Open vs. Closed Joint Metal Rainscreens: Pros and Cons

Metal rainscreens combine architectural design with practical exterior protection and are widely used in modern commercial buildings. However, choosing the right joint design is just as important as selecting the metal panels themselves.

Open and closed joint metal rainscreens have different advantages in terms of appearance, ventilation, water management, and installation.

For architects and developers, this choice also affects panel dimensions, fixing methods, supporting structures, and manufacturing requirements.

This guide compares the two systems and explains how customized aluminum metal wall panels can meet different facade design needs.

What Are Open and Closed Joint Metal Rainscreens?

Open and closed joint metal rainscreens are two approaches to connecting exterior metal wall panels.

An open joint system leaves visible gaps between adjacent panels. These gaps allow air to move through the facade cavity, while some rainwater may enter the space behind the panels.

A closed joint system uses overlapping edges, interlocking profiles, gaskets, or sealants to reduce direct water entry through panel connections.

Both systems can be manufactured using aluminum and other architectural metals. The right choice depends on the building design, weather conditions, and waterproofing requirements.

For commercial projects, metal wall panel systems offer flexible options for panel shapes, finishes, perforations, and fixing details.

Advantages of Open Joint Metal Rainscreens

1. Improved Cavity Ventilation

Open joints provide pathways for air movement behind the exterior panels. When properly designed, this helps the cavity release moisture and supports drying.

For projects requiring additional ventilation and shading, perforated aluminum facade panels can provide customized openings and patterns.

2. Modern Architectural Appearance

Visible gaps create clean shadow lines and a layered exterior appearance. Architects can also use different panel colors and background materials to create visual contrast.

3. Flexible Panel Shapes and Patterns

Open joint designs work well with flat, folded, perforated, and custom-shaped metal panels.

PRANCE provides customized aluminum panels with different sizes, thicknesses, edge details, and perforation patterns. These options help architects coordinate panel layouts with different facade concepts.

4. Easier Individual Panel Replacement

Depending on the fixing method, individual panels can be removed for inspection or replacement without dismantling the entire facade.

This is particularly useful for large commercial buildings where long-term maintenance access is important.

Disadvantages of Open Joint Metal Rainscreens

1. Higher Waterproofing Requirements

Rainwater can pass through open joints and enter the cavity. Therefore, the water-resistive barrier, flashing, and drainage details must be carefully designed.

2. UV Exposure

Open gaps may expose the underlying waterproofing membrane to direct sunlight. Suitable UV-resistant materials or additional protection may be necessary.

3. More Detailed Installation Planning

Panel spacing, subframe alignment, cavity depth, and drainage openings need to be coordinated before installation.

For this reason, accurate panel fabrication and installation drawings are important for achieving consistent facade joints.

Advantages of Closed Joint Metal Wall Panels

1. Reduced Direct Rainwater Entry

Overlapping edges, gaskets, and properly designed connections help reduce the amount of rainwater entering the facade cavity.

2. Clean and Continuous Appearance

Closed joint panels create a more uniform exterior surface with fewer visible gaps.

PRANCE offers aluminum wall panels with customizable dimensions, profiles, and finishes, making them suitable for commercial facades that require consistent panel alignment.

3. Flexible Fixing Options

Different fixing methods can be selected according to panel design and installation requirements.

PRANCE metal facade products support concealed or exposed fixing options, as well as customized systems. The appropriate connection should be confirmed through project-specific drawings.

4. Suitable for Large Commercial Facades

Closed joint designs can be used for office buildings, shopping malls, airports, and other projects that require a consistent architectural appearance.

Disadvantages of Closed Joint Metal Wall Panels

1. More Attention to Joint Details

Gaskets, sealants, and interlocking connections must be correctly installed to maintain their intended performance.

2. Thermal Movement Considerations

Aluminum panels expand and contract as temperatures change. If joints do not allow sufficient movement, deformation or connection problems may occur.

3. Maintenance of Sealing Materials

Sealants and gaskets may deteriorate over time depending on material quality and environmental exposure. Regular inspection is necessary.

