Through the years an assortment of veneer forms has developed some confusion within the construction industry. Perhaps a discussion of these terms will enable the specifier to accomplish his firm's design objectives more efficiently and to inspect the final job to assure that he has received his specifications. In general, this discussion of veneers applies to paneling as well as doors, but the greatest confusion exists in door veneer specifications.

  

Possibly 60% of the doors in the commercial buildings in this area are birch, 30% are Lauan, 5% are Walnut, and the balance are miscellaneous other veneers. It is these principle woods, Birch and Lauan, with which this article deals.

  

Birch for veneer is logged from stands of Yellow Birch (Betula lutea). It grows extensively from Newfoundland westward to northern Minnesota and south to North Carolina.

  

The most desireable veneers of either Red or White are graded as Premium Grade Select White Birch or Premium Grade Select Red Birch. A door from these veneers will not only b uniform in the color selected, but will have book matched grain pattern. These two specifications represent the finest quality of Birch in Rotary Cut Veneers. Rotary Cut Veneers are cut around the log as it turns against the cutter knife. Different variations in the patters of the grain can be accomplished by slicing the log at various angles. If veneer lengths in excess of 10 feet are required, they will have to be sliced veneer. Generally speaking, the same grades available in Rotary are available in Sliced Birch, but because of the increased price of slicing veneer, it is seldom specified except in Premium Grades.

  

An interesting compromise of design and economy can be found in the specification of Premium Grade Uniform White or Premium Grace Uniform Red Birch. These veneers are highest quality veneers, uniform in color, but are not necessarily book matched within the panel.

  

Rotary Natural Birch or Plain Sliced Natural Birch may, and does, contain Red and some White within the door.

  

The Rotary Natural Birch category is divided into three grades of veneer, Premium Grade, Good Grace, and Paint Grade. Premium Grade Rotary National Birch is of highest quality veneer, may contain red and white coloring, and is book matched for color and grain. The good grade Rotary Natural Birch door is made of sound veneer for color but not necessary matched for grain.

  

Either of these two doors makes an acceptable door for clear varnish finishing. A Paint Grade Rotary Natural Birch door, which can be used interchangeably with Paint Grade Maple or Sycamore, is sound veneer which is unmatched for either color or grain. Frequently narrower veneer pieces are used for this purpose. This surface is designed as an excellent surface for receiving paint. Frequently a specifier will call for a Vertical Grain Fir door to obtain a good paint surface, and a door of superior exterior quality. This specification has two shortcomings. First, Vertical Grain Fir veneer is in the same price category as Plain Sliced Walnut. It is beautiful wood, and resists checking very well when Sliced Vertically, but compared to Maple, Birch, or Sycamore, it is relatively soft. Secondly, the local availability of Fir veneers encourages the millwork houses to obtain the doors locally. Generally speaking, the doors manufactured on the West Coast have not performed as well as Eastern manufactured doors. It is this exterior door specification that has given owners their greatest maintenance and replacement expense.

  

An exterior door in this climate requires a top performing wood door. One of the newer innovations along this line might be this specification:

  

Exterior Doors shall be: as manufactured by Roddis Golden Dowel, United States Plywood Algoma or Curtis American, with Hi Density Plastic Overlay, Aluminum Flashing on door bottoms, and written Lifetime of Structure Guarantee.

  

This door will cost less than a vertical Grain Fir door and greatly exceeds it in performance and length of life.

  

Because of the relatively low cost, Japanese Lauan Doors have become very widely used. Lauan resembles several species of true Mahogany, and to the layman has come to be called Mahogany or Philippine Mahogany. Unfortunately, this now common and much over used wood has taken the lust from the outstanding beauty of African and Honduras Mahogany.

  

Because of the availability of imported veneers here on the West Coast, the specifications for Mahogany, Philippine Mahogany, and Lauan will most often be furnished with a locally manufactured Lauan door. While the initial cost of these doors is less, most specifiers agree they do not perform as well as the Eastern Manufactured doors.

  

At the September meeting of C.S.I., there will be available at no charge, an excellent reference, "Characteristics of Modern Woods" It has been a valuable reference of specifiers in its six editions over the last twenty years.