Roofing from galvanized steel: features, advantages, installation
- 29 Jul 16:00
- Repair Of
Now the roofing can be made of different materials. One of them is galvanized steel. About the features of the roof of galvanized steel and will be discussed in our article.
- material characteristics
- Varieties galvanized coating
- seam roofing
- profiled sheets
- Polymeric materials
- coating of polyester
- Coatings plastizola
- Coatings Puranas
- Selection Criteria galvanized roofing
- Installation work
- Roof maintenance
distinctive feature of galvanized sheetfrom the usual cold-rolled steel is the presence of anticorrosive coating. Thanks to the presence of a layer of zinc( more than 0.2 mm), the life of the material significantly increases.
Basic parameters of galvanized roofing steel:
- length - 0,7-3 m;
- width - 0,5-1,25 m;
- thickness 0.5-1 mm.
Application of zinc can be done in two ways:
- is hot.
In an electrolytic method, the material is immersed in a special bath filled with zinc solution. Electricity passes through the sheet. As a result, zinc particles break up and settle on the surface of the roofing material.
The hot method involves lowering the sheet into a molten zinc container. When burning the sheet becomes a homogeneous structure with increased ductility. The result of this process is getting a galvanized sheet for a roof of 0.6-1 mm thick. This coating is more reliable than electrolytically obtained.
The advantages of a galvanized roof include:
- is light weight;
- attractive appearance;
- propensity to handle( smoothly cut and drilled without problems);
- resistance to precipitation, ultraviolet radiation, temperature fluctuations and mechanical loads;
- ease of installation;
- minimum amount of waste;
- possibility to create roof of any configuration( due to the flexibility of the material);
- fire safety.
A smooth surface of a roof of galvanized iron allows you to drain the water in the presence of even a slight deviation. Due to this property, the life of the roof is increased.
Perhaps the only drawback of the material is the noise when it rains and blows a strong gusty wind.
Varieties of galvanized coating
The main types of galvanized roof are:
- folding design;
- roof profile.
False is a seam obtained as a result of the connection of galvanized sheets. Falsis are:
- single and double;
- lying and standing.
Double standing falses are considered to be the best indicator of tightness. Laying galvanized roof can be done manually or with the use of special equipment.
Folding roof is created on roofs, slope of which is 10º or more. The lath is made of wooden beams with a section of 5 * 5 cm in a step of 25 cm. Laying the beam is at right angles to the rafter system.
An indispensable condition for ensuring long life of the roof is the creation of an even grid. There should be no protrusions and depressions. Otherwise, the density of the folds will decrease, which will lead to the destruction of joints and the occurrence of leakage.
A more practical alternative will be a roofing device made of galvanized steel in rolls. With the help of this technology, the arrangement of the roof substantially reduces the number of transverse joints.
Corrugated board is made of cold rolled hot dip galvanized steel, which is covered with a polymer. To increase stiffness, the material is profiled.
The type of lath depends on the brand is placed on the corrugated board. When covering the roof with a material that has the mark of С-8 or С-10, the frame is solid. In other cases, the angle of the slope roof and the size of the profile are taken into account.
Special cutaways fitted with EPDM lining are used to fix the corrugated board. Such fasteners tightly close the holes and protect the roof from penetration of water. The cost of screws is 5-7 pieces per 1 m2.Self-tapes are bought in the same color as the color of the profiled sheet.
The device of the roof of galvanized corrugated board assumes:
- fastening wind strips, made of the same metal;
- mounting of angle bars using a silicone sealant in the places of touch of a corrugated board with walls;
- fixing the crest on the crest of a wave of roofing material.
Compared with conventional galvanized sheet, roofing material, which consists of polymers, has a more complex multilayer structure:
- polymer of a certain color.
There are various polymer coatings. More commonly used:
The coating of their polyester
is a polyester protective paint that creates a glossy finish. Polyester has the following benefits:
- resistance to temperature fluctuations;
- preserving the original color during operation.
Lack of polymer coating from polyester - a small thickness of the protective layer. As a result, the roof is not sufficiently resistant to mechanical loads. What threatens the reduction of the roof's operating period.
