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Roofing membranes is a relatively new material for roofing operations, which has been increasingly popular in the market. This is due to the combination of good customer experience and technological properties. First of all, is is the improved durability and faster application. Due to the various roll width, it is possible to perform roof waterproofing of almost any configuration and minimize the number of seams.

PVC-membranes are characterized by high cold endurance; that is why roofing may be performed anytime, ensuring high quality of coating. Producers note that membrane based roofing has an appealing appearance and does not require additional maintenance during service life.

Membrane materials are recommended to be used on gently sloping roofs. Such roofs are usually lighter than roofs with steep slopes and are less expensive to construct and maintain.

The key specifications of roofing membranes are as follows:

• thickness: 0.8-2 mm;
• weight of 1 m2 of membrane roofing: 1.3 kg;
• sheet size (width х length): 15 m х to 60 m;
• cold endurance: down to -60ºС.

The main factor limiting all-out application of PVC membrane roofing is the price. Hence the need to consider the price to quality ratio when choosing the right material, on a case by case basis.

Bitumen-polymer grouts are represented by roof grout used both as a separate roofing material and as a component of seamless roofing system. Usually, grout is applied on a prepared surface in liquid form, and afterwards dries into damp-proof film with no joints or seams.

Bitumen-polymer grout consists of the following components:

• thermoplastic polymer (polymeric petroleum resin, artificial rubber, etc.);
• binding agent (bitumen);
• filler material;
• solvent;
• various additives.

These exact components give the material such properties as flexibility, corrosion resistance, high strength, resistance to aggressive media, oxidation and ultraviolet ray resistance, lightness and durability.

One more advantage of bituminous grout is that it can be applied on any surface: concrete, steel or ruberoid. However, the surface of any configuration should be perfectly flat to guarantee equal thickness of grout coat.

There is a wide range of roofing materials on the market currently and the customer is faced with a reasonable question: which particular product to prefer? The choice is further complicated by the fact that most parameters, like waterproofing, cold endurance, plasticity and heat endurance are very similar. That is why we recommend looking at ageing resistance. Service life of bituminous grout can reach 20 years.

According to the commonly accepted classification, there are three groups of modern roofing materials for rolled-roofing: materials based on bitumen, complex composition bitumen-polymer materials and fully polymer materials based on polymeric petroleum resin or rubber.

Bitumen-polymer materials, as the name implies, consist of bitumen and polymer components. However, the amount of the latter usually doesn’t exceed 12%.

Bitumen polymer materials in somewhat different form were used since the middle of the previous century. With time, these material started to see broader use than roofing materials based on bitumen. This was facilitated by polymer compound conferring higher flexibility to roofing material. Due to this property, the material is easily applied and assumes the required shape.

To produce bitumen-polymer materials, special equipment is used. GlobeCore offers a wide range of UVB-2 series plants, designed for modification of bitumen with polymers, with capacity of 4 to 40 m3/hour.

This equipment is able to:

• work with all currently known polymers;
• use various forms of modifiers: powder, granules, etc.;
• implement any process of bitumen modification;
• add the required amount of polymer.

Application of GlobeCore technologies can raise the quality of roofing materials and ensure long life of roof coating!

Modified rolled materials for roofing are produced of reinforced base (Fiberglass mats, glass fabric or polyester), bitumen and polymer modifier.

While choosing the underlying material, keep in mind that fiber cloth has high tensile strength, polyester has much better specifications but is also much more expensive. Its durability is similar to that of glass fiber, but with stretch ratio 10-25 times higher. Thus, polyester can withstand loads without base deformation.

Face surface of rolled materials meant for upper layer application is covered with coarse-grained or flake-like surface dressing, ensuring protection from the sun and air oxygen. The following materials can be used as surface dressing:

• sand;
• schist granulate;
• mica-vermiculite;
• aluminium or copper foil.

The bottom surface of the upper layer, and both surfaces of the underlying material should be secured from adhesion by application of fine-grained sand or powdery surface dressing. Low melting  polyethylene film is applied for melting materials.

