[01] GENERAL JOBSITE/HOME CONDITION

ONLY INSTALL FLOORING IN ROOMS UNDER ADEQUATE LIGHTING CONDITIONS. TAKING THIS IMPORTANT STEP ALLOWS FOR GREATER VISIBILITY AND WILL HELP AVOID COSTLY INSTALLATION MISTAKES.

Important: The requirements listed below are considered standard practices for the flooring industry and are required by most building codes. Following these simple guidelines will greatly extend the life of any fixture in the job site/home. Local building codes may vary and will prevail.

The job site/homeowner’s designated installer is responsible for inspecting flooring before installation. Inspect every plank for inconsistency with the finish, texture, milling, color, graining, tongue and groove integrity, and dimensions. Also, check the suitability of the flooring product to its environment. Flooring products installed with pre-existing defects or incorrectly acclimated CANNOT be claimed after installation.

Verify there are enough materials to complete the job with a minimum of 2% or one box of extra (whichever is greater) for future plank replacements.

Allow a minimum of 5% waste for culling, shipping damage, and on-the-job waste.

Drainage from roofs, rain gutters, and other sources of moisture around the job site/home must be directed away from the site.

If there is a crawl space, make sure there is at least an 18” clearance from the dirt to the bottom of the beams. Remove all cardboard from the concrete walls, pillars, and footings, as it will trap and hold moisture. The entire crawl space must be covered with a minimum of 6 MIL plastic (puncture resistant) with all seams overlapped 18” and fully sealed with moisture-proof tape.

To prevent excessive moisture buildup, all crawl spaces must have a minimum of 1.5 sq. ft. of ventilation for every 100 sq. ft. of crawl space at the house’s exterior for cross ventilation, or an air exchanger will be needed. It may be necessary to install temperature/humidity-activated exhaust fans to create air movement in the crawl space.

All exterior doors, windows, drywall, painting, and venting must be properly installed before the delivery of the flooring to the job site/home. Do not store in exterior sheds, garages, or rooms that are not temperature-controlled.

All heating and cooling systems are required to be installed and functioning for at least 14 days before the installation begins.

Use a hygrometer that reads temperature and RH (relative humidity) to check job site/home heating and cooling systems. They must be able to maintain a minimum of 35 to 55% RH and 65 to 80°F before and during the flooring installation. Post installation, the temperature must be maintained between 60 to 80°F.

Small humidifiers are not capable of properly maintaining the humidity levels in large job sites/homes. Local heating and cooling air service contractors can provide information for automatic humidifiers/dehumidifiers that work with pre-existing heating and cooling systems.

Solid hardwood flooring is not recommended to be installed in any area of the job site/home that has extreme temperature and moisture fluctuations. For example: saunas, hot tub/pool rooms, greenhouses, exterior porches, or garages. The manufacturer does not warrant against these types of moisture-related issues or related damages under their warranty.

[02] IN-FLOOR RADIANT HEAT SYSTEMS RADIANT HEAT REQUIREMENTS FOR SOLID WOOD

Note: Solid wood flooring CANNOT be installed over in-floor radiant heat unless it is marked as approved for in-floor radiant heat. It is the job site/ homeowner’s and installer’s responsibility to check with the manufacturer for a current list of approved wood products that are warranted for in-floor radiant heat installations.

Note: If the solid wood is approved for in-floor radiant heat, all NWFA wood installation guidelines must be followed.

In-Floor Radiant Heat Systems:  At no time during the life of the floor should the boiler setting exceed 110 degrees Fahrenheit, or the sub-floor surface temperatures ever exceed 80 degrees Fahrenheit. It is recommended that the surface temperature stickers (heat sensors) be installed under the wood floor, directly over the in-floor radiant heat source for every 300 SF installed. These temperature stickers can be used to validate that the surface temperature is never exceeding 110 degrees Fahrenheit.

Operate the in-floor radiant heat systems for at least 14 days before the wood flooring is installed. All moisture in the substrate must be evaporated off. This will also ensure all systems are in good running condition.

The in-floor radiant heat systems CANNOT be installed directly below the wood flooring. It must be embedded a minimum of 1/2” in the concrete, gypcrete (if using a subfloor sleeper system), or installed under the wood subfloor. This will ensure the radiant heat is evenly distributed across the substrate before the heat comes into contact with the wood flooring.

[03] MOISTURE SPECS FOR SOLID WOOD

IMPORTANT: One of the leading causes of wood flooring failures is moisture level inconsistency and/or rapid swings in temperature on the job site/home. Wood flooring performs best when installed in a room with moisture levels in the air between 35 to 55% relative humidity, with air temperatures ranging between 65 to 80 degrees Fahrenheit. The humidity level and air temperature will also greatly impact the wood’s performance life of the furniture, cabinets, doors, and trim work.

