KR-18 and SSR Plus: Description, Features, Applications, and Advantages of Standing Seam Roofing Systems

Introduction

KR-18 and SSR Plus are two important solutions in the field of metal roofing systems, especially for industrial, commercial, and large-scale construction projects. Both systems are associated with the Standing Seam Roof (SSR) concept, in which metal panels are connected by raised seams and secured to the supporting structure using concealed clips or fasteners. Unlike conventional exposed-fastener roofing, these systems are designed to reduce penetrations through the roofing panels and provide a cleaner, more continuous, and more weather-resistant roof assembly.

KR-18 is commonly identified as a structural standing-seam roofing profile with an effective coverage of approximately 18 inches, or 45.72 cm. Typical technical information also indicates a rib height of approximately 6.35 cm (2.5 inches). Depending on the manufacturer, KR-18 may be available in gauges such as 22, 24, and 26, with galvanized, aluminum-zinc-coated, or pre-painted finishes.

SSR Plus, meanwhile, is generally described as a standing-seam roofing system that is roll-formed and mechanically seamed at the construction site. It uses concealed clips, which means the roofing panels do not normally need to be directly perforated with exposed screws. This design helps reduce potential leakage points while creating a clean architectural appearance.

What Is KR-18?

KR-18 is a metal roofing profile designed for applications where durability, structural performance, weather resistance, and long continuous roof panels are required. The system is commonly manufactured from coated steel and can be produced in long lengths, sometimes directly at the construction site using portable roll-forming equipment.

The “18” in KR-18 generally refers to its approximately 18-inch effective coverage width. The profile has a raised standing seam that connects adjacent panels. During installation, concealed clips attach the panels to the underlying steel structure. The clips are then incorporated into the standing seam, leaving the primary roof surface free from conventional exposed fasteners.

One of the major advantages of this configuration is the ability to produce a roof panel extending from the eave or gutter area toward the ridge with few or no transverse joints. Several technical sources describe KR-18 as being manufactured as a continuous piece from gutter to ridge, helping minimize potential leakage associated with transverse laps.

Main Features of KR-18

One of the most important features of KR-18 is its concealed fastening system. Instead of penetrating the exposed surface of the panel with screws, clips are used to attach the panel to the supporting structure. This reduces the number of exposed penetration points and contributes to the overall watertightness of the roofing assembly.

Another important feature is mechanical seaming. The longitudinal edges of the panels are joined and mechanically formed into a standing seam. Depending on the specific system, different seam configurations may be available. This mechanical connection provides continuity between adjacent panels and helps improve resistance to wind and weather.

KR-18 also offers considerable flexibility in panel length. Several manufacturers indicate that the panels can be produced without a fixed maximum length when they are roll-formed on site, although the practical length must always be determined according to engineering requirements, transportation, thermal movement, equipment limitations, and project conditions.

The typical effective width is approximately 45.72 cm, while the profile depth is approximately 6.35 cm. Available gauges vary among manufacturers, but common specifications include gauges 22, 24, and 26.

What Is SSR Plus?

SSR Plus is another type of standing-seam roofing solution. It is generally characterized by panels that are roll-formed and mechanically seamed on site. The system uses concealed clips instead of conventional exposed fasteners. According to product information from metal roofing suppliers, the concealed fastening arrangement helps reduce the risk of water infiltration because the roof panel itself does not have to be directly perforated during installation.

One of the main advantages of SSR Plus is its flexibility for large roofing projects. Because the panels can be formed on site, contractors can manufacture long roofing panels according to the dimensions of the building. This can be particularly useful for industrial facilities, warehouses, logistics centers, and other structures with large roof areas.

SSR Plus is therefore not simply a sheet of metal. It should be understood as a complete roofing system, including the metal panels, clips, seams, supporting structure, flashings, drainage components, and other accessories required to create a functional roof assembly.

Features of SSR Plus

The first major feature of SSR Plus is its hidden fastening system. Concealed clips are installed underneath the standing seams, providing a clean exterior appearance while helping reduce exposed penetration points.

The second feature is field seaming. The panels are joined together at the project site using specialized equipment. Mechanical seaming creates a continuous connection between adjacent panels.

The third feature is long-panel production. Since the panels can be roll-formed on site, SSR Plus is well suited to buildings requiring long roof panels. This can reduce the number of transverse joints and potentially improve the overall weather resistance of the roof.

Another advantage is its architectural appearance. The raised seams create long, regular lines across the roof surface. This gives industrial and commercial buildings a modern and relatively clean appearance.

KR-18 and SSR Plus: Similarities

KR-18 and SSR Plus share several important characteristics.

First, both belong to the Standing Seam Roof family. They are based on the principle of connecting adjacent metal panels through raised seams rather than relying primarily on exposed screw fasteners.

Second, both can use concealed clips. This helps reduce exposed penetrations through the roof surface and contributes to improved weather resistance.

Third, both systems can be suitable for large-scale roofing applications. Their ability to use long panels makes them particularly attractive for industrial buildings and other structures with large roof areas.

Fourth, both systems can be combined with insulation. Depending on the project design, materials such as fiberglass insulation, extruded polystyrene, and polyisocyanurate can be incorporated into the roofing assembly. This allows the roof to provide not only weather protection but also improved thermal performance.

Applications

KR-18 is widely used for industrial buildings, warehouses, logistics centers, commercial facilities, manufacturing plants, and large roof structures. It is also suitable for composite or insulated roofing assemblies and reroofing projects.

Industrial warehouses are particularly suitable because they often have large, relatively simple roof geometries. Long continuous KR-18 panels can reduce the number of transverse joints while providing an efficient roofing solution.

Distribution centers and logistics facilities can also benefit from KR-18 because these buildings typically require large roof areas, good weather protection, and relatively fast construction.

Commercial buildings may use KR-18 when appearance is also important. The concealed fastening system creates a cleaner roof surface than many conventional exposed-fastener systems.

SSR Plus has similar applications. It can be used for industrial and commercial roofs where long panels, concealed fastening, and field-formed standing seams are desired. Its field-production capability can be particularly advantageous on projects where roof panels need to be manufactured according to the actual dimensions of the building.

Advantages of KR-18 and SSR Plus

The main advantages of KR-18 and SSR Plus can be summarized as follows:

1. Concealed fastening: Clips are hidden within the standing seam, reducing exposed penetrations.
2. Improved weather resistance: The absence of numerous exposed screw penetrations can reduce potential leakage points.
3. Long continuous panels: Panels can be manufactured in long lengths, reducing the need for transverse overlaps.
4. Modern appearance: Standing seams create a clean and consistent architectural appearance.
5. Fast installation: Field roll-forming and mechanical seaming can improve construction efficiency on large projects.
6. Insulation compatibility: The systems can be combined with different insulation materials to improve thermal performance.
7. Large-project suitability: Both systems are particularly appropriate for industrial buildings, warehouses, logistics facilities, and commercial structures.
8. Design flexibility: The systems can be adapted to different roof geometries and project requirements when properly engineered.