An update filed at Companies House by liquidator Quantuma Advisory revealed the scale of the debts at the business when it collapsed in April.
Unsecured trade creditors have been left holding unpaid invoices totalling £4.3m while Quantum also owed its 24 staff £194,000 in unpaid wages.
The firm had been in business since 2002 working on new build and refurbishment projects across the country.
One local rival said: “They were a long standing company and had a decent name in the industry.
“But is looks like they failed due to silly profit margins and inflation. Margins at 2-4% are a killer in our industry, and as much as people are blaming covid and inflation for firms going under, the big issue is construction margins, especially when you look at the risks involved.”