PRODUCTION OF ROOFING AND PROTECTIVE WORKS 3. Sheet roofing materials.

  PRODUCTION OF ROOFING AND PROTECTIVE WORKS 3. Sheet roofing materials.

3.1 Flat metal sheets

Sheet materials have deep historical roots: lead, copper and zinc sheets covered the roofs of unique structures (palaces, cathedrals) many centuries ago. Interestingly, in 1997, zinc sheets for roofing appeared again on the Russian roofing materials market. Roofs made of non-ferrous metals are very durable, but also very expensive. Roof steel, which appeared in the 19th century, at first black (in need of periodic painting), and then more corrosion-resistant - galvanized, became the main type of sheet material for roofs. The roofing of sheet steel requires skilled manual work, and the decorative properties of such roofs are small. Recommended roof pitch of steel sheets 14-20 °; weight - 4.5-7 kg / m2. Galvanized steel is produced mainly in the form of sheets of 1.25x2.5 m with a thickness of 0.55 mm.

Copper as a roofing material has a high architectural expressiveness and is used in exceptional cases (the cost of 1 m2 of copper sheet is many times higher than that of galvanized steel). The durability of the roof over 100 years. The copper roof in the first weeks has a “copper” color, but then darkens, acquiring a dark brown color; over time, copper, becoming covered with a patina, acquires a specific bluish-gray tint. The main supplier of copper for the roof of the company is the Navy. Copper is produced in the form of rolls with a width of 670 mm; sheet thickness 0.6 and 0.8 mm. Copper is deoxidized with phosphorus, which postpones the appearance of the patina for 20-25 years.

Zinc for roofing is used in the form of an alloy with a very small amount (0.1-0.2%) of titanium and copper. These supplements give zinc cold ductility. In the building materials market, roofing zinc is often called “zinc-titanium”. The largest supplier of roofing zinc is a Russian-French company UNION ZINC, organized on the basis of MZOTSM. The company produces folded roofing sheets of up to 5x0.66 m in size and rolls in widths from 0.2 to 0.66; zinc sheet thickness from 0.2 to 1.0 mm. In addition, zinc elements are made of spillway systems and other accessories. The color of the zinc sheet and, accordingly, the roofing coating can be: natural silver-shiny, turning into a noble matte light gray with time; matt light slate; matt gray-coal.

Zinc is recommended for roofing of any configuration with a slope of at least 5% on a solid basis. Zinc roofs are characterized by high durability - up to 100 years or more. The zinc roof in Moscow can be seen on the buildings of the Historical Museum, the Baltschug Hotel and other buildings.

3.2 Profiled sheets

A special place among the sheet roofing materials occupy the profiled sheets obtained from various materials. The simplest option is corrugated sheets made of galvanized steel and aluminum sheet. The profile (wave) on such materials, besides giving them rigidity, simplifies the joining of sheets (laying overlap) and creates an additional decorative effect. The laying of profiled sheets is carried out on a cobbled crate directly or on a layer of glassine (roofing felt) with the help of special nails. It is possible to lay profile sheets on the old roll and other types of roofing. Asbestos cement sheets were one of the first profiled sheet materials. Following the asbestos cement sheets, corrugated sheets of galvanized steel, aluminum, plastic sheets (for example, fiberglass, PVC, polycarbonate, etc.), bitumen-cardboard corrugated sheets - Ondulin and its analogues appeared.

In recent years, a new type of sheet materials with a complex profile - metal tile.

3.3 Asbestos roofing sheets

Asbestos cement is obtained from a mixture of short-fiber asbestos (15%) and Portland cement (85%). Asbestos cement corrugated sheets, often referred to as “slate”, proved to be durable (up to 50 years), a technological and quite decorative material. They are recommended for roofs with a slope of more than 12 °; weight of 1 m2 of roof - 10-14 kg. Slate sheet of an ordinary profile has a size of 1.2x0.7 m, the height of the corrugation is 28 mm. Now it is also possible to purchase slate of medium (corrugation height 40mm) and high (51mm) profile, and the size of such sheets ranges from 1.75x0.98 m to 2.5x1.15 m. The novelty slate, painted with polymeric phosphate dyes, is interesting. It allows you to give homes a more picturesque view compared to traditional gray slate roofs. Working with slate is extremely simple. Sheets are put overlapped and fastened to the sheathing with nails with a lining of rolled roofing material . When installing a slate roof, it is recommended to make a lining layer of glassine or roofing material. It should be noted that slate roofs are characteristic only for Russia and the CIS countries, as everywhere in Europe there is a struggle with the use of asbestos in construction.

