Solid Hardwood Floors
Let’s start at the very beginning to discuss how solid hardwood floors are made. Once the trees that will be used for flooring have been chosen based on their lack of knots and grain pattern, they are cut into planks using a specific cutting method. The three most common cutting methods are flat or plain sawn, quarter sawn, and rift sawn.
Three Cutting Methods for Solid Hardwood
Flat sawn or plain sawn refers to the most common and inexpensive manner of cutting lumber – in long, straight planks with the annual rings running parallel to the plank. Quarter sawn is a method of cutting lumber into 4 quarters at a radial angle. The annual growth rings intersect the face of the board at a 60-90 degree angle and the wood feature a coveted straight grain pattern. Rift sawn is the most expensive and least common method for cutting lumber. The annual rings are typically between 30-60 degrees and the lumber is manufactured by cutting perpendicular to the rings which produces a linear grain pattern without any flecking.
The different cutting methods produce different grain patterns and stability levels of the wood. Flat sawn typically offers the most inexpensive choice while rift sawn is the most laborious and expensive method for cutting solid hardwood planks.
Once the boards have been cut using one of the three cutting methods, they are graded based on appearance. The different grades of hardwood flooring (Clear, Select, No. 1 Common, No. 2 Common) refer to the wood planks’ appearance, not the quality or durability of the wood. Clear grade is taken from the center of the tree and is considered the highest grade because of its uniformity and lack of any blemishes, marks, knots, etc. Number 1 Common Grade is a lower grade of wood where each plank may look different than the others due to variations in color, small knots, streaks, etc.
After grading, the planks are planed, given tongue and groove edges, and possibly distressed if that is the type of look the boards will have. Unfinished hardwood will be sent to the marketplace for installation and pre-finished will undergo several coats of stain and protective finish.
Engineered Wood Floors
To construct engineered wood planks, 3 or more plies of wood are bonded together in alternating directions with an adhesive to create one single plank. The top layer or veneer is glued on top of the core board. There are three methods of cutting the veneer from the lumber.
Three Cutting Methods for Veneers
Dry solid-sawn refers to the process of cutting veneers where the wood is first dried slowly in a low humidity environment to keep the moisture level inside the wood in equilibrium. It is then sawn, and the outcome is an engineered plank that appears and behaves like a solid. Sliced-peel cutting entails cutting length-wise from one end of the log to the other end. It is more expensive than rotary-peel cutting because it uses less of the log. Rotary-peel cutting entails cutting in a circular motion from the outside of the log into the center. It is let expensive than sliced-peel cut wood because it uses more of the log.
The thicker the veneer, the more times it can be sanded and refinished. If it is less than 2mm thick, it cannot be sanded at all. After each ply is bonded together, the planks are given tongue and groove edges. Many engineered hardwood floors can be installed by floating it over an underlayment. Some engineered wood will be distressed, and nearly all will be stained and sealed with a protective coating.