Almost one third of B.C. residents are now condo owners. But living in a strata comes with hidden dangers. For example, what if your strata hires an under-the-table contractor and something goes wrong? Chris Olsen shows you the potential cost.

Heather Thomson came home to find water dripping from the ceiling in her den. But her real problems started when she insisted that a worker -- hired by her strata to fix the ceiling -- prove he was licensed, insured and covered by WorkSafe BC.

He refused. Thomson suspected he was working under the table, so she checked WorkSafe BC.

"No clearance letter, no nothing," she said. "I called them and they've never heard of him."

That means he wasn't covered in case of an accident. She filed an access to information request with the City of Surrey to see if he had a business licence.

"I got an email back from them saying they looked everywhere and there wasn't a business licence for that person," Thomson said.

She doesn't know if he had liability insurance.

CTV News took the matter to the Condominium Home Owners' Association of B.C.

"I think the owner was probably doing the job the strata should have been doing in the first place," CHOA's executive director, Tony Gioventu, said.

He says he hears about this a lot.

"Every day we will hear of a strata corporation or an owner in a strata corporation who has a problem with a supplier or contractor that relates to probably using someone who isn't qualified to do the job , competent to do the job, and with no written agreements, [and ] no contracts," Gioventu said.

His association studied the issue and found there is a lot of risk and no real savings when strata organizations hire contractors based on price without a proper contract and tendering process -- even for small jobs.

"If someone comes to you and says ‘I can do this for a much cheaper price,' then they are doing a much cheaper job because the cost of materials and labour are about the same," Gioventu said.

Thomson has now been billed $500 by her strata after a vote of other residents held her responsible for not letting the unlicensed worker complete the job. A different, fully-licensed and insured contractor completed the work

Tony Gioventu thinks the strata is wrong to bill Thomson.

"If the strata corporation sends a person who is not qualified, not licensed, not insured and the owner declines their access to be able to do the work, the strata corporation needs to look at their business practices," he said.

He's looking into her case.

Thomson's strata council president maintains the worker is "legitimate" and strata owners were right to fine Thomson for turning away the repair man.

The vast majority of problems with contractors are preventable. A good experience starts with hiring a fully-qualified person or company.

With a report from CTV British Columbia's Chris Olsen