Long and safe operation of the roof depends on the quality of the corrugated sheet and its correct installation. Compliance with the technology allows achieving high tightness and resistance of the structure to precipitation and wind loads.
Profiled sheeting is widely used for roof covering. In terms of strength and durability, steel is superior to other materials, but its heavy weight requires significant reinforcement of the rafter system. With the advent of corrugated metal sheet technology, manufacturers have achieved reduced weight and greater rigidity of the material.
Features of corrugated sheets
The metal profile is a thin steel sheet with a geometrically shaped corrugation. For additional protection from moisture and sun, the material is coated with several layers of polymer agents.
First, a phosphate is applied against rust formation, then a primer. The next step is a polymer coating, and the lower part is varnished. The products are manufactured using a cold method on profile bending equipment from hot-dip galvanized steel.
Installation of corrugated sheets is widely in demand in various construction works. Corrugated sheets are produced for wall finishing, forming foundation formwork, erecting fences and covering roofs.
High-quality corrugated sheets have the following advantages:
- long service life;
- low weight;
- affordable cost;
- ease of installation and dismantling;
- resistance to temperature changes.
important note: Looking for roof repair services near me in Dunwoody, GA? Our experts provide fast, reliable repairs to keep your roof strong. Call now for a free estimate!
Classification of material
Before using corrugated sheets for roofing, we suggest that you familiarize yourself with the classification.
- H is a high-quality material intended for covering and cladding floors and various surfaces. It can be used for permanent formwork. Strength and load resistance are ensured by the presence of stiffening ribs, special height and thickness of the profile.
- C — installation of this category is used when constructing fencing structures. The cost of the material is less than that of class “H”, but the characteristics are also lower.
- NS is a combined building material that is suitable for roofing. Such a roof should not experience significant loads, and the slope should be steep.
On the roofs of private houses, the installation of profiled sheets of grades C10, C20, C21 is mainly carried out. The material has a good quality-price ratio. Also in demand are non-load-bearing wall panels НС35, they are installed on roofs with a minimum slope in regions with snowy winters.
Metal profiles with a wave of 60 mm or more are rarely used in the construction of private houses due to their high cost. This is a self-supporting coating, the need for which arises when arranging industrial facilities.
Material thickness
When choosing, it is important to pay attention to the thickness of the corrugated sheet for installation . It can be 0.35-0.9 depending on the brand. For the roof, a material with a thickness of 0.5 mm is required, which has sufficient rigidity and strength. It should be taken into account that with a metal thickness of 0.5 mm, a solid sheathing must be made. If it is sparse, it is worth choosing a thicker metal profile. When choosing, specialists are guided by the possible snow load, the slope of the slope.
Wave height
The larger the corrugation, the more rigid the material. To install on a roof, it is not recommended to take material with a wave height of less than 20 mm.
Working width of sheet
This is an important indicator for calculating the volume of material. When covering, an overlap of 1-2 waves is performed, therefore, the useful width is calculated.
Type of coating
The cheapest material is galvanized sheets, they are used in unheated buildings. The application of polymers allows manufacturers to provide a 50-year guarantee on the material.
Color of metal profile
You can choose a color scheme so that the roof fits harmoniously into the architecture of the building and the landscape.
Determining the roof pitch
For correct installation of the material on the roof, you should know the angle of inclination. The overlap on the adjacent sheet depends on its size:
- at a slope of 12-15 degrees, the metal profile is laid with an overlap of 20 cm;
- if the angle is 15-30 degrees, one sheet overlaps the other by 15-20 cm;
- at an inclination of 30 degrees, the sheets are placed with an overlap of 10-15 cm.
A slope of up to 12 degrees requires additional sealing with silicone sealant.
To calculate the volume of material, it is recommended to contact specialists. They will correctly calculate the quantity and consult for the optimal choice.
