floor care

Hardwood is a living substance, which reacts to changes in relative humidity. Wood gains and loses moisture before and after installation, as surrounding conditions fluctuate. Indeed, wood expands in the summer when humidity level is high and contracts in the winter when the humidity level is much lower. To minimize the expansion or contraction of your hardwood floor, it is recommended that the building should be well ventilated and the relative humidity level maintained at 45 % all year long. Before you begin, plastering and cement work must be completely dry. It is strongly recommended that the wood be left to acclimatize at house temperature for a period of at least 24 hours at the ideal relative humidity level, which is 45 %.

Test concrete slabs for excess moisture

Rubber Mat Method (Useful Only On Light-Colored Concrete) — Lay a flat, non-corrugated rubber mat on the slab. Place a weight on top to prevent moisture from escaping and allow the mat to remain 24 hours; if the covered area shows dark, wet marks, too much moisture is present.

Polyethylene film method — Tape a 12" (30 cm) square of clear polyethylene film to the slab with plastic moisture-resistant tape, sealing all four edges. If no condensation collects under the film after 24 hours, the slab is dry enough for floor installation.

Make tests in several areas of each room. When test indicates excess moisture, wait for the slab to dry naturally or accelerate drying with heat and ventilation, then test again before installing floors.

Installation methods on slab

Plywood-on-slab — Begin by covering the slab with a vapor retarder of either asphalt felt, building paper or polyethylene.

Asphalt felt or building paper — First, prime the slab and apply cold, cutback asphalt mastic with a notched trowel at the rate of 50 sq.ft. per gallon (1m2 per liter). Allow to set for two hours. Unroll 15 lb (6.8 kg) asphalt felt or building paper, lapping the edges 4" (10 cm) and butting the ends. Over this, apply a second similar coating of mastic and roll out a second layer of asphalt felt or paper in the same direction as the first, staggering the overlaps to achieve an even thickness.

Polyethylene — When the slab is well above grade and the expected annual rainfall is light to moderate, cover the entire slab with 4-6 mil polyethylene film, overlapping the edges 4-6" (10 to 15 cm), and allowing enough film to extend under the baseboard on all sides.

When moisture conditions are more severe, prime the slab and apply cold, cutback mastic with a straightedge or fine-tooth trowel (100 sq.ft. per gallon) (2 m2 per liter). Allow to dry for at least 90 minutes. Unroll 4-6 mil polyethylene film over the slab, overlapping the edges 4-6" (10-15 cm).

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In either cases, roll the film flat or "walk" it in, stepping on every square centimeter to insure proper adhesion. Puncture bubbles to release trapped air.

Install the plywood after the vapor barrier is in place. Loosely lay a nailing surface of 3/4" x 4" x 8" (19 mm x 1.22 m x 2.44 m) exterior plywood panels over the entire area, leaving a 3/4" (19 mm) space at the wall line and 1/4"-1/2" (6-12 mm) between panels. Cut plywood to fit within 1/8" (3 mm) near doorjambs and other obstructions where finish trim will not be used. Lay plywood diagonally across the direction of the finished floor to help prevent cracks along panel edges.

Fasten plywood to the slab with power-actuated fasteners, securing the center of the panel first, the edges, using nine or more nails.

Do not use power-actuated fasteners or concrete nails when radiant heat pipes are imbedded in the slab. Instead, cut the plywood into 4' x 4' (1.22 m by 1.22 m) squares, score the backs 5/8" (16 mm) deep on a 12" x 12" (30 cm x 30 cm) grid, and lay the panel in cut-back mastic applied with a 1/4" x 1/4"(6 mm x 6 mm) notched trowel. (35 sq. ft. per gallon) (0.7 m2 per liter).

Screeds System (sleepers) — Flat, dry, preservative-treated 2" x 4" (5 cm x 10 cm) screeds in random lengths from 18" to 48" (0.5-1.2 m) can also serve as a sub floor.

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Begin by sweeping the slab clean, applying an asphalt primer and allow to dry. Apply hot (poured) or cold (cut-back) asphalt mastic and imbed the screeds. Stagger joints and lap ends at least 4" (10 cm) and leave a 1/2" (12 mm) space between lapped edges. Be sure there is enough mastic for 100% contact between screeds and slab. Leave a space of 3/4" (19 mm) between ends of screeds and walls with a continuous run of screeds at end walls.

Before installing the floor, loosely lay an additional vapor retarder of 4-6-mil polyethylene film over the screeds, overlapping the edges on top of the 2 x 4s. Avoid bunching or puncturing the film, especially between the screeds. Nail the finished flooring to the screeds through the film.


