Hardwood Flooring Types
There are 2 basic types of hardwood floors with several different variations of engineered hardwood flooring.
Solid Hardwood Flooring
Solid hardwood floors are cut from a wood log into a solid plank and the tongue and grooves are milled on all four sides. They range from 5/16" to 3/4" in thickness and come in various widths and generally are in random lengths. Solid wood planks are sold in both unfinished bundles or prefinished at the factory and sold in full cartons. You can buy solid wood flooring in a variety of North American wood species as well as exotic hardwoods from different countries from around the World.
Because solid wood planks are sensitive to changes in humidity they are only recommended for on or above ground level. Use caution if on grade above a crawl-space. Solid wood floors are meant to be nailed-down over a wood type subfloor and should be installed perpendicular to the floor joists.
Engineered Hardwood Flooring
Engineered hardwood floors are also called laminated wood floors because they consist of several thin, wood plies that are glued together under heat and pressure. The plies can vary from 3 to 9 plies and are offered in a variety of widths from 2-1/4" to 8" wide and in many different stained colors. Engineered wood planks are more dimensionally stable than solid wood planks and can be use on all grade levels, including in dry basements over fully cured concrete slabs. The top ply of an engineered wood plank is called the finish layer and can be any hardwood specie, both North American or exotic hardwoods.The plies underneath the top finish layer are a softer wood.
Many engineered hardwood floors can be glued-down, stapled down or floated over wood subfloors. They can also be glued-down or floated over dry concrete slabs and some types of hard surface floor coverings, such as vinyl flooring or vinyl floor tiles. (Note: the existing flooring must be well secured to the subfloor.)
Acrylic Impregnated Hardwood Flooring - are really an engineered hard wood floor where to top, finish ply has been totally saturated in acrylic and stain. This allows the color to go all the way through the top ply rather than only partially staining the top ply. Saturating the entire top ply makes the finish layer harder than nornal wood flooring, but this also means you cannot refinish the wood floor. You can re-coat the floor's surface though.
Longstrip Hardwood Flooring - are really engineered hard wood floors that are 3-plies and generally around 7-1/2" to 8" wide. The top finish layer is usually 2-3 rows of thin, hardwood slices all glued to the center wood core. This gives each plank the appearance of being 2-3 rows of planks already secured together. Longstrip wood planks are not very common, although they are a bit easier to install for do-it-yourself installations.
Recommend Hardwood Flooring Over Different Types of Subfloors
| Substrate / Subfloor | Recommended Type Wood Floor |
| Concrete Slab | Solid Wood Floors - only over a sleeper system with 3/4" plywood and moisture barrier. Engineered Wood Floors - glued or floated |
| 5/8" - 3/4" Plywood | Solid Wood Floors - nailed-down Engineered Wood Floors - glue, staple or float |
| Particle Board | Its best to remove all particle board Solid Wood Floors - NOT recommended Engineered Wood Floors - float only |
| 5/8" - 3/4" OSB | Solid Wood Floors - nail or staple Engineered Wood Floors - float only |