.  PVC membranes are very resistant against ultraviolet light, thermal ageing and low temperatures.  PVC products of different sizes membranes are installed quickly and provide the economy of effort. Thermoplastic membranes are: EVA (ethylene vinyl acetate copolymer), ECB (ethylene copolymer bitumen), PE (polyethylene) and PP (polypropylene), PEC (polyethylene), PVC (polyvinyl chloride) 

Application methods

Single layer systems have several types used in new buildings and repair of low roofs: inverted roof system and installation free or on gravel, adhered fully or partially, detected mechanically. Inclination of the roof, construction of support, contact with chemicals and weather conditions must be considered to determine the system.

Ballast System 

Ballast system is currently the most used system. It is freely placed on thermal insulation and construction of support forming the whole of the roof and it remains stable thanks to the weight of the ballast. The ballast is usually attached to the part with 2.5 cm in diameter. The free movement at all with the separation of the membrane of the construction of support and low cost are of the primary advantages. However, the weight of gravel break additional load to this building and all the roofs cannot between designated to support such weight. The people who will decide on the ballast system must assess the structural conditions of the building and confirm the weight of the ballast to install: 50 - 75 kg/m2


Complete adhesion system

This system is ideal not only for sloping roofs but the roofs unable to bear the load of ballast. The membrane is attached completely to the Sub-layers of special adhesive. The complete adhesion system is light; easy a test and maintain and provide choices in different colors. Complete adhesion systems in general are the most expensive single layer systems.


Mechanic detection system

The advantage of mechanical detection systems is being lightweight. It is freely placed on the layer under the membrane and after detected with instruments for mechanical detection offered by the manufacturers. There are several types of mechanical detection. The most popular system is the one connected directly a sub layer and that perch the underlayment. The disadvantage of systems with mechanical detection is that the forces of the wind rise and swell the membrane and the extension in the connection points.  Some services such as calculating the wind load and determine the detection points to support these extensions create the difference between companies.


Inverted roof system

Inverted roof system is a type of traditional ballast system. In this system, the membrane beneath the thermal insulation and the ballast is located on the felt on the thermal insulation.  Insulation and ballast protects the membrane of the negative effects of sun rays and reduces fluctuations in temperature and thermal shock.  Inverted roofs have needs more than ballast compared with those of traditional type. If there is a pedestrian circulation, these types of roofs have excellent performance. 

Future of one layer membranes

Statistics show that one layer membranes have excellent performance when they are exposed to the external impacts of long term. The effective dominance' to the % 70-80 of the membranes with a layer in certain regions of the world is the main proof of this development and progress. This technology that gave us these membranes of today will undoubtedly advance and more architects, contractor, building owners will discover the benefits of membranes of one layer.