An outbreak of mold at Rolling Terrace Elementary School was discovered the second week of classes. It was found on walls, desks, chairs and carpets — blotches of fungus identified in 21 classrooms.

Cleanup started right away, and Montgomery school officials maintain that Rolling Terrace is safe and under close monitoring. But many parents say they were kept in the dark about the problem for four days and worry that children have been sickened, either by the mold or the products used to clean it.

“It’s disheartening, and I just feel they are not doing enough,” said Michaela Johnson, a mother of three students at the school, who said her first-grader had suffered from two weeks of headaches, a couple of nosebleeds and a spike in asthma symptoms.

Principal Jennifer Connors said Friday that she and others regret not informing parents more quickly “so they could make decisions for themselves” about whether to send their children to school. Still, she adds, “I didn’t at any time feel the building was unsafe for children.”

The tension at the Takoma Park school of nearly 900 students has been high for two weeks, as parents have asked questions, pressed for a public meeting and deluged the school e-mail group list..

Health issues are a dominant concern — and one that parents say the school has yet to specifically address.

Heidi Lovett, a parent, says she is aware of 16 student illnesses. No one knows whether they were caused by mold, she said. Parents have relayed incidents of itchy eyes, sore throats, sniffling, rashes and asthma flare-ups.

Connors said Friday that she was in the process of arranging for a health expert to visit soon.

James Song, director of facilities management for Montgomery schools, said the district has done extensive cleanup and testing and, as an extra measure, hired an independent firm for further investigation, including mold sampling.

Now, Song said in an interview, the district will take steps to improve communication with families and provide parents with testing results and information about short -term and long-term actions.

Song also said the district is also researching federal recommendations on information to share with families about mold’s impact on human health.

Parents said Friday that they are preparing a list of requests, including a detailed action plan on what will be done if mold is found again, and a survey to determine the extent of student health problems.

“We’d like to know what the strategy is here: Is it just Whac-A-Mole, or is there some kind of action plan?” asked parent Craig Sharman.

School officials say the problem was caused by a highly humid summer, mechanical problems and thermostats set at the wrong temperatures.

But they also say the problems at Rolling Terrace reflect aging facilities in the system of 202 schools and the challenge of funding maintenance of existing buildings and the expense of new construction, which has been needed as student enrollment swells.

“There’s definitely a push-pull there,” said schools spokesman Dana Tofig. Funding for heating, ventilating and air conditioning projects is behind schedule, he said. At Rolling Terrace, the HVAC system is 26 years old — not the oldest in the district, but dated, officials said.

School officials have received more than 40 complaints about mold in school buildings since July, but the problems at Rolling Terrace were the most widespread, according to Song.

Connors said Friday that 30 classrooms, two offices and an art room had been affected.

She added that a small amount of mold was noticed this week but that it has been cleaned quickly. “We’re not going to have it happen again,” she said of the widespread problems.