Solid vs. Engineered Hardwood: Which Is Right for a Napa Valley Home?

What is the difference between solid and engineered hardwood?

Solid hardwood is one piece of wood, typically 3/4 inch thick. Engineered hardwood is a real hardwood veneer bonded over a core of cross-laminated plywood or high-density fiberboard. Both have genuine wood on the surface, cut from the same logs, and once installed and finished you cannot tell them apart by looking.

The difference is entirely in how they behave. Because engineered wood's core layers run at right angles to one another, the board barely moves with changes in humidity. Solid wood moves a great deal.

Which one should I choose?

Choose solid hardwood over a wood subfloor in a house you plan to keep, because it can be sanded and refinished many times over its life. Choose engineered hardwood over a concrete slab, over radiant heat, or at plank widths above about five inches, because its stability is what makes those possible.

In Napa and Solano counties, the foundation usually decides it for you.

Side by side

Does my house have a slab or a crawl space?

This is the question that settles it, and you can usually answer it yourself.

If there is a crawl space or basement under the house — an access hatch, a vent along the foundation, floors that sound hollow underfoot — you have a wood subfloor and solid hardwood is on the table.

If the floor sits close to the exterior ground level with no crawl space access, the house is almost certainly slab-on-grade. That describes most Fairfield, Vacaville and American Canyon housing from the 1970s onward, and a good share of newer Napa subdivisions.

Solid hardwood over a slab absorbs moisture vapor from the concrete below while drying above, and it cups. This is not a risk to manage; it is what happens. Engineered hardwood with a moisture barrier is the correct answer there.

What is a wear layer, and why does it matter so much?

On engineered wood, the wear layer is the depth of real hardwood above the core. It is the single number that decides whether the floor can ever be refinished — and manufacturers are notably reluctant to put it on the front of the box.

• Under 2 mm — cannot be refinished. Plan on 15 to 25 years.
• 2–3 mm — one very light screen at best.
• 3–4 mm — one full refinish.
• 4–6 mm — one or two, and a 40-to-60-year floor.

Ask for the figure before you buy. A cheap engineered floor with a 1.5 mm wear layer is a disposable product wearing a hardwood label.

How is each one installed?

Solid hardwood is nailed or stapled through the tongue into a wood subfloor. There is essentially one method, and it has not changed much in a century.

Engineered has three. It can be nailed down over a wood subfloor exactly like solid. It can be glued down over a slab with the manufacturer's adhesive and a moisture barrier, which gives the most solid feel underfoot. Or it can float, locking to itself over an underlayment, which is the fastest method and the most forgiving of a subfloor that is not perfectly flat.

Floating floors sound hollower. It is worth standing on a floating sample before committing to one, because it is the thing people notice afterwards and cannot unhear.

Is engineered hardwood worth less at resale?

Much less than it used to be. Twenty years ago engineered was treated as a compromise. Today, good engineered flooring with a thick wear layer is specified as standard in high-end new construction — particularly wide-plank white oak — and appraisers treat it as a real wood floor.

Where solid still wins is longevity. A 3/4-inch solid floor can outlive everyone in the house. If you are on a wood subfloor and planning to stay for decades, solid remains the better long-term asset.

What about wide plank?

Almost all wide-plank flooring sold today is engineered, and there is a good reason. A 7-inch solid board moves visibly across a Napa Valley year — more so in Calistoga and St. Helena, where the summers are hotter and drier than at the valley's southern end.

Engineered wide plank stays flat. If you want the wide-plank look, that is the route.

The decision in one paragraph

If your house has a crawl space, you plan to stay, and you want a floor your grandchildren could refinish, choose solid hardwood at a conventional width. If your house is on a slab, has radiant heat, or you want plank wider than five inches, choose engineered with the thickest wear layer you can afford. Both are real wood. Neither is a compromise.

Related reading

• Hardwood flooring installation
• How long does a hardwood floor installation actually take?
• Wood floors and wine-country humidity

Sources: NWFA technical publications, CARB Composite Wood Products Program, EPA formaldehyde standards for composite wood.