Cladding firm鈥檚 hired hand believed lack of key safety component in architect鈥檚 drawings reflected 鈥榙ifferent route to compliance鈥

The freelancer hired by Harley Facades to work as 鈥減roject designer鈥 on the Grenfell Tower refurbishment believed the omission of a key safety feature from architect Studio E鈥檚 plans for the scheme was deliberate policy, the inquiry into 2017鈥檚 fire disaster has heard.

Kevin Lamb told the Grenfell Tower Inquiry that he knew the windows of buildings needed to be surrounded by cavity barriers to stop the spread of fire in accordance with Approved Document B of the 好色先生TV Regulations.

Kevin Lamb, who worked for Harley Facades on a freelance basis during the Grenfell Tower refurbishment

Kevin Lamb, who worked for Harley Facades on a freelance basis during the Grenfell Tower refurbishment

But he told Thursday鈥檚 hearing he thought the project architect was using a 鈥渄ifferent route to compliance鈥 to stop the spread of fire via cavities at windows and took Studio E鈥檚 approval of his drawings as confirmation that there was not a problem.

Lamb was brought in to cladding specialist Harley to make up for a staffing shortfall in the summer of 2014, after Rydon was picked as main contractor for the west London tower block and appointed Harley to deliver the fa莽ade package for the scheme.

Seventy-two people died when fire engulfed the building in the early hours of 14 June 2017. Combustible aluminium composite material (ACM) cladding and combustible insulation used in the refurbishment have been identified as the main causes of the spread of fire.

However a report by chartered fire engineer and Grenfell Tower Inquiry expert witness Dr Barbara Lane said the lack of fire barriers around windows meant there was a 鈥渄isproportionately high probability鈥 that if a fire started near a window it would spread into the cladding.

On Wednesday Lamb said that despite his 鈥減roject designer鈥 title, he had been hired by Harley to act as a drafting service to transfer Studio E鈥檚 drawings into fabrication drawings for the external cladding system proposed for Grenfell to be manufactured and installed.

Thursday鈥檚 hearing explored how Lamb and Harley approached ambiguity about Studio E鈥檚 plans for incorporating cavity barriers into the proposals.

Lamb said he had assumed that the lack of all-around cavity barriers in Studio E鈥檚 window plans meant it was pursuing an 鈥渁lternative route to compliance鈥 with 好色先生TV Regulations, such as a holistic fire-engineered approach.

鈥淚 didn鈥檛 give it a vast amount of thought but I did know that the architect was backed up with a fire engineer,鈥 Lamb said. 鈥淎nd we followed the architect鈥檚 advice.鈥

Inquiry barrister Kate Grange QC asked whether he was ever told that that the plan for Grenfell was not to follow the ADB approach. Lamb answered 鈥渘o鈥. He added: 鈥淚 was always told follow the architects鈥 drawings.鈥

Lamb said there had been discussions about the cavity-barrier issue within Harley and that he had looked into the requirements of Approved Document B himself as he had been getting 鈥渧ery little feedback鈥.

Illustration of the changes made to Grenfell Tower's windows during the refurbishment

Source: Grenfell Tower Inquiry

Illustration of the changes made to Grenfell Tower鈥檚 windows during the refurbishment

Inquiry chairman Sir Martin Moore-Bick asked why, when there was debate about what Studio E鈥檚 drawings did actually show, he didn鈥檛 seek advice from the architect.

Lamb replied: 鈥淚 was happy with advice from Harley. They were the cladding specialists, they obviously felt that it wasn鈥檛 necessary, or they had discussions. I didn鈥檛 know.鈥

Grange asked Lamb whether Harley could have been keen to avoid the 鈥渇iddly鈥 work of installing cavity barriers around the windows and were looking for an excuse not to do it.

鈥淣o, that鈥檚 definitely not the way they would operate,鈥 Lamb said.

Lamb also rejected the suggestion that Studio E had supplied Harley with early-stage drawings and that it 鈥渨ould have been obvious鈥 to the facades specialist that its job was to develop the design with regard to cavity barriers.

鈥淚t wasn鈥檛 my understanding that was what we were doing,鈥 he said. 鈥淚 was told to follow these drawings.鈥

Lamb subsequently said he was 鈥渓oosely aware鈥 that drawings he submitted to Studio E were a departure from the guidance in Approved Document B. Asked why more checking wasn鈥檛 done, he replied: 鈥淚 asked Harley what to do and I did exactly what they told me to do.鈥

He said Studio E had accepted the drawings returned to it from Harley and that was a stamp of approval of the work from the architect.

鈥淏y virtue of following drawings, we鈥檝e produced our drawings and he鈥檚 approved them,鈥 Lamb said. 鈥漎ou can expect that he鈥檚 happy that there is conformance.鈥

Lamb was also asked about his role in specifying products used for the Grenfell refurbishment.

He said he had suggested the use of Kingspan Thermapitch TP10 for infill panels between windows. He denied specifying the product, which was combustible and should not have been used.

Lamb said he had not conducted any checks on the material but had been 鈥渁ssured it was a Class O product many, many years ago鈥. He said he had never seen any British Board of Agr茅ment certificates for the panels.

鈥淚 put this to the Harley team as a Class O product and they were happy, and so was the architect,鈥 he said.

Under further questioning, Lamb said he had not considered that the product may have had combustible material inside and be unsuitable for use on external walls of a building above 18m in height.

鈥淚t was offered to the team,鈥 he said. 鈥淗arley鈥檚 got far more experience of this kind of thing than myself, as has the architect.鈥

Regulations ambiguity

At the end of her questions, Grange asked Lamb what he would have done differently on the project knowing now how it turned out.

鈥漌ithout the luxury of hindsight, and just considering that I was a freelance design resource, I don鈥檛 think that there was anything different that I could have done,鈥 he said.

鈥滺owever, it鈥檚 quite clear from a lot of our conversations that there鈥檚 a total lack of clarity in the regulations that everyone鈥檚 supposed to adhere to.鈥

He concluded: 鈥淚 really think something needs to be done just to take the ambiguity out of the documentation that everyone鈥檚 supposed to conform to.鈥

The inquiry continues.