This is David Hawbaker's version of paradise:

Standing on scaffolding 40 feet above ground in weather so hot that he can barely get the paint off his brush and onto the mural before it dries.

Lugging gallons of acrylic paints and brushes up and down a ladder to his perch above a concrete parking lot.

Checking over a completed mural and finding an unfixable flaw.

An art teacher for 29 years and an artist since he could handle a pencil, Mr. Hawbaker, along with his wife, Fran, took up mural painting about three years ago.

They have completed projects for the Sprout Fund, a Pittsburgh nonprofit group that, among other projects, each summer pays artists to paint large-scale murals on buildings around Pittsburgh.

It is a job that Mr. Hawbaker, 51, relishes.

"To me, art is like a disease. I can't get away from it if I tried," he said, adding that his summers off from teaching ninth- and 10th-graders at North Allegheny Intermediate High School allow him the time to do the work. "And working on the scale of a large mural is exhilarating. To me, it's like a vacation."

The Hawbakers since 2006 have completed three projects for Sprout, including one along Terminal Way on the South Side and one along Brighton Avenue in the North Side's Marshall-Shadeland neighborhood. The largest, Mr. Hawbaker said, was 40 feet high and covered 1,800 square feet.

This summer, Mr. Hawbaker also got to complete a project that was extra special for him -- adding an 18-foot by 17-foot mural to the entrance of North Allegheny Intermediate School.

Over four weeks, he designed and painted the mural, which features six students and a teacher, armed with a stopwatch, standing in front of the school.

"I jumped at the chance to do the mural. It's my building and the entrance was like a blank canvas," said Mr. Hawbaker, of Franklin Park.

Mr. Hawbaker said the mural is meant to show the evolution of an insecure freshman into a young adult who is full of confidence. When painting the teacher in the mural, Mr. Hawbaker drew the image of Gene Modic, a science teacher who retired last year after more than 35 years.

The stopwatch, he said, is to show students that it's time to take school seriously, if they haven't done so before.

"When students come in as ninth-graders, they are still kids, they are shy, a little nervous or too loud to overcompensate for being nervous," he said. "But they will leave [the intermediate school] as high school students, and be more mature.

"The stopwatch is just a little reminder to them that things count more now. It's a reminder to stay on task."

The school's principal, Brendan Hyland, said he was thrilled with the final product and the inspirational message that it, as well as Mr. Hawbaker, gives to students each day.

"I couldn't have asked for a better result," Mr. Hyland said. "He is a wonderful, wonderful teacher, but more importantly, I think he is a tremendous role model for our students. ... He has a true passion for bringing out the best in everyone and teaching others to appreciate art.''

Mr. Hawbaker started drawing and painting as a child, spending days in his room honing his craft. A 1976 graduate of North Hills Senior High School, he headed off to Westminster College in New Wilmington, Lawrence County, and pursued various majors before realizing that art was his calling.

Attending classes part time while teaching, he then earned a master's degree in art teaching from Carnegie Mellon University.

Over the years, he has continued to learn about being a better artist, thanks to spending time with his wife, students and, he said, simply maturing.

That's why, when he catches mistakes in his work that can't be corrected, it no longer bothers him.

Nor does a surprise rainstorm that causes four hours of mural painting to wash over and ruin eight hours of work from the previous day.

"The flaws, the mistakes, they are amusing at this point. You have to laugh at them," he said. "It's nothing to let bother you."

Mr. Hawbaker said he and his wife, who teaches art at North Allegheny Senior High School, hope to have the chance to do future murals in and around the city.

"The making of art is a great deal of fun, it's very active and it involves all the senses," he said. "You bring in everything you know. When you are going to create, you create with everything you got."