1346 



AMERICAN FORESTRY 



pine country many floors were made of that extremely 

 soft material. It was a favorite wherever it was 

 known. It was convenient, cheap, and it worked easily. 

 A similar custom prevailed in far western regions in 

 regard to redwood and sugar pine. Convenience, in 



ROUGH FLOORING STOCK 



Seasoning is one of the first and most important processes through which flooring is passed in its 

 preparation for the planing mill. It may be dried in kilns in a few days, or it may receive its season- 

 ing in the air. That process takes longer but the seasoning by air is always popular. 



many instances, counted for more than the length of 

 service that might be expected when the wood was laid 

 in floors. Even a floor of white pine would last several 

 years, and builders seldom looked farther ahead than that. 



Clear white pine is quite soft and as floors it wears 

 rapidly if subjected to much use; but the knots are hard 

 and wear slowly. Consequently, white pine floors be- 

 come very uneven after a few 

 years. Every knot becomes a 

 high place and the clear wood be- 

 tween wears away, leaving va\- 

 leys between the knots. Hard- 

 wood floors wear more regu- 

 larly. With them less difference 

 in hardness exists between the 

 knots and the clear wood. 



The usual kind of modern 

 floor is known as tongued and 

 grooved, or it may be known as 

 matched. Such has been in use 

 hundreds of years, but there are 

 different sorts of tongues and 

 grooves. Generally the tongue is 

 cut in one edge of the flooring 

 piece, the groove in the other, 

 and these pieces fit edge to edge. 

 Sometimes both edges are 

 grooved and a flat dowel, made 



as a separate piece, fits in both and serves as a tongue 

 for both. The Egyptians seem to have been acquainted 

 with that method of joinery, so it dates back a long time. 

 Carpenters and planing mill operators have exercised 

 their ingenuity in devising and laying new kinds of floor- 



ing. The chief purpose of all is to provide a floor that 

 is practically waterproof, dust proof, airtight, and which 

 will remain solid and presentable under heavy wear and 

 for a long time. 



Some floors are laid double, the lower being known as 

 the sub-floor, while the upper 

 layer forms the visible finish. 

 The sub-floor is not seen un- 

 der ordinary circumstances, and 

 the lumber in its construction 

 need not be selected with a 

 view to its appearance. It is 

 not subject to direct wear 

 and for that reason the wood 

 is not required to be hard, 

 though it must be strong enough 

 to safely carry all the load 

 placed on it. Such is really 

 a two-ply floor, and the boards 

 of the two plies generally cross 

 each other at right angles, or 

 obliquely. The top layer is for 

 show as well as for service, and 

 in most instances a fine hard- 

 wood is selected, one that looks 

 well and wears long. This floor 

 may consist of narrow strips matched side by side and 

 end to end, and perhaps of less than half an inch in 

 thickness. It is not necessary to use thick lumber for 

 this top floor because it is supported by the sub-floor, 

 which carries the load. The principal advantage in using 

 thin lumber for the upper floor is that it effects a saving 

 of valuable wood. The thin shell is sufficient. 



Oti^. 



■\ 



BLOCK FLOOR IN* LARGE FACTORY 



The floor shown in the above illustration is made of redwood blocks of 4x6 inches surface and a depth 

 of two and a half inches. It is doing service in a shipbuilding plant on the Pacific Coast. Such 

 blocks have become popular in certain kinds of plants where wear is heavy and the elements of decay 

 are active. 



Manufacturers and users of flooring lumber make 

 much use of the term "grain." That word is common 

 with most people who deal with dressed and finished 

 lumber. The term is not understood in the same way 

 by all people who employ it, but the flooring people give 



