Our customers frequently ask for educational information they can use to better understand factors that influence plank and strip flooring markets. Most feel that increasing their understanding of these factors assists them in selling more flooring while making more informed purchasing decisions.
There are many subtle as well as obvious factors that contribute to a well-manufactured solid hardwood floor. With all manufactured products, the raw materials and attention to details play a significant factor in the quality of the final product produced.
Starting with the timber, northern sawmills typically do not accept sheared logs into their decks. Sheared versus sawn timber is the difference between cutting the timber or literally shearing it from the stump. Sheared timber creates stress in the log which results in compression wood and fractures parallel to the growth rings that are difficult to detect until installation and exposure to HVAC.
Great detail must be attended to in the kiln drying process to create quality lumber from which flooring is produced. Green lumber that has been properly stickered and bolstered before air drying, pre-dryer time and kiln drying is essential to insure flat, stable lumber that produces flat flooring. Following the scientific schedule for drying lumber in efficient, well maintained pre-dryers and kilns eliminates drying defects such as checking, honeycomb, internal stress, sticker stain, and wet pockets in the lumber. A quality manufacturer does not rush this process or take short cuts. Constant monitoring is required to guarantee the outcome, including daily quality control checks for moisture content, stress, and steam equalization.
In the manufacturing process of hardwood flooring, some manufacturers rip their lumber on the bias, meaning a board going into the rip line with significant crook will come out of the rip line with the same crook. This process maximizes yield but delivers a bowed/crooked flooring board to the consumer. Quality manufacturers saw through that crook to produce a straight rip for delivery to side matching.
Balanced side matcher heads, well-maintained moulders and attention to detail nets a quality side matched blank for further processing into flooring. Holding a piece of flooring in both hands and using the lighting in a room to inspect the knife marks on the face of flooring will give customers great insight into the attention paid to quality in a flooring mill. Optimal knife patterns create 16 knife marks per inch (KMPI) of material.
In addition to attention paid to the face of the flooring, a manufacturer using dedicated insert cutters on their tongue & groove heads will produce a consistent side matched pattern that does not evolve over the life of the knife. Using dedicated cutters insures that the T&G pattern you see today will match the pattern you see in material several years from now. These cutters are expensive to maintain but quality tooling creates quality flooring.
Running flooring at a measured pace helps keep any plus/minus variance to a minimum. When you fit a floor together there should be little if any under/over wood where the edges meet when laid on a flat surface. The pieces should go together smoothly, not too tight, and the tongue and groove should not cause the tongue side of the piece to rise up or bridge. It should remain flat.
The end-match on flooring narrower than 6” in width provides no structural integrity to the floor. Wider than 6” and the end-match does help interlock the individual boards together. The primary purpose of the end-match is to create a square end joint. Although this may look like a simple tooling pattern, an end-matcher is a highly complex machine that must maintain incredibly accurate tolerances to keep a square end-match joint.
Newer end-matchers use concave lugs and pressure belts to maintain a square cutting platform that holds the end-match uniform in the end-matching process. In addition, an indexing coping saw on the groove cutter, pre-copes the groove joint to eliminate tear out at the side-match and end-match grooves intersection. Measured in thousandths of an inch in tolerance, a quality end-match is the telltale sign of a quality flooring mill.
When the finished product is delivered to your warehouse with clearly labeled placards on well stacked units that are wrapped in quality packaging materials you can be confident that the manufacturer has taken great pains to produce a quality product they are proud of. None of these processes are easy and cutting corners is never an option in a quality mill. The few cents per square foot more that you pay for a quality product is cheap insurance against problems on the job site.