New regulations implemented | HZCRSLMJ releases application standards for non-A grade insulation materials

2026-03-11 10:36:41

With the continuous tightening of building fire protection codes, the compliant use of non‑A‑class insulation materials has become a central focus of the construction industry. As regulatory requirements evolve toward higher fire safety standards while simultaneously maintaining or improving energy efficiency targets, designers, contractors, and developers are being pushed to rethink conventional insulation strategies. In response to this shift, a set of supporting application technical standards has been jointly released by industry organizations, clarifying requirements for material selection, node detailing, construction procedures, and acceptance criteria. These standards are intended to help contractors and design institutes mitigate safety risks, achieve dual compliance with energy conservation and fire protection objectives, and promote the standardized development of the sector.

At the core of this development is the growing recognition that not all projects can or will use strictly A‑class (non‑combustible) thermal insulation materials. In many building types and climate zones, alternative insulation systems—often involving organic or composite materials with superior thermal performance—remain attractive or even indispensable due to cost, weight, or performance characteristics. However, these non‑A‑class materials inherently present a higher fire load compared with strictly non‑combustible solutions. This reality has made the question of how to apply such materials in a compliant and safe manner one of the most pressing technical challenges for the building envelope and interior fit‑out fields.

The newly released application technical standards address this challenge from multiple dimensions. First, they set out a systematic framework for material selection. Rather than treating non‑A‑class insulation as a monolithic category, the standards differentiate between various subclasses based on combustion performance, smoke development, and contribution to fire spread. Insulation materials are required to undergo standardized fire testing according to relevant national and international methods. The standards further specify how to interpret test results in the context of actual engineering practice, including façade systems, roof structures, internal partition walls, and mechanical and electrical service insulation.

Material selection guidance also incorporates considerations beyond fire behavior, such as thermal conductivity, water absorption, vapor permeability, dimensional stability, and environmental performance. By integrating fire performance and energy‑saving indicators into a unified evaluation model, the standards provide design teams with a structured methodology to balance fire safety and thermal efficiency, rather than prioritizing one at the expense of the other. This integrated evaluation approach is especially important under stricter building energy codes, where high‑performance insulation materials are critical to achieving low‑energy or near‑zero‑energy building targets.

Second, the standards pay particular attention to node detailing, recognizing that the majority of fire‑related failures in insulation systems arise not from the bulk material itself but from weaknesses at interfaces and junctions. Critical nodes such as floor slab edges, window openings, balcony slabs, expansion joints, parapet walls, roof‑wall junctions, and penetrations for pipes, ducts, and cables are all analyzed in detail. For each type of node, the standards provide recommended configurations, including fire‑stopping measures, the use of fire barriers or fire‑blocking zones, and the minimum widths and continuity criteria of these barriers.

For example, in external wall insulation systems using non‑A‑class materials, the standards may stipulate horizontal and vertical fire‑blocking belts at specified story intervals or around openings, using materials that achieve an A‑class rating. The positioning and anchorage of these belts are described in relation to the structural components to ensure effective compartmentation and to reduce the risk of vertical or lateral fire spread on the façade. Similar principles apply to internal partitions and service shafts, where insulation materials are required to be coordinated with fire‑rated doors, dampers, and penetration seals to maintain the integrity of compartmentation lines.

Third, the standards define clear construction procedures. Recognizing that even the best designs can fail if poorly executed on site, the document organizes construction requirements into stages: substrate preparation, primer application, mechanical and/or adhesive fixing, layering sequence, joint treatment, fire‑blocking installation, and surface finishing. Each stage includes key control points and inspection items.

For instance, it is emphasized that substrates must meet flatness, strength, and dryness criteria before insulation boards or systems are applied, to prevent debonding or the formation of concealed voids that might exacerbate fire spread. The type and quantity of mechanical fasteners are detailed according to wind load zones and system weight, with special notes for high‑rise and super high‑rise buildings where façade insulation can be exposed to greater wind suction. Adhesive coverage rates and application patterns are likewise specified to ensure continuous adhesion and minimize air gaps.

