Passengers wait for their flights at Shenzhen Bao'an International Airport on Monday. Shenzhen Airport Group, owner of the airport, said leaks that occurred on Sunday were only slight and the problem could be solved when the rain stopped. Xuan Hui / for China Daily

Architects say the new 7 billion yuan ($1.12 billion) terminal at Shenzhen Bao'an International Airport might continue to experience leaks during severe storms, as it includes more than 38,000 skylights.

However, Shenzhen Airport Group, the owner, said leaks that occurred on Sunday were only slight and the problem could be solved when the rain stopped.

The death toll from rainstorms in Guangdong province has risen to 15, while four people remain missing, local authorities said on Wednesday.

The quality of the terminal, which has been operational for just five months, was questioned after online posts reported "waterfalls" inside the building during Sunday night's storm, the worst recorded in the city during March in 30 years.

The airport group said in a statement on Monday that some Internet users were exaggerating the situation. It held a news conference on Tuesday to explain the situation.

"We found more than 20 small leaks in the new terminal, which were not in the major passages to departure or arrival halls," said Yang Haibin, the group's deputy general manager. "The storm did not affect the normal operation of the terminal."

In contrast, leaks during a storm in mid-December were much worse, he said, with 100 leakage points discovered in the main building and 68 in corridors.

Yang said the group has been working hard with construction companies to fix the leaks.

He also promised solutions after netizens took pictures of flooding in underground parking lots, with a major cause being attributed to a hotel and office building being built over the site.

Architects said the terminal, which features more than 38,000 honeycomb-shaped skylights, would pose a significant waterproofing challenge.

"Every skylight has six edges, which could all possibly lead to leaks. So leakage could happen at more than 200,000 points in the terminal," said Huang He, the Beijing Institute of Architectural Design's chief architect.

Wang Ying, a waterproofing expert at the Civil Engineering and Architectural Society of Shenzhen, said the terminal operator must keep checking the construction and carry out repairs, because sealing materials could be affected by the environment and temperature.

"It's really hard to provide a one-time solution for such a big construction to solve the leakage problem," she said.

Zhu Jiuchun, an architect working in Shanghai, said the quality of the new airport terminal in Shenzhen and the building materials used are quite poor.

"The design might have some problems, but I guess the construction companies were urged to meet a tight deadline, which could lead to poor quality," he said.

Construction of the terminal, the first airport project for Italian architects Massimiliano and Doriana Fuksas, was completed in three years.

The building is 1.5 kilometers long and the designers believe that the honeycomb motif allows natural light to filter through.

Shenzhen, a semi-tropical city, can experience up to five typhoons annually with strong rainfall.

Contact the writer chenhong@chinadaily.com.cn