Unfinished Engineered Hardwood
Engineered hardwood eliminates the need for extra floor height when installing solid 3/4" hardwoods on concrete. More common methods in the past have been the sleeper system and 3/4" plywood, or 3/4" plywood over concrete. In both cases, the systems are designed to nail or staple genuine solids to a wood substrate. However, a major drawback has always been the increased vertical height of the finished floor, not to mention costs.
With an engineered product the final vertical height becomes 5/8 to 3/4 inch (depending on sources) of an inch whereas the others are approximately 1 1/2 inches and up to 2 3/4" Baseboards are no longer compromised. Entry doors and kitchen appliance clearances, just to mention a few items, are no longer a problem. Most of the higher quality unfinished engineered have a very similar wear layer to that of common solid hardwoods shown in the illustration below. They can be refinished multiple times, stained to any color and comes unfinished in a variety of species and widths.
How Is It Installed?
The product is installed like any other engineered wood floor. For concrete applications it is glued direct with a urethane adhesive, as in the case of the industry leader Bostiks Best. Over wood subfloors the product can be glued, stapled, or nailed. Some of the better manufacturers include Owens Plank and Real Wood Floors.
Cost Savings Versus Older Methods of Site Finished Floors On Concrete
The savings are substantial with concrete slab applications, not only in material costs but labor as well. Let's use an example of 1,000 square feet over concrete.
Group A- Is using the 3/4" plywood method, then nailing or stapling 3/4" hardwood. It is then finally sanded and finished on site to the customers expectations. First they haul in the plywood at a cost of approximately $1.25 per square foot. Moisture barriers and labor to install the plywood may run another $1.00 to $2.50 per square foot depending on how costs are in your region.
Now comes the actual installer who may request to install your unfinished floor for $ 3.00 per square foot. Our costs are already up to $ 6.50 per square foot. Bring on the guys with the sanding and finishing systems and another $ 3.00 per square foot may be added. Final cost without material? Approximately $ 9.00 per square foot.¹
Common Rotary Peeled
Group B- Is using the glue down application on concrete. Yes, glue down floors can be finished with sanding equipment, but it's wise to wait a few days for the adhesives to cure proper. In this example, labor and material costs to install the plywood are gone.
In group B's example; labor costs and adhesive may run in the $3.50- 4.00 per square foot range. Very near a savings of $2.00 per square foot, or $2,000. Once the finisher is completed with his work, costs are near $ 6.75 per square foot.
Sounds Good, But We Don't Like The Look of Engineered Floors
The better engineered products are solid sawn. Quite different from many standard prefinished products as final appearance will have everyone thinking (including professionals) it's a solid 3/4" hardwood floor. Most engineered floors that are rotary peeled often give the appearance of a plywoody look (comparison above) for lack of a better term. We also have the benefits of longer lengths (shown below) compared to common engineered hardwoods that may not exceed 48 inches.
Update November 2011 - With more recognition of adverse effects and high moisture conditions with concrete slabs in recent years, many professionals now rely on sealers designed for hardwood floor applications. With that said, costs increase. Labor to apply may run $1.00 per square foot with material adding another dollar and more. Two part sealer and adhesive applications can reduce the amount significantly.
¹ Costs will vary significantly from one region to another. Our estimates are more of a guesstimate on the low side. Figures represent a natural finish applied.