Roofing membrane

Andrei Ivanov domestic technical literature to highlight three types of soft roofs, which differ in composition of waterproofing coatings: bitumen-polymer or roll roofing, mastic roofing and membrane roofing. Sometimes there are texts where the membrane is called bitumen-polymer materials. To the prevailing standards of Russian technical texts is wrong, and the error caused by the fact that English's technical literature, the term membrane called all types of roll roofing materials, including bitumen-polymer. In Russia, however a widespread membrane roofs have only recently, so the total proportion of membrane roofs in this country among all types of soft roofing does not exceed one-half percent. Slightly more than two percent today make roofing mastic, and the rest fall on asphalt roll roofing. For comparison, in western Europe, the proportion of membrane roof reaches eighty-seven per cent. In most cases the roofing membrane used to cover roofs with low slopes, the so-called flat roofs. Flat roofs are usually lighter than pitched, and as cheaply as in the device, and in operation. Operated flat roof provides extra space on the roof of the building, which can be used in summer for recreation and sport activities. Lately it has become fashionable to cover the roof of a carpet of vegetation, creating a so-called green roofs. In the latter case, the roofing membrane based synthetic rubber or thermoplastic olefin virtually irreplaceable. Proportion of membrane roofing in domestic urban development is growing fast enough. The attractiveness of membrane roofs lies in their unique life in relation to all other types of roofs (40-60 years of operation), as well as the simplicity of their installation and repair. The durability of membrane roofing is best confirmed firm the warranty period of 15-20 years, who give their products the leading manufacturers of membrane materials for membrane roofing. The thickness of the roofing membrane is from 0,8 to 1,5-2 mm. Average weight per square meter - 1,3 kg. Experienced builders say that under identical conditions, membrane roofing installation takes one and a half times faster than the installation of bitumen-polymer roof. Brigade professional builders for one shift may cover membrane roof over 600 square meters. m. Cloths roofing membrane is extremely flexible (more than 400% for membranes made of synthetic rubber), have high puncture resistance (leaf membranes reinforced with polyester mesh), resistant to UV radiation and aggressive media, have a high frost resistance (up to - 60 C) and fire resistant. A distinctive feature of the roofing membrane is a large size range is dense (width from 0.9 to 15 meters, length up to 60 meters), which allows to choose the optimum width of roll roofing of any configuration, minimizing the required number of stitches. Materials for membrane roofs are usually sold with adhesives, sealants, fasteners for the adjacency, Pipe clamp, ready to internal and external corners, holes and overflow. Depending on the polymer material constituting the base cloths, roofing membranes are divided into three types of EPDM, PVC and TPO. We consider in detail the shortcomings of the advantages of each type of roofing membrane. The disadvantages of membrane roofing include except that the higher cost of polymer fabrics, more than 1.3 times the value of the bitumen-polymer materials. However, this difference is not commensurate with the benefits of roofing membranes, even in the most perfect of bitumen-polymer-rolled materials. The fact is that over time the bitumen highlighted the volatile fractions, with the loss of which the material becomes brittle, covered with cracks and loses its waterproofing properties. Another reason for the formation of cracks in the bitumen-polymer materials are low temperature, typical for the winter season in most parts of Russia. Among soft roofing membrane fraction of Russia does not exceed 1,5%. In western Europe - 87%. The study VNIINTPI conducted in 1992, after two years of operation proceeds to 30% of roofs with waterproofing layer of bitumen-containing materials. Among the bitumen-polymer roofing with a five-percentage-of-life flowing roof is 70%, while those of the roof, which have been maintained for seven years or more exist in virtually everything. Practice shows that the repair of old bitumen-polymer roofing costs significantly more than the membrane, since in this case, as a rule, requires removal of old material, repairing ties extra aeration for the withdrawal of accumulated condensation from the roof of the old pie. EPDM membranes With EPDM (EPDM) membrane combines the membrane, the base of which is polymerized ethylene-propylene-diene-monomer (synthetic rubber). In order to increase the strength characteristics of the rubber base are reinforced with polyester mesh. Design life of roofing membranes of this type reaches fifty years. Since this type of membrane was introduced in the U.S. is a half-century ago, the timing of aging such as EPDM roofing membranes are defined not by artificial aging processes in climate chambers, and the usual practice of their operation. From other types of membranes EPDM membranes are characterized by a low-cost and higher flexibility. The highest quality brand EPDM membranes, supplied by "Firestone Building Products" (Firestone), "GenFlex" (Evergard), "Trelleborg" (ELASTOSIL) have elasticity to 425%, while the best type of PVC membranes that figure does not exceed 200% . Because of such high elasticity and absolute waterproof EPDR membrane is used as a waterproofing material for tunnels, water tanks for storage of waste, industrial lagoons, artificial ornamental ponds and fish, etc. Other advantages of EPDM membranes is insensitive to the bituminous materials and environmental safety associated with the absence of harmful