The opinion that asbestos-cement products are harmful due to the presence of asbestos has been strongly exaggerated in recent years and has no serious grounds and is dictated by purely opportunistic considerations: Russia has the largest deposits of asbestos, while in most economically developed countries there is practically no asbestos. In addition, in asbestos-cement products, asbestos is in a bound state and is not released into the environment.

The domestic industry produces several standard sizes of asbestos cement sheets: from 1200 to 2500 mm long and from 5.5 to 8.0 mm thick, respectively. Sheets are fastened on a cobbled crate with special “slate” nails.

To increase durability and make decorative asbestos cement sheets covered with paint compounds or painted in bulk. One of the latest developments of the leading manufacturer of asbestos-cement products, ZAO Krasny Stroit (Voskresensk), is Novinka Slate, asbestos-cement corrugated sheets, painted with Polyphane polyphosphate paint (brown-red, green, blue, and other colors). The painting layer reduces water absorption, increases the frost resistance of asbestos cement and increases its service life by 1.3-1.5 times.

3.4 Bitumen Impregnated Beads

Corrugated sheets on a cardboard basis with bitumen impregnation and decorative coating of the front surface are produced by many companies under various names: Online, Euroline, Ondura, etc. The championship in this area belongs to the French company Ondulin, which has been producing this material for more than 50 years.

Ondulin - flexible corrugated sheets molded from cellulose fibers and impregnated with bitumen. On the front side, the sheets are coated with a protective and decorative paint layer based on a thermosetting (vinyl-acrylic) polymer and light-resistant pigments; Coating colors: red, brown, green and black. Sheets are produced with a single painting, with a matte surface finish, and with a double ("Ondulin Lux"), having a brighter color and greater durability. Ondulin, which looks like asbestos cement sheets, is much easier than them and is devoid of fragility. The size of sheets Ondulin is 2000х940 mm; thickness (2.7 ± 0.2) mm. The roof covering from Ondulin is one of the lightest - the weight of 1 m2 is about 3

kg Ondulin's heat resistance is not lower than 110 ° C. The minimum slope of the roof from Ondulin is 6 °. With slopes from 6 to 10 °, Ondulin is recommended to be laid on a continuous crate with a longitudinal overlap of at least 300 mm, with a slope from 10 to 15 ° it is laid on a cobble crate with a step of 450 mm, and for large slopes - with a step of 600 mm. Due to its low weight and ease of installation, Ondulin can be used as a new roofing directly on the old (for example, roll coating, etc.). It is possible to use Ondulin for wall cladding. Sheets are fastened in all cases with nails with plastic gaskets. If necessary, the sheets are easily cut with an ordinary saw or a sharp knife. Ondulin is used as a roofing coating in individual low-rise construction, agricultural construction and small-scale architecture in many countries, both with hot and cold climates.

3.5. Metal tile

For a long time, it remains in our market, judging by sales, perhaps the most popular roofing material. Why is this so? One of the reasons is that this material is very beneficial to builders in terms of the ratio of installation costs and speed, as well as the manufacturability of the installation. After all installation of square meter of a roof still costs almost 10 dollars a year ago. And what is to lay one sheet with an area of ​​almost 6 square meters. Installing such a sheet takes only a few minutes, even if you put it on the screws (as expected), and not on the nails (as is sometimes done). And these few minutes of work were estimated at almost $ 60. Now the prices for work have somewhat decreased, but this work is still very profitable for builders. And who will give up their own benefits?

Another reason for the popularity of metal tiles is that it is very much like a piece of ceramic tile from a distance. But only from afar.

In the west, it is used mainly as a roofing covering of small structures, mainly for household use: gas stations, warehouses, farm buildings. In individual construction, it is used much less frequently than in Russia. We have just some kind of boom on this material. Perhaps this is due to the historical inclination of our consumer to metal roofs, or maybe just the consumer is always trying to choose a roof that requires minimal maintenance. And here they offer just a metal roof, and yes even similar to natural tile. Apparently the combination of these qualities and made such a surge of popularity.

