Roofing material of the rkk 350 brand - technical

Roofing material has become a popular roofing material during the Soviet deficit, when the choice was limited to them and slate. However, even the increased competition in the construction market did not affect the sales of this inexpensive but effective material. Roofing material RKK 350 has earned the trust of builders and has been successfully used for the construction of the upper layer of roofing pie of private and industrial buildings and farm buildings. This article will tell you what technical characteristics this bitumen-based roofing material has, how it is produced and used.

Properties

The quality of waterproofing and durability of roofing depends on the properties of the material used. To the roof served not 5-6 years, you should use certified products of well-known companies. Technical characteristics of roofing material of the RKK 350 brand are regulated by GOST 10923-93 or regulatory documents (TU or TP) adopted by the manufacturer. Quality material has the following properties:

1. The width of each roll of roofing material of the RKK 350 brand is 1.0 m, GOST allows deviation from this value within 5 cm.
2. The length of the roll of ruberoid specified brand is 10 m, while the deviation from the regulated size may be in the range of 0.5 cm in the smaller or larger side.
3. The coverage area of ​​one roll of roofing roofing material with coarse-grained dressing is 10 square meters. m, from this value indicator may deviate 0.5 square meters. m
4. Each roll of bitumen-based roofing material of the RKK-350 brand weighs 27 kg, but deviations in weight from the specified value are not a criterion of rejection.

Important! About good waterproofing qualities of roofing material says moisture absorption rate of 2% for 24 hours. The tensile strength according to GOST must be at least 32 kgf, and the weight of 1 square meter of coating is at least 800 g.

Excellent technical characteristics make roofing material RKK 350 the optimal material for waterproofing roofs in terms of price and product quality. Provided proper installation and regular maintenance of the assurances of manufacturers, it will serve at least 5 years.

Composition

Roofing material has a high degree of protection against moisture penetration, which is achieved by layer-by-layer deposition of different types of bitumen on the substrate. The components used in production complement each other, improving the performance of the material. They are arranged in the following order:

• Coarse-grained topping. A dressing of stone powder or granulate is applied to the surface of the RK 350 grade roofing felt to increase protection from wetting, mechanical stress and sunlight. Dusting silver reflects up to 40% of sunlight, due to which it heats up less than black.
• Layer of refractory bitumen. Refractory bitumen - a product of oil refining, which has a higher melting point and a more solid structure. The disadvantage of this component is that when exposed to negative temperatures, it becomes brittle and cracks.
• Roofing paper impregnated with low-melting bitumen. For the impregnation used bitumen brand BNK 45/180, it is a thick, oily liquid of even color. Cardboard is of the type B-350, whose moisture absorption is not less than 135%, and the soaking time does not exceed 55 seconds.
• The bottom layer of refractory bitumen. This layer is needed to weld roofing material onto the roof surface. Since refractory bitumen is used for it, the coating should be heated to 150-180 degrees with a gas burner to make it sticky.
• Sprinkle bottom surface of pulverized type. In order to protect the roofing material from sticking, a layer of talcomagnesite is applied to the refractory bitumen from below.

Important! Roofing material RKK 350 is poorly protected from temperature effects: at -5-10 degrees when bent, it cracks, and at 200-250 degrees it burns. This material does not belong to fireproof, therefore its laying on the roofs of baths or industrial premises with high risk of fire is not recommended.

Production

The demand for roofing material of the RKK 350 brand in recent years has remained at a high level, so it is produced by the majority of large firms specializing in this type of product (TechnoNOCOL, Evega, KRH). The production of roofing material resembles the making of a cake in which one layer is laid on top of another. The technological process is carried out according to the following scheme:

1. Roofing paper grade B-350 is impregnated with a mixture of low-melting technical bitumen, which is a product of oil refining, coal or shale.
2. On the lower and upper surface of the roofing paperboard brand B-350 is coated with a modified refractory bitumen. It has a thicker, viscous consistency and melts at a higher temperature.
3. On the lower surface of the roofing material, a protective coating of powdered dressing is applied. The most commonly used is talc-magnesite, a rock of volcanic origin of gray color or chalk.
4. On the upper surface of the roofing material, a layer of coarse-grained dressing in the form of granulate or stone powder is applied.

Roofing material is rolled into rolls and packaged into paper wrapper with marking RKK 350. The letters and numbers of this abbreviation designate: “P” is the name of the material, that is, roofing paper, “K” is the purpose, roofing, “K” is the type of dressing used, that is coarse. The numbers in the label indicate the density of the base, the letter “B” after the numbers indicates the brand of roofing paperboard.

Note! Technical characteristics of roofing material may deteriorate as a result of improper storage. When purchasing a roofing material in a store, look at how rolls lie, vertically or horizontally. Do not buy roofing felt that was folded horizontally, since such storage leads to sticking of the layers between them. Agglomerated material is difficult to roll, but is easily damaged during separation.

Laying technology

Roofing material of the RKK 350 brand belongs to the class of the built-up materials and is used as a finishing coating in the composition of the roofing pie. Ease of installation - the strength of the roof of this type. For installation requires bitumen mastic, gas burner with a balloon and a sharp knife. The installation process takes place in this order:

• First of all, the base of the roof is cleaned of the old coating or dirt. Bitumen mastic is applied to the surface in 1-2 layers using a roller or a brush. Leave for 1-2 days until completely dry.
• 1-2 layers of lining roofing material are laid on the base and fused so that the seams between the strips do not coincide, that is, in a run-up.
• Roofing material is laid in the lower point of the roof, rolling a roll across the ramp slope. Fill the roofing material, heating the base of the roof, and then the roofing material itself with a gas burner.
• Installation is carried out at a temperature of +5 degrees, as in colder weather, it takes more time and gas to warm up the base of the roof and bitumen.
• The finish coating of roofing material of the brand RKK 350 is placed in 1 layer, depositing it on the lining in a run. To protect the seams from leaking, the strips are laid with an overlap of 10-15 cm.

Important! One layer of the roofing material from the RKK 350 material corresponds to 2-3 layers of lining roofing material with less density and resistance to water. The lifetime of a properly mounted roofing pie made of bitumen impregnated materials reaches 10-15 years.

Over time, the surface of the roof cracks from temperature fluctuations or mechanical stress. In order to prolong the operation of the coating, a seasonal inspection and repair is carried out, sealing defects with liquid bitumen.

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