Tongue & Groove Installation Instructions

NOTE: This is a generic installation guide only. Installation instructions from the product's manufacturer must be followed.


Inspect ALL materials carefully BEFORE installation. Wood is a natural product containing characteristics such as variations in color, tone and wood grain. Some variation in color is to be expected in a natural wood floor. Even though our product goes through many inspections before it leaves the plant, it is the customer and installer’s responsibility to do the final inspection prior to installation. Warranties DO NOT cover materials with visible defects once they are installed.


Basic tools and accessories include:

  • broom or vacuum
  • chalk line
  • tapping block
  • hardwood surface cleaner
  • hand or electric jam saw
  • miter saw
  • moisture meter
  • safety glasses
  • straight edge
  • table saw
  • tape measure
  • square
  • utility knife
  • pry bar
  • Urethane wood flooring adhesiveif gluing - towels and trowel
  • if stapling - an 18 gauge, 1 1/4" staple or longer, with a power nailer is recommended - Caution: Improper use of a power nailer can mark the surface of the flooring.



Your engineered hardwood flooring must be stored in the room where it is to be installed for at least 48 hours prior to installation in order to acclimate the flooring to the room.

In new construction, hardwood flooringshould be one of the last items installed. All work involving water or moisture (plumbing, plaster /drywall ceilings or wall finishes, painting, etc.) should be finished with ample time for complete drying prior to the wood flooring installation. Heating and air systems should be fully operational 5 days prior to wood acclimation, maintaining a consistent room temperature between 60-80o F and a constant relative humidity range of 35%-65%.

Flooring should not be delivered until the above guidelines are completed.

It is the responsibility of the installer/owner to determine if the job site's sub-floor and job site conditions are environmentally and structurally acceptable for wood floor installation. Wood failure resulting from or connected with sub-floor, subsurface, job site damage or deficiencies after hardwood flooring has been installed is the responsibility of the customer.



Concrete Sub-Floors

New concrete slabs require a minimum of 60 days drying time before covering them with a wood floor.

Lightweight concrete

Lightweight concrete that has a dry density of 100 pounds or less per cubic foot is only suitable for engineered wood floors when using the floating installation method. Many products have been developed as self-leveling toppings or floor underlayment. These include cellular concrete, resin-reinforced cementations underlayment, and gypsum-based materials. Although some of these products may have the necessary qualifications of underlayment for wood flooring installations, others do not. To test for lightweight concrete, scrape a coin or key across the surface of the subfloor. If the surface powders easily or has a dry density of 100 pounds or less per cubic foot, use only the floating installation method.

All Concrete sub-floors must be dry, smooth (level with 3/16” in a 10 foot. Radius-1/8” in 6’) and free of structural defects. Hand scrape or sand with a 20-grit #3-1/2 open face paper to remove loose, flaky concrete. Grind high spots in concrete and fill low spots with a Portland based leveling compound (min. 3,000 p.s.i.) Concrete must be free of paint, oil, existing adhesives, wax grease, dirt and curing compounds. These may be removed mechanically but do not use solvent-based strippers under any circumstances. The use of residual solvents can prohibit the satisfactory bond of flooring adhesives. It is important to ensure a proper bond between the adhesive and the concrete, and planks or strips. Your hardwood flooring may be installed on-grade, above grade, as well as below grade where moisture conditions do not exist.

To ensure a long lasting bond, make sure that the perimeter of the foundation has adequate drainage and vapor barrier.

Wood sub-floors

Wood sub-floors need to be well nailed or secured with screws. Nails should be ring shanks and screws need to counter sunk. The wood sub-floor needs to be structurally sound and dry. They should not exceed 13% moisture prior to installation. If the sub-floor is single layer, less than 3/4” thick, add a single cross layer for strength and stability (minimum 5/16: thick for a total 1” thickness). This is to reduce the possibility of squeaking Wood sub-floors must be free of paint, oil existing adhesives, wax grease, dirt and urethane, varnish etc. Underlayment grade OSB (not the wax side) is also suitable sub-floors. Particleboard is not an acceptable sub-floor for staple down or glue-down installations but can be used as a sub-floor in floating installations. When installing over existing wood flooring, install at right angles to the existing floor.

Sub-floor moisture check

Above, on, and below grade applications are susceptible to moisture and should be tested for moisture prior to installation in several locations within the installation area. Acceptable conditions for above, on, and below grade applications are:

  • Less than 3lbs./1000 sq. ft./24 hrs. on a calcium chloride test.Less than a reading of 5.0 on a Tramex Concrete Moisture Encounter (moisture meter). Wood Substrates must have a moisture reading of less than 13% when using a Tramex or equivalent moisture meter and the moisture content of the wood should be within 4% of the subfloor moisture content.

To correct any sub-floor problems concerning moisture, either wait until the sub-floor dries to meet specifications or use an appropriate moisture barrier.



Remove all moldings and wall-base and undercut all door casings with a hand or power jam saw using a scrap piece of flooring as a guide.

