Engineered wood flooring is most commonly constructed of a plywood substrate with a real wood veneer on top. There are also fiberboard-core flooring products available, but they are considered inferior. All engineered floors are tongue and grooved on all four sides, some are even constructed to be click-locked together. There are many different species, widths, and colors available with prefinished engineered flooring. Unfinished engineered also has many different species, widths, & grades available. The most common widths are 5", 6", and 7". Some manufacturer's have random width patterns available as well.
Plywood substrates are constructed with each layer being glued and pressed perpendicular to the next. The real wood veneer is then glued and pressed to the top. Less expensive products will only have a few layers of plywood, while superior products will have 7 or more layers. The real wood veneer layer is also called the "lamella" or the "wear layer". Once again, cheaper products have a thinner wear layer .6-2mm, while superior products have a thick wear layer 3-5mm. Thicker wear layers allow for sanding and refinishing in the future, allowing the lifespan of engineered products to be comparable to solid hardwood flooring. We'll discuss wear layers in more depth soon!
In summary; the more layers of plywood and the thicker the veneer, the higher the quality and price! The higher quality products provide higher value because you can sand and refinish them, whereas inferior products become trash once the veneer is worn out.
A distinct characteristic of prefinished wood floors are the bevels around the edges. There are many different types and sizes of bevels, from pillow edges to hand-scraped bevels, even micro bevels. Whatever bevel floats your boat, just know that dirt and bevels get along real well :) Obviously the smaller the bevel, the less prone it is to trapping dirt. The bevels serve the purpose of allowing the floor to be installed easier over unlevel surfaces, thus making the un-levelness less noticable. This is not as much issue with unfinished products that must be sanded because some un-levelness can be sanded out, making the floor appear completely flat.
Sawn Cut Vs. Rotary Cut
These are the two primary methods for producing wood flooring veneers.
Sawn cut is produced by running the log through special saws to cut it to a desired width veneer. This produces the highest quality, most stable, and most expensive veneers. It is much more visually appealing because it appears exactly like solid wood flooring, with tighter grain patterns and more grain variance. Sawn cut will produce thicker, longer lasting veneers that won't dent or scratch as easily.
Rotary cut, or rotary peeled veneer is produced by rolling the log about a lathe which peels off a thin sheet of veneer. This process produces a lower quality, less stable, and less expensive veneer. It has a similar appearance to that of plywood, with very wide "leaf" grain. Rotary cut will produce thinner, shorter lasting veneers that will dent, scratch, and de-laminate much easier.
There are very durable finishes available with prefinished engineered floors. Superior products will have up to 12 coats of finish! The most common types of finish are UV-cured polyurethane and Aluminum Oxide. Both are extremely durable, and depending on the manufacturer's finish process they can be made even more durable by applying many thin coats. Some manufacturer's even use a blend of the two.
There are also different sheens associated with finishes. The most common sheen is satin, which has just a little shine to it. Prefinished manufacturer's also use satin-matte, matte, & semi-gloss. Every now and then you may find a prefinished wood floor with gloss finish.
Most of the time these finishes can actually be re-coated, without the need for sanding the floor. This is best left to a professional though because you never know what type of finish might be on your existing floor to begin with. Not all finishes are compatible with each other. There have been instances where homeowners have used certain cleaners, polishes, or waxes that leave residue behind. This is problamatic for re-coating because certain finishes will not adhere to those potentially invisible residues. There are processes that can remove or neutralize some old polishes and residues so new finish can be applied - but once again, this should be left to the pros!
What To Know About Engineered Wood Flooring
by Brian Kelley
Engineered Wood Flooring is a great alternative to solid hardwood flooring! It can have the same asthetic appeal without the expansion and contraction associated with solid hardwood. It has also been steadily gaining popularity in new homes as well as remodels. You may find that it suits your needs perfectly. The most common engineered floors are prefinished, but there are also unfinished products available - both have their benefits. Most engineered products are either 1/2" or 5/8" thick, with widths ranging from 2 1/4" to 7".
This is a unique product in our current market, and does not seem to be widely available. Fortunately we do carry these products, and we specialize in sanding and finishing them once they are installed.