substances in the installation and operation of membrane roofing EPDM type. Among the ballast roofs share EPDM membranes is 90%. The disadvantages of EPDM-membranes are usually related to the adhesive connection technology fabrics with a special adhesive tape. It is clear that the strength of adhesive bonding is usually less than the weld. Some manufacturers of EPDM membranes producing membrane of the roof are joined by vulcanization by welding, hot air (500 C). The elasticity of the joint obtained in this case is the same as the main fabric. This type of compound used in the membranes ELASTOSIL brand, manufactured by "Trelleborg". On the market today are a few domestic manufacturers of EPDM membranes, including: Elon (temperature range from - 60 to + 120 C) - Ufa Plant of Elastomer Materials, components and structures "; Epikrom - producer of" poly "; Akvalasten - Ogneizolkrovlya ; Kromel - Neftekhim-prom. " The average cost of imports such as EPDM roofing membranes - 250 rubles per square meter. The cost of domestic membranes, with similar physical-mechanical and operational characteristics of several times lower. Composite EPDM membranes Besides pure EPDM membranes are manufactured composite roofing membrane, the top layer which consists of synthetic rubber, and the bottom consists of a visco-plastic polymer-bitumen material. Between the layers rasplozhena reinforcing mesh of fiberglass. EPDM layer gives the material a high weather resistance, elasticity and durability, while bitumen layer gives additional strength and provides additional protection in case of damage to the layer of EPDM during installation or operation. If necessary, attaching the membrane to the bottom of the roof instead of glue, you can use the melted bitumen. This type of roofing membranes are manufactured by the German "Foenix", trademark Rezitreks. According to strength as a membrane roof Rezitreks comparable only with the SST-membranes, surpassing last for flexibility. Cost per square meter Rezitreks twice the cost of conventional EPDM membranes. Joints in the membrane leaf Rezitreks welded with hot air. Application of roofing membranes Rezitreks justified on the roofs of irregular shape, in the same way at high mechanical stress during installation and operation. PVC membrane based on PVC membranes is plasticized polyvinyl chloride, reinforced polyester mesh. In order to increase the elasticity of polivinihroida its members impose large proportion (40%) of volatile plasticizers. Canvases are welded using special equipment with hot air. PVC-membrane favorably with those of other types of roofing membranes more resistant to UV radiation, fire resistance and a wide range of colors colors membrane fabrics (up to 9 colors). It is true when choosing a color of the roof of the PVC membrane should be borne in mind that over time the color fades significantly canvases. Disadvantages of PVC membranes are in lack of sustainability of bituminous materials, oils and solvents. Volatile fraction belonging to the polyvinyl-nilorida make this material problematic in terms of ecology. In addition, as the evaporation of plasticizers deteriorate mechanical properties of the membrane semitone. Widespread in the Russian market of roofing membranes have such imports of PVC materials, such as Synthetic roofing membranes - Manufacturer Company "Alkor Draka"; Zikaplan - "Sika Trocal", Sarnafil - "Sarnafil International AG", Protan - "Protan AG". Domestic manufacturers offer the following brands of PVC roofing membranes: Lodzhikruf - producer TechnoNICOL, Krovlelon - producer of "Stroyplastpolimer" Ogneizol - Ogneizolkrovlya. Average price of imported PVC roofing membrane is about 270 rubles per square meter. The cost of domestic membranes, with similar physical-mechanical and operational characteristics of the two times lower. TPO membranes basis for this type of membranes are thermoplastic olefins, developed in the early 90's American corporation Genflex, reinforced with polyester mesh and (or) cloth made of fiberglass. Issued also reinforced TPO membranes. Polyester material, consisting of a mixture of ethylene-propylene rubber and polypropylene products from different manufacturers is different naming: elastic polypropylene - FPP, flexible polyolefin alloy - FPA, flexible polyolefin - FPO or thermoplastic polyolefin - TPO. Polymeric membranes based on poliofelinov represent the most advanced single-ply roofing membrane strength. Price per square meter of the membrane is slightly higher than for membranes made of synthetic rubber or PVC. TPO membranes do not contain volatile plasticizers, environmentally safer and more durable than PECVD membranes (more than 50 years of operation). In addition, they do not lose elasticity at low temperatures, so they can be mounted even in the winter without losing quality. Membrane roofs of this type the most hardy (operating range up to - 62S) and are widely used in most northern regions of Russia. To connect the paintings TPO membranes using hot air welding or a mechanical fix overlap (at least 12 mm). Strength of welded joints for TPO membranes twice the strength characteristics of the leaf diaphragm. TPO roofing membranes are less elastic than EPDM and PECVD membranes (less than 180%), but they have higher strength. They should be used on the roofs of irregular shape, where a high risk of accidental damage to the membrane, or where the roof is exposed to high mechanical loads during operation. In the Russian market are well represented TPO membrane companies "Genflex", "Carlisle", "Trelleborg Building Systems", "Sarnafil International AG". The material comes in rolls in width from 1 to 2 m. The average price of imported TPO roofing membranes is about 300 rubles per square meter. Domestic manufacturers of TPO membranes are unknown. See also: Installation of roofing membrane