In general, rolled materials are various but the main differences usually concerns the kind of base and the type of modifier.

To improve properties of bitumen for roofing applications, three modifiers are used most often: atactic polypropylene (APP), styrene butadiene styrene (SBS) and ethylene-propylene-butene (EPB).

Bitumen, modified with APP, does not have disadvantages characteristic to common bitumen materials: low flexibility at subzero temperatures and aging tendency. Atactic polypropylene is an elastic material with similar properties as caoutchouc. Because of the wide range of properties, this substance did not find another application but an additive to bitumen binders.

Introduction of APP retains the high adhesion and waterproofing of regular bitumen, but at the same time gives it high resistivity to ultraviolet rays and high heat endurance (above 120ºС). Flexibility and elasticity of materials obtained based on APP modifier at cold temperature is lower than that of materials with SBS modifier. That is why folding while laying the material in cold temperature can cause minor cracks to appear.

The processes of bitumen modifications with APP and SBS also differ. In the former case this means the usual mechanical mixing, but in the latter, chemical interactions of molecules of caoutchouc and bitumen occurs. This interaction creates three-dimensional cross-linked structure of macromolecules of polymer which influences the properties of modified bitumen. APP bitumens are more resistant to aging, due to the fact that polypropylene molecules do not have double bonds.

EBP modifier combines the advantages of APP and SBS modified bitumens. It has the high heat endurance and resistivity to aging of APP, the low temperature elasticity of SBS. EPB for roofing material modification is produced in the form of granules which can be added to molten bitumen at 200ºС. Due to links saturation, the material has resistance to ultraviolet rays and low oxidation decomposition.

Service life of roofing materials based on modified bitumen greatly exceeds that of regular bitumen roofing materials, though the latter are much cheaper.

Currently the primary method of modifying bitumen for roofing and waterproofing applications is the introduction of polymer additives. Such approach allows to significantly improve flexibility at subzero temperatures, improve heat endurance, aging resistance, as well as fatigue durability. In most cases. up to 30% polymer is enough for modification of bitumen.

Еhe following substances can be used as modifiers:

• Atactic polypropylene (APP);
• styrene butadiene styrene (SBS);
• ethylene-propylene-butene (EPB),

The resulting product properties are determined by several factors. Among them we need to emphasize the following:

• mixture homogeneity;
• initial compatibility of bitumen with modifier;
• the amount of modifier.

The price of bitumen-polymer roofing and waterproofing materials is several times higher than that of usual bitumen products. But their service life can reach 15-20 years, and number of layers does not exceed two (compare with four or five layers of regular bitumen materials).

Application of roofing made of bitumen-polymer materials is performed on a solid base at slopes not exceeding 50º. Technically, this operation can be performed either by gluing or burning heating.

For the gluing method, special mastic resins are used. Polymer bitumen materials can be laid on the surface, in spots, in stripes, etc. “Briefer” roof is characterized by the presence of air chambers between the roof cladding and base, connected with atmosphere. Such roofing is installed to remove moisture from the base which is critically important for repair operations or in cold season. To intensify the process of moisture removal, the air chambers should be made wider. For example, the first layer is laid with a coarse-grained grit downwards, or perforated materials are used.

For softening of bitumen layer, special solvents can be used. It is also possible to use materials with adhesive coating.

Heating is mostly performed using fire from gas burners. Infrared heaters can also be used without open flame. In both methods the downside of modified bitumen is melted and applied to the roof base.

Bituminous roofing material is more like a general concept meaning flat, membrane roofing, shingles, rolled roofing materials, etc.

Speaking about the chemical composition of modern bituminous roofing, it may include either air blown or modified bitumen. Until recently, air-blown bitumen was predominantly used. It may be explained by the relatively low cost and simplicity of production. Now the situation has changed completely: most roofing and waterproof materials are produced based on modified bitumen. This is now possible due to longer lifetime and good service properties of these materials.