The first thing to note about unfinished engineered products is there aren't any bevels on the edges. Once sanded and finished it will have the exact appearance of a solid hardwood floor. In general, unfinishes product will have a more substantial wear layer than prefinished products. This allows for the initial sanding process that is required upon installation. If the subfloor in your home is completely flat, there will not be much sanding required at all to achieve a perfectly flat floor once installed. In most cases, some leveling will be necessary to properly install unfinished engineered floors. We will discuss more on leveling and installation soon.
Another benifit of unfinished products is that you have a little more freedom in choosing your floor. There are different grades available, they usually include Select & Better, #1 Common, and #2 Common. Although each manufacturer of prefinished wood flooring may use different grades of material, you generally don't have the option of choosing grades within a specified line of prefinished products. This choice allows you to further customize the look of your floor. Lower grades will have wider, darker grain patterns creating a a more casual or "country" feel. Higher grades feature tighter grain patterns that create a more formal or elegant appearance.
As with prefinished product you have choices in species and widths. Species can include red & white oak, maple, brazilian cherry, walnut, and more. Reclaimed antinque pine has also become a recent option. The most common width available are 3 1/4", 4", 5", 6" and 7". In some cases a 2 1/4" width can be special ordered.
One additional benifit on unfinished products is that custom installation and custom transitions are achieved much easier. For example; a pattern, border, or inlay is possible with unfinished. If you want to change directions of the flooring on an angle, unfinished will allow a more seamless look because there are no bevels to contend with.
Installation, Subfloors, & Prep
Engineered wood flooring can be installed almost anywhere inside a residential or commercial building. It can even be installed below grade, over radiant heating, and in bathroom & kitchens. This is because it is such a stable product and won't expand and contract like solid flooring. Additionally it can be nailed/stapled, glued, or floated on top of concrete of wooden subfloors. Some manufacturer's even produce click-lock type engineered floors that don't require glue or nails.
This may be the most simple method if your home has a wooden subfloor. Just like solid hardwood, special nailers or staplers are required that shoot the fastener into the tongue at an angle. This method will usually require minimal prep. The wooden subfloor needs to be relatively flat and level - sometimes sanding of plywood seams and high spots is necessary, as well as plating of low spots.
This will be one method of choice if you're installing over a concrete slab. Properly preparing a concrete slab for gluing can be fairly intensive, depending on several factors. In older homes, there is often old paint and texture on the concrete. This must be removed for proper adhesion. Don't let your contractor tell you he doesn't need to remove that old paint! It needs to happen.
Often times, the most overlooked step of prepping a concrete slab is to check for flatness. This is done with a straight-edge or laser. Many manufacturer's specify that the subfloor needs to be within 3/16" in a 10' radius. Do you think most installer's follow these specifications? Nah. Well they should, and we do! In fact, we like to get slabs within about 1/8" in a 10' radius (budget permitting). Leveling a concrete slab is achieved by by applying a concrete-like product (commonly called "float") to the slab. Smaller areas can leveled with a trowelable type float, where larger areas may require a self-leveling type float. Self leveling float is generally a thinner mixture that can flow into low spots better, and is best left to a professional.
This is the easiest method of installation. Glue is simply applied in the grooves of each board and then tapped together. Nothing hold the floor down except gravity and each adjacent board. A floor can be floated over just about anything; including concrete, wooden subfloors, old un-salvagable wood floors, vinyl, and sometimes even tile. Don't be fooled into thinking that this method will allow you to remove and re-use the flooring in the future, it won't.
The wear layer is simply the real wood veneer, which is the top layer of an engineered floor. It's perhaps the least discussed but most important component of an engineered wood floor, aside from the quality of the wood itself! Basically the thicker the wear layer is, the more value your hardwood floor has because it will last longer. Thicker wear layers can be sanded, whereas thin veneers can not. Once a thin veneer wears out, guess what, you have to replace that floor. Once a sandable veneer wears out, it can be sanded and refinished, which is much cheaper and easier than replacing a floor!
I can't count the number of times we have been called to see if we can refinish a prefinished floor that has dents, scratches, worn finish, or "wrinkles" in it. Probably only 10% of those floors could actually be sanded and refinished, the other 90% had too thin of a wear layer to even consider it. So the homeowner is left to either live with the floor as is, replace the problematic boards (if they happen to have the exact material on hand), or replace the entire floor.
If those homeowners had only been educated on wear layers at the time of purchase, there would be many more happy wood flooring owners out there.
For a full discussion on wear layers go here