A high‑performing building envelope is the first line of defense against energy loss, water intrusion, and premature deterioration. Modern codes therefore steer designers toward rainscreen walls—cladding that stands off from the air‑ and vapor‑controlled structure to create a ventilated, drained cavity. What happens inside that narrow gap is decisive:

Continuous insulation keeps the structure warm.
Sub‑framing or girts hold the cladding outboard.
Ventilation paths let incidental water drain and dry.

Traditional steel Z‑girts pierce the insulation with conductive materials, forming thermal bridges that undermine all three goals. Composite metal hybrid solutions such as the GreenGirt CMH™ continuous insulation and SMARTci® building enclosure systems replace that weak link, giving the rainscreen assembly a step‑change in performance.

CMH Systems at a Glance

GreenGirt CMH is a continuous insulation Z-girt comprised of a composite fiberglass Z-profile base and steel flanges. SMARTci is a building enclosure system that combines the GreenGirt CMH Z-girts with custom-profile rigid insulation to create an air- and water-tight barrier. Together, they create a thermally broken, structurally capable, and code‑compliant sub‑frame that is not only thermally efficient, but also maintains the building’s structural integrity.

Six Ways CMH Can Improve Rainscreen Assemblies

Superior Thermal Performance

Steel Z‑girts can cut R‑values by 40–50%.
CMH systems are 92-99% thermally efficient and retain a high effective R-value for the insulation.
A higher effective R-value means increased energy efficiency, lower peak loads, and steadier indoor temperatures for increased thermal comfort.

Robust Moisture Management

Continuous insulation keeps sheathing above dew‑point temperature.
There is less risk of mold, corrosion, and finish failures when using CMH systems.

Thermally Broken Cladding Support Systems

CMH systems support screw pull‑out values that exceed the fasteners themselves.
Assemblies have passed ASTM E‑330 pressure cycling tests.
CMH Z-girts lessen dead loads, easing installation and labor time.

Faster, Cleaner Installation

CMH Z-girts arrive pre‑punched; a single self‑tapping screw bites the steel-reinforced flange and establishes a permanent steel-to-steel connection that eliminates “unavoidable failure.”
Insulation can be easily installed between the Z-girts because of built-in ThermaLock technology, holding the insulation in place, eliminating the need for extra fastening materials.

Verified Fire and Code Compliance

CMH systems achieve ASTM E84 Class A flame‑spread and smoke ratings.
CMH passes NFPA 285 façade fire tests with different insulation materials, offering fire resistance and flexibility in insulation options.

Sustainability Beyond Energy

CMH systems are verified with third‑party Environmental Product Declarations (EPDs).
CMH systems do not use halogenated flame retardants or red‑list chemicals in any part of the system.
CMH systems have a Declare Label that provides full transparency for architects and builders to make informed choices about the materials they select for their projects.

Conclusion

As energy codes continue toward net‑zero targets and climate resilience, continuous insulation systems that balance durability and thermal efficiency must become the norm rather than the exception. GreenGirt CMH and SMARTci already embody that future, delivering high-quality performance without having to make any sacrifices to building performance requirements. By using CMH in rainscreens, GreenGirt CMH and SMARTci systems elevate the building envelope from a passive barrier to an active contributor to performance, durability, and occupant comfort.

A2P is a proud founding member of the Rainscreen Association in North America (RAiNA), focused on educating the public about high-performance rainscreen assemblies that enhance building durability, resilience, health, energy efficiency, and safety—learn more.

Get Project-Ready Documents for GreenGirt CMH & SMARTci Systems for Your Rainscreen Project

Get the key documents you need to properly specify GreenGirt CMH and SMARTci systems for your next rainscreen project.

Download A2P’s Technical Documents

Need support in designing continuous insulation with your rainscreen project? Our expert engineers are available to offer technical guidance.

Talk with A2P’s Expert Engineers

Related Resources:

SMARTci System Overview

GreenGirt CMH Systems Overview

View “Best Practices: Building Health”

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Frequently Asked Questions

How much does a steel Z-girt reduce effective R-value in a rainscreen wall?

Steel Z-girts can significantly reduce a wall’s effective R-value due to thermal bridging, often cited as roughly 40–50% loss depending on the assembly. Thermally broken sub-framing systems are designed to keep more of the insulation’s nominal R-value “intact” in real-world performance.

How do GreenGirt CMH and SMARTci help manage moisture in a rainscreen wall?

The GreenGirt CMH and SMARTci systems help keep the sheathing warmer, often above the dew-point, so incidental moisture is less likely to condense within the assembly. By reducing condensation risk, CMH-based rainscreen assemblies can lower the likelihood of mold, corrosion, and finish failures.

What installation features make GreenGirt CMH faster or easier to install in rainscreen assemblies?

GreenGirt CMH Z-girts arrive pre-punched, and installation uses a single self-tapping screw into the steel-reinforced flange to create a permanent steel-to-steel connection. Built-in ThermaLock technology helps hold insulation in place between Z-girts, reducing the need for extra fastening materials.