Structural Flakeboards and Composites 3023 



The first of these species mixes, which includes southern pine and four 

 hardwoods, is fairly representative of densities of woods that can be found 

 throughout the entire southern pinery. See table 24- 1 2 for fabrication procedure. 



The second mix (seven hardwood species) is representative of bottomlands 

 and pine lands in south central Louisiana. See table 24-21 for fabrication 

 procedure. 



The third mix, with baldcypress as its largest component, is appropriate for 

 some areas in North Florida. See table 24-13 for fabrication procedure and the 

 following tabulation for species composition: 



Species or species group Species proportion 



Percent 



Baldcypress 35.4 



Red oaks (15.4 percent) and white and live oaks (1.7 percent) 17.1 



Black tupelo (15.1 percent) and water tupelo (2.3 percent) 17.4 



Sweetgum 8.4 



Ash. sp 6.4 



Red maple 6.2 



Sweetbay 4.8 



Elm sp 1.3 



Hickory sp .8 



Basswood .4 



Magnolia sp .4 



Cedar .4 



Other minor species 1.0 



100.0 



24-17 THICK ROOF DECKING 



Hardwood flakeboards for sheathing and decking are usually not thicker than 

 3/4-inch for use on spans that generally do not exceed 4 feet. It is possible, 

 however, to make thicker structural particleboards of hardwood that can span 5 

 or 6 feet. Roof decking for commerical and industrial buildings is a major 

 potential market for such thick structural particleboard. 



POTENTIAL MARKET 



Fergus et al. (1977) studied the market for roof decking applicable to 2,000- 

 sq-ft and larger, non-residential structures that have flat roof systems with a 

 slope of less than 1 inch per foot. They noted that estimates of market size varied 

 from 1/2 billion to over 2 billion square feet annually, and that the largest share 

 of the commercial and industrial market is concentrated in the east north central 

 and northeastern regions of the United States. Other large markets are the 

 Southern States and the West Coast region. Most buildings in the east north 

 central and northeastern regions use ribbed steel decking for roofs. In the 

 Southern States, gypsum and plywood have larger shares of the market, but steel 

 is the major material specified. On the West Coast, plywood is the leading 

 commercial and industrial roof deck material, with reinforced concrete, poured 