For new construction or renovations:

  • Be sure to maintain occupancy-level temperature and humidity for at least five days. The house must be heated at 65 degrees.
  • Using a hygrometer, verify the sub floor (plywood) humidity level; it must not exceed 12 %. If the humidity level is too high, turn up the heat and open the basement windows 1/2" (1.25 cm).
  • Remove baseboards and doorsills.
  • Screw the sub floor securely and if necessary, install a double layer of 15 lb (6 kg) or a single layer of 30-lb (14.5 kg) asphalt felt or building paper.
  • Using a handsaw, slit the bottom of the doorframes 3/4" (2 cm) in order to slide a hardwood plank beneath the door.

Tools and material required:

  • Hardwood floor nailer (with rubber mallet)
  • Electric drill and bits
  • Tenon-saw, circular saw or handsaw
  • Claw hammer and nail punch
  • Measuring tape
  • Chalk line

Before you begin, it is important to verify the working condition of the hardwood nailer to prevent damage to the planks.

Step by step installation

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  • Using the chalk line, draw a line parallel to 3 1/2" (25 mm) larger than the planks width. Never nail closer than 3" (75 mm) towards the end of the plank.
  • Select the planks, and then lay them out on the floor in the general pattern in which they will be installed. The straightest planks should be used for the first and second rows.
  • Always select your planks with care. Those with flaws must be recut.
  • Lay the tongue edge of the plank on the guideline, leaving a 3/4" (19 mm) space between the groove edge and the starting wall. This expansion space will allow the wood to expand if necessary.
  • The first row must be secured to the floor using screw shank flooring nails. Drill holes on the surface of the planks at 1" (2.5 cm) from the edge approximately 12" (30.5 cm) apart. Next, secure using a claw hammer and punch.
  • Measure and cut a plank the required length to finish the first row. As the remaining section will be used to start the second row, the plank selected for the first row must be long enough to yield a remaining section of adequate length. Leave a 3/4" (19 mm) space between the wall and the plank in each row.
  • Start the second row with a plank of at least 6" (15.2 cm) shorter or longer than the plank used in the first row; this will avoid aligning the joints. Set the plank in place, drill a hole on the tongue edge at a 45° angle, and then nail at every 8" (20.3 cm) or 10" (25.4 cm).
  • The subsequent rows must be installed in the same manner, but using a hardwood floor nailer. Try a few hammering tests on a piece of scrap wood to determine the pressure needed to properly drive nail.
  • For best appearance, leave enough distance between the joints by alternating with planks of different lengths to avoid aligning joints.
  • The last four or five rows must be installed in the same manner as the first two rows. The use of the hardwood floor nailer is impossible since the last rows are too close to the wall.
  • Conceal the nail holes using a special wax or colored fillers.
  • Finish trim is nailed only to the wall and never on the planks.

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Maintenance (prevention tips)

  • Do not pour any floor cleaner directly on floor.
  • Never allow any liquid to remain on floor.
  • Avoid dripping mops, which leave excess water on floor. Some manufacturers recommend cleaning hardwood floors with a mop rinsed in a water and vinegar solution. This is acceptable so long as the mop is squeezed dry beforehand.
  • Never use wax, oil-based detergent or any household cleaners. These may dull or damage the finish, leaving a greasy film, making the floor slippery and more difficult to clean.

Things to avoid

  • Do not pour any floor cleaner directly on floor.
  • Never allow any liquid to remain on floor.
  • Avoid dripping mops, which leave excess water on floor. Some manufacturers recommend cleaning hardwood floors with a mop rinsed in a water and vinegar solution. This is acceptable so long as the mop is squeezed dry beforehand.
  • Never use wax, oil-based detergent or any household cleaners. These may dull or damage the finish, leaving a greasy film, making the floor slippery and more difficult to clean.

General Installation Info

Subfloor Preparation

Note: In order for your GrandForest Floors Warranty to stay valid, please follow the following installation instructions. PLEASE READ ALL INSTRUCTIONS CAREFULLY!

A floor can only be as good as the subfloor underneath.

Subfloor Specifications

  • The surface of the subfloor must be level to within 1/8" in an 8 ft radius. This can be checked by using the edge of an uninstalled plank. Use an approved leveling compound to fill excessive voids or variations in the subfloor suitable for the application.
  • Concrete subfloors must not contain more that 3 lbs moisture. The moisture content of a wood subfloor must be between 6-10% moisture content. You must concrete subfloors prior to installation. Moisture is a factor of considerable importance when installing a floor and has a large impact on the final result. It is important to know how moisture affects a floor and floor installation and how to deal with the problems it may cause.
  • The subfloor must be clean.
  • Relative humidity at the job site must be kept as a minimum 30% and a maximum 60%. Temperature must be set within 15◦ of normal operating range.


