One in ten decks fails inspection in the Halifax Regional Municipality, statistics obtained by CBC News show, but experts say the percentage is likely much higher.

The data covers a one-year period beginning Sept. 20, 2013, two days before a deck collapsed in Dartmouth, injuring 15 people.

The city inspected 294 decks in that time and 30 failed.

"There's a lot of times we go out and somebody's not building something the way they said they were going to build it and it doesn't meet code," says Matt Covey, HRM's manager of building standards.

Covey says the biggest offences are improper stairs, guards and the way the deck is connected to the house.

Covey says part of the issue is people building without a permit.

'I'm saying more like 60 or 70 per cent [of decks are faulty].' - Darren Smith, Halifax Home Inspections

"I've got about a 100 times a year that we've got people working without permits that we're catching that are constructing decks."

Darren Smith, who runs Halifax Home Inspections, says the percentage of faulty decks he sees in the city is considerably higher than the city's estimate.

"I'm saying more like 60 or 70 per cent and I think I'm accurate on that just because it's what I do everyday," he says. "Most of the decks built horrible are ones that someone has done themselves."

Victim calls for better inspection regime

Amanda Lenko, one of six students injured when a third-storey deck on a house on Brussels Street in Halifax collapsed this September, says the city needs to improve its inspection service.

"I've seen better maintenance in other cities," she says. "I think that maybe they should do more of a background check on who is doing it [building the deck] and have inspectors there as the deck is being built so they know what's there."

A building permit expires after two years. Homeowners are supposed to call the city when they are ready to have their work inspected. But in some cases, the deck is being used for months before that happens.

"We're hoping to put in a process where we're catching things before the permit expires," says Covey. "We're going to do a drive-by and if it appears it's being occupied then we may approach that owner, the applicant, to see if they ready to have a final inspection or if they're occupying the deck."