Publication - Consultation analysis

Multi‑storey residential buildings - fire risk posed by external wall systems: consultation analysis

Published: 11 Feb 2021

An independent analysis of consultation responses to the Draft Scottish Advice Note (SAN): Determining the fire risk posed by external wall systems in existing multi-storey residential buildings.

Multi‑storey residential buildings - fire risk posed by external wall systems: consultation analysis
7. Non-ACM Cladding Panels

7. Non-ACM Cladding Panels

Question 5. Is the guidance on non-ACM cladding (including High Pressure Laminate) panels helpful?

Overview of Responses

Table 14: Is the guidance on non- ACM cladding (including High Pressure Laminate) panels helpful?
  Yes No
  Number % Number %
Individual 7 88% 1 13%
Organisation 11 65% 6 35%
Fire Safety / Engineering / Consultants 2 50% 2 50%
Misc Construction 1 33% 2 67%
Finance and Insurance 3 100% 0 0%
Housing and Property Management 1 50% 1 50%
Local Government 2 100% 0 0%
Residents and Tenants Groups 1 50% 1 50%
Further and Higher Education 1 100% 0 0%
Total 18 72% 7 28%

N=25.Percentages do not all add up to 100 due to rounding.

7.1 A majority of consultation respondents noted that the guidance on non-ACM cladding (including High Pressure Laminate, HPL) panels was helpful (18, 72%), Table 14. Individuals were more likely to hold this view.

7.2 Most of these respondents did not provide any wider qualitative feedback.

7.3 Where wider feedback was provided, this in the main acknowledged that the guidance provided in the Draft SAN regarding non-ACM cladding, including HPL, was welcomed given that the fire classification of this type of cladding varies significantly, the potential risks associated with non-ACM cladding, and the increased prevalence of its use in buildings. These points are reflected in the respondent quotes below.

"The UK Government's Independent Expert Advisory Panel was clear on the potential risks associated with Euroclass C and D HPL, and any HPL panels used in combination with combustible insulation".

National Fire Chiefs Council

"It is critical that this document clearly outlines the limitations and risks of other types of cladding systems and does not solely concentrate on ACM cladding. By providing a holistic approach to assessing all cladding systems there is now a framework for assessing new systems as they appear".

Individual

7.4 There were also a couple of comments that suggested areas where the guidance on non-ACM cladding, including HPL, could be further clarified and/or improved, as outlined below.

7.5 UK Finance felt that greater clarification would be required in the guidance for buildings with a timber clad external wall system, including retrofitted systems, and in relation to walls with external insulation.

7.6 Kingspan noted that "while the guidance pertaining to HPL is helpful, there are a large number of cladding materials available with different reaction to fire performances". Wider reference was then made to the focus of the guidance on Euroclass performance to establish whether the prescription guidance in the Scottish Technical Handbooks has been adopted (A1/A2 materials should be used over 11m, and also have different levels of fire performance).

"Even with A1/A2 systems it's important to consider quality of install of the components, correct cavity barrier placement and detailing of the façade system. There is evidence of a number of systems comprised of A1/A2 materials which have failed when tested to BS 8414, which is acknowledged as an alternative method of compliance in the Scottish Technical Handbooks.

It is positive that the current guidance provides the option of large scale testing as a means of demonstrating compliance with the functional requirements of the Building Regulations. Tests such as BS 8414 can provide an insight into how façade materials will interact and perform in the event of a real fire, and this information can be useful for fire engineers in developing strategies for buildings".

Kingspan

7.7 Over one-quarter of respondents felt that the guidance on non-ACM cladding panels was not helpful (seven, 28%), Table 14. As with earlier questions, organisations were more likely to note disagreement.

7.8 A common theme that emerged was a perceived narrow or limited focus of the guidance on HPL non-ACM cladding. For example, an Individual respondent noted that other types on non-ACM cladding such as timber, insulated core sandwich panels, rendered EPS "are as prevalent as MCM and HPL".

7.9 Rockwool Ltd and MIMA also reiterated their concerns as noted at Section 6 (Question 4) regarding the UK Government test and analysis report "Fire performance of cladding materials research". Their view is that the research was flawed, and minimised the risks and potential dangers associated with using non-ACM combustible materials. Both recommended that reference to the research be removed from the Draft SAN. In support of this, it was further noted that:

"The UK Government remediation fund is now available for buildings with HPL cladding, providing a clear indication that the UK Government does not consider the use of HPL to be safe".

Rockwool Ltd

7.10 The same two respondents also raised concern with the "narrow focus on ACM PE in Scotland". It was suggested that this has resulted in other types of combustible materials and combinations having been overlooked or their risks downplayed. This is reflected in the respondent quotes below.

"The inclusion of only HPL as "non-ACM cladding" continues this worrying trend by neglecting to expand on what this could include beyond HPL. There are many combustible façade materials in common use other than ACM and HPL, all of which should be identified and remedial works urgently undertaken where required".

Rockwool Ltd

"Many other types of combustible materials and combinations have been discounted or less weight given to their risks due to the limited focus on ACM PE in Scotland. There are many combustible façade materials in common use other than ACM and HPL e.g. the inclusion of only HPL as "non-ACM cladding" fails to highlight what this could include beyond HPL. All such materials should be identified and remedial works urgently undertaken as necessary. Examples are as follows: High Pressure Laminate (HPL): "Class B HPL with stone wool insulation met the BR 135 performance criteria when tested to BS 8414 and may be considered to be safe."

MIMA

7.11 ARUP also felt that the guidance was limited, and suggested that it could potentially be "construed as misleading", as noted below.

"…the guidance on HPL is based on a single set of tests carried out by the UK Government, rather than presenting an opinion on the basis of all existing literature. Regardless of test results, the field of application for HPL must still be considered to determine whether it is appropriate for the building in question. The advice on green walls is limited to the point of being unhelpful, as it does not clarify the Scottish Government stance on the acceptability of green walls with respect to how they meet the functional intent for External Fire Spread. It would be prudent to acknowledge other HPL tests undertaken e.g. by MCRMA, which has demonstrated that unmodified HPL cladding does present a very high risk also".

7.12 There were a couple of wider comments that suggested: that many building owners might not fully understand the detailed information provided on non-ACM cladding including HPL; and/or that the indication of combustibility used in the advice note was confusing for the reader ("there is no consistency of this measure across the cladding types, nor is this translated into any concept that would be meaningful to any owner who is stated to be among").


Contact

Email: Colin.hird@gov.scot