  • Before installing GrandForest Floors, inspect the job site thoroughly to determine if the grade, subfloor, and subfloor conditions are in acceptable condition for installation method desired.
    • Exterior: Inspect the outside surroundings for proper drainage and obvious sources of moisture. The yard should be graded to slope away from the foundations. Be sure that the gutters and eaves prevent rain from penetrating the foundation.
    • Under the house: Foundation vents must provide cross-ventilation with no dead air space. Vents should be located throughout the foundation. If excessive moisture is present under the house, you must lay a 6 mil black polyethylene moisture barrier on the ground in the crawl space below the installation area.
    • Interior: Check moisture content of the subfloor. Room conditions can also indicate high moisture and relative humidity. Look for water stains, peeling paint near windows and doors, or rusty metal.


Wood Subfloors: Moisture content must be less than 12%. To prepare the subfloor for installation, renail any loose areas that squeak. Sand or plane any high spots and fill any low areas. The subfloor should not vary more than 1/8" in an 8' radius.

  • Preferred Subflooring: ¾" CDX grade plywood subfloor/underlatyment 4'x8" sheets or ¾" OSB subfloor/underlayment with joint spacing 19.2" on center joint construction.
  • Minimum Subflooring: 5/8" CDX plywood subfloor/underlayment 4' x 8' sheets, maximum 16" on center joint construction.

Follow panel manufacturer installation instructions for spacing and fastening. Typical spacing is 1/8" around perimeter and fastened every 6" on bearing edges and every 12" along the center supports.

Door casing should be undercut or notched to avoid difficult cuts.

If you are nailing the floor for installation, we suggest covering the subfloor with 15lb or higher asphalt felt or rosin paper to minimum moisture and help alleviate variations in the subfloor.

Concrete Subfloors: Lightweight and standard-density concrete subfloors are ideal for the installation of GrandForest Floors. Concrete subfloors must be dry and free of standing water and discolorations. Inspect concrete subfloor for cracks and buckling. An approved foam or rubber underlayment must be used and installed properly. Be sure that any concrete subfloor is at least 50-60 days old before installing a wood floor over it.

Other Subfloors: GrandForest Floors can be installed over other existing floors like rubber tile, terrazzo and existing wood floors. The subfloor or existing floor must meet the requirements for installation listed in the above "Subfloor Specifications". In these instances, GrandForest Floors must be installed using the float-in method.


Calculating for minimum board width ensures that the last board of the installation is not too narrow. Follow the steps below to reach this objective.

  • Step 1: Measure the width of all open areas from the staring wall to the finish wall or obstruction, in inches. Round to the nearest ¼".
  • Step 2: Convert inches obtained above into a decimal number. (1/4" = .25, ½" = .50, ¾" = .75)
  • Step 3: Multiply required expansion space by 2. Use the chart below.
    • Under 144" - 1/4" (expansion space) x 2 = .50"
    • 144" – 288" - ½" (expansion space) x 2 = 1"
    • 288" – 480" – ¾" (expansion space) x 2 = 1.5"
  • Step 4: Subtract total expansion needed from the open area width to determine actual floor width.
  • Step 5: Determine the total number of rows of flooring needed by dividing the actual floor width by the board width.
  • Step 6: If the result in Step 5 contains a decimal less than .38", you must rip the statring row to ensure proper width of the last row.

Expansion Space

The proper expansion space around all walls, doors, and vertical obstructions is critical for installation and performance of any hardwood floor. Improper expansion space could cause buckling of the floor if improper moisture levels are not maintained.

  • The minimum expansion space required by GrandForest Floors is ½". This can be obtained by placing several shims between the first installed plank and the wall or vertical obstructions. These should be kept in place throughout installation to avoid the installed floor from moving and shifting.
    • For open areas up to 24' x up to 72' = ½" expansion space is required.
    • For open areas 24'-40' x 72'-120' = ¾" expansion space is required.
    • For open areas 41'-80' x 121'-160' = 3 ½" expansion space is required.
  • No flooring should be installed in an open area greater than 80' in width and 160' in length without the use of a "T-molding".

Floating Installation Instructions

Never attach any permanent object through the flooring, affixing it to the subfloor. A float-in floor must be free to expand and contract in all directions.


Do not open packages until ready to begin installation! Inspect the boards as you go. GrandForest Floors engineered hardwood flooring is sealed at the factory with an 8% moisture content. Opening cartons to acclimate the flooring could result in a difficult installation.