Due to wood’s unique grain structure and density, some moisture meters will not properly test all types of wood flooring. It is critical to use only approved moisture meters that have been properly calibrated for your particular wood flooring and environment. Inexpensive lumber testers are usually not adequate for testing wood flooring. These types of meters can give an inaccurate reading. Please contact a professional flooring installer to verify your moisture meter is approved for testing wood flooring. Follow the moisture meter manufacturer’s instructions on how to properly calibrate and use the meter. It is highly recommended that all moisture testing be documented with photographs.

HOW TO TEST MOISTURE CONTENT OF SOLID WOOD FLOORING AND WOOD SUB-FLOORS:

Using an approved pin or electromagnetic moisture meter, test both the wood sub-floor and wood flooring for moisture content labeled in percentages. The wood sub-floor and wood flooring should test within the same ranges as the highlighted area on the EMC chart shown below (usually between 6 to 10%, but never exceeding 12% moisture content).

It is recommended to test multiple pieces of the wood flooring inside every box and a minimum of every 300 ft2 of the wood subfloor. Pay special attention to exterior walls and areas around plumbing fixtures.

It is not recommended to install wood flooring over any wood subfloor that tests above 12% moisture content. If the moisture content is above 12% check for possible sources of moisture from sources such as leaking plumbing fixtures or poor venting from the crawl space.

Solid wood flooring moisture content must be dried down within 2% of sub-floor moisture content before installation begins (follow the EMC chart).

Accepted ranges for moisture content of wood sub-floors & flooring.

How to read the EMC chart:

Test the air for temperature and humidity levels in the room in which the flooring will be installed. The horizontal row on the top of the chart below is the humidity range. The vertical column on the far left is the temperature range. Where the two meet is what the general moisture content of your flooring should be.

IMPORTANT: This is only a guide and is subject to change. Consult a flooring professional to address any concerns.

[04] ACCLIMATION TIPS FOR SOLID WOOD

IMPORTANT: Wood flooring comes in two distinct construction types, solid and engineered. These different construction types can also be packaged and manufactured differently. Be sure to read the manufacturer installation guides inside each box for its particular requirements on acclimation. The information below is only a general guide until you receive the actual boxes of wood.

General acclimation tips: When the moisture content of the substrate is documented and it is acceptable for wood flooring, deliver the wood flooring to the job site/home. Test the wood flooring planks with an approved moisture meter. Write the wood flooring moisture content on the back of the planks. After 48 hours, check the planks to see if the moisture content is increasing or decreasing. Document these changes on the back of the planks. Repeat these steps until the wood planks have achieved an equilibrium point, neither gaining nor losing moisture. Once the solid wood planks test within the acceptable range (within 2% of the substrate), they can then be installed.

Wood flooring will usually acclimate while in the box if there is no plastic covering the wood flooring or the box. Some wood flooring products are wrapped in plastic to protect the materials from absorbing moisture in transit or storage. If the wood flooring or the box is wrapped in plastic, remove it once the product quality, color, and application are approved by the end user. This will allow the wood flooring to acclimate properly.

Always acclimate the wood flooring in the temperature-controlled room where it will be installed.

Wide plank wood flooring generally takes longer to acclimate than narrower planks. Wide plank wood flooring has a greater chance of shrinkage or expansion issues if it is not properly acclimated.

Run a humidifier/dehumidifier as needed to maintain proper humidity levels. Keep relative humidity in the air between 35 to 55% for at least one week before the delivery of the wood flooring.

Avoid loading wood flooring into the job site/home when it is raining. If the boxes of wood flooring get wet, it can extend the amount of time it takes for the wood flooring to acclimate.

Never cover wood flooring before, during, or after installation with any type of plastic or tar paper. It must be allowed to breathe. Use only breathable materials like construction paper to protect a wood floor.

The boxes of wood flooring need to be elevated a minimum of 4” off the concrete substrate during the acclimation period.

Keep the stacked boxes/loose planks of wood flooring a minimum of 3” apart to allow air circulation around the boxes.

Installing wood flooring before it has properly acclimated will greatly increase the chances of plank shrinkage, squeaking, or popping issues, and may void your warranty.

Propane heaters are not an approved source of heat and can give off extreme amounts of moisture and do not provide a reliable and consistent source of heat. The manufacturer warranty will be voided if the job site/ home’s heating and cooling system is not fully operational at least two weeks before installation.

[05] MOISTURE RETARDER REQUIREMENTS

If installing on approved solid wood over radiant heating systems, be sure to only use moisture retarders that are approved for in-floor radiant heat systems. Check with local building codes and the manufacturer of the radiant heat systems for recommendations. Important: It is not recommended to use any moisture retarder that is oil or tar-based over any type of in-floor radiant heat substrate unless it is marked suitable for radiant heat as these may give off toxic fumes.

Nail/Staple down method: If the nail/staple down method is being used, it is recommended to use a silicone vapor shield to cover the entire substrate.

Aquabar “B” underlayment can be used as a vapor retarder but is not recommended over radiant heat.

[06] APPROVED SUBSTRATES FOR SOLID WOOD FLOORS

THE MANUFACTURER WILL NOT WARRANTY SOLID WOOD FLOORING INSTALLED OVER CONCRETE OR GYPCRETE; HOWEVER, SOME ADHESIVE MANUFACTURERS MAY PROVIDE A SEPARATE WARRANTY.

