e lan hansen from align roofing he does roofing and residential work and involved in boma the buildings of manager's association. we in the building department have to work with various industry groups. and henry navarro who is the roofing supervisor for the port of san francisco. for 20 years? >> 23 years. >> you have seen roofs come and roofs go. >> 38 years worth. >> how long does a roof usually last? >> dependos the climate and the pitch of the roof. >> uh-huh. from? >> a couple of years. >> from 15. i asbestos roofs go for 15 years. you said you put a roof on your house you expect to last? >> 75 year. i wish you luck. >> only going to do it once. >> people know what they are doing with their roofs that will last for a long time and not have to redo it. is this the same concept as painting where it takes a lot of effort to get ready and the prep work and the materials are such a large part of the expense or the materials are a big piece of the expense. i tell people in painting, buy the best material you can because you don't want to keep redog it. is this the same concept. >> it is