Preliminary thermal insulation
Before laying the metal profile, the structure is insulated. For this purpose, mineral wool and vapor barrier are used. Insulation is sold in mats and rolls. The insulation is laid in the gaps between the rafters on glue or screwed on with screws. The material should not be pressed too much, since heat retention is provided not by the wool, but by the air in the pores.
To protect against moisture, mineral wool must be covered with a vapor barrier. This will protect the material from absorbing moisture, which rises with warm air. Wet insulation loses its properties, so vapor barrier is a mandatory stage of roof preparation.
To ensure air circulation, the triangle at the top of the roof is not insulated.
Installation of roofing from corrugated sheets
For proper installation of the material, it is necessary to follow the instructions. When cutting, it is necessary to treat the edges with a protective compound to prevent rust.
During installation of the corrugated sheet, you can only move in soft shoes and you need to be careful not to damage the coating. It is advisable to step only on concave parts and screws. The foot should be placed parallel to the slope, move on the toes. Place only one foot in one recess.
Some recommendations:
- Profiled sheeting C10 with a thickness of 0.5 mm is laid with an overlap in two waves (slope slope less than 15 degrees), in one wave (slope at an angle of more than 15 degrees). Solid sheathing is used with a step of 30 cm, respectively.
- Brand C21, thickness 0.5-0.7 mm. Installation is performed by overlapping the material in one wave (slope less than 15 degrees) with a lathing pitch of 30 cm or less. If the angle is greater, the pitch can be 65 cm.
- Profiled sheet C44 with a thickness of 0.7-0.9 mm. Perform the overlap in one corrugation with a lathing pitch of 50 cm (angle 15 degrees), 100 cm (more than 15 degrees).
- H60 with a thickness of 0.7-0.9 mm is installed on industrial sites; on roofs with an angle of more than 8 degrees, the lathing pitch is 3 meters.
- H75 is suitable for industrial buildings; the lathing is performed with a step of 4 meters at a slope of more than 8 degrees.
Transportation of material
The metal profile is transported on a flat surface, avoiding the risk of bending and kinking the sheets. For delivery, trailers and bodies are used that are as long as the packaging with the material or slightly longer. It is necessary to secure the products so that they do not move along the way. Soft slings are used during unloading. The material is lifted onto the roof along the joists.
To avoid damage during installation of corrugated sheets , you should follow the rules:
- feed sheets along installed boards;
- you can step on the material in places where the lathing elements pass;
- Do not place heavy objects or tools on them so as not to bend them or leave scratches;
- If small scratches occur, they must be covered with paint.
Ventilation and waterproofing
It is necessary to carry out waterproofing and ventilation in advance. Such works will eliminate the formation of condensation in the under-roof space and will not allow damage to materials.
The waterproofing is laid on the rafters, from the lower slope of the roof and goes along the eaves. Installation is carried out with a slight sag (2 cm) to avoid breaks in the coating during sudden temperature changes.
The individual strips are placed overlapping each other so that the edges of the strips that are lower are hidden under the edges of the strips above. The overlap of the materials should be at least 10 cm. For better insulation, the joints are sealed with adhesive tape. The lathing is laid on top.
To ensure air circulation, ventilation holes are created between the ridge strip and the roofing material. Greater air movement is achieved by creating channels by installing slats on top of the waterproofing.
Installation of rafters and lathing
Rafter strips or steel purlins (if the profile height is 4 cm) are attached on top of the waterproofing layer. The sheathing is mounted on them. The sheathing pitch is selected taking into account the roofing material. The structure can be made from a 3×1 cm board, a 5×5 beam, or moisture-resistant plywood 1 cm thick.
The lathing is made solid or thinned. Solid is suitable for installation around the chimney, along the ridge and on the ribs. In other places, the fastening of the elements is carried out with a step of 5 cm, which is observed over the entire surface.
Stages of lathing installation:
- apply an antiseptic against fungus, mold and insects to the lumber;
- nail the counter-battens on top of the rafters and the membrane for waterproofing;
- mark the places where the boards will be installed;
- lay the sheathing elements perpendicular to the rafters and align them according to the markings;
- start fastening from the cornice board, keeping the cornice line perfectly straight;
- screw the boards.
