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Chapter 22 



The disks must be treated with preservative before laying, to prevent early 

 loss through rot. Bois suggested soaking freshly cut green disks at least 24 

 hours — preferably 48 hours, in tubs filled with pentachlorophenol in mineral 

 spirits. After the disks are in place and have dried somewhat, so that checks have 

 developed, they should be sprayed with the preservative solution, thoroughly 

 drenching bark and sapwood. He recommended that, for long life, the patio 

 should receive such spray treatment annually. 



A double-diffusion process for treating, in which the green disks are first 

 soaked overnight in a 4-percent sodium fluoride solution and then in a 4-percent 

 copper sulfate solution, is even more effective in prolonging patio life. 



Figure 22-66. — Site for 20- by 40-foot patio was bulldozed out of a steep slope and 

 framed with retaining wall of native stone. Some 200 preservative-treated oak disks, 

 3 inches thick, were used. (Photo from Bois 1967.) 



22-n WOOD STRUCTURES 



Pioneers in the Appalachian region routinely built houses, commercial build- 

 ings, and a great variety of farm structures of round and hewn white oak posts 

 and beams. Oak was also much used for floors, walls, and mill work; and 

 structures were commonly roofed with split white oak shakes. Log cabins of oak 

 were also common. Since pioneer days, however, hardwood has lost favor as the 

 primary material for structures. Softwood studs, joists, rafters, and sheathing 

 now are predominant. There remain, however, some structures for which hard- 

 wood can be competitive. Following are some references relating to a few of 

 these structures: 



