Modern architecture and construction are tasked with finding solutions, such as horizontal insulated metal panels (IMPs), that combine the best of aesthetics and performance.

These single-component, complete exterior wall systems are visually appealing while delivering a range of building envelope benefits, which is why they have become a material of choice in multi-story construction projects.

“Code compliant, lightweight, incredibly efficient, and easy to install are just some of the reasons that make IMPs the go-to wall component for multi-story structures,” said Green Span Profiles Brian N. Jaks, P.E., Vice President of Sales and Marketing. “Add in that all our horizontal profiles are available in a multitude of different colors and there isn’t a multi-story building project in the country that would not benefit from using IMPs.”

Reasons for Choosing IMPs for Multi-Story Structures

Horizontal IMPs are cladding solutions that consist of two metal sheets bonded to an insulating core material, typically made of polyurethane or polyisocyanurate foam.

These panels are designed to provide excellent thermal insulation, weather resistance, and structural integrity, making them ideal for use in multi-story structures where energy efficiency, durability, and aesthetics are of paramount importance.

Among the numerous advantages that make horizontal IMPs an ideal choice for cladding in multi-story construction:

• Energy Efficiency: The high insulation properties of IMPs contribute to reduced energy consumption by maintaining a comfortable indoor environment and reducing heating and cooling costs.
• Weather Resistance: IMPs provide an effective barrier against weather elements, preventing moisture infiltration, air leakage, and thermal bridging.
• Design Flexibility: With various colors, finishes, and profiles available, architects can achieve a wide range of design aesthetics, enhancing the visual appeal of the structure.
• Speed of Installation: IMPs are manufactured off-site and can be quickly installed, saving both time and labor costs during the construction process.
• Structural Integrity: The composite nature of IMPs ensures excellent load-bearing capacity, enhancing the overall structural performance of the building.
• Durability: IMPs are resistant to wear, impact, and corrosion, ensuring a longer lifespan for the building envelope.
• Code Compliance: IMPs often meet or exceed building code requirements for factors such as fire resistance, thermal performance, and weatherproofing, ensuring a safe and compliant building envelope.
• Lightweight Construction: The lightweight nature of IMPs reduces the overall load on the building's structure, potentially leading to cost savings and greater design flexibility.

Coordination with the Design Team

Coordination with the project's design team is crucial when using horizontally installed IMPs.

Failure to coordinate can lead to design inconsistencies, delays, and cost overruns.

It's essential to collaborate closely to ensure that the IMPs align with the overall architectural vision and that details such as openings, joints, and connections are properly integrated.

Proper performance of horizontal IMP wall systems may hinge on an understanding of the interaction between the floor system and wall supports, which are typically tube steel supports or steel stud walls.

Interaction between Wall Supports and Floor System

Understanding the interaction between the wall supports (such as steel stud walls or tube steel supports) and the floor system is key to proper IMP performance.

Floor deflections, which are the downward movements of the floors under load, can potentially transfer stress to the IMP system, leading to damage or distortion of the cladding.

To mitigate this, proper consideration of the building's structural behavior and load distribution is essential.

Remember, that floor deflections are a natural response to the applied loads and are expected in any building. However, they can have implications for the entire structure, including the cladding systems like IMPs that are used on the exterior walls.

Here's a breakdown of why floor deflections matter and how they can affect the building envelope:

• Impact on Cladding Systems: Floor deflections can transfer movement to the building's exterior walls, including the cladding systems like IMPs. The degree of movement transferred depends on the design of the building's structural system, the materials used, and the load distribution.
• Distortion and Damage: Excessive floor deflections can potentially cause distortion, waviness, or even damage to the cladding system. This is especially true if the cladding system is rigid and lacks flexibility to accommodate such movements.
• Waterproofing Concerns: In addition to the potential for visual distortion, transferred movement from floor deflections can lead to issues with waterproofing. The shifts in the cladding system may compromise the integrity of seals, joints, and connections, allowing water infiltration and damaging the building envelope.
• Aesthetic Challenges: If the cladding system is not designed to handle the movement from floor deflections, it can result in an aesthetically displeasing appearance with visible deformations or misalignments.
• Long-Term Performance: Over time, the cumulative effects of transferred movement from floor deflections can lead to premature wear and tear on the cladding system, affecting its long-term performance and durability.

Understanding Inboard vs. Outboard in Wall Studs

Using wall studs that are inboard of the slab edge is a common practice in multi-story construction, especially in regions where building codes and regulations stipulate stringent fire safety requirements.

This practice is aimed at providing what is known as a "fire stop" or "fire barrier" and in multi-story buildings it can add benefits such as fire containment, fire compartmentalization, and protection of evacuation routes.

While “inboarding” wall studs offer significant fire safety benefits, architects and designers must also consider the potential challenges associated with floor deflections, as discussed earlier.

In this construction method, the stud system will deflect along with the floor, which can then transfer the load to the IMPs which are not designed with expansion joints and usually can only accommodate up to one-quarter inch of floor deflection.

One solution with wall studs that are inboard of the slab is to place vertical IMPs at the midpoint (or even more frequently if possible) of the column spacing – preventing a continuous wall column-to-wall column run – to help relieve some of the stress.

The preferred solution when working with horizontal IMPs in multi-story construction is the use of bypass stud or tube steel construction – called outboard.

This approach limits the transfer of loads to the wall framing and IMP system. The bypass construction method isolates the IMP system from the floor movement, ensuring the panels' structural integrity and aesthetics are preserved.

When this method is chosen, additional firestop solutions will be needed at each floor location, but building designers often find the performance and weatherproofing advantages make the trade-off worthwhile.

Pre-Project Discussions with Your IMP Provider

Prior to embarking on a multi-story construction project involving horizontal IMPs, architects, project designers, and builders should engage in detailed discussions with their IMP provider.

These discussions should cover:

• Location-Specific Considerations: Understand the specific environmental challenges of the project site, such as wind loads, seismic activity, and temperature variations.
  
  
• Performance Expectations: Clearly define the desired performance metrics for the IMPs, including thermal insulation, fire resistance, and structural integrity.
  
  
• Installation Process: Discuss the installation process, including sequencing, connections, support framing, and any special requirements.
  
  
• Maintenance and Upkeep: Understand the long-term maintenance requirements of the IMP system and ensure that the chosen solution aligns with ease of maintenance.
  
  
• Integration with Other Systems: Coordinate the IMP system with other building systems, such as HVAC, lighting, and insulation, to ensure seamless integration.
  
  
• Warranty and Support: Clarify warranty terms, after-sales support, and any maintenance agreements offered by the IMP provider.
  
  
• Testing and Certification: Confirm that the chosen IMP system meets relevant industry standards and certifications for performance and safety.
  
  
• Customization Options: Explore customization options for finishes, colors, and profiles to achieve the desired architectural vision.
  
  
• Budget Considerations: Discuss the cost implications of the chosen IMP system, including both upfront costs and potential long-term savings.

Contact Green Span Profiles today for the highest-quality vertical and horizontal IMPS manufactured in America and perfect for your multi-story structure.