This has an engineered backing with real oak top about 1/4 thick.
If you are planning to sand them be careful with the large floor sanders which use a horizontal cylinder as often offered by hire shops. They are OK but can cut very quickly so any hesitation and you could cut through you 1/4 oak. Random orbit sanders are slower but do a better job and produce a flatter surface, in my opinion.
Since engineered wood is a relatively recent development it isn't too likely you will find someone who has refinished some though. You might try calling around to a few refinishing specialists. The thickness of the real wood layer on better engineered wood flooring is essentially identical to the thickness above the tongue of solid hardwood ... therefore refinishing is done the same way and the same cautions apply.
I've sanded dozens and dozens of them, but I've been a wood flooring contractor for a very long time. 1/4 inch of real oak is very comprarable to a solid oak floor. You can only sand 5/16 off of those before you reach the tongue/groove. Good Luck
