Teenagers are recruited from across the country, and this week, hundreds of them have ended up in Longview.
They're called World Changers and their mission is to serve others.
KLTV 7's Lakecia Shockley shows you how their hard work and sweat is giving east Texas home owners a makeover.
They're young, able, and willing - and they shovel out the old to bring in the new.
The world changer teens from Alabama, Mississippi, Austin and Houston are re-roofing Longview homes for free.
"It's called World Changers because it seems like we would go out and we would be changing their world by putting a new roof on their house, but really we're the ones that walk away changed," said Kassidy Hill, who is from Satsuma, Alabama.
She's one of 200 teens putting in work.
"I tell people all the time this is the best trip I get to take with my youth group...even if that means standing on a hot roof in the middle of July in Texas," she laughs.
Youth from First Baptsit church in Longview are also helping, hammering down on roofs to make a difference.
"We have an opportunity to come back and visit the homeowner and see how they're doing. See if there's any other needs as a church or community can help meet," said Jason Miller of the First Baptist Church.
Sarah Jones is one of seventeen homeowners getting new roofs.
"For this big old house, I hate to see how many thousands of dollars it would cost not only in materials but in labor....I feel like it's a blessing from God to have young people. You know, you hear all the bad about teens but this is the good."
Good teens, doing a good deed for a good cause.
"You really do walk away with your whole world changed."
As part of this project, more than 22,000 students are working on community projects nationwide. Teens have to pay their way to go on this mission trip.
However, the city of Longview Community Housing Development picked up the tab for all the supplies and materials.