If you visit retailers, you will notice that a great many of them are selling engineered hardwood flooring with softwood backings. Usually spruce plywood or worse. Now why does this matter?
This matters because different species of wood will expand and contract at different temperatures and humidity levels. logically if you were to have a shift in temperature and/or humidity levels with a more dense hardwood laminated or glued to a less dense softwood, resistance is inevitable. This may cause warping and/or checking (cracking).
Better than Solid Hardwood?
Engineered Hardwood of days ago was installed primarily in basements or in condominiums with concrete floors, and was of the "click" or floating variety. i.e. not nailed down. This is because unless a sub-floor was installed over the concrete, solid hardwood floors could not be installed. Well times have changed. 3/4" Engineered hardwood flooring is now recommended over solid hardwood flooring because of it's extreme expansion & contraction stability factors when in comparison to solid hardwood flooring. Contrary to popular belief, quality Engineered hardwood flooring can be sanded down at least once if down the road a colour change was desired.
North American made
We have touched on the topic elsewhere on the site with regards to why you should by Canadian hardwood flooring, Engineered hardwood is no different. If you know what to look for, you will be armed with important knowledge that can save you from a potential disaster down the road.
Lock tabs refer to plastic tabs that are incorporated into the sides of each floating floor board. This does not have anything to do with the nail down version of Engineered Hardwood. StairSteps will suggest that installing a floating floor without "lock tabs" is okay, provided the installer does not knock off the tabs that click the boards together during the installation process, and that these tabs are not too shallow which makes separation far too easy for "Mother Nature"