This article will talk about how to properly handle material such as corrugated board, and special attention is paid to the question of how and with what to cut corrugated board, which is one of the most common roofing materials today.
The corrugated board for the roof is selected in such a way that the length of the sheet is no less than the length of the roof slope, which makes it possible to exclude transverse joints.
This leads to an improvement in the moisture-proof characteristics of the roof, while simplifying the process of its construction. If the length of the sheet exceeds the length of the slope, you can adjust the corrugated board - cutting this material is discussed below.
If the length roofing sheeting less than the length of the slope, the most convenient way is to lay horizontally in order, starting from the bottom row and moving towards the top.
You can start both from the left and from the right corner, while each next sheet should cover the previous one.
Important: at the joints of the sheets along the slopes, an overlap of at least 200 mm is made, after which the joints are filled with bituminous sealant.
When laying, you should leave an air gap for ventilation with a height of 20-40 millimeters between the thermal insulation layer and the top sheet of the roof. In places such as the ridge and a zone of one and a half meters around the perimeter of the roof, the sheets are double fastened to the crate and girders.
Regardless of the complexity of the slope, the sheets are laid parallel to the horizontally aligned cornice, leaving an overhang of up to 40 millimeters behind the cornice.
To fasten several adjacent sheets, one self-tapping screw is used. When laying the corrugated board, as well as choosing how to cut the corrugated board, it is important to ensure that the decorative and protective coating of the sheets is not damaged.
Useful: in case of incorrect selection of sheets and the formation of too large overhangs after their installation, it may be necessary to cut the corrugated board to remove excess.
Fastening of corrugated board
To fasten the corrugated board to the wooden crate, self-tapping screws are used in the amount of 6-8 pieces per square meter of the surface to be covered, while the following basic rules should be observed:
- The corrugated board should be fixed at the point of contact with the crate of the trapezium (wave), which prevents the appearance of a lever between the point of application of force to the self-tapping screw and the attachment point;
- Fastening sheets of corrugated board to the lower and upper purlins is carried out in each wave (trapezium), since in these places the greatest loads from wind flows occur. Fastening of corrugated board to intermediate purlins can be carried out through one trapezoid (wave);
- The step of fastening sheets in places of longitudinal joints should not be more than 500 mm;
- Fastening of corrugated board to the wind bar is carried out in each purlin;
- The best fit of adjacent sheets of corrugated board is achieved by shifting the centers of fasteners of joined waves by 5 millimeters in the direction of the overlap for the top sheet, and in the direction from the overlap - for the bottom one, while the top sheet should be pressed against the bottom one.
Before screwing in a screw, a hole should be drilled in the profiled sheet, the diameter of which should be 0.3-0.5 mm larger than the diameter of the self-tapping screw.
Screws must be screwed in at an angle of 90 ° to roof lathing. Sheets of corrugated board are pressed closely against the purlins, therefore, incorrect screwing in of the self-tapping screw with the seal skewed often leads to the formation of a through hole in the roof.
Self-tapping screws are best driven using tools such as a screwdriver or a low-speed drill. The drill at the end of the self-tapping screw allows you to drill through metal, so the corrugated board can even be attached to a metal crate. In this case, it is recommended to pre-pierce the hole.
Important: it is not allowed to use nails for fastening corrugated board, which can lead to their separation as a result of exposure to wind currents.In addition, gas cutting and welding of profiled sheets, as well as making holes in these ways, should not be used.
Consider a few more nuances of fastening this material:
- In those places where corrugated sheets adjoin vertical surfaces (pipes, walls, etc.), it is recommended to install joint strips.
- The ridge element located in the upper part of the roof should also be securely fastened to the crate using a sealant.
- In the event that a flooring made of steel with a thickness of less than 0.7 millimeters is being installed, it is advisable to use wooden scaffolds and special shoes, which will prevent various damage to the flooring, such as dents, etc.
- After the installation of the corrugated board is completed, debris and chips should be removed from the coated surface, scratches and cuts should be tinted, which will protect the corrugated boards from corrosion.
- Three months after installation, the self-tapping screws should be additionally tightened, since any fastening to wood weakens over time.
How and with what the corrugated board is cut
The structure of the corrugated board resembles a tin sheet, differing only in the application of the profile. Considering such a question as corrugated board - how to cut it, it should be noted that the methods for cutting it are slightly different from the methods for tin sheets.
The corrugated board is not a pure steel sheet, it has a special coating that protects against corrosion, so cutting the material should not damage this coating.
When choosing how to cut corrugated board, it is important to remember that its coating does not withstand high temperatures, so cold cutting methods must be used.
It is in accordance with this requirement that the tool is selected. It is immediately clear that such methods as plasma, autogen, etc. not suitable due to very high temperatures.
This also includes abrasive tools ("Bulgarian"), causing the destruction and charring of the coating at the site of the cut.
Consider which tool for cutting corrugated board is recommended to use:
- The safest tool for cutting corrugated board can be considered an ordinary hacksaw. Although all the work is done by hand, it does not take much time, because the material is cut quite easily, and high temperatures do not occur, which ensures the safety of the coating of the sheets. The disadvantages of this tool are the impossibility of cutting complex shapes, as well as the fact that a special table is required to complete the work.
- To cut more complex curved shapes, you can use a tool such as a jigsaw - manual or electric. The use of a jigsaw allows you to both simplify and speed up the process of cutting corrugated board.
- Scissors for cutting corrugated board, which can also be manual or electric. They are not a widely used tool, but nevertheless allow you to cut metal sheets of corrugated board quite easily and quickly. In this case, the edge may turn out to be uneven, but it may be covered by the next sheet when laying.
- Another tool is a grinder, on which, instead of an abrasive disc, a special disc for cutting corrugated board is installed.Cutting material with this disc is thinner and more delicate. This is ensured by the material from which the disk is made and its shape: this disk is made of an alloy of a special strength, and at its end there are teeth made of the same alloy, which allows them not to break during the metal cutting process.
Cutting of corrugated board
Having dealt with the tool, one more question should be considered: corrugated board - how to cut? Even with maximum care, the integrity of the protective coating will be violated at the cut site, which can lead to a decrease in the life of the sheet.
The tools listed above allow you to make the area of violation as small as possible, since it is not possible to restore this coating with your own hands. In addition, it is possible to treat the cut points with anti-corrosion and moisture-resistant preparations.
After the sheet is cut correctly and beautifully, the cut edges of the sheets should be painted over. To do this, it is recommended to use the factory paint, usually attached to the material itself.
If paint is not included in the kit, it is best to immediately buy a can of paint that matches the color and texture. This will protect all seams from negative environmental influences.
That's all I wanted to talk about cutting corrugated board and fixing it. Compliance with the rules and recommendations listed in this article will allow the laid corrugated board to serve for a long time and reliably, pleasing to the eye for many years.
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