Video report by ITV News Consumer Editor Chris Choi
Contractors who fitted cladding to Grenfell Tower chose not to use fire-resistant materials which reportedly cost £2 extra per panel, it has emerged.
Fuller details about the insulation material that appears to have helped allow the spread the flames across the building became public today.
The cladding panels added to the block last year were a product called Reynobond PE - a flammable hard-plastic core coated with aluminium.
A fire resistant version was available - reportedly costing £2 more per panel - but was not used in the refit.
The insulation firm Celotex has also confirmed that it supplied a plastic core for use in refurbishing the building.
It has acknowledged that the material "will burn if exposed to a fire of sufficient heat and intensity".
Both the cladding an insulation met all building codes and safety standards.
But campaigner Pilgrim Tucker said that the more expensive cladding should have been used.
The new details came out as many residents throughout the UK waited to hear if their building had also been covered in insulation material that could pose a fire risk.
The government said it still does not know how many buildings have been fitted with similar cladding - meaning that safety checks cannot immediately take place.
The Fire Brigades Union also announced there had been a 26% drop in fire risk checks by the fire service over the past five years, with a 50% drop in London.
Spokesman Matt Wrack said there should be no drop in specialist inspections of the fire risk to properties.