How to Nail Tongue and Groove Flooring over Concrete Part 2

In Part 2 of installing nailed tongue and groove flooring to a concrete floor, you will lay down the furring strips to create a suspension for the flooring panels. (Click to return to Part 1 or move ahead to Part 3.)

Step 1: Lay the Perimeter of the Furring Strip Floor Suspension

To keep the floor above the concrete and allow for expansion of the hardwood, you need to install a furring strip suspension for the floor boards. First, measure and cut a furring strip the width of the room. This perimeter strip will run parallel to the tongue and groove floor boards. Lay this strip down 1/2 inch from the exterior wall of the room, selected in Part 1 as the guide wall for laying the floor boards.

Step 2: Add the Furring Strips Perpendicular to the Perimeter Strip

The other furring strips will all run perpendicular to the perimeter strip and thus will lie at right angles to the tongue and groove boards. Place these strips on the floor and attach them to the perimeter board at the exterior wall and the interior wall. Space the furring strips about 16 inches apart for adequate floor support.

Step 3: Level the Furring Strips

Slip one or more 1/16-inch shims under the strips to level them if they are not level. Check their state of levelness with a carpenter's level. Fasten the furring strips at 3-foot intervals to the plywood subfloor with the pneumatic nailer.

Step 4: Lay the First Perimeter Tongue and Groove Board

Along the exterior wall, following the chalk line measured earlier, place the first tongue and groove board. You must place this first board with the groove portion facing the wall, so that the tongue is exposed to attach the next board. The groove on the perimeter board will also serve to anchor one or more ratchet clamps, to push the tongue and groove boards together snugly.

Step 5: Nail Down the First Perimeter Board

Using either 1-inch finishing nails or the pneumatic nailer with staples, attach the first perimeter tongue and groove board to the furring strips. Drive the nail through the tongue portion of the board at each furring strip so it contacts the strip at 45 degrees. When you drive in the nail, push it through the 90 degree angle formed by the tongue piece and the strip and hammer firmly to drive it below the floor board surface. Insert the staple firmly and quickly at 90 degrees to the tongue straight into the furring strip. The staple makes two points of contact with the strip below the board, so it does not have to be angled.

In Part 3, you will continue attaching tongue and groove planks to the suspension, and tighten them with a ratchet clamp. Once you have finished laying the floor, follow the directions to finish it.