What is a Live-Edge Slab?
Definition of Slab
Hardwood lumber typically has four square edges and is sold in random widths and random lengths. Commercial grading rules may be applied. By contrast, construction, or softwood lumber, is manufactured and sold in specified widths, thicknesses and lengths such as a 2-inches by 4-inches by 8-feet long. The words "slabs" or "live-edge slabs" have become common terminology that has developed in the last few years. These terms refer to pieces of lumber with the irregular edges left on, often with the bark. A square-edge piece of lumber is created by removing the irregular edges from a slab.


Species
Lumber is referred to as softwoods, such as construction lumber, or hardwoods which have applications such as furniture, flooring, cabinets, and millwork. Some hardwoods are lighter and softer than some softwoods. For example, basswood, a hardwood, is much lighter than Southern yellow pine, a softwood. The hardwoods contain numerous species with exceptional beauty. Currently, American black walnut (pictured) is the most popular for slabs. It has rich brown-colored heartwood and white sapwood and many people prefer these natural colors in a slab. Commercial walnut lumber is steamed which makes each piece more uniform in color. I am not aware of anyone steaming slabs. Other poplar species include cherry, hard maple, oak and ash. For details on each species, please refer to the hardwood species publications listed at the bottom of this page.
Size and Weight
Hardwood lumber is sold in quarter-inch increments. Thus "4/4" means a rough, dry board is about 1 inch or 15/16 inches thick and "8/4" is about 1 and 15/16 inches thick. Most slabs are irregular in shape and contain various characteristics such as knots, cross grain, and irregular grain patterns. As this type of material dries, it is prone to warping and twisting. Be sure to select pieces thick enough that they will be uniformly flat when finished. Our larger slabs are mostly 8/4 and that allows the piece to finish up at a minimum of 1 1/2 inches thick, and mostly likely it will be 1 3/4 inches thick.
Walnut weighs 37.9 pounds per cubic foot, cherry 34.6, and the oaks, hickories, maples, and ash are in the 40 to 50 pounds per cubic foot range. These weights can vary greatly. A slab of walnut 2-inches thick, 12 inches wide, and 6 feet long will contain one cubic foot and, thus, weigh about 38 pounds. A table top 2-inches thick, 4-feet wide, and 12-feet long will contain 8 cubic feet and weigh over 300 pounds.


Character
Most consumers want a slab that is at least 12 inches wide, if not over 20 inches in width. For a 20-inch wide slab the log will need to be at least 20 inches inside the bark on the small end. The large end could easily be 26 inches. That is large for a walnut log and most woods-grown trees of this size are going to the large commercial lumber or veneer manufacturers. For the slab market, that leaves woods-grown logs that are not suitable for the commercial industry or urban logs. To obtain the wide widths desired, the log is "live sawn". The sawyer starts on one face and saws piece after piece until he gets to the opposite side of the log. The widest pieces are from the center of the log and these will also have the most character. Pieces that are cut side-by-side can be opened like a book. This is called book matching and results in beautiful patterns. End matching is also possible to achieve longer lengths. We keep our logs intact and numbered so that at least one good book match can be obtained from a log. Book matched slabs are most commonly used for tables to achieve wide surfaces with a beautiful, natural pattern. The narrow outer slabs are good for benches.
Moisture Content
Hardwood lumber for interior use is dried to 6 to 8 percent moisture content. Slabs should be at the same moisture content. It is important to make sure that the core of the piece is dry as lumber dries from the surface and 8/4 lumber takes time to dry all of the way through. Thick 8/4 lumber or slabs may take up to a year to dry to the 6 to 8 percent moisture content. Once dried, the material has to be stored in climate-controlled condititions. Lumber or slabs that are just dried outside in prevailing atmospheric conditions is called air dried. Lumber or slabs thought to be dry because they have been "sitting for years in a barn, unheated garage, or damp basement" will commonly be between 12 to 18 percent moisture content and will not be acceptable for interior use. It will likely dry once moved inside and warp, twist or end check.


Applications
The unique use of slabs is limited only by your imagination. Typical uses include commercial and residential dining room tables and bar tops, kitchen counter tops, mantles, coffee and sofa tables, computer tables, book shelves, headboards, benches, chairs, or any other application where the natural beauty and uniqueness of each piece of wood is desired. Some people simply choose to put up live- edge slabs as art. One unusual application that I have is seen, is a set of four slabs with brackets mounted horizontally on the wall to serve as a 8-foot by 12-foot wine rack behind a commercial bar.