Racking the Floor”

Whether your choose to install the floor with glue, nails, or staples start by using random length planks from the carton or by cutting four to five planks in random lengths, differing by at least 6”. As you continue working across the floor be sure to maintain the 6” minimum between end joints on all adjacent rows. Never waste material; use the left over pieces from the fill cuts to start the next row or to complete a row. Note: When installing a pre-finished wood floor be sure to blend the wood from several cartons to ensure a good grain and shading mixture through out the installation.




There are two ways to install when gluing down engineered hardwood flooring (wet lay meaning to lay directly into wet adhesive and dry-lay method meaning to allow the adhesive to flash or to tack up.) Caution: Whether you choose to install using the dry or wet method follow all guidelines set by the adhesive manufacturer. By not adhering to the guidelines you can void your flooring warranties.

Wet Lay Method

Step 1 - Select a starter wall. It is recommended to start the installation along an exterior wall; it’s more likely to be straight and square with the room. Measure out from the wall the width of two planks and mark each end of the room and snap your chalk line.

Step 2 - Spread adhesive from the chalk line to the starter wall using the recommended trowel. It is important to use the correct trowel at a 45% angle to get the proper spread of adhesive applied to the sub-floor, which will produce a proper and permanent bond. Improper bonding can cause loose or hollow spots.

Step 3 - Install the first row of starter planks with the tongue facing the starter wall and secure into position. Alignment is critical and can be achieved by securing achieved by securing a straight edge along the chalk line (2’x 4’s work well), or by top nailing the first row with finishing nails (wood sub-floor), or sprig/pin nails (concrete sub-floor). This prevents slippage of the planks that can cause misalignment.

Step 4 Once the starter rows are secure spread 2-1/2 to 3 feet of adhesive the length of the room. (Never lay more adhesive than can be covered in approximately 2 hrs.)

Place tongue into groove of plank or strips and press firmly into adhesive never slide planks or strips through adhesive. Use a tapping block to fit planks snug together at side and butt ends.

Clean any adhesive off the surface before it cures using clean terry cloth towels and a urethane remover or mineral spirits.

Use caution when using a rubber mallet to butt material together, it can burn the finish and cause marring

Note: Never work on top of the flooring when installing with the wet lay method.

Dry Lay Method

Step1 - Start by selecting your starter wall and measure out from the wall 30” when installing 5” planks. This will allow adequate working space. Snap chalk line.

Step 2 - Apply adhesive from the chalk line out 2.5’-3’. Allow adhesive to flash as per the instructions affixed to the top of the adhesive container. The humidity chart will aid in allowing the appropriate flash time based on the temperature and humidity.

Secure your starter rows with a straight edge (2’x 4’s). If you must work on top of the newly laid flooring use a kneeling board.

Once the remainder of the floor has been installed go back to the beginning and remove straight edges and spread adhesive on the remainder of the open subfloor, allow flashing for the appropriate time and lying flooring as instructed. Remembering that the planks closest to the wall may need cutting to fit, due to irregularities along the wall.

Clean Up

Use clean white terry cloth towels to clean as you go, along with mineral spirits. Both are easy and convenient to use. Adhesive that has cured on the surface of the flooring can be difficult to remove and will require the use of a urethane remover. This product has been recommended by the adhesive manufacturer and is safe for the finish of your pre-finished hardwood floor.



Your engineered hardwood floors may be installed over wood sub-floors using staples.

When installing your engineered wood planks or strips by stapling, it is necessary to use the proper type of flooring staples for your engineered wood floors.

Recommended Staplers

When installing a 5" wide product, an 18 gauge, 1 1/4" staple or longer, with a power stapler is recommended

Step 1 - You must staple 1”-2” from the ends and every 6”-8” along the edges. This will help insure a satisfactory installation. It is best to set the compressor PSI at 80-85lbs. to keep the staples from going through or breaking the tongues. Improper stapling techniques can cause squeaks in the floor.

Adjustments may be necessary to provide adequate penetration of the staple into the nail bed. You want it flush in the nail pocket. Use a scrap piece of flooring material to set tools properly before installation.

Before installation of the engineered flooring begins, install a 6-mil polyethylene layer over the sub-floor. This will retard moisture from below and may help prevent squeaks. Keep in mind there is no complete moisture barrier system for staple or nail down installations.

Note: 15lb roofing felt or resin paper may be substituted for the polyethylene and installed as below.

Installing 6-mil Polyethylene

Install the polyethylene parallel to the direction of the flooring and allow a 3” overhang at the perimeter. Make sure each run of polyethylene overlaps the previous run by 6” or more.

Layout the job

Measure out 3.5” from the ends of your starting wall when installing 5” planks and mark both ends. Where possible lay the flooring at 90* angles to the floor joists. Make a chalk line along the starting wall using the marks you made.

Beginning installation

Note: Expansion space is required along the perimeter of room(s) of intended installation, expansion space is dictated by the thickness of the product, for example, 3/8” thick floor requires a 3/8” expansion space, 1/2” thick floor requires 1/2” expansion space.