Metal Rainscreen Panel Profiles and Fixing Methods

The joint design determines how panels meet, but the panel profile and fixing method determine how they are supported.

These details should be considered together when selecting metal wall panel systems.

Flat Metal Wall Panels

Flat panels provide a simple surface for both open and closed joint designs.

They are suitable for commercial buildings that require regular panel layouts and consistent exterior finishes.

PRANCE can customize panel dimensions, edge treatments, and surface colors to suit different facade elevations.

Folded and Formed Metal Panels

Folded panels use shaped edges to create stronger profiles and connection details.

They are particularly useful for closed joint designs that require overlapping edges or concealed connections.

Different folding depths and edge configurations can be selected according to the project drawings.

Perforated Aluminum Panels

Perforated panels are suitable for exterior screens, decorative facades, and architectural shading applications.

PRANCE offers perforated metal facade panels with customizable hole patterns, panel dimensions, and finishes.

They can also be combined with open joint layouts to create layered facade designs.

It is important to distinguish panel perforations from open panel joints. Both can change the appearance and airflow of a facade, but they require different technical considerations.

Concealed and Exposed Fixing Systems

Fixing methods affect both appearance and installation.

PRANCE can customize panel edge details and fixing arrangements according to project requirements. The supporting structure and connection capacity should be verified through project-specific engineering.

Which Metal Rainscreen Is Better for Different Commercial Projects?

The best choice depends on the architectural concept and the practical requirements of the building.

Office Buildings

Office buildings often require consistent facade lines and a professional exterior appearance.

Closed joint aluminum panels can be suitable for large, continuous wall surfaces. Open joint panels are another option when architects want stronger shadow lines or a more layered design.

Shopping Malls and Commercial Centers

Commercial developments often use metal panels to create distinctive building entrances and exterior feature walls.

Open joint panels and perforated aluminum screens can be combined to create decorative facade elements.

Airports and Exhibition Centers

Large public buildings usually have complex elevations and extensive exterior surfaces.

Custom aluminum panels can help coordinate different facade sections, including curved surfaces, feature walls, and large-format panel layouts.

For these projects, panel dimensions, production scheduling, and installation drawings should be coordinated early.

FAQs 

1. Are open joint metal wall panels waterproof?

Open joint metal wall panels are not designed to stop all rainwater at the outer panel surface. Water may enter through the gaps and drain through the cavity. A properly designed water-resistive barrier, flashing, and drainage system are therefore essential to protect the building structure.

2. Do closed joint metal wall panels prevent water leakage?

Closed joints help reduce direct rainwater entry, but they do not automatically make a facade waterproof. Joint connections, gaskets, sealants, flashing, and the secondary water-control layer must all be designed and installed correctly.

3. Can aluminum metal wall panels be used for both open and closed joint systems?

Yes. Aluminum panels can be fabricated with different edge profiles and fixing details for open or closed joint layouts. Panel thickness, dimensions, folding details, and support connections should be selected according to the project design and engineering requirements.

4. What is the difference between open joints and perforated metal panels?

Open joints are gaps between adjacent panels, while perforations are holes formed within the panel itself. Both can support airflow and create decorative effects, but they have different design, drainage, and installation requirements.

5. Which joint system is more cost-effective for commercial buildings?

There is no fixed answer. Open joint systems may require more attention to the backing membrane and drainage details, while closed joint systems may involve additional edge forming, gaskets, or sealants. The final cost depends on panel design, material thickness, fixing methods, facade area, and installation complexity.

Conclusion

Open and closed joint metal rainscreens serve different architectural purposes. Open joint panels are suitable for facades that emphasize visible gaps, shadow lines, and layered designs. Closed joint panels are more appropriate when a continuous exterior appearance and reduced direct water entry are priorities.

PRANCE provides customized aluminum wall panels, perforated panels, folded profiles, and surface finishing options for different commercial facade designs.

Whether your project requires open joint detailing or closed joint connections, PRANCE can help develop suitable metal panel configurations based on your drawings and specifications.

Contact the PRANCE team to discuss your panel dimensions, facade design, and customization requirements.