Hardwood Flooring is available in almost any hardwood species. The product has the natural characteristics of the selected wood species as opposed to a photographic layer. The “engineered” product has been designed to provide greater stability, particularly where moisture or heat pose problems for hardwood floors.
Engineered hardwood flooring is a product made of a core of hardwood, plywood, or high density fiber and a top layer of hardwood veneer that is glued on the top surface of the core.
Wood floors come in two basic types:
• Engineered wood flooring
• Solid wood flooring
Engineered hardwood can be installed below grade in basements on grade, above grade. Engineered hardwood floors can be usually be nailed to wood subfloors and glued or floated on concrete slabs.
The main issue to consider with solid hardwood floors is its susceptibility to expansion and contraction due to humidity changes in the home. Solid hardwood also may require doors to be trimmed and height variances to other flooring that may not have been anticipated.
Basics of Engineered Wood Floors
What is a floating floor? It is a method of installing a floor rather than a specific type of flooring material. In this method, the individual planks or boards attach to each other – either by means of gluing or snapping together, but do not attach to the sub floor on which it is being installed.
Engineered floors are the ideal solution for hardwood flooring on concrete. The dimensional stability of the way they are constructed. Each ply layer is pressure glued and set in the opposite direction. Engineered hardwood floors expand and contract with high humidity, as opposed to hardwood flooring. The more plies the greater stability.
Engineered hardwood floors are constructed similar to that of basic plywood with the top surface being actual hardwood. Products come in two to ten ply construction depending on the manufacturer. Many manufacturers have increased the surface (also known as veneer or wear layer) layer that will result in some engineered floors lasting as long as the traditional 3/4 “solid flooring. One of the most important factors contributing to the longevity of any hardwood floor is the amount of refinish-able material.
Flooring Hardness Rating
The Janka Scale is used to compare the hardness of different species of wood, and their resistance to scratches, dents and wear.
The softest and lightest wood, Balsa, has a Janka rating of 90. The hardest wood species is Lignum Vitae (4390), which has been exploited to the brink of extinction and is now an endangered species.
Red Oak, the most commonly used species for flooring in the U.S., has a Janka rating of 1290 – and this is sometimes used as a benchmark.
Hickory, with a Janka rating of 1820, is 41% harder than Red Oak.
Some species, such as Aspen (Janka rating of 350), White Pine (420) and Chestnut (540) are too soft to be used for hardwood flooring.
The durability of flooring depends not just on the hardness of the wood, but also upon the finish.
Janka ratings apply only to solid wood flooring; for engineered wood flooring; the hardness will depend on the species used for the veneer, the thickness of the veneer, the composition of the sub layers and the bonding process.
The hardness of wood flooring is measured by the Janka Test. A. 444 inch steel ball is driven into the wood to half the ball’s diameter. The test measures the force needed to embed a steel ballot half of its diameter in the piece of wood being tested, with rating measured in pounds of force per square inch. With this rating, the higher the number the harder the wood.
Wood hardness is important since one of the key considerations in selecting the species of wood floor, you should be aware how much resistance the wood has to scratches and indentations. If you have a dog with long nails then scratching the floor is a consideration and you should select a species with a higher rating such as hickory, maple, oak, or ash or the newer high tech finishes.
o Softer wood species can be hardened to some degree by the manufacture’s application of the new high tech finishes.
o Harder wood species are usually more expensive than the softer and medium grade woods.
Hardwood Floor Appearances Can Differ
Hardwood veneers have the same surface appearances as solid hardwood flooring because they are both natural hardwoods. Different appearances result from the different ways the hardwood is sawn.
The different sawing methods are:
o Flat Sawn (also referred to as plain sawn) – can be flat grain, which has a cathedral or gothic effect or vertical grain which has a radial or edge grain effect.
o Rotary Cut – method of cutting wood in which the hardwood layer is peeled off the log using large wood lathes. This peeling method shows dramatic, wilder graining.
o Off-Set Rotary Cut – method of cutting wood which gives a sliced appearance and grain pattern with the added cross grain stability of sliced, without the sliced cost. Hardwoods are more dimensionally stable across the grain, and off-set rotary cutting takes advantage of this property. The yield is lower than a regular rotary cut creating a slight price increase vs. standard rotary.
o Sliced Cut – method of cutting wood in which the hardwood layer is sawn like regular lumber. This shows finer graining.