Teenagers and adults from across the country spent this week roofing and putting new siding on Tom Martinez's house — free of charge — and he had no shortage of adjectives to describe how it felt.

"Oh, it's terrific. It's electrifying," he said. "It's awesome. It's overwhelming and exhilarating."

"It's a blessing and a miracle to me. I've been very happy and very overwhelmed. Of all the good things that have happened to me in life up until now, this is the biggest."

Martinez is one of thousands of people across the country to benefit from the efforts of World Changers, a Southern Baptist group that organizes weeklong volunteer service trips each summer for junior high through college students. The World Changers were in Salt Lake City this week for the first time, with 309 volunteers working at 27 homes in South Salt Lake and Salt Lake City.

The students and their adult leaders arrived Saturday and worked Monday through Friday. They stayed at Granite Park Junior High School, spending the nights on the floors in sleeping bags and showering in the locker rooms. The school's cafeteria staff cooked them breakfasts and dinners, and lunches were provided at the job sites by local churches.

Spending a week far from home pounding nails on a roof during the hottest month of one of the hottest summers on record probably doesn't seem like a teenager's dream vacation. Not only do they not get paid, they also have to pay $260 just to participate. Many of the kids earn the money themselves, often holding yard sales, bake sales or working summer jobs, said Casey Phillips, World Changers communication specialist.

Despite the challenges, however, the participants insist that the chance to serve makes it well worth it.

"When you get here, you just enjoy it so much for some reason," said 15-year-old Sam Meeks, who was participating for the first time. "It's a chance to serve the community and serve God."

There are also plenty of new friendships to be made. Most participants arrive with members of their home churches and are then divided into crews with people from all over.

"By the end of the week you're so close with your crew you don't want to leave," said 16-year-old Bianca Fortik, who took part in World Changers for the second time.

Meeks agrees.

"Working is a good way to get to know someone," he said. "When you're up on a roof with someone and it's 100 degrees you just start talking because you've got nothing else to do."