The boards are connected lengthwise so that the joint is on the counter-batten. The joint in adjacent rows should not be on one bar – it is better to do it in a checkerboard pattern, which also increases the reliability of the entire structure.
To prevent condensation, a diffusion gasket is used, which is fixed with small nails to the lathing. The installation must be approached responsibly, as the reliability of the roof depends on it.
important note: Need roof repair services near me in Sandy Springs, GA? Our skilled team offers fast, reliable repairs to protect your home. Call now for a free estimate!
Formation of the eaves overhang
The work is carried out during the installation of the corrugated sheet in the bottom row. First, it is necessary to install the cornice strip below the waterproofing. The design is designed to drain condensate into the gutter and pipe. If you do not make an overhang, moisture will get on the walls and lead to their destruction.
Lifting sheets onto the roof
Some sheets of metal profiles are large in size and their lifting can be difficult. In order not to damage or deform the products, they are lifted on special joists. This device is rested on the ground and the eaves strip. The gap between the joists should be less than the width of the sheet. Using this lifting technology allows two people to lift large products.
Cutting sheets
Cutting the material increases consumption and reduces quality, so it is recommended to buy products according to the dimensions of the slope. However, during installation , it may be necessary to trim the sheets by width or length. For such work, you cannot use an abrasive tool that damages the protective coating.
The following rules should be followed when cutting metal sheets:
- use an electric drill with a disc attachment;
- treat the edge with a protective compound (paint).
Fastening corrugated sheets to the lathing
It is suggested to start the installation from the right or left end with a rectangular roof slope. When the slope is of a complex configuration – in the form of a trapezoid, triangle, it is necessary to first calculate the position of the sheets and make a layout on paper.
During installation, the material is fixed along the eaves line. If a drainage system is provided, an overhang of 40-60 mm is made. If a drainage system is not planned, the sheets can hang more. For the NS-20 metal profile, an overhang of up to 100 mm is permissible, for NS-35, S-44 from 200 to 300 mm.
The first sheet is aligned along the end of the roof and the eaves. It is fixed with one screw in the ridge area. Then the second one is laid. Both profiled sheets are fixed with screws in the place of the longitudinal overlap. In this way, 3-4 sheets are connected to each other and aligned along the eaves. After this, they are fastened to the sheathing. The installation of the next sheets of profiled sheeting continues by fastening to the previous one, and then to the sheathing.
The products can be fixed at the top of the profile or at the bottom. The choice of technology depends on the roof slope. If the slope is less than 20-25 degrees, it is recommended to install the material at the top. When fastening at the bottom, it is advisable to use self-tapping screws 4.8x 29/35.
Fastening step:
- at the cornice – 300-400 mm, then rows of screws go in a checkerboard pattern every 1000-1500 mm;
- at the pediment they are fixed in increments of 500-600 mm;
- with longitudinal overlap, fasten along the top every 300-500 mm;
- At the ridge, the corrugated sheet is fixed along the top with long fasteners at 300-400 mm intervals.
When fastening from above, do not tighten the screws too tightly, so as not to crush the surface. It is necessary to use special roofing hardware with a rubber gasket.
The standard consumption of screws is 6 pcs. per 1 sq.m. Screws 4.8x 28-35 mm are suitable for installation . Additional elements are fastened with hardware 4.8×50/60 mm.
The use of high-quality fasteners ensures:
- complete waterproofing of the roof;
- connection reliability;
- minimal risk of damage to the protective coating;
- preventing corrosion.
If the screw is screwed in correctly, a rubber gasket will protrude by 1 mm. Screws should be screwed into the material perpendicularly, directly into the deflection of the vertical wave. This allows you to create a reliable fixation in the lower wave. At the same time, water from the upper wave will not get into the under-roof space.
