By admin 
A pitched roof made from corrugated metal sheets is one of the most widespread roofing types in modern construction. Corrugated metal sheets combine high strength, light weight, and affordable cost, making them an excellent choice for private houses, industrial buildings, utility structures, and commercial facilities. Such roofing is durable, resistant to weather influences, and easy to install.
Additionally, corrugated metal sheets offer good aesthetics due to a wide selection of colors and profile shapes. They are often chosen due to their ability to quickly provide reliable protection from precipitation, wind, and other external factors.
This article thoroughly reviews the structure, installation features, operation, material selection, calculations, roof preparation, maintenance, and repair of pitched roofs from corrugated metal sheets.
Structure of a Pitched Roof from Corrugated Metal Sheets: Main Components
A pitched roof consists of one or more slanted slopes resting on a rafter system. Corrugated sheets are laid on a prepared batten that transmits loads to rafters.
Key components include the rafter system, waterproofing, batten, counter-batten, and the corrugated sheets themselves. Rafters define the roof shape and bear the weight of all layers, including snow and wind.
Waterproofing protects the structure from moisture ingress and condensation. The batten provides a support base for sheets and must have appropriate spacing depending on profile type and sheet thickness.
Counter-batten creates a ventilation gap preventing moisture accumulation under the metal, extending the roof lifespan.
Sheets are fixed to the batten with screws equipped with sealing washers ensuring waterproofing and resistance against weather.
Types of Corrugated Sheets and Their Characteristics for Pitched Roofs
Corrugated sheets come in various wave shapes and heights, affecting stiffness and decorative features. Common wave heights range from 8 to 57 mm.
For pitched roofs, sheets with wave heights from 18 to 35 mm are most frequently used due to adequate strength and ease of installation.
Sheets vary by steel thickness — typically from 0.4 to 0.8 mm — and by coating type: polyester, plastisol, polyurethane, etc. Coatings offer corrosion protection and affect aesthetics and longevity.
Selecting profile and coating depends on operational conditions, budget, and desired appearance.
Determining the Slope Angle of Pitched Roof from Corrugated Sheets
The pitch angle is crucial to ensure effective water drainage and prevent sheet uplift by wind. The minimum recommended slope for corrugated sheets is 8 degrees, with an optimal range between 15 and 30 degrees.
Lower slopes risk water retention and mechanical impact on roofing elements, shortening service life.
Excessively steep slopes complicate installation and increase wind load vulnerability.
Slope calculation considers climate, snow and wind loads, and building architecture.
Rafter System for Pitched Roof from Corrugated Metal Sheets
The rafter system forms the load-bearing framework of the roof, providing a secure mounting base for all elements. Depending on slope and span, rafters can be either inclined or suspended.
Wood, often coniferous species treated with antiseptics and fire retardants, is commonly used for rafters.
Proper rafter preparation ensures a flat foundation for the batten and reduces risks of sagging and deformation of corrugated sheets.
Special attention goes to joint quality, fastening, and roof ventilation.
Batten and Counter-Batten: Their Importance for Corrugated Roofs
The batten consists of horizontally arranged boards or bars that support the corrugated sheets. The counter-batten, installed above waterproofing, forms a ventilation gap.
The batten spacing depends on the corrugated sheet profile and expected loads. For most standard profiles, spacing is 300-500 mm.
Counter-batten prevents condensation and ensures airflow, significantly extending roof lifespan.
Batten materials are typically dry, treated wood or metal profiles for more demanding structures.
Technology of Installing Corrugated Sheets on Pitched Roof
Installation follows manufacturer instructions strictly after leveling the batten and preparing tools.
Sheets are laid with overlaps; overlap size depends on roof slope (smaller slopes require larger overlaps) to ensure waterproofness and stability.
Sheets are secured with self-tapping screws with sealing washers placed in the valley of corrugations to prevent leaks.
Fastening points coincide with ridges for uniform load distribution and minimal sagging risk.
Special attention is given to ridge and edge components requiring sealing and wind protection.
Insulation of Pitched Roof with Corrugated Sheets
Corrugated sheets do not provide thermal insulation themselves; thus, roof insulation is a critical system part.
Common insulators include mineral wool, polystyrene foam, and other modern materials.
Insulation can be mounted between rafters or over the batten depending on design.
Vapor barriers prevent moisture buildup and loss of insulation efficiency.
Proper roof ventilation via counter-battens helps maintain insulation performance.
Roofing Accessories and Additional Components
Complete roofing protection requires ridges, edge trims, snow guards, and vents.
Ridge trims protect the joint line from weather ingress.
Edge trims provide sealing and aesthetic finishing at roof edges.
Snow guards prevent sudden snow slides, protecting structures and occupants.
Correct selection and installation of accessories enhance roof reliability and longevity.
Climate Influence on Corrugated Sheet and Roof Design Choices
Regional climate strongly influences profile type, steel thickness, coating options, and structural design.
Areas with heavy precipitation and snow require stiffer battens and reduced spacing to support loads.
Wet climates favor coatings with enhanced corrosion resistance.
Strong winds require rafter reinforcement and secure fastening.
Climate also dictates insulation and ventilation needs.
Maintenance, Care, and Repair of Pitched Roof from Corrugated Sheets
Regular inspection identifies damage, corrosion traces, and waterproofing breaches.
Cleaning sheets from dirt, leaves, and snow prevents moisture retention.
Damaged sheets can be partially replaced, ideally using identical materials and colors.
Fasteners should be checked and tightened or replaced if needed.
Timely maintenance extends roof service life and avoids major repairs.
Comparative Table of Corrugated Roof and Alternative Coverings
| Parameter | Corrugated Sheet | Metal Tile | Roofing Felt | Ceramic Tile |
|---|---|---|---|---|
| Weight per m² | 4-8 kg | 5-7 kg | 4-6 kg | 40-50 kg |
| Minimum Roof Slope | 8° | 12-14° | 15-20° | from 25° |
| Service Life | 25-40 years | 30-50 years | 5-10 years | 50-100 years |
| Fire Resistance | High | High | Low | Very High |
| Installation Cost | Low-Medium | Medium | Low | High |
| Rafter Requirements | Medium | Medium | Low | High |
Conclusion: Advantages and Features of Pitched Roof from Corrugated Metal Sheets
Pitched roofing from corrugated sheets offers an optimal combination of strength, ease of installation, and cost. Properly designed and installed, it lasts for decades resisting snow and wind, and a broad range of profiles and coatings enables an attractive and durable roof.
However, adherence to manufacturer installation guidelines, correct material choice, and foundation preparation are essential.
Regular care and timely repairs maintain the roof’s functional and aesthetic properties, protecting the building against environmental challenges.