How To Correctly Calculate The Consumption Of Self-tapping Screws For 1m2 Of Profiled Sheet For The Roof, Fastening Scheme

2024 Author: Bailey Albertson | [email protected]. Last modified: 2023-12-17 12:53

How and what to fix the profiled sheet: self-tapping screws just right

How many fasteners to take and how to fix the material with them depends on exactly where you need to attach the construction raw materials. If the installation site is a roof, and the material used is a profiled sheet, then you have to work hard. Roofing work is complex, and most of the problems are associated with the calculation and fastening of self-tapping screws.

Content

• 1 Which is better - screws or rivets

  1.1 Video: self-tapping screws as a fastener

• 2 Fastening the roofing profiled sheet with self-tapping screws

  • 2.1 Installation diagram of corrugated board on self-tapping screws

  • 2.2 Technology of fastening the profiled sheet with self-tapping screws

    2.2.1 Video: features of fastening corrugated board

• 3 Consumption of self-tapping screws for 1 m² of profiled sheet

Which is better - screws or rivets

The professional sheet is attached to the roof surface with both self-tapping screws and rivets. These elements are very different in appearance, which means that their installation and the effect of the application are not the same.

Without further hesitation, self-tapping screws are often chosen to fix the corrugated board, because they are easily screwed into the material using a conventional screwdriver or screwdriver. And the immersion of rivets in a profiled sheet is not considered simple: in order for the fasteners to "enter" the metal material, a special device is needed - a rivet gun.

Rivets look much better than self-tapping screws, but they are inferior to the second in terms of installation technology

If it is not possible to invite professionals and you need to fasten the corrugated board to rivets yourself, then theoretically you can do without a tool. True, in this case, you will have to specially create technical holes - act on the material with a drill with a drill, and then manually insert rivets into the holes and pull them out to connect the profiled sheet with the roof lathing.

The decision to cover the roof with corrugated board using self-tapping screws can be canceled due to the insufficient reliability of these fasteners. The rivets withstand an unexpected "invasion" of vandals or a powerful gust of wind much better and, moreover, look more organic in combination with a professional sheet. True, when the time comes to dismantle the roofing material, you will need to work hard to remove the rivets.

Self-tapping screws "insert" into the material using a simple screwdriver, which makes them invariably popular

It turns out that the best option is to fix the roofing sheeting with self-tapping screws. They are considered indispensable fasteners, since they are equipped with a gasket that blocks the access of moisture, and are sharpened at the tip, which is why they do not peel off the protective coating when immersed in the material.

Video: self-tapping screws as a fastener

Fastening the roofing profiled sheet with self-tapping screws

Before screwing the screws into the profiled sheet, you need to understand what position they should take.

Installation diagram of corrugated board on self-tapping screws

Each self-tapping screw should be immersed only in such a place of the profiled sheet where the wave decays. In this case, the mount must fall exactly in the middle of the designated area.

The place of attachment of the corrugated board is the base of the wave

Self-tapping screws are screwed into the corrugated board at regular intervals. Along the edge of the waves of the material, fasteners are placed at a distance of 30 cm from each other. And in the central part of the sheet between the screws leave "gaps" of 40-50 cm.

In the end zones of the roof, self-tapping screws are screwed through the corrugated board into all the bars located along the width of the slopes. In the area at the ridge of the roof, fasteners are placed in every second wave.

Some areas of the laying of corrugated board, including the area at the ridge of the roof, need reinforced fastening with self-tapping screws

The self-tapping screw is screwed in so that a tiny space remains between it and the roofing material. The fact that the fastener is immersed in the profiled sheet with a force of normal intensity is signaled by the exit of the rubber seal from under the screw head by about 2 mm.

The self-tapping screw must be screwed in, avoiding distortion and excessive compression.

The technology of fastening the profiled sheet with self-tapping screws

In order to fix the corrugated board on the roof correctly with the help of self-tapping screws, perform the following tasks:

1. Starting from the lower corner of the roof, lay out the first row of corrugated sheets. They are necessarily connected by the edges, forming overlaps of 5–20 cm. The degree of overlap of one sheet on another depends on the slope of the roof: with an increase in the slope of the slopes, the amount of overlap decreases. The edge of one profile is imposed on 20 cm of the edge of the other, only if the roof is tilted by 5-15 degrees. The line created from the corrugated board is leveled, focusing on the cornice.

   

   It is better to level the corrugated board and fasten it to the base of the roof in four hands

2. Self-tapping screws are screwed into the corrugated board. In the areas where the profiles are joined, the fasteners are displaced from the middle of the wave base by literally 5 mm. On the top sheet, the self-tapping screw is brought closer to the overlap, and on the bottom sheet, it is removed from it. This will make it possible to strengthen the connection of the profiles to each other. The screwdriver is turned on at a low speed so that the drill does not force the screws to overtighten the roofing material.

   

   Self-tapping screws are screwed into the crate at the same distance

3. The joints of the profiles are treated with a sealant. It is mandatory to resort to this when arranging a roof, the slopes of which are slightly inclined.

4. If the roof slope is longer than the corrugated sheet, then a second line of corrugated board is laid out over the first row of material. In this case, the sheets are mounted by making transverse overlaps. The material of the top row is placed so that its edge is in contact with the edge of the sheet of the first row at least 2 waves. The sheets are fixed in place with self-tapping screws.

   

   The second row of corrugated board is laid out with an overlap on the first, in order to prevent moisture from seeping into the space under the roof

Video: features of fastening corrugated board

Consumption of self-tapping screws for 1 m² of profiled sheet

When fastening profiled roofing sheets, you need to adhere to the rule: the deficit of self-tapping screws is as bad as their excess. The average number of fasteners per 1 m² is 4–8 pieces.

What is the consumption of self-tapping screws for 1 m², you can calculate by sketching on paper a scheme for the layout of the corrugated board.

Having depicted on paper where you have to screw the screws, you can easily count their number

Suppose you need to fix a profiled sheet 1.1 m wide and 8 m long on the roof. We take into account that the metal material is supposed to be fixed to the extreme supports with each wave, and to the intermediate ones - with every second ridge. In addition, we have in mind the following: fastening to the lathing bars is carried out in half a meter increments.

Taking into account all the above conditions, we come to the conclusion that 5 screws must be immersed in the upper and lower parts of the corrugated board and 4 pieces must be screwed in two rows in the central area of the material. Hence, to fix only one profiled sheet, 18 self-tapping screws will be needed, and from 2 to 4 self-tapping screws will be needed to fix 1 m² of material.

However, calculations for the consumption of screws for attaching sheets of the same size sometimes give completely different results. The reason for this is the uneven slope of the roof and, accordingly, another step between the battens of the sheathing. For example, on a roof slope with an angle of inclination of more than 30 degrees, a crate with reduced cells is built, and this leads to a greater consumption of fasteners than was planned.

The number of screws depends on the pitch of the sheathing and the angle of inclination of the roof

It is necessary to increase the number of screws under such circumstances as:

• strong wind impact on the roof;
• excessive snow load;
• the presence of a large number of ends at the roof;
• the need to fix additional elements well;
• an urgent need to better fix the lower edge of the material or the place of joining of sheets.

Since the fastening of profiled sheets to self-tapping screws is carried out according to strict rules, this construction task requires a certain number of fasteners. The exact number of self-tapping screws is easy to calculate, but 10% must be added to it for safety reasons.