The survey heard that although each US state has its own regulations, a national body called the National Fire Protection Association (NFPA) “has had a huge influence” on how fire safety is implemented across the country.
He learned that the United States follows higher fire safety standards, including using sprinklers, progressive evacuations and installing two staircases in buildings.
“Unlike in the UK where you have the prevalence of functional requirements…in the US you have the option of performance based design but the primary means of ensuring fire safety is a very strict, strict and prescriptive,” the professor said. Torero said.
He said the codes followed in the United States are “effectively prescriptive codes with an option for minor deviations.” He accepted
The United States has a similar large-scale fire test – NFPA 285 – to that of the United Kingdom – BS 8414.
In a submission to the investigation into the regulatory system in the United States, the NFPA said: “[The NFPA 285] The test is similar to BS 8414 and is mandatory for use primarily on high rise buildings where a combustible component may form part of the exterior wall assembly of the building.
“Having a rigorous test is not enough to control the risk of fire. It is important to ensure that what is specified and installed is the same as what is tested.
When questioned, Professor Torero agreed that the NFPA 285 standard was not the best way to assess the fire behavior of exterior facades.
“A test is a test, a test gives you information, but as a criterion for acceptance, the only thing it does is cut the tail. It doesn’t give you a robust methodology for acceptance,” he said, agreeing that means the only thing it does is exclude the worst performing systems.
He said you were left with systems “that could be potentially very bad, but are still able to pass the test.”
“The only thing you can say at the end when you apply these tests is that if he fails the tests, that’s absolutely terrible,” Professor Torero said.
He said earlier that NFPA 285 was used in an otherwise “rigid” system in the US, while in the UK the test is open to interpretation.
“If you have a complicated situation that has multiple variables and you fit it into a system that allows for multiple solutions, the chance of making a mistake is huge,” Professor Torero said.
The NFPA said: “The US faces many of the same challenges as the UK when it comes to fire safety in tall buildings.
“Both countries have responded to the challenge with regulatory requirements, including the use of fire tests on facades. Some of the biggest differences can be found in the application of requirements.
Professor Torero said he agreed with that.
Earlier, the inquest heard the conclusion of evidence from Professor Luke Bisby, who previously told the inquest that UK government policy had ‘perpetuated and encouraged’ the guidelines ‘poorly applied and exploited in the service of the generation of profits while avoiding liability”.
Today he was asked about the process of desk studies – the method by which test evidence is interpreted to assess the compliance of a system that differs from the one being tested.
Professor Bisby said he believed the UK system allowed for computer-based study because any test evidence required the assessment of a competent professional in order to interpret how it works in the real world.
But he said he was concerned about the competence of some of those who carried out the assessments.
Asked to comment on such an assessment, carried out by consultancy H and H Fire, which justified the use of the coating product later used on Grenfell on another building, Prof Bisby said it was “particularly upsetting “.
“It exposed some of the misconceptions that this investigation faced,” he said. “I don’t use the word incompetent lightly, but it is, in my view, a totally incompetent report.”
Professor Bisby has raised significant concerns about the government’s new guidance to risk assessors who will examine the safety of building facades, PAS 9980.
Its report states that the document “does not clearly define what is meant by competent, nor does it provide much guidance on how this competence should be assessed, verified, maintained, controlled or monitored across the sector. “.
He added that it “does little to raise the bar for the coatings fire risk assessment community and instead offers a formula-based methodology for undertaking such assessments.”
“I also think it should be recognized that the existence of PAS 9980 could perhaps counter-intuitively create a risk that fire risk assessors who lack the required skills could be given a false sense of jurisdiction and therefore could use PAS 9980 to undertake fire hazard assessments of the coating they themselves or their professional insurance might otherwise decline,” he said.
“I think it helps people feel like they have the skill, when in reality they don’t have it and that’s why I think it’s dangerous,” he said.
The investigation continues with new evidence from Professor Torero tomorrow.