Installation Instructions

Installing NOFMA-Certified Solid Wood Flooring Directly to a Slab Using a Wood Flooring Adhesive
The following recommendations and instructions apply to "on grade" and "above grade" slab construction. "Below grade" application of solid wood flooring is not recommended.

Historically, NOFMA has not recommended glue-down application of wood flooring to a concrete slab.  The basis for this position has been that NOFMA standards for wood flooring manufacture assume the flooring will be installed on wood based subflooring systems with mechanical wood fasteners, nails, cleats, staples, etc.  Today, building homes on concrete slabs in the normal construction technique in many areas of the country.

In recent years, advancements in adhesive technology and moisture retarders have made it possible to successfully glue solid wood flooring to concrete slabs in situations other than parquet applications.  A concrete slab does not behave the same way as a traditional wood system, particularly with respect to nailing.  In addition, a slab can be a potential moisture source and adversely affect the performance of the flooring in dramatic fashion.  As such, glue-down applications require the installer to take additional steps to ensure success.  Still, some wood flooring manufacturers may not approve of direct glue down of their solid wood products.  As such you should always follow the instructions and limitations published by the manufacturer.  When in doubt, NOFMA recommends checking with the manufacturer prior to installation.

For more information, please see the technical information published on the NOFMA website regarding glue-down installation.

Installing NOFMA-Certified Solid Wood Flooring Using Traditional Nailing
"To install 5/16" strip or plank you need a clean, dry flat wood sub-floor about 3/4" - 7/8" thick.  5/16" x 2" oak strip can be laid with a 4 or 5 board border, if desired.  The corners or offsets are either mitered or log cabined for desired effect.  Some border incorporate "feature strips" of contrasting color; such as walnut, mahogany, redwood, teak, etc.  These feature strips come in 5/16", 1/2" and 3/4" widths and are used either one or two per border.
Click on Image to see LargerOn occasion, patterns are built into the corners depending on the skill of the floor layer, and the designs detailed.  The border should be squared to the room and any necessary rips scribed in at the wall line to take care of irregular runs in the wall line.  The field is racked out loose, with the ends overlapping the positioned border.  The flooring is then accumulated into a close or tight position by hand and then using any type of tool suitable for the purpose:  i.e. a nail set, screw driver, chisel or like driver at a slight angle against the rack of loose boards, start a nail about a half inch in from the edge nearest you in the furthest board, apply tension with your took and while the rack is under tension, tack and set the nails.  DON'T NAIL LOOSE BOARDS WITHOUT APPLYING TENSION; they can split.  Accumulate and tack the whole floor into position and cut in rips as required.  Strike chalk lines seven inches apart across the room and 1/2" in from the edge of the boards.  Butt joints are also nailed 1/2" or 3/4" in from the ends of the boards.
In the case of plank flooring, care should be taken in nailing the butts; to keep them out of the way of any plugs or dowels that may be desired in the floor.  These floors are nailed with 1" 15 gauge flooring brads, using our new Pneumatic Top Nailers, a Cavanaugh or equal nailer, making sure the boards are down to the subfloor and not up in the air.  Floor should be trowel filled with wood filler.  The filler seals floor and fills nail holes and any cracks.  After filler has dried, sand and finish like any other wood floor."
For more resources on general wood flooring information and for questions regarding installation, please visit the National Wood Flooring Association's website.