A former chairman of the Hong Kong Institute of Surveyors warned on Wednesday that some renovators in the construction industry may not have the knowledge to correctly fit toilets to the sewage and ventilation pipe systems of buildings.
Kenny Tse said some of them simply rely on their "experience", and some new to the industry may not even know the correct standards for modifying discharge pipes. All this may lead to defects in the pipe system, he said.
His comments came as officials were investigating whether modified toilet pipes at a Tsing Yi public housing estate flat may have been involved in transmitting the coronavirus.
The suspicion arose after a 62-year-old woman, who lives 10 floors below a man who had earlier been diagnosed with the virus, had been infected. Her son and daughter-in-law, who live with her, also caught the disease, while the daughter-in-law's father who was in close contact is also ill.
Authorities suspect modifications done at the woman's flat may have led to a faulty pipe connection in the toilet.
"The owners or the occupiers should not modify their drainage system, if they want to modify their drainage system they must appoint a professional to design and give advice and appoint an appropriate contractor to carry out the work," Tse said.
"If they notice some bad smell they should be caution about that, because such kind of bad smell may indicate the drainage system may have problem," he told RTHK’s Janice Wong.
The expert urged the government to strengthen their regulation of small construction work to tackle this problem.