Finishing the pediment cut
It is important to provide wind strips and slats during installation. They protect the roof and corrugated sheets from wind and moisture, and prevent the structure from being destroyed.
In the case when installation is carried out with an allowance of up to 5-7 cm, a wind strip can be installed. A product measuring 2.5 x 8 cm is fastened with self-tapping screws. If there is no allowance from the pediment, it is necessary to install a wind strip. Such parts are fastened with an overlap of up to 15 cm with a fixation step of 20-30 cm.
When connecting the slope to the wall longitudinally or transversely, corner strips are installed. They are also fastened with an overlap of 10 cm or more. The fastening step is 20-30 cm.
important note: Looking for commercial roof replacement services in Vinings, GA? We provide durable, high-quality roofing solutions. Get a free estimate today!
Installation of accessories
Such products are manufactured with standard parameters. For profiled sheeting with a polymer layer, the length is 2 meters, for roofing made of galvanized steel – 2.5 meters. These elements complete the installation of profiled sheeting .
A seal is installed between the extension and the material, which provides maximum waterproofing, while allowing the roof to “breathe”. Special elements are used for cornices and ridges.
When installing roofing profiled sheets , valleys are attached at the internal joints of two slopes going in different directions. Such an additional element must be laid under the profiled sheet. In the case when the roof has a complex shape and internal joints, additional pads are used. Such a solution ensures an attractive and neat appearance of the roof, protects the transitions between the slopes from water getting inside.
A crucial stage in the installation of corrugated sheets on the roof is the output of pipes, which consist of two parts. The lower part is laid along the profile, and the upper part is visible above the roof. In situations where the through passage is located in the lower part of the roof, it is recommended to install a snow stop.
The sewer ventilation system is organized by means of a non-insulated pipe with a diameter of 10 cm (without a head). When installing radon, a tube with a head is used. The structure can be installed before or after the installation of the roofing profile sheet .
In the second case, it is necessary to make a hole for the pipe and close it with material. During finishing works, the cuttings are made from galvanized aprons or modern building materials.
To bypass the chimney, an apron is made of galvanized steel and strips are mounted. In this case, the installation is performed as follows:
- on the sides of the chimney, you need to mark a line 150 mm above the plane of the corrugated sheet;
- make three parts of the apron – bottom and side, which should rise by 150 mm;
- connect the elements and fix the lower part to the lathing;
- place the upper part of the apron under the ridge on top of the metal profile;
- make the top part so that it reaches the markings and covers the side parts;
- connect the top and side parts of the apron;
- seal the joints;
- secure the abutment strip along the perimeter of the chimney;
- close the groove with sealant.
The extensions in the dormer window area require cutting the corrugated sheet into two parts at the lower end of the valley. Next, install the lower sheet and bottom strip. The next step is to attach the upper corrugated sheet.
Snow guards are installed when there is a risk of snow sliding off the roof. When corrugated sheets are used to cover the roof, fixation is carried out on the second line – 30-40 cm from the eaves. Fastening is carried out with self-tapping screws with a step of 1-2 waves.
To design the inner and outer corner when changing the direction of the slope, finishing elements are used. They give the joints an attractive appearance and protect against moisture.
The ridge is fixed with screws at intervals of 20-30 cm. It is also necessary to use a sealing gasket and provide a ventilation gap. When installing the profiled sheet , start from the edge that experiences less wind loads.
The profile is selected taking into account the taste of the homeowner. The market offers simple and figured profile systems.
Roof maintenance
Snow practically does not linger on corrugated sheets, so there is no need to clean the roof. However, if repairs are required, plastic shovels should be used, which do not scratch the surface.
No special care is required, the roof is easily cleaned by rain. When corrugated sheets are installed on the roof , the drainage systems and gutters should be cleaned from accumulated leaves once a year.
If you need to wash the roof, use a hose from which water is supplied under pressure up to 50 Bar. You can add detergents designed for treating painted surfaces.
Read Other: Why is The Air Conditioner Not Cooling?
