THE MECHANICAL contracting market started its turnaround in 2004 and really gained steam last year. Now the nation's largest mechanical contractors are reporting robust business around the country in healthcare, education, high rise condominiums, utilities, warehouses and water and sewer. The fire sprinkler market is expanding rapidly because of legislative mandates. The only difficulties facing the Giants may be a labor shortage in the near future and rising commodity prices, especially the cost of gasoline. Our complete Book of Giants coverage begins on page 32.