Seam roofing is a metal covering for the roof, including elements connected by special locks – folds.
The roof’s pictures (elements) are different roofing products with different shapes – plates, sheets, or strips of metal. The features have curved locking edges specially designed for seam connections in every condition.
Seams are hermetic locks located horizontally or vertically, connecting roofing pictures (elements). Single, double, recumbent, and standing folds are distinguished in construction. For any seam, the connection is made using manual roofing frames or a unique electromechanical tool, which “rolls up” the edges of the relationship of the elements of the seam roof.
It galvanized roll roof. For its device, galvanized steel is used prepared specially. Cold-rolled steel is hot-dip galvanized. For installing a seam roof, galvanized steel sheets with a thickness of 0.45-0.7 mm are used. Such a roof usually has a perfectly smooth surface, a uniform gray tint, and low weight. The seam roof is resistant to corrosion, does not ignite, withstands atmospheric loads – gusty winds, heavy snowfall.
Steel with polymer coating. A galvanized seam roof can have an additional layer – polyester, matte polyester, pure, and matt portal. Such modern coatings are applied to steel sheets to increase the resistance of steel sheets to mechanical damage and temperature changes. At the same time, steel sheets are painted under color catalogs according to the German RAL color standard.
Nonferrous metals. Often, metal alloys are used in constructing seam roofs, for example, zinc-titanium alloy, sheet copper, and aluminum. Roofs made of nonferrous metal sheets are durable and wear-resistant. They do not require additional care and seasonal painting. Seam roofing made of nonferrous metals and alloys can be mounted on roofs with a slope of 3°.
Seam metal roofing is deservedly considered to be very airtight since, during its installation, fasteners (self-tapping screws, screws, nails) do not directly fix the roofing patterns. They do not leave holes in the coating. This, of course, reduces the protective and insulating properties of the roof. Roofing elements are fixed to the base using clamps included in the folds and hermetically clamped simultaneously.
The anti-corrosion properties of the seam roof are achieved through the use of multi-layer protective coatings from which the elements of the roofing material are made. For the production of roofing elements, wear-resistant metals are used, which have a zinc or polymer coating, which gives the roof reliable protection against corrosion and oxidation.
The tightness of the entire seam roof structure is ensured by mounting the roof elements. Rolled metal is laid across the width of the roof slope and eliminates the need for additional horizontal seams. The tightness of the coating is increased if the longitudinal edges of adjacent elements are rolled up using the double standing seam method, which can protect the roof from moisture penetration.
The durability of the seam roof ensures the quality of the materials used, which have a long service life. Copper roofing can last 150-200 years without repair and seasonal maintenance, aluminum – 100-150 years, zinc-titanium – more than 100 years, galvanized and polymer-coated – 30-50 years.
The weight of a roof made of modern technological materials with a thickness of 0.45-0.7 mm is relatively tiny. This simplifies installation and significantly reduces its time.
The first step is the device “roofing cake.” The seam roof structure does not need a reinforced truss system, and its calculation is based on SNiP 2.01.07, which indicates the control loads that are allowed during the construction of buildings and structures for various purposes. The truss structure for such a roof is mounted from wooden beams with a section of 50×500 mm and a step distance of up to 2 meters. It is necessary to prepare a base with a ventilation gap for such a roof. An air gap is arranged between the roofing and the waterproofing material, which, thanks to the ventilation holes, allows air to freely penetrate it and thereby eliminate the occurrence of condensate.
In the case of a ventilated structure, a seam roof will require a careful selection of waterproofing, insulating materials, and vapor barriers that will prevent the formation of internal condensate.
The second stage is the laying of roofing sheets. Roof elements are laid on a solid flooring of wooden boards, according to GOST-24454, then weather-resistant plywood is laid, according to GOST-11539, or chipboard, according to the requirements of GOST-4598. Seam roof sheets are mounted using traditional and roll technologies. When using conventional technology, sheets are pre-cut into elements and prepared for folding. The vertical edges of the features are fastened with a single standing seam. The horizontal sides are attached with a single lying seam. With roll technology, the dimensions of the roof elements are calculated directly at the installation site, gradually rolling out the roll of metal. The strips are rolled out along the width of the slope – this eliminates the need for fastening with horizontal folds, which can reduce the tightness of the roof. Metal strips are attached to the crate with clamps and connected with a double standing seam.
The third stage is the direct installation of the ridge, cornices, and other adjacent roof elements. A ventilated bank is made from separate sections with an overlap in the longitudinal direction. When installing a non-ventilated ridge, brackets are mounted to fix the slope sheets securely. The overlap of the sheets must be at least 200 mm, and their fastening must be carefully sealed.