This paint composition is one of the most expensive products. Its composition includes:
- polyvinyl chloride;
Steel sheets are covered with a layer of plastisol up to 200 microns thick. For this reason, the roofing material has excellent resistance to mechanical stress and corrosion. Galvanized steel, covered with plastisol, has a textured pattern.
Thanks to the high durability of the coating, on the roof, made of corrugated board with plastisol coating, it is possible to move without problems. This greatly simplifies the procedure for the implementation of installation work.
Surface of Purala
Polymer includes polyurethane. The thickness of the deposited layer is about 50-60 microns. The main characteristics of the roofing material with the purala are:
- anti-corrosion protection;
- resistance to mechanical loads;
- resistance to high humidity and aggressive environments.
Mounting of a roof with pural coating can be carried out at a negative temperature( even at - 15ºС).The presence in the puril of acrylic makes the material hard and rough.
Selection criteria for galvanized roof
Proper choice of material - the main requirement for the installation of roofing of galvanized steel. After all, the presence of defects leads to a significant reduction in the life of the roof.
Attention is drawn to:
- integrity of the sheets;
- lack of scratches and cracks;
- presence of bundles and coarse compounds;
- thickness and zinc coating;
- quality zinc coating.
Minimum thickness of galvanized roof should be 0,5 mm. The device for hanging and slipping is made of material in the thickness of more than 0.7 mm.
As for the thickness of the zinc coating, its optimum size is 250-320 g / m2.Moreover, the zinc coating should be even without patches and bubbles.
Sales of galvanized steel sheets( except rolled material) are made in two versions:
- for manual loading - in packages up to 80 kg;
- for automated loading - in a container up to 5 t.
Packages should be wrapped in sheet metal and tied with a steel tape.
Work begins to create a solid and smooth frame. The angle of inclination of the roof is recommended at a level of 18-30º.A smaller size can cause a slow drain of water. And this is fraught with corrosion of the metal surface.
When arranging wooden beams, special attention is paid to the transverse joints. To ensure that the galvanized roof does not bend, boards are placed on such areas. The minimum width of the boards, which will serve as the basis for horizontal folds, is 10-11 cm.
Of course, the best option is to create a solid frame. Due to this:
Irrespective of the type of frame, effective waterproofing is achieved by laying a parchamine or ruberoid.
Installation of a galvanized roof begins with the preparation of the material. Along the edges of the leaves, the folds are cut off. The short sides of the sheets are connected with the pictures with the help of lying folds. The folding pattern may consist of several sheets. The distance between the lowering folds must be less than the length of the sheets at 3-5 cm.
If low ramps are covered, then the painting is carried out throughout the length of the design. Only after the secure connection of the short sides is the docking of the long sides of the material. For this purpose, standing falsities are used.
Glades are used to fix the roof of a galvanized roof to a frame. One end of the fasteners is connected to the lattice, and the other - with standing folders. The step of fastening of glades is 0,5-0,7 m.
For the arrangement of the cornice edge of the galvanized roof, T-shaped bones are used. They are nailed at a distance of 0.6-0.7 m from each other.
If you can not find a cricket, you can use rectangular metal stripes. The step of their installation is 0,3-0,4 m. At the final stage, the diameter of the chimneys is measured and the collars are made for them.
Roofing material from metal requires special care. Over time, the roof will have to be repaired. In order to achieve the maximum service life of galvanized coating, it is necessary to adhere to:
- flooring technology;
- Roof Care Rules.
The main rules of care for galvanized roof include:
- periodic removal of dirt, which holds off the drainage of moisture;
- painting of a metal roof;
- alignment of the joints of the continuous bobbin.
Different paint and varnish products are used for roof painting: iron sulfur, ocher, acrylic primer-enamel. Paint application takes place in 2-3 layers. The first coloring is carried out 10 years after the flooring of the galvanized roof, the next processing - every 2-3 years.
Rust may appear not only in the upper part, but also from the attic space. To prevent this, the frame should be solid. After that, the joints between the boards are closed with the help of chalk paste with the addition of small sawdust and drying. When the "mastic" is dry, the seams are covered with two layers of oil paint.
Video about installation of galvanized roof: