How to Install a Hardwood Floor

When it comes to natural beauty and durability, wood is the material of choice for floors. In living rooms, dining rooms, family rooms, and more, wood flooring is both beautiful and practical.

Because wood expands and contracts with moisture-and can rot if left in contact with water for a long period of time-many homeowners shy away from choosing wood flooring for bathrooms and kitchens. Actually, wood can be a warm, beautiful flooring option for these rooms as long as it’s given a sturdy, protective finish and is dutifully maintained.

Traditional strip or plank wood flooring is fastened to subflooring and then sanded and finished. Newer prefinished wood floorings are fastened the same way but do not require finishing.

Unless you’re experienced in sanding and finishing wood floors, you'’l do well to hire a qualified local hardwood flooring installer or, if you want to do it yourself, choose the prefinished type. Floor sanding is incredibly dusty work, and a drum sander, in the hands of an amateur, can leave visible marks and ridges on the floor.

Base for flooring
New wood flooring should be laid on a clean, smooth, level, structurally sound flooring base.

Installation steps
Before installing wood flooring, stack it indoors for a few days to allow the wood time to adjust to your home’s humidity level. Plan to install the flooring perpendicular to the floor joists.

Mark the positions of the floor joists along a wall for reference, as shown in step 2, and cover the subfloor with a layer of 15-pound asphalt felt to provide some moisture protection and minimize squeaks. Mark the centerline of the room using a measuring tape and chalk line as shown in step 1.

If the room is seriously out of square, position the tongue of the first row parallel to the centerline and rip (cut lengthwise) the groove side at an angle parallel to the wall.

To rip flooring, you will need a power saw that has a fence, such as a job saw (portable table saw). For crosscuts, you can use a power circular saw with a carbide-tipped 40-tooth blade or, better yet, a power miter (“chop”) saw with the same type of blade.

During installation, you’ll find it’s helpful to lay out several rows of boards, staggering them so no end joint is closer than 6 inches to an end joint in the next row. As you install the strips, cut pieces (at least 8 inches long) to fit at the end of each row; allow for a 1/2-inch gap at the wall.

When blind-nailing with a hammer and finishing nails, don’t try to drive the nails flush or the indentations will show. Instead, leave each nailhead projecting up about 1/8 inch and then place a nail set sideways over it along the upper edge of the tongue and drive the nail home by tapping the nail set with a hammer. Finally, use the tip of the nail set to recess the nail’s head flush with the wood.

1. Cover the subfloor with a layer of 15-pound asphalt felt, overlapping seams by about 3 inches. Tack the felt down to the subfloor with a staple gun.

Measure the room’s width at two or more points to establish an accurate centerline, and snap a chalk line parallel to your starting wall. Working from the joist marks along the walls, snap chalk lines to mark the locations of the support members.

2. To indicate the edge of the first row of flooring, snap another chalk line about 1/2 inch from the starting wall exactly parallel to the centerline. This 1/2-inch gap between the flooring and the wall will allow for expansion; it will be covered by a base shoe or baseboard molding.

3. Choose the longest boards or widest planks for the first row. Near the wall, where the nailheads will be covered by a base shoe or baseboard molding, drill pilot holes for 1 1/2-inch finishing nails and then face-nail the first row through the plywood subflooring to the floor joists or sleepers. Use a nailset to recess the nails below the surface.

4. Blind-nail this and the next two rows by hand. Drill pilot holes at a 45-to-50-degree angle through the tongues, centered on each joist or sleeper, at the ends and every 10 inches along the lengths. Fasten with 1 1/2-inch finishing nails. Use a nail set to finish driving each nail.

5. When installing the second row and every row thereafter, move a short piece of flooring along the edge and give it a sharp rap with a mallet or hammer to tighten the new row against the previous row before nailing.

Remember that end joints in two adjacent rows should not be closer than 6 inches; end joints should also not line up over a joint in the subfloor. If you’re installing a wide-plank floor, some manufacturers recommend leaving a crack the width of a putty-knife blade between planks for expansion.

6. If you’re installing flooring over a large area, use a wood floor nailer once you’ve installed the first three rows. Slip it onto the board’s tongue and, using a heavy rubber mallet, strike the plunger to drive 2-inch nails or staples through the tongue into each joist and into the subfloor midway between joists. Be extremely careful not to scratch or otherwise damage the flooring.

7. When you reach the final row, use a block and a pry bar to wedge the last boards tightly into position. Drill holes and face-nail boards where a base shoe or baseboard molding will cover, using the reference marks along the wall to locate the joists. Set the nailheads below the surface using a hammer and nail set.

8. If your new floor will cause a change of level to a hallway or adjoining room, install a reducer strip for a smooth transition. This strip, milled with a rounded or beveled top, fits onto the tongue of an adjacent board or the ends of perpendicular boards.

It can also be butted against the edges or ends of grooves. Face-nail the reducer strip at the edge of the floor, set the nailheads below the surface, and fill with wood putty. Last, install a base shoe or baseboard molding.