As an installer, it is your responsibility to be aware of the grade, relative humidity of the room, and moisture content of the subfloor. You should check that each plank is free of damage or manufacturing defects.

  • Step 1Start in a corner and lay the first board with the tongue side towards the wall. Proper expansion space can be achieved by pulling the floor away from the wall once the first rows have been installed. For proper expansion space required, please refer to the section "Expansion Space" under "Subfloor Preparation".
  • Step 2Hold the second board against the first board along the short end at a 45̊ angle. Insert the tongue of the second board into the groove of the first board. Lay second board flat. Continue until you have the first row of hardwood installed. Cut the last board to the correct length, allowing for an expansion gap between the wall and the hardwood floor.
  • Step 3Install the second row the same as the first. If possible, start the second row with a left-over piece from the last row. Hold each board at a 45̊ angle to the board in front. Press forward to engage the joint and lay the board flat on the floor. The end joints or butt seams must be staggered by a least 20". In hallway installations, there must be a butt seam in each row regardless of width. Lay the entire row and cut the last board to the correct length, allowing for the expansion gap.
  • Step 4When three rows have been installed, pull floor away from the starting wall until there is a proper amount of expansion space. Place expansion shims between the floor and wall to maintain this space then continue with installation as desired.
  • Step 5If the first or last rows need to be cut to match a crooked wall, first disengage the row of boards adjacent to the crooked wall by gripping the long side and pulling upward while lightly tapping along the entire length of the board. Trace the shape of the wall onto the first/last boards, making sure space is allowed for expansion. Saw to the shape that was traced on the board.
  • Step 6After sawing the row to shape, lift entire row and reinstall to adjacent row. Place expansion shims between floor and wall.

After installation, remove shims and use the required molding and trims to cover expansion spaces and make transitions. Always nail molding to the wall, NEVER to the flooring.

Claims Procedure

GrandForest Floors will stand behind any defective product if it is determined to be manufacture related. Outside of manufacturing, GrandForest Flooring would like for the following steps to be taken when handling a claim.

  • Please read the warranty information found under the "Warranties" tab to determine whether you have a legitimate claim.
  • You and your installer are responsible to inspect flooring before installation. GrandForest Floors accept no responsibility for liabilities, claims, or expenses, including labor cost, where flooring with visible defects had been installed.
  • All orders of GrandForest Floors hardwood will be picked up at a participating retail outlet closest to the Homeowner. At the time of pick up, the Homeowner will be asked to visually inspect all items on the pick-up ticket for any damages to the materials and to make sure that the cartons are within manufacturer's specifications. The Homeowner will be required to sign a pick- up release before the materials will be loaded onto the vehicle. Any damages must be noted on the pick-up ticket and reported immediately to GrandForest Floors by the participating retailer. If necessary, appropriate action will be determined and taken. However, if after the pick-up release has been signed, there is damage to the cartons, the Homeowner assumes all responsibility for the damaged materials. GrandForest Floors products are shipped at an 8 % (+/- 2 %) moisture content. Therefore, please inspect carton wrappings for tears. Tears in the shrink wrapping could cause swelling of the wood, making installation difficult.
  • In the event there is a claim, the following procedures will take place.
    1. The Homeowner will completely fill out the claim form found at and submit to GrandForest Floors for consideration.
    2. At GrandForest Floors' discretion, an independent inspection service will be contacted and a request for an independent inspection will be issued. The inspection service will contact the Homeowner and arrange a suitable time for the floor to be inspected.
    3. After an inspection has taken place, the independent inspector will report his findings concerning the claim to GrandForest Floors in writing. A letter will be sent to the homeowner from GrandForest Floors stating the findings of the inspection.
    4. Depending on the results of the inspection, appropriate action will be taken to resolve the issue. If it is determined that it is an installation or handling problem from the retailer, the participating retailer will be responsible for the resolution of the claim and the cost of the independent inspection. It will be the Homeowners responsibility to contact the Retailer to resolve the claim. If the claim is determined to be a result of Homeowner installation, maintenance, or a condition of the home, the homeowner will be responsible for the inspection cost and their credit card will be billed for this cost. In this instance, No replacement or credit for material will be given by GrandForest Floors. As stated above, GrandForest Floors stands behind the product it sells. If for some reason the inspection indicates the claim is a manufacturing defect, please refer to the "GrandForest Remedies Under Our Warranties" section under the "Warranty" tab found at GrandForest Floors will contact the Homeowner to resolve the claim after the inspection.