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

8. Guidance on Partial Cladding

Question 6. Is the guidance on partial cladding helpful?

Overview of Responses

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

8.1 A vast majority of consultation respondents reported that the guidance on partial cladding was helpful (19, 76%), Table 15. Less than of one-third of these respondents went onto provide any qualitative feedback on Question 6.

8.2 Where feedback was provided, some simply noted the helpfulness of the advice in terms such as "reasonably so", or "the notes are helpful to direct consideration of these items in terms of fire spread risk within existing conditions" (Fire Sector Federation).

8.3 A couple of other respondents went onto note aspects where there was considered to be the potential for confusion and/or where further detail or clarity would be required. The specific points raised are reflected in the quotes below.

"While the Advice gives plenty of areas of consideration, there is a risk that this could be considered confusing, given how in-depth some of these appraisals need to be. This seems less aimed at building owners/ managers, and more at the individuals tasked with carrying out the risk assessment/external wall appraisal".

Kingspan

"There should be consideration of other wall systems which are not mentioned, for example brick slip systems which can be combustible".

UK Finance

8.4 Almost one-quarter of respondents noted that the partial cladding guidance was not helpful (six, 24%), Table 15. Organisations were more likely to hold this view.

8.5 Most of the points raised by this cohort of respondents noted that the guidance on partial cladding could be improved, expanded and/or clarified in some way in order to more clearly communicate fire safety risks to building owners/managers.

8.6 The points raised have been summarised below:

• Rockwell Ltd and MIMA asked that the guidance define and distinguish between terms used in the Draft SAN (e.g. "extensively and "partially" clad with combustible panel). It was further noted that this would help the reader to "determine which advice they are required to follow";
• Ravelston Terrace Cladding Working Group suggested that the guidance could provide an indication of the level of partial cladding covering that could be considered "trivial, significant or substantial, and the level of risk that each might pose";
• An Individual respondent felt that the guidance on partial cladding was limited and queried its focus on only MCM. It was suggested that the guidance could be expanded "to give owners, enforcing authorities and building professionals confidence when applying risk-based thinking".

8.7 ARUP went further and hold the view that partially clad Category 3 MCM should be removed from a building regardless of other features present or outcome of a risk assessment. This is reflected in the quote below.

"The combustible cladding, by its nature, allows fire and smoke to spread on the external wall regardless of its location and extent. Therefore, partial Category 3 cladding does not meet the functional requirement of Schedule 5 Section 2.7 of the Building (Scotland) Regulations 2004, such that "the spread of fire on the external walls of the building is inhibited"

Even in the instance that MCM does not cross compartmentation, flaming debris from the panels can start secondary fires in other areas of MCM. This can occur both under gravity and wind. There are many variables that make it very challenging to model the behaviour and justify the retention of partial cladding.

Point (g) references considering how the fire and rescue service can tackle a fire in a partially clad building. It is recommended that this consideration is only undertaken in consultation with the fire and rescue service. It is clear from the DCLG tests that Category 3 MCM with PIR insulation failed the BS8414 test. Therefore, it should be recommended that even in partially clad category 3 MCMs, if combustible insulation is present, the cladding and insulation should be removed and remediated accordingly".

ARUP