Insulation and Sarking Selector for Non-Combustible Walls in Class 2 – 9 Buildings

Depending on the type of construction, non-combustible sarking and insulation may be mandatory to meet the requirements of the BCA. Specifically, Clause C1.1 and C1.9 of the BCA defines that any Class 2 to 9 building of Type A & B Construction must have non-combustible external and common walls. To achieve this, all building components must be deemed non-combustible in accordance with 1530.1.

To understand the requirements, firstly, identify the type of construction required in the table provided by C1.1 below:

C1.1 Type of construction required

If the building is classified as Type A or B, the external and common wall components are required to be non-combustible. This includes both insulation and sarking-type materials.

C1.9 Non-combustible building elements

CSR Bradford offers a wide range of suitable non-combustible insulation and non-combustible sarking options for commercial construction – refer to the selection guidance below:

Selecting Insulation for Non-Combustible Walls

The following list of Bradford insulation products are all deemed non-combustible in accordance with AS1530.1 and are suitable for use where non-combustible insulation materials are required:

If technical supporting documentation is required, contact a Bradford Technical Representative for more information on 1800 354 044.

Selecting Sarking Products for Non-Combustible Walls

There are a range of sarking products suitable for use within non-combustible external wall applications that must be chosen based on the climate zone of the construction. However, there are a limited number of non-combustible sarking products in the market that can provide weather tightness whilst complying to NCC non-combustible provisions.

Compliant sarking products offered by CSR Bradford are listed in the table below. Always check each products performance option met the requirements for the climate zone of construction prior to use:

  • It is recommended that is has a Water Barrier: HIGH classification under AS/NZS4200.1, to provide protection against wind driven rain – if a sarking material is perforated or considered a Water Barrier: Unclassified in accordance with AS 4200.1 it may not be compatible with lightweight clad.
  • For cooler climate zone use vapour permeable sarking
  • For hot humid climates use vapour barrier sarking

Always request satisfactory supporting documentation for use in non-combustible walls.

CSR Bradford Compliant Solutions Summary

This table is a summary of the content below.

Thermoseal Firespec
Non-Combustible Sarking
Thermoseal Wall Wrap XP Enviroseal RW
Vapour Control Classification Class 2 Vapour Barrier Class 1 Vapour Barrier Class 4 Vapour Permeable
Climate Consideration Recommended for warmer climates where lower insulation values are used Recommended for hot to tropical climates where lower insulation values are used Recommended for cooler climates where higher insulation values are used
Water Control Classification Water Barrier Water Barrier Water Barrier
Duty Classification Extra Heavy Duty Medium Duty Light* Duty
Non-Combustible Supporting Documentation AS1530 Part 1/2/3 test reports and CSIRO report FCO-3235 Fire Performance of Wall Wrap - Evidence of Suitability (Stephen & Associates - Report 2013/277.32) Fire Performance of Wall Wrap - Evidence of Suitability (Stephen & Associates - Report 2013/277.32 R2.5)

Deemed-To Satisfy Solution:


Thermoseal Firespec Non-Combustible Sarking

Firespec is made from a white woven fiberglass cloth that has been laminated to a layer of aluminium and is deemed suitable for non-combustible applications in accordance with BCA 2016 Volume 1, Amendment 1, Clause C1.9 (e)(vi) and Volume 2 clause 3.7.1.2

Supporting Documents for Suitability

AS1530 Part 1/2/3 test reports and CSIRO report FCO-3235

Climate Consideration:

This product is classified as a Class 2 (Medium) Vapour Barrier in accordance with AS/NZS 4200.1 and is recommended for applications in warmer climates where lower insulation values are used and the risk of condensation entrapment within the stud frame is lower.

Download the Thermoseal Firespec datasheet here.

Alternative Solutions:

There are other membranes that although not non-combustible as per AS1530.1 can be offered as alternative solutions.


Enviroseal RW or Enviroseal CW

Enviroseal RW and CW are highly vapour permeable sarkings manufactured from spundbond and vapour permeable film. For cooler climates, it is able to reduce the risk of condensation by allowing internally generated moisture to escape from the thermally insulated building envelope.

Supporting Documents for Suitability

Fire Performance of Wall Wrap - Evidence of Suitability (Stephen & Associates - Report 2013/277.32).

Climate Consideration

This product is classified as a Class 4 (Low) Vapour Permeable in accordance with AS/NZS 4200.1 and is recommended for cooler climate zones where higher insulation values are used. It is not suitable for use in tropical climate zones.

Download the Enviroseal RW datasheet here.
Download the Enviroseal CW datasheet here.


Thermoseal Wall Wrap XP

Wall Wrap XP is made from a layer of aluminium layer laminated to polyweave using a hot melt adhesive. It is able to provide an outward facing reflective R value when the antiglare ink surface faces a 25mm air cavity. This cavity can be provided as in brick veneer construction or by using a top hat batten in a light weight wall construction. This product is ideal for use where higher R-values, such as; Rt3.3 are required. Note: It is not possible to achieve Rt3.3 with a 90mm stud without the reflective air-gap provided by this product.

Supporting Documents for Suitability

Fire Performance of Wall Wrap - Evidence of Suitability (Stephen & Associates - Report 2013/277.32 R2.5).

Climate Consideration:

This product is classified as a Class 1 (High) Vapour Barrier in accordance with AS/NZS 4200.1 and is recommended for hot to tropical climates where lower insulation values are used.

Download the Thermoseal Wall Wrap XP datasheet here.


If further technical support is required, please contact a Bradford Technical Representative for more information on 1800 354 044.

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