Modification of bitumen is the process of controlled change its properties by introduction of polymer additives. Correct selection of the modifier allows to endow the roofing materials such properties as elasticity, improved heat and cold endurance, long lifetime and resistance to fatigue.

The most widely used modifying additives are:

• atactic polypropylene (APP) (sometimes as a mixture with isotactic polypropylene (IPP));
• styrene butadiene styrene (SBS).

Every modifier and material made with it it have both advantages and disadvantages. APP materials are resistant to ultraviolet rays, acids and alkalies. Compared with SBS-materials, they have higher heat endurance and good adhesion to glass and metal.

SBS-materials are elastic, frostproof and easily follow the shape of the surface they are laid on. Due to low heat endurance there are some difficulties with laying this material by melting.

Atactic polypropylene belongs to thermoplastic range of substances. It possesses high melting temperature and confers high heat endurance, good flexibility, as well as good resistance to ultraviolet rays to roofing materials. APP materials can be molded, but at the same time have low elasticity. Application of polyether bases helps to obtain higher cyclic load endurance. High size stability and good adhesion make APP materials excellent for restoration of old roofing. To modify bitumens with polymers, UVB-2 plants produced by GlobeCore can be used. They ensure high quality blending of modifier with bitumen. Keep in mind, that high quality material can be produced only if bitumen is compatible with atactic polypropylene.

SBS polymer is an artificial rubber of high elasticity. This substance ensures excellent flexibility of roofing materials at low temperatures. Heat durability of styrene butadiene styrene is lower than that of atactic polypropylene, but if high quality modifier is used, the temperature may reach up to 100ºС. Roofing made with SBS has good adhesion and high resistance to cyclic stress. Elasticity of these materials can reach 1500-2000%.

The UVB-2 can also be used to produce SBS modified bitumens. They allow working with SBS polymers in powder or granule form.

Bitumen-polymer roll materials are used in roofing operations. Their contents include modifiers (usually polymers). The modifiers help to avoid some of the disadvantages typical for bitumen materials.

The base of bitumen-polymer materials is often made of glass fabric, fiber glass mats or elastic polymer fibers. Regulatory documents specify durability and stretching as quality factors for roofing bases.

The most widely spread is glass fabric roofing. It possesses high rupture and needle tear strength. Glass fiber does not burn or rot and is bio- and waterproof. To provide glass-cloth with proper hardness, it is impregnated with special substances preventing impact of bitumen at high temperatures.

To produce high quality roofing material, glass fabric should have fabric weight of at least 160 g/m2. Reliable adherence of bitumen binding to the base is ensured due to saturation of the latter with the covering or penetrating bitumen.

Bitumen-polymer materials are more expensive than bitumen, but require less layers when applied. Besides, bitumen-polymer materials serve 5 to 10 times longer.

Appearance of bitumen-polymer materials gave start to principally new construction materials with higher economic and environmental efficiency. In terms of roofing, we need to mention the so called shingles, also known as roofing slates.

Slate tiles, cut of polymer-bitumen material, allow light and good-looking roofing on 12% slopes. Shingles ensure long life high elasticity which are not common for most currently known roofing materials.

A sealant layer is applied to a new roof before application of shingles to enhance tightness. If the slope exceeds 18%, the sealing coat is applied only in the most critical places, e.g. side end parts of roofing, roof canopies, etc.

Most often a shingle is a flat mat made by pressing and cutting from rolled bitumen-polymer. The surface of this mat is covered with mineral chips. Shingles are waterproof and do not require any specific maintenance; they also generate less noise in rain.

Colour and texture of the surface depend on tje type of applied mineral material. That is why the customer can buy material of any colour. Roofs made of shingles resembles roofing made of slate or wood. It is more durable than similar materials, service life of which is limited by loss of plasticity.

Shingles do not require elasticity required of roll materials, as they don’t create a uniform coat and deformations do not lead to loss of uniformity.