Tongue-and-groove wood flooring usually is nailed down over a wood subfloor, but if your subfloor is a concrete slab, you'll need to use a different installation technique. When laying a wood floor on concrete, you'll need to glue down the floor. You don't need special tools as you do with a nail-down floor, but you do need to make sure the flooring you buy is rated by the manufacturer to allow glue-down installation. Make sure the slab is clean and dry before you start.
Use a hammer and pry bar to remove the floor trim in the room. Don't break it as you remove it. Set it aside.
Use your notched trowel to spread floor adhesive along the floor by the wall where you want to start. Don't start on the side of the room near the doorway. Spread the adhesive along the whole length of the floor, coming about 2 feet out from the wall.
Set your first floorboards in place, with the grooved sides facing the wall. Put wall spacers between the boards and the wall as you lay them. This will create an "expansion gap'' that will allow the floorboards to expand with climate changes. Clip the ends of the boards together. Use a miter saw to cut the ends of the boards to fit at the perpendicular walls.
Set the next rows in place alongside the first, knocking the boards together at their tongue-and-groove edges with a hammer and a piece of scrap flooring, to protect the edge of the floorboards.
Continue laying flooring across the room, spreading more adhesive and working your way backward, until you run out of room to work.
Let the adhesive set overnight, so you can stand on it. Finish the last section of flooring. Cut the final row lengthwise on a table saw so it fits against the wall, while leaving an expansion gap.
Reinstall your floor trim to cover the gaps.
Wear goggles when cutting the floorboards.
Tips and warnings
- Wear goggles when cutting the floorboards.