The instructors of this unusual boot camp in Northeast Philadelphia laid out the hazards awaiting those few who make it:

Working through sweltering heat and freezing cold at dizzying heights. Long days with only a porta-potty for a bathroom.

"It's heavy. It's hot. It's hard. It's dirty," cautioned Charles Brock, who runs the center at 10401 Decatur Rd.

And then there's the skepticism — not to mention the sexual harassment.

The 30 recruits who showed up Wednesday morning were not dissuaded. Each was hoping for a coveted spot in a program that will train women to be carpenters.

Sue Schultz, chair of the Sisters in the Brotherhood —  a network for women within the carpenters' union — explained the idea behind the organization's new and free six-week course for female carpenters.

The first lesson to those who straggled in: On a construction site, being on time means being 15 minutes early.

Less than 2 percent of professional carpenters in the United States are women, according to the Department of Labor. And the carpenters famously lost their right to work at the Convention Center in 2014 due to high costs and disputes with customers and other unions. The local has since changed leaders.

The program is up-front about construction's challenges. The course will cover skills from handling concrete and operating power tools to how to best carry a sheet of plywood.

Schultz wanted to be clear that the work isn't glamorous. She said she didn't want anyone saying, " 'You didn't tell me I would have to go to a bathroom in a Porta-John.' "

Only 12 women will be selected. Another round of applicants had registered for an evening information session. After a review of high school transcripts and applications, the center will conduct interviews and hold physical tryouts.

Applicants were reminded they were interested in a trade that's dominated by men. Schultz played an introductory video, in which female carpenters spoke of facing double standards, as well as sometimes needing to report harassment.

In 2014, the Department of Labor found that across the construction industry, 88 percent of women experience sexual harassment on the job.

"It's an important part of our discussion," she said. "We have classes on that, to recognize it and what to do."

After completing the program, the women get to apply for apprenticeships, which take at least four years to complete. They must complete at least 5,200 hours of on-site training.

Incomes will rise gradually as they gain more experience. Journeymen (or "journeywomen") make, on average, $48,350 a year.

The boot camp first started in New Jersey with nine female apprentices. Now there are 78 there. The program has also been offered in New York and Maryland. Philadelphia's inaugural students are set to start classes March 26.

The aspiring carpenters brought a variety of experiences to the session.  Kendra Jones had worked as a housepainter and said she wanted to learn more about construction.

Oak Troise heard about the session from her partner, who noticed the event advertised on Facebook. Troise had done some work in farming and carpentry and had applied to apprenticeship programs before.

"I like the idea of being able to build a house," she said.

Schultz said she found carpentry by luck. After overhearing her cousin on the phone with a friend in 1979, Schultz found out that an apprenticeship program in Connecticut was accepting applications

When she began, "I couldn't nail in a nail," she said. Schultz remembers her colleagues thinking she wasn't going to "stick it out," and sometimes making inappropriate assumptions when she was working with a male coworker.

She doesn't want any other women to find carpentry by chance. Her first step was changing the fliers.

"Most of the marketing material didn't have women in it," she said. "[Now] when they see it, they say, 'This could be me.' "