GMS (GMS) - Get Report went public Thursday morning at $21 a share and immediately traded up over six percent. The wallboard and ceiling distributor's CEO Michael Callahan said the housing shortage in the country is creating a big demand for his products. 'In just about every major metro market that we serve there is a real shortage in housing and in many cases you hear about homes being listed and sold above the asking price. That is becoming much more routine,' said Callahan. Callahan said his business is 40 percent residential and 60 percent commercial so U.S. housing starts are a very important guidepost for him. U.S. housing starts rose more than expected in April as builders ramped-up the construction of single and multi-family homes. Groundbreaking rose 6.6 percent in April to a seasonally adjusted annual pace of 1.17 million units, the Commerce Department reported last week. That was ahead of Wall Street's consensus forecast of a 1.13 million-unit pace. Founded in 1971, GMS provides a comprehensive solution, or one-stop-shop, for all its customers for wallboard, ceilings and complementary products.