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

5. Metal Composite Material Cladding

Question 3. Does the advice clearly explain the risk of Metal Composite Material (MCM) cladding?

Overview of Responses

N=24

5.1 A vast majority of consultation respondents reported that the advice clearly explained the risk of MCM cladding (19, 79%), Table 12. Individuals were more likely to report this than organisations. Similar to previous questions, levels of agreement to Question 3 also varied by organisation sub-group.

5.2 Only a handful of respondents that reported the Draft SAN clearly explained the risk of MCM cladding went onto provide wider commentary in their consultation response.

5.3 There were a few comments that simply confirmed that the advice was clear. This is reflected in various respondent quotes, including from USHA Fire (Scotland) Group and UK Finance, such as "yes reasonably so", "the level of technical detail is clear within the SAN and it will assist fire risk assessors undertaking the fire risk appraisal", and "the advice is clear and appropriately supported by experimental data".

5.4 However, a few respondents caveated their "yes" response, and noted that the Draft SAN could benefit from greater clarity regarding the risk of MCM cladding:

• It was suggested that the advice could be more structured in its recommendations/requirements for MCM cladding to ensure that there is no ambiguity or lack of clarity regarding outputs; and
• An Individual respondent felt that the advice regarding MCM cladding had "too many caveats" attached to it.

5.5 Wider individual points noted include the following:

• UK Finance pointed to the different levels of technical knowledge and expertise among the intended audience for the Draft SAN, and given that the category of MCM cannot be determined from a visual inspection, that "lenders will be reliant on the expertise and recommendations of the risk assessors"; and
• Kingspan considered it important to note that "MCM is quite a broad term", as it might include products with different metals, cores and coatings, and that there is also wide variance of performance for Category 2 MCM between manufacturers.

5.6 Around one-fifth of respondents (all organisations) felt that the advice did not clearly explain the risk of MCM cladding (five, 21%), Table 12.

5.7 A common theme that emerged from the feedback provided by these respondents was that the advice note's reference to the risk of MCM cladding could be further simplified, clarified and/or improved to avoid confusion and to aid greater understanding for the intended audience (e.g. by reducing the use of "jargon" in sections relating to fire performance, by ensuring clear and full definitions of terms used, by annexing the technical detail with clear and simplified messaging in the main body of the document).

5.8 Another common theme related specifically to reference to different categories and terms used within the Draft SAN (e.g. "Category 1, 2 or 3 MCM", "limited combustibility", "extensively clad"). Much of the feedback noted that the language used could cause confusion for the reader. Note: Category 1, 2, 3 are taken directly from the UK Government's BS8414 fire tests and the results were published on its website using this system.

5.9 The following respondent quotes are, however, reflective of the points made.

"….the introduction of Category 1, 2 or 3 MCM referenced throughout the advice note…risks creating further confusion. Construction products for sale in the UK are not categorised or labelled in this way. It also does not align with the way that building regulations in Scotland or the latest Technical Handbooks are written. Presenting categories in this way risks exacerbating the confusion which was created through referring to both the British and European reaction to fire classifications…. as such, classifications should align with European Reaction to Fire system only….Not only would this align with the latest technical handbooks but the European standard is a far more technically robust way of assessing and categorising the reaction to fire performance of products".

Rockwool Ltd

"One of the panels is described as "limited combustibility". As this term does not exist in Scotland, it would be helpful to the reader to explain what this term means in a Scottish context with reference to the European Classifications. The use of the term "extensively clad" should be defined clearly and with an evidence base".

ARUP

5.10 While there was some acknowledgment across the feedback that the advice note clearly describes the different types of MCM cladding and that fire performance varies, there was feedback that it did not go far enough in terms of:

• Clearly explaining the risk of MCMs more generally i.e. "what about their build-up and construction makes them particularly dangerous" (ARUP);
• Describing the greater risk from a fire safety perspective associated with the shaping/cutting of MCMs on site (ARUP); and
• Giving due consideration of the "time available to evacuate" (Ravelston Terrace Cladding Working Group).