Jay Brenton Liptrot, 43, was among the first on the scene of the blaze in Prestatyn in October, 2012.
He gave evidence at the trial of one of the tenants, Melanie Smith, who was convicted of five murders.
Mr Liptrot will appear before Prestatyn magistrates on Friday.
The blaze resulted in the deaths of Lee-Ann Shiers, 20, her partner Liam Timbrell, 23, their son Charlie, 15 months, Ms Shiers' nephew Bailey, four, and niece Skye, two.

A report by the Scottish Affairs Select Committee said details were needed on issues such as bank regulation, pension payments and the national currency.
It also asked about Scotland's share of the national debt and whether Scots would need passports.
The SNP dismissed the report as "shoddy" and as an "embarrassment to the authors".
The committee's inquiry began in October last year, looking at the potential impact of independence following a ballot, which the Scottish government wants to hold in autumn 2014.
The report, called the Referendum on Separation for Scotland: Unanswered Questions, has set out six areas where the Scottish Affairs Committee believe information is needed.
They include issues such as Scotland's defences and the costs of independence.
The committee called on Scottish Secretary Michael Moore to work with it to provide "a joint provision of factual and unbiased information to the people of Scotland".
Committee chairman, Labour MP Ian Davidson, said: "The big question about such an unknown quantity as separation is the terms of the 'divorce settlement' - how resources, rights and responsibilities will be broken up.
"The responses we've had clearly show that there is confusion and concern about this, but also that you only need to scratch the surface to reveal how many complex questions there are across banking, pensions, currency, national defences - but also many more personal things."
He added: "The purpose of this inquiry is to set out from the start some of those questions and begin to explore their answers, with the aim of helping to make this process as clear and fair as possible.
"You cannot ask a big question about separation - however you construct it - without first asking and answering all these questions about how it will affect every aspect of every life, in Scotland and the UK as a whole."
SNP Westminster chief whip Stewart Hosie said the committee's inquiry had been overtaken by events and the report was "an embarrassment to its authors".
He continued: "Firstly, it talks about 'separation for Scotland', when Scottish government policy is for independence, not separation.
"But apart from its predictably pejorative approach to the issue of Scotland's constitutional future, this shoddy report from the anti-independence parties has been totally overtaken by events.
"It raises questions which have been dealt with in detail by the Scottish government's white paper published way back in 2009.
"The issues it raises include the currency of an independent Scotland, which is now widely accepted will be sterling, with even Scottish Secretary Michael Moore accepting that Scotland will keep the pound after independence."
Shadow Scottish Secretary Margaret Curran said the committee was asking questions "the people of Scotland need answers to".
She added: "This is an important analysis of the questions that need to be answered about separation, and I expect it to play a big part in the debate ahead."
Scottish Tory constitution spokesman David McLetchie said the onus was now on the Scottish government to fully co-operate with the inquiry to ensure the Scottish people had "all the information they need" before the referendum was held.
The SNP government is currently running a public consultation into the independence issue.
The UK government, which had said it wanted the poll sooner rather than later, is also conducting a consultation.
A firefighter who owned the house in which five people died in an arson attack has been summonsed to appear in court in connection with manslaughter through gross negligence.
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A Westminster committee has called for clarity on the "unanswered questions" of Scottish independence.