Things You'll Need
Polyurethane floor adhesive
Fine-tooth wood blade
100-pound floor roller
Laminate and hardwood floors often use Masonite, a brand of pressed-wood fiberboard, as an underlayment floor covering. Masonite covers a wooden subfloor or concrete slab's imperfections, giving the laminate or hardwood flooring a smooth and flat surface to bond against. The flooring materials bond to the Masonite with standard adhesives. Before installing the Masonite in a building, the Masonite must sit unwrapped on a flat surface until it adapts to the building's environmental conditions, which usually takes about 24 hours.
Shave the debris from the subfloor or slab's surface, using a floor scraper. Clean the subfloor with a broom and dustpan.
Apply a 3-foot-wide strip of polyurethane floor adhesive to the subfloor or slab next to a wall, using a V-notch trowel to spread the adhesive.
Lay the first row of Masonite flooring on the subfloor or concrete slab's adhesive, keeping the Masonite's smooth side facing up. Cut the piece of Masonite next to the wall to size, using a circular saw equipped with a fine-tooth wood blade.
Spread a 3-foot-wide strip of the flooring adhesive on the slab or subfloor next to the previous row of Masonite, using the V-notch trowel to apply the adhesive. Keep the adhesive off the installed Masonite.
Place the previous row's cutoff piece of Masonite on the adhesive next to the wall -- this uses the scrap material, reduces waste and creates a staggered Masonite pattern. Lay the remaining pieces of Masonite on the adhesive, working from the cut piece across the room. Cut the Masonite's last row to size with the circular saw. Continue to install the Masonite across the room, using the same method used on the second row.
Press the Masonite flooring into the adhesive, using a 100-lb. floor roller. Work the roller across the room lengthwise, then work the roller across the width of the room.
Secure the Masonite to a wooden subfloor with flooring staples, using a staple gun to drive the staples. Place a staple every 3 inches around the perimeter of each sheet of Masonite. Run additional staples through the Masonite board's body at a rate of 1 staple every 6 square inches. Concrete slabs do not flex, and Masonite does not need additional support.
Smooth the joints between the Masonite flooring panels with a sanding block, removing all the raised edges.