Roof from metal - a reliable and well-proven option. Today, sheet steel was replaced by corrugated sheet - galvanized steel sheet with an anti-corrosion coating and a protective polymer( polyester) layer.
Selection of material
For the arrangement of the roof, it is best to prefer the profiled sheeting H, specially designed for this purpose. It has sufficient thickness, reinforced stiffeners and optimal corrugation parameters( from 45mm and more).Its cost exceeds other brands, but this is compensated by the durability and strength, an additional advantage is that, due to the ability to withstand heavy loads, the crate can be made with a large step and fasteners are used less often. In general, the more hollow the roof, the more dense and corrugated should be profiled.
For accurate calculation of the required amount of material, it is necessary to know the exact dimensions of the future roof and its shape. Ideally, the length of the ramp should coincide with the length of the sheet of corrugated board, this will reduce the probability of moisture falling under the cover. It is necessary to take into account when calculating that the sheets are overlapped both horizontally and vertically, and that the profnastina sheet should protrude 15-20 cm beyond the cornice, and the higher the profile height, the larger the protrusion.
Subtleties of work and the necessary tool
When working with corrugated board it is necessary to adhere to certain rules:
- Walk on the cover only in soft shoes and do not step on the ribs and elevated areas. You can build wooden boards and move on them.
- For cutting profiled sheeting use special cut-through scissors, hard-alloy teeth or saber saws, but not bulgaria, as her abrasive surface damages the polymer layer and the roof quickly undergoes corrosion. For longitudinal cuts, you can use conventional metal scissors. After cutting, it is better to treat the edges with enamel for polymer coatings to avoid moisture ingress.
- When lifting upwards and when transferring sheets of corrugated board, it is necessary to ensure that they do not bend. Storing them is allowed only horizontally and on a flat surface. Crumpled sheets do not fit, and it is almost impossible to straighten them.
- The trimmed edges of the corrugated board are rather sharp, so it is better to work in protective gloves.
In addition to the corrugated sheet itself, additional elements will be required depending on the shape of the roof:
- skate,
- end plate,
- end,
- curtain rod,
- windshield,
- parapet.
It is necessary to pay attention that their color exactly coincides with the color of the corrugated board, as the coating in different batches may differ slightly. Calculate the required length of these elements, also taking into account the fact that they are laid with overlap.
You will also need the fixing material - self-tapping screws 4.8 * 28 mm with anti-corrosion protection. On their quality, you can not save, because rust on them will lead to damage to the entire roof. It is better to use special roofing screws with a rubber seal and a protected head.
Preparatory work
As with the roofing of any material, it is necessary to build a roofing cake before installing the corrugated board. It does not differ from designs for other types of roofs. Also at first on the crate of the rafter system( how to do it, read here) is laid a layer of vapor barrier, then a heater and waterproofing. It is also necessary to provide ventilation for the roof, in order to avoid the accumulation of condensate. Above the waterproofing is mounted a control bar approximately 2-3 cm thick to ensure ventilation, and it is already fastened to the corrugated board.
Mounting of corrugated board
You can start the installation of a gable roof from either side, and draw it from the right or left corner, but if the length of the sheet is not enough for the entire ramp, then the lower row is first laid. The first row, or sheet, should be parallel to the cornice and hanging from it by 15-20 cm, and from the end by 10 cm. The first sheet is fixed to only 1 self-tapping in the deflection exactly in the middle so that it can be rotated and aligned.
After final alignment, the following sheets are overlapped, so that the anti-capillary grooves on the previous sheet are closed. The straightness of the laying is checked with a cord. The sheets are fastened with self-tapping screws with a pitch of 55 cm, exclusively into the cavities, usually 4-6 self-tapping screws are used per square meter.
The second row of corrugated board is mounted as follows: its first sheet is connected to the first sheet of the first row overlapping, fixed with screws, and only then it is screwed to the crate. The size of the overlap depends on the flatness of the roof, making 30 cm for ramps with a slope of up to 15 degrees and 10 cm for 30 degrees. On the inner edges of the sheets it is better to apply a sealant.
On the perimeter of the cornice it is necessary to install snow traps, which will be secured in the winter from the descent of large masses of snow. Between the snow catcher and the sheet a special sealing tape is laid.
After covering the whole roof, the front edge is strengthened with the help of an end plate, which gives additional strength to the structure. Mount it, starting from the edge to the ridge, screwing the screws to the end dock every 80-100 cm.
The roofing is finished from the corrugated board with the skate device. Better if it is laid under the sealant. If necessary, the elements of the ridge are overlapped with each other overlapping with 30-40 cm overlap.
All roofing work should be carried out in a calm weather, observing safety precautions. A few months after their end, you need to climb up again to the roof and check the screws, you may need to tighten them for greater strength.