The ratio of advantages and disadvantages of metal tiles is much inferior to ceramic tiles. It has a very low noise insulation, which in the attic construction of the house (namely, this design is the most popular in our time, because it allows not to lose a single meter of the useful volume of the building) makes you arrange a more powerful noise and at the same time thermal insulation. After all, not many people like to fall asleep under the drumming of rain on the roof or howling of the wind. Thermal conductivity of metal is also high. Consequently, good insulation is simply vital. There is another feature of this material that must be taken into account - this is the increased formation of condensate on the bottom surface of the sheets (the dew point is located on this surface). The formation of condensate causes, for example, a difference in day and night temperatures. Condensate is formed in such quantities in such a way that it must be removed outside. But about the fact that it is necessary to lay a waterproofing layer under the layer of metal tile, both the customers themselves and the builders, as a rule, do not know or forget. The fact that the customer does not know about this is understandable, but the builders are simply obliged to know and remember about this property of metal tile. Installation of an additional layer of waterproofing, of course, will cause additional costs (~ $ 1 per square meter) and no one wants to bear these costs, but it helps to avoid many troubles during operation.

When attaching the metal willy-nilly, you have to break the surface protective layer. And once the protective layer is broken, a potentially corrosion-hazardous zone is created. In addition, large sheets always have a large linear expansion, therefore, with fluctuations in temperature there will be a constant loosening of fasteners. That is, the mounting holes will constantly expand. Over time, these expanding holes will have to be smeared with some kind of mastic.

The modern market offers the buyer metal with a coating of mineral granulate. This coating imitates natural tile tiles to the maximum extent. The same mineral granulate gives the metal tile maximum heat and sound insulation. But the price of a metal tile at the same time increases approximately twice.

In recent years, metal tiles of Finnish, Swedish, German, and English production have appeared and became widespread on the Russian market. These are sheets made of galvanized steel or aluminum, stamped in the form of a tiled roof . The size of the sheets depends on the manufacturer, for example, the metal metal tile of the company Rannila (Finland) has dimensions of approximately 7x1 m.

Different companies use colored polyvinyl chloride, polyester, plastisol and similar polymeric materials with a thickness from 20 to 200 microns as a front coating of metal tiles . Moreover, the service life increases significantly with increasing thickness and quality of the polymer layer.

A number of Western companies have established production of metal tiles in Russia, for example, the company Rannila Taldom, a subsidiary of the Finnish concern Rautaruukki, produces metal tiles from materials and equipment supplied from Finland. The volume of Russian production is 10-20% of the total metal tiles sold by the company in Russia. Another company that manufactures metal roofing on equipment purchased from Western manufacturers from materials made by British and Swedish companies is the Industrial Company Metal Profile. The metal tile is issued 8 various modifications.

Copper roof. Copper roof has always stood alone, given its high cost (> $ 20 / m2). However, such a roof is very much liked - over time, it is oxidized or covered with a layer of so-called patina. The color of the patina is brown with a greenish tint. The advantages of this material is its high corrosion resistance, but this advantage is preserved only with full compliance with the rules of installation. Violation of these rules, for example, the presence of direct contact with iron or aluminum accelerates corrosion so that it negates all the advantages. This phenomenon occurs, for example, when using steel nails when mounting a roof or installing a Velux skylight with not copper, but with an aluminum salary. Disadvantages in terms of condensation on the inner surface of the roof (which is connected with more thermal conductivity than steel), this material has the same as the metal tile, so we will not dwell separately on them. The disadvantages of all metal roofs, without exception, include the fact that they have the ability to accumulate static and atmospheric electricity. In this regard, there is an urgent need to equip metal roofs with a lightning conductor system. To make a virtually eternal roof, you can use copper tape. For its manufacture uses copper with a purity of 99.9%. The tape thickness is 0.6 or 0.8 mm, and its width is 0.67 m. Installation of such roofs requires special skills and equipment. Over time, the copper roofs darken, which gives even the newly built buildings a touch of "noble antiquity".

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