All of Canada's front-line navy frigates have had serious mould problems, something that has routinely affected the health of sailors deployed overseas, a CBC News investigation has determined.

The navy has struggled to deal with the blight in the ventilation systems of the warships since it was first documented aboard HMCS St. John's in the fall of 2011, but a former senior non-commissioned officer says his repeated pleas to fix the situation fell on deaf ears.

In fact, former chief petty officer Patrick MacLaughlin claims the design flaw could have been entirely rectified during the recent life-extension program for the frigates, but federal officials deemed the cost — $1.2 million per ship — to be too much.

A series of documents and videos obtained by CBC News show not only mould-crusted vents, filters, ducts and even food stores, but also serious safety hazards resulting from an extraordinary buildup of condensation, which spills and splashes over electrical panels.

When it comes to maintenance, the navy is 100 per cent broke. - former chief petty officer Patrick MacLaughlin

MacLaughlin, who retired from the navy in 2005 but worked as a civilian in the naval engineering section of National Defence headquarters until 2013, says he raised alarm bells time and again about the problem. But he says he was told there was no money — in either the overhaul budget or the ongoing maintenance program — to correct the problem.

"The navy is broke," MacLaughlin told CBC News in an exclusive interview. "We don't have money to buy parts. The navy is broke. When it comes to maintenance, the navy is 100 per cent broke."

The commander of the East Coast fleet, Commodore Craig Baines, acknowledged mould is a fleet-wide concern, but said the navy has been proactive to come up with a solution outside of the refit program.

A civilian contractor watches as condensation and humidity buildup in the engine room of HMCS St. John's pours on to an electrical panel during an October 2011 inspection of the warship's ventilation system. (CBC) It has now instituted an engineering fix on 10 of the 12 frigates, but that repair work will be subject to further evaluation, he said.

"We're going to see what the result is of our engineering changes and then assess whether we still have a problem or not," Baines said.

The delay has not been for a lack of funding but rather, Baines said, was a matter of finding the right technical solution.

"We have absolutely no concern about the mould in the ships," Baines told CBC News in an interview.

"What we do have is a concern about is making sure we provide the safest environment possible for our sailors. And that's why we're doing as much as we possibly can to make sure that the mould is reduced."

Ships 'harbouring respiratory bacteria'

The navy has been dealing with the problem for almost five years.

An engineering team was dispatched in 2011 to investigate persistent unsatisfactory status reports from the St. John's, which was launched in the mid-1990s and is therefore among the newest of the patrol frigates.

What they discovered shocked them.

Mouldy ventilation pipes aboard HMCS St. John's, as seen by an engineering team during an October 2011 inspection of the warship. (CBC News)

There was "mould and moisture throughout the ship," said a Nov. 30, 2011, internal presentation obtained by CBC News.

The precision air-conditioning units "were not effectively dehumidifying the ship," creating a literal flood of moisture buildup within the system, which led to "conditions for harbouring respiratory bacteria" and "potential crew-wide health issues."

The navy went further and commissioned an independent report that found the ventilation system "was showing signs of severe water retention, and this poses a significant health risk to ship's crew."

The Oct. 12, 2012, analysis, by Bronswerk Climate, also said the fresh air system was in a "serious state of disrepair," despite a recent overhaul.

The company inspected at least three other frigates — HMCS Halifax, HMCS Toronto and HMCS Calgary — in 2012 and 2013 and found similar conditions.

The navy's maintenance budget between 2011 and 2013 was routinely raided and clawed back for other priorities at National Defence, MacLaughlin said.

The department, at that time, was lapsing hundreds of millions of dollars back to the federal treasury (that is, returning part of its unused budget) on an annual basis in the former Conservative government's drive to balance the budget — something that angered MacLaughlin.

"People have to understand the consequences," he said. "Most people in the public service will not say anything because it's their job on the line."

HMCS Halifax, shortly after arriving in St. John's harbour in March 2009. (Submitted by Jim Fitzgerald)

Health issues?

A two-month investigation by CBC News has uncovered a myriad of health complaints from sailors, but no long-term, debilitating illnesses.

Short-term exposure to mould can cause nasal and sinus congestion, coughs, as well as sore throats. It has been linked to asthma, nosebleeds and upper respiratory tract infections.

MacLaughlin said crew members on deployed operations routinely complain of what they call the "AC flu" and the "CPF hack." Before going to sea, they stock up on cough medicine and cold medication because they know they'll get sick at some point during the voyage.

"If they have a name for it, then obviously it's an issue," MacLaughlin said.

Baines said the navy has been monitoring the health of ships' companies and there have been no reported illnesses linked to mould exposure.

"We do monitor air quality within the ships," Baines said. "There is a complex filtration system that is used both internally and externally to the ship. And we change those filters regularly and monitor how they're doing."

MacLaughlin said that before he left he developed a cleaning regimen for frigate crews to follow, but he has no idea if it was implemented.

"Not only do we not have the money to maintain the system, but we don't have the personnel to do it," he said. "We don't have the technical skill knowledge because the sailors' training has been degraded."