Plank Hardwood Flooring

NOTE: With wide plank over 4" extra care is necessary for good performance since the units move more with changing conditions. Proper acclimation before and after installation is critical. After acclimation and before installation, sealing the back surface may help prevent some cupping normally associated with wider widths.

This flooring is normally made in 3" to 8" widths and may have countersunk holes for securing planks with wood screws. These holes are then filled with wood plugs.

Random width Plank is installed in the same manner as strip flooring, alternating courses by widths. Start with widest boards, then the next width, etc., and repeat the pattern. Manufacturers' instructions for fastening the flooring vary and should be followed.

The general practice is to blind nail through the tongue as with conventional strip flooring. Then countersink one or more flat head screws, No. 7 - No. 9 phillips head or dry wall screws at each end of each plank and at intervals along the plank to hold it securely. Cover the screws with wood plugs glued into the holes. Take care not to use too many screws which, with the plugs in place, will tend to give the flooring a "polka-dot" appearance.

Be sure the screws are the right length. Use 1" if the flooring is laid over 3/4" plywood on a slab. Use 1" to 1 1/4" in wood joist construction or over screeds. Some manufacturers recommend face nailing in addition to other fastenings.

Another practice sometimes recommended is to leave a slight expansion crack, about the thickness of a putty knife, between planks. Consult manufacturer's installation instructions for details.



The existing wood floor can serve as a subfloor. Drive down any raised nails, re-nail loose boards and replace any warped boards that can't be made level. Sweep and clean the floor well, but don't use water.

Remove thresholds to allow the new flooring to run flush through doorways, remove doors and baseboards. Lay asphalt felt or building paper over the old floor.

Do not install the new floor to the old floor in the same direction. Install at a right angle or on a diagonal. If the preferred direction is in the same direction as the old floor, overlay the old floor with 3/8" to 1/2" plywood.



The styles and types of block and parquet flooring as well as the recommended procedures for application vary somewhat among the different manufacturers. Detailed installation instructions are usually provided with the flooring or are available from the manufacturer or distributor.

This section applies only to 3/4" tongue-and-groove parquet flooring where tongues and grooves are engaged.



Lay both blocks and the individual pieces of parquetry in mastic over a double layered wood subfloor or a concrete slab with a moisture retarder.
Use a cold, cut-back asphalt mastic spread at the rate of 35-40 sq. ft. per gallon. Use the notched edge of the trowel. Allow to "flash off" overnight or as directed by the manufacturer. The surface will be solid enough after 12 hours to allow you to snap working lines on it. Use blocks of the flooring as stepping stones to snap lines and begin the installation.


There are two ways to lay out parquet. The most common is with edges of parquet units (and thus the lines they form) square with the walls of the room. The other way is a diagonal pattern, with lines at a 45° angle to walls.

Square pattern. Never use the walls as a starting line because walls are almost never truly straight. Instead, use a chalk line to snap a starting line about 3 ft. or so from the handiest entry door to the room, roughly parallel to the nearest wall. Place this line exactly equal to four or five of the parquet units from the center of the entry doorway.

Next find the center point of this base line, and snap another line at an exact 90° angle to it from wall to wall. This will become your test line to help keep your pattern straight as the installation proceeds. A quick test for squareness is to measure four feet along one line from where they intersect, and three feet along the other. The distance between these two points will be five feet if the lines are true (Fig. 8).

Diagonal pattern. Measure equal distances from one corner of a room, along both walls, and snap a chalk line between these two points to form the base line. (This pattern need not be at a precise 45° angle to walls in order to appear perfect.) A test line should again intersect the center of the base line at an exact 90° angle (Fig. 10).

Special patterns. Most existing parquet patterns can be laid out with these two working lines. Herringbone will require two test lines, however; one will be at the 90° line already described; the other crosses the same intersection of lines, but at a 45° angle to both.

If such elaborate preliminary layout preparation seems a bit overdone, keep in mind that it is wood we are installing. Each piece must be carefully aligned with all of its neighbors. Small variations in size, natural to wood, must be accommodated during installation to keep the overall pattern squared up. You cannot correct a "creeping" pattern after it develops; the more carefully laid out floor causes less problems during field work.

Wood parquet must always be installed in a pyramid, or stair-step sequence rather than in rows. This again prevents the small inaccuracies of size in all wood from magnifying, or "creeping" to gain an appearance of misalignment. Place the first parquet unit carefully at the intersection of the base and test lines. Lay the next units ahead and to the right of the first one, along the lines. Then continue the stair step sequence, watching carefully the corner alignment of new units with those already in place. Install in a quadrant of the room, leaving trimming at the walls until later. Then return to the base and test lines and lay another quadrant, repeating the stairstep sequence.

Install the last quadrant from the base line to the door. A reducer strip may be required at the doorway.

Most wood floor mastics will allow the tiles to slip or skid when sideways pressure is applied for some period after the open time* has elapsed. You avoid this sideways pressure by working from "knee boards" or plywood panels laid on top of the installed area of flooring. For the same reason no heavy furniture or activity should be allowed on the finished parquet floor for about 24 hours. Some mastics also require rolling the flooring after installation.

Cut blocks or parquetry pieces to fit at walls, allowing 3/4" expansion space on all sides. Use cork blocking in 3" lengths between flooring edge and wall to permit the flooring to expand and contract.


"With blocks, a diagonal pattern is recommended in corridors and in rooms where the length is more than 1 1/2 times the width. This diagonal placement minimizes expansion under high humidity conditions.