In the implementation of fire‑blocking measures, the standards prescribe not only the type and class of materials to be used but also their installation sequence relative to the thermal insulation layers. This is to avoid situations where fire‑resistant components are inadvertently bridged or bypassed by combustible layers due to improper ordering of work. Tolerances on dimensions, alignment, and overlap lengths are laid out so that supervision engineers and quality inspectors can verify compliance through measurable criteria.

Fourth, the acceptance criteria in the standards translate these technical principles into practical inspection and testing requirements. Acceptance is understood as a multi‑tier process: factory inspection of materials, on‑site sampling and testing, process inspection during construction, and final project acceptance. For each phase, the standards propose documentation requirements, including product certificates, fire test reports, installation records, photographic evidence of concealed works, and acceptance checklists signed by responsible parties.

On‑site inspections focus not only on visible surfaces but also on concealed components that are crucial for fire safety, such as embedded fire‑stopping layers, cavity barriers, and penetration sealing systems. Random sampling may include pull‑out tests of mechanical fixings, adhesion tests of bonded insulation, and localized exposure of nodes to verify that they match approved detail drawings. The standards encourage coordination between the design institute, contractor, fire engineering consultant, and building supervision authority throughout the process to ensure that deviations from the design are promptly corrected and documented.

A key contribution of these application standards lies in helping contractors and design institutes systematically avoid safety risks associated with non‑A‑class insulation. By providing detailed, scenario‑based guidance, they reduce ambiguity in how codes should be applied, particularly in complex building types such as high‑rise residential towers, large public buildings, transportation hubs, hospitals, and educational facilities. For each of these typologies, the acceptable range of insulation solutions is narrowed and clearly linked to specific fire strategy objectives, such as limiting external vertical fire spread, maintaining safe egress routes, and protecting critical structural elements for a defined fire resistance period.

To support the dual goal of energy conservation and fire safety, the standards also promote the concept of system compatibility. Rather than evaluating insulation materials in isolation, they consider their interaction with other envelope components: cladding panels, sub‑framing, air and vapor control layers, structural substrates, and surface finishes. Guidance is offered on how different combinations affect both thermal bridges and potential fire propagation paths. For example, an external wall system might combine a non‑A‑class insulation core with non‑combustible claddings and continuous fire‑blocking measures to achieve an overall risk level comparable to or better than traditional solutions, while still meeting or exceeding energy performance benchmarks.

Furthermore, the standards emphasize the importance of performance‑based design where prescriptive provisions alone are insufficient. For certain innovative materials or complex façade geometries, fire engineering analyses and large‑scale system tests are encouraged or required. The results of such studies must then be translated into project‑specific detailing, construction controls, and maintenance requirements, ensuring that the theoretical fire performance is actually realizable in practice.

Beyond individual projects, the broader objective of these technical standards is to promote the standardized development of the construction and insulation industry. By unifying terminology, test methods, design principles, and quality control procedures, they facilitate communication among stakeholders and enable more consistent enforcement of regulations across regions. This standardization also lays the groundwork for training programs, certification of skilled workers, and qualification of specialized enterprises engaged in insulation and fire‑stopping works.

In the longer term, the widespread adoption of such standards is expected to drive innovation. Manufacturers are incentivized to develop new non‑A‑class insulation materials and systems that meet stringent performance envelopes defined by the standards. Design professionals gain a clearer framework within which they can explore high‑performance building envelopes, low‑carbon materials, and integrated façade systems without compromising life safety. Contractors, conversely, benefit from having structured process guidelines that reduce rework, disputes, and liability exposure.

As building fire codes continue to tighten, the path forward for non‑A‑class insulation materials is neither outright prohibition nor unconstrained use. Instead, it lies in rigorously defined, technically justified, and carefully supervised application scenarios. The combined publication of these supporting application technical standards by industry institutions provides a much‑needed roadmap. By clarifying material selection, node detailing, construction processes, and acceptance requirements, they help all parties in the construction chain navigate the increasingly complex regulatory environment. In doing so, they make it possible to simultaneously reach advanced targets for energy conservation and robust fire protection, and thereby contribute to the orderly, standardized, and high‑quality development of the construction industry as a whole.