“What is your approach to resanding an old engineered wood floor?”
Matt Thrane
Gehl Flooring
One of the first things that I would do is to decipher the thickness of the actual top layer of real wood. If no uninstalled pieces of flooring can be found, this can be done by removing a heat register, pulling a piece of baseboard off to view the side profile of the flooring utilizing a dental mirror, or in the worst case scenario, drilling a hole in the inside corner of a closet. If it has been determined that there is enough material for a sanding (2.5 mm or greater), I would minimize the use of the big machine during the sanding process by only utilizing it for one sanding pass. Starting with the finest grit possible that will remove the finish and flatten the floor. Any subsequent passes would be completed utilizing a planetary sander. If a water-based finish system is to be used on this freshly sanded floor, use caution in not applying the coats too heavy as the edges of the veneer can sometimes curl if exposed to too much moisture.
Kjell Nymark
NWFA
The most important things to consider when resanding engineered floors are wear layer thickness, bevel depth, and floor flatness. The wear layer must be a minimum thickness of 3/32”. Sometimes 3/32” is not enough if the beveled edges are so deep that sand through may occur by the time the bevels are sanded out. Floor flatness is equally important, if the floor is out of flat it could lead to uneven sanding and possible sand through.
John Alford
Alford’s Custom Hardwood Floors
Sanding an old engineered floor can sometimes be quite challenging. The texture of the floor and the wear layer really dictate the way that you would go about it. If there is enough surface on a handscraped engineered floor to resand, you will need to sand to the bottom of that scraping or you will need to rescrape the floor to resurface it. You likely will need at least a 3 mm wear layer to accomplish this. Some engineered floors are sawn face, while others are rotary peeled veneers. You do not want to get too aggressive with sanding a rotary peeled veneer as coarser grit sanding paper will tear out the grain and leave it with a very open, ugly look. I would typically start with at least 60 grit or higher on a rotary peeled product.
The biggest consideration with any engineered floor is to be sure there is enough wood to sand and the floor is flat so you don’t sand through to wear layer. And take it slow.