2744 Chapter 23 



ceiling surface; aluminum-siding backer board is used to improve insulation of 

 aluminum siding. 



Interior. — Building board is a general-purpose board for interior construc- 

 tion. Ceiling tile is embossed for decorative interior use, usually to improve 

 architectural acoustics. Sound deadening board is employed to control noise 

 levels in buildings. 



Industrial products. — Industrial insulation boards include mobile-home 

 board, expansion-joint strips, and boards for the automotive and furniture 

 industries. 



HARDBOARD 



Excluding those that manufacture MDF-dry, there are 23 plants manufactur- 

 ing hardboard in the United States, 9 of which are in the South and 7 in the West 

 (table 23-2). No new plants have been built since 1971, but several have 

 expanded significantly. (See figs. 29- 12 ABC for growth of annual capacity and 

 consumption and import and export data). An analysis of the economic feasibil- 

 ity of building a new hardboard siding plant to utilize southern hardwoods can be 

 found in section 28-30. 



Like insulation board, hardboard markets are tied closely to housing markets. 

 Development of methods to simulate natural wood-grain patterns on hardboard 

 has permitted it to capture about 20 percent of the interior paneling market. 

 Hardboard siding is probably the most economical exterior wall cladding 

 available and it should continue to be competitive. Industrial board includes 

 products for the automotive, furniture, and construction industries; consumption 

 of such board has increased modestly in the last decade. 



MEDIUM-DENSITY FIBERBOARD (MDF-DRY) 



MDF-dry is produced in 12 plants (table 23-3), seven of which are in the 

 South; all have been built since 1965. The first plant was designed to produce 

 exterior siding, but was soon converted to manufacture core stock for furniture 

 panels. Most of the output of the entire industry is sold for this purpose. MDF- 

 dry competes successfully with particleboard, a lower cost core material, be- 

 cause MDF has more uniform structure and its machined edges can be finished 

 without edge banding. Industry experts expect MDF-dry to make further inroads 

 in the particleboard market, and annual production should continue to grow at 

 about 10 percent a year. MDF-dry production in 1975, 1976 and 1977 was 

 215.5, 280.0, and 441 .4 million board feet, y4-inch basis. Production trends are 

 graphed in figure 29-13 top. 



