Commercial Calamities by William Lotz Commercial calamities can happen to anyone. Here are a few I've run into. Sugar-Cane Deck The New Hampshire school was built in 1965 with a Tectum or Insul- Rock type structural deck on bar joists. The BUR (built-up roof) was applied directly to the deck. The deck is made from compressed bagasse (sugar-cane stalks) mixed with a cement-type binder. The deck is approximately 2½ inches thick and in addition to its structural properties, has accoustical properties and an R-value of about 4.5. This product is made by at least two manufacturers and has been especially popular for use in schools and motels. This type of deck is frequently left exposed on the interior as it makes a nice looking