PART VII 



STRUCTURAL TIMBER 

 QUALITY 



265. Blinds of Timber. All timber for structures carrying 

 live loads shall preferably be of longleaf yellow pine, Douglas 

 fir, white oak or western hemlock; for other structures short- 

 leaf yellow pine, spruce, white pine or other equivalent good 

 timber may be used. Chestnut and Norway pine may be used 

 for piles. 



266. Quality of Timber. All timber must be cut within 

 eighteen (18) months of the time of delivery, from sound trees 

 and sawed to standard size. (Par. 267.) It must be close grained 

 and solid, free from defects such as injurious ring shakes and 

 crooked grain, unsound knots, knots in groups, decay, large 

 pitch pockets, or other defects that will materially impair its 

 strength or fitness for the purpose intended. (Pars. 269 to 274.) 



267. Size of Sawed Timber. All timber shall be sawed true, 

 out of wind and shall, when dry, not measure scant in thickness 

 more than the following: 



^ in., for flooring and boards up to 1J in. thick, rough size; 

 J in., for planking from If in. to 5| in. thick, rough size; 

 and 



J in., for dimension timber from 6 in. thick and up, rough size. 



268. Dressing of Sawed Timber. When dressed timber over 

 l in. in thickness is required the dimensions specified shall refer 

 to rough sizes, unless otherwise mentioned. 



A reduction of not more than -J- in., beyond that specified 

 in Par. 267 will be allowed for each planed surface. 



269. Shingles. Shingles shall be of pine, cedar, or cypress, 

 as specified in the contract. They shall be from 16 to 18 in. in 

 length, from 4 to 6 in. wMe ; fg in. in thickness at the tip and from 



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