The importance of self-tapping screws when arranging a roof from corrugated board is difficult to overestimate. Today, this fastener is a well-designed element that is adapted to all the nuances of this kind of work. This kind of hardware should be correctly selected. Only in this way will you be able to achieve a positive result. The material for the manufacture of self-tapping screws is carbon steel grade C1022. Fasteners are made according to state standards. According to them, the surface of the self-tapping screw should have a zinc coating so that the product has anti-corrosion properties.
Fastener Reliability
It should be borne in mind that the fastening of corrugated board at the joints can undergo high loads. This should include snow, wind and operational impact. That is why every batch of self-tapping screws passes tensile tests. The optimal value is 102 kg / cm. But on sale you can find self-tapping screws, in which this parameter varies in higher limits: from 150 to 170 kg / cm.
The choice of self-tapping screws for corrugated board
If you plan to mount the corrugated board with self-tapping screws on the roof, then it is important to choose these elements correctly. They can be intended for installation on a wooden or metal frame. In the first case, the fastening should be selected taking into account the rare thread pitch. It will guarantee ease of use and fastener strength. This belief is true even if you have to work with the hardest types of wood.
If the profiled sheet is installed on a metal structure, which is subjected to increased wind loads during operation , then self-tapping screws with a special sharpening and a drilling tip should be chosen. These products must be based on stainless steel. When arranging the roof, additional and ridge elements will be installed. In this case, a longer screw should be purchased.
Why else is it worth choosing a self-tapping screw
All three varieties provide a special tip in the form of a drill. Thanks to him, it is not necessary to make holes in the roofing material in advance. But the heads in the form of hexagons will allow to fix the element in the chuck of a screwdriver or drill. This simplifies the workflow and reduces time consumption, positively affecting the quality of installation.
Determining the number of screws on one sheet of corrugated board
If you will fasten corrugated board with self-tapping screws on the roof, then you need to start work from the side of the eaves overhang. The first sheet fits into the bottom row. And the second is mounted with an overlap in one wave. After alignment of the canvases along the edge of the cornice, the profile is fixed to the lower beam of the crate in each wave. In the overlap area, the web should be joined. This is done with rivets. After installing the first two lower sheets with an overlap, the width of which is 200 mm, you can proceed to the installation of the left in the second row. But that is not all.
In the place of overlapping, the sheets should be fixed to the crate in each wave. In the interval, the canvases are fixed in a checkerboard pattern. Fasteners must be installed through two waves. For reliable fixation, the distance between the screws should not exceed 500 mm. The above technology determines how many parts are needed per sheet. Based on this, you should perform the calculation. If you use a sheet with a length of 8 m, the width of which is 1.1 m, and the distance between the fasteners will be 500 mm, then you need to spend 10 screws for the profile in the lower and upper parts. Eight pieces will be needed to fix the middle part of the sheet. From this we can conclude that the consumption of fasteners on the profiled sheet will be 18 pieces. This figure will need to be multiplied by the number of sheets on the roof. This will allow you to get the number of screws that will be necessary for fastening the sheets. Everything, as you see, is simple.
When the corrugated board is fastened with self-tapping screws on the roof, the number of elements can vary. This will depend on the width and length of the sheet. If we are talking about impressive slopes, the distance between the location of the screws must be reduced. This will increase consumption by 1 m 2 . When fixing the material, it is recommended to pay the greatest attention to the joints of the coating. It is in these locations that leaks are likely. At the ends, in those places where the gable overhangs are located, the sheet should be strengthened to each bar of the crate. This will also increase the number of screws. Therefore, after the calculations, it is necessary to purchase fasteners 10% more, since there is a chance of marriage and unforeseen expenses, as well as damage to parts and their loss.
Correct Mounting Technology
Fixing the corrugated board with self-tapping screws on the roof should be carried out according to a certain method. It provides for the use of colored or galvanized elements with polypropylene washers. The diameter can vary from 0.48 to 0.63 cm. While the length usually varies from 1.9 to 25 cm. It is important to consider when buying a self-tapping screw that the threaded part should be 3 mm longer than the width of the materials being joined.
The average consumption per square meter of coverage is usually about 7 pieces. To securely fasten the profiled sheet in a straight section, an average of 8 parts will be needed, while closer to the ends, the number should be increased so that the structure can withstand wind loads. Screw the screws must be strictly perpendicular. In this case, distortions are completely unacceptable. Experts recommend screwing fasteners into waves that are adjacent to the crate or girders. When the corrugated board is fastened with self-tapping screws on the roof, it is recommended to consider the photo in advance. This will allow you to understand that at the first stage the material is laid out in a strict position and order. It is important to ensure an overlap, which should be larger with a smaller inclined angle.
Important Nuances
If you will be installing corrugated board on the roof, the distance between the screws should be considered. He was discussed above. But the technology provides for compliance with many other rules. Among them, it is necessary to highlight the need to control the force when tightening the fasteners manually. Otherwise, the coating may be damaged. If you do not tighten the screw, then the roof will not perform its functions. Laying sheets of corrugated board, it is necessary to gradually move up. In this case, the paintings of the first row should hang over the edge of the roof by 5 cm. This will protect the walls of the building from rain and melt water.
Specialist recommendations
Quite often, home masters independently fix corrugated board with self-tapping screws on the roof. The instruction will help even those who have been doing similar work for some time. From it you can find out that sheet installation is carried out by fasteners with rubber gaskets. They provide water resistance and absolute tightness. Steel rivets for joints are also used. But it is recommended to refuse aluminum. After all, they are not able to ensure the durability of the installation at the proper level.
In order to fasten the sheets together, it is not recommended to use welding. Indeed, at high temperatures, the polymer and zinc protective coating will fade. After that, the sheet itself remains without corrosion protection. Fixing corrugated board with 21 screws on the roof is the surest solution. Nails are strictly not recommended.
Limitations
If you have to work with a roof, the inclination of which is greater, then the overlap should be wider. This is worth considering. If we are talking about a roof whose angle of inclination exceeds 10 degrees, then there will be enough overlap in one wave. There is one more option. If the angle of inclination is even greater, then it is necessary to make an overlap, the width of which is two or three waves. It is necessary to start moving during installation from the end parts, and not from the middle. It is important not only the step of fixing the corrugated board with self-tapping screws on the roof, which was discussed above, but also the correct arrangement of the sheets. They should go along the roof. Even a slight slope is not welcome. To control the location of the elements on the surface, you can pull the thread, adhering to the laying line in the first row of corrugated board.
Conclusion
It is considered the most optimal way to fix corrugated board described above. A gable roof, the number of screws for which you can calculate using the technique used in the article, will look attractive if you do everything according to the rules. The use of this type of fastener can not be called random. This mechanism ensures maximum reliability of the connection of the material with the crate. Among other things, self-tapping screws have special gaskets that exclude moisture from getting inside. They also make the connection softer. Proper fixing of the corrugated board on the roof with self-tapping screws eliminates damage to the sheet.