Place the planks with the tongue facing away from the wall and along your chalk line. Use brads or small finishing nails to secure the first starter row along the wall edge 1”-2” from the ends and every 6”-8” along the side. Counter sink the nails and fill with a wood filler that blends with the flooring installed. Place the nails in a dark grain spot in the board. The base or shoe molding will cover the nails when installed after completion of the installation.

Blind nail at a 45*-degree angle through the tongues. It will be easier IF YOU PRE-DRILL THE HOLES IN THE TONGUES. Nail 1”-2” from the ends and every 6”-8” along the sides. It will be necessary to blind nail the next 2 rows. A brad nailer with 1”-1-/38” brads can also be used to blind nail and no pre-drilling is needed.

Continue the installation using an engineered wood flooring stapler, using staples recommended by a wood flooring professional. Staple the flooring 1”-2” from the ends and every 6”-8” along the edge tongues.

Final Touches

Install the proper trim molding at the doorways to achieve the transition and along the walls to cover the edges of any gaps along the wall due to irregularity.

Complete the job by using wood filler that blends with the installed flooring to fill any gapping along the joints and cleans the finished floor with Professional’s Choice Flooring Cleaner.


Subfloor Preparation

 Subfloor preparation is more critical for a floating engineered floor than for a staple or glue down application, the floor must be flat to 1/8 inch in 10 feet. If the floor requires correction the high areas can be ground down and the low areas may be filled by floating latex fortified Portland leveling compound. The leveling compound must be allowed to dry according to the manufacturers instructions before the floor is installed over it. The use of sand or extra padding to fill low areas is not acceptable.


 Floating installation of your engineered hardwood flooring requires the use of suitable 2 in 1 underlayment padding. Underlayment requirements are very critical in a floating installation.

Expansion Space

 An expansion space of at least 3/8 inch must be maintained around the perimeter of the room, all pipes, counters, cabinets, fireplace hearths, doorframes and any other fixed vertical objects in the room.

Glue and Glue Placement

 The recommended glue for floating installation is Tongue and Groove engineered flooring glue. Glue placement is very important. The glue must be placed along the topside of the groove the full length of the grooved side and end. This can be accomplished by inverting the plank and applying a bead of glue (3/32”) to the topside of the groove (side of the groove nearest the face of the plank), when the plank is turned back over the glue will run down the back of the groove giving total coverage. Apply only a 3/32-inch bead of glue, if the groove is filled with glue it will be difficult to close the seam not allowing a tight fit.

Getting Started

Spacers must be used to establish the minimum 3/8” ” expansion space from the walls. These three rows must be straight, square and in rack because they establish the alignment of the rest of the floor. After putting these three rows together allow the glue to set (15 to 45 minutes) before proceeding with the installation. With the tongue facing out the planks can be tapped together with a tapping block on the tongue to make a snug fit. After installing 8 or 10 rows of flooring stand back and check for crowning or heaving due to tension strapping or any damage caused by improper tapping.

Clean AS YOU Go

 If any glue squeezes out of the seam between the planks allow it to dry for 10 to 15 minutes and then lightly scrape it away with a plastic scraper or putty knife, any glue left may be cleaned with a damp cloth or other method recommended by the adhesive manufacturer. Do not allow the glue to dry on the face of the flooring; it will be very difficult to clean off.


Your 1/2" Engineered Hardwood Flooring (with the exception of Brazilian Cherry (Jatoba) and Maple), can be installed over radiant heating system on the ground floor, second floor, or in the basement by following the instructions below.

As there is a wide array of systems on the market, each with its own features, it is recommended that you consult your radiant flooring dealer to ensure your installation method is the right one. Wood floors can be successfully installed on radiant floors, provided you know how the latter work and how they may interact with flooring.

Preparing the subfloor for concrete slabs with a radiant system is the same as for slabs without such a system. Follow theinstructions in the Glue-down or Floating Installation section.

Preparing the subfloor for a beam and joist floor with a radiant systemis the same as for a conventional system. Follow the instructions in the Nail Installation section. With this type of system, it isimportant to ensure that fasteners are not so long that they penetrate and damage the heating elements.Precautions and recommendations:

Precautions and recommendations:

  1. Heat the installation site for 5 to 6 days before board delivery, regardless of the season, to remove residual moisture in thesubfloor.
  2. Ensure that ambient humidity and temperature are the same as when the area is occupied.
  3. The radiant floor surface must never be warmer than 85°F (29.44°C) during installation or while the floor is in use.
  4. To minimize sudden fluctuations in ambient humidity and temperature that could impact wood moisture levels, it is recommendedthat you install 3 thermostats. The first is to monitor the temperature of the under-floor radiant system, the second is to monitor roomtemperature, and the third is to monitor temperature outside the room. This combination allows rooms to warm gradually in relationto outside temperatures.
  5. Use caution when turning the radiant systems on and off at the beginning or end of the seasons. Gradually increasing thethermostat temperature over a one week period will help to minimize any undue stress on the hardwood floorboards.