Seerets of specifying hardwoods

If,/HAT is the key to helping builders and archirecrs

Y Y specify hardwood products intelligently and cost effectively? According to the Hardwood Manufacturers Association, it's understanding both the unique physical characteristics of hardwoods, and how hardwood species naturally occur in North American forests.

Smart specifiers understand that some hardwood species are more abundant than others in the forest. They realize this relates directly to their commercial availability and relative affordability. Smart specifiers know:

Why some species are harder than others.

Why species take stains differently.

Why some species can be finished to resemble others.

They know why hardwood products come in a variety of dimensions and a full range of grades. Most important, smart and successful specifiers apply their knowledge and understanding of hardwoods to their projects.

HMA suggests: l. Ur" what's readity available.

Specify hardwood lumber in widely available dimensions to control costs. Generally, in any species, hardwood lumber that exceeds 10" in width commands a oremium.

A hardwood tree may be 55 feet tall and 2-4" in diameter, but it will yield boards that are no more than 12" wide. Mouldings will necessarily be narrower than that. Larger trees may yield wider lumber, yet wide boards are more difficult to work with because of hardwood's natural expansion and contraction characteristics. Since standard minimums are 5" widths for upper grade hardwood lumber, using stock moulding profiles is an affordable alternative.

The following chart shows the availability of North American hardwood species used most often in residential applications. Higher abundance generally implies lower cost, although some species may be more readily available in certain areas of the country.

Species Share of Total U.S. Hardwood Production

ft 4. Use lumber grades.

You can use accepted industry standards and grading systems to describe the look your customer wants, and the best way to achieve it within the budget.

Hardwood lumber grades and grading rules have been established and are governed by the National Hardwood Lumber Association. The NHLA grading system, which is used by buyers and sellers of hardwood lumber, describes the amount of "usable" clear material in a board. The highest grade boards are long, wide and fiee ofdefects.

Boards featuring character marks are not premium grade, but they are preferred for built-ins and many other applications because they add character and visual interest. They're also a great choice for applications where wood will be painted or not be visible. Higher grades, which have few, if any, character marks, generally are preferred for applications such as fine tabletops and cabinet doors.

For a built-in desk and bookcase, specify upper-grade hardwoods for visible areas, such as the desktop and cabinet doors. Build non-visible areas-sides and interior shelves-from a variety of species in No. I Common, a lower-cost, intermediate grade priced less than FAS.

O. Use craftsmanship standards

The Architectural Woodwork Institute sets standards for appearance, engineering, fabrication, finishing and installation. Builders and architects need to be aware of three AWI grades when specifying work to be done: premium, custom and economy.

Most architectural woodwork is custom grade, with premium grade reserved for special projects or focal points, and economy representing the minimum expectation of quality, workmanship, materials and installation.

For example, in custom grade millwork, the gap between doors, drawers or panels and frames must be l/16" or less. In premium grade work, the tolerance is 1132": in economy, 3/32" is acceptable.