PLYWOOD OR OSB/CHIPBOARD:

Solid wood flooring can be installed over wood sub-floors that are ON or ABOVE GRADE.

Do not fasten wood flooring directly over an ACQ-grade plywood subfloor. ACQ-grade plywood has corrosive properties that will break down fasteners. To ensure proper subfloor construction for nail/staple down installations, verify the plywood or OSB subfloor is exterior grade with a TECO or APA certification stamp.

Wood sub-floors (when walked on) must not exceed 1/4” deflection over a 6’ span. If it does, this condition must be corrected before the installation begins. The subfloor will not stiffen up after the wood flooring is installed.

Fix all squeaks coming from the wood subfloor before installation. Use wood screws, a minimum of 2-1/2” lengths, fastened every 6” through the wood subfloor into the joist. Squeaks from wood sub-floors will not go away after the new wood floor has been installed.

Acceptable minimum wood subfloor thickness is determined by the distance between the joists/trusses.

Subfloors over joist systems: Must be TECO or APA subfloor grade CDX plywood/OSB.

The joist span cannot exceed 16” on center when using 5/8” CDX plywood or 3/4” 40lb OSB, 19.2” on center when using 3/4 plywood or 3/4” 40lb OSB, or 24” on center when using 7/8” plywood or 1” 40 lb OSB.

Solid wood flooring can be installed over wood plank subflooring under  3-1/4” wide. It must be properly installed with vertical deflection under 1/4” over a 6’ span. If the wood planking has lippage or any type of crowning or buckling it must be sanded smooth and CANNOT have any dips or rises exceeding 3/16” over 10’ or 1/8” over 6’. If there is, and it is not corrected before the wood installation, the manufacturer’s warranty will be voided.

Do not nail/staple or glue down new wood flooring over any existing wood plank flooring wider than 3-1/4”. If the wood plank flooring is wider, properly fasten a new 5/8” thick plywood layer over the top. Install the wood floor directly over the new plywood.

Fix all squeaks coming from the wood planks before installation. Use wood screws, minimum of 2-1/2” lengths, fastened every 6” through the wood planks into the joist. Squeaks from plank substrates will not go away after the new wood floor has been installed.

Particle Board and MDF Sub-Flooring:

Important: It is not recommended to fasten or glue solid wood flooring down over particle board sub-floors. Either remove the particle board or install new 5/8” thick plywood over the particle board. Install the new wood floor over the new plywood.

[07] GENERAL SUBSTRATE CONDITIONS FOR SOLID WOOD

All substrates must be flat and free of dust, loose particles, paint, drywall compound, and structurally sound.

If leveling of the substrate is required, use only cement-based leveling compounds. Be sure to follow the leveling compound manufacturer’s installation guidelines.

Sand and/or flatten the substrate to within 3/16” dip or rise over 10’ or 1/8” dip or rise over 6’ for all nailed/stapled, floated, and glued down installations. Important: hand-held angle grinders with special cupped diamond grinding wheels and vacuum attachments can be rented or purchased from your local rental or home-building center. This system works well with any type of substrate. Use precautions when sanding any surface. Check the substrate for any health hazards. Always wear safety equipment and an approved dust mask.

[08] SOLID HARDWOOD WASTE FACTOR

Important: Adding additional materials to the total square footage of the entire job can allow you to be more selective with the actual wood flooring that is installed.

The additional waste factors below are only recommendations. If you are concerned about:

Color or graining: add 2-4%

Board lengths: add 1-2%

Small, cut-up rooms with lots of vertical objects: add 1-2%

Installing on a diagonal: add 5-10%

IMPORTANT: Be extremely careful when nailing over radiant heating systems as improper fasteners or usage of tools may pierce the sub-floor, puncturing the heating element.

The waste factors above are only a guide. Jobsite/home conditions and personal taste may vary. Always inspect every plank before installation. When practical, use cut pieces with at least one factory end joint to start or end the next row. This practice will reduce waste. The recommended waste factor for first-quality flooring products is 5% of the total job and 10% with a job that has angled walls.

[09] APPROVED INSTALLATION METHODS FOR SOLID WOOD

Tongue and groove method:

Solid wood floors can be installed using the nail/staple down installation methods. In some cases, solid wood flooring can be installed using the nail/staple/glued method when using the TuffGrip WGA Glue Assist.

NAIL/STAPLE-DOWN METHOD

NOTE: Never nail/staple down or fasten flooring over the top of any underlayment pad, cushion, or foam.

Approved fasteners for 1/2” to 3/4” thick solid wood flooring nailed/stapled down:

Staples, 7/16” or 1/2” crown,15.5 or 16 Gauge (check tool specs), minimum 1-3/4” up to 2” long.

Cleats, “T” or “L”,15.5 or 16 Gauge (check tool specs), minimum 1-3/4” up to 2” long.

When fastening down a wood floor, fastener spacing needs to be 1-1/2” from the ends of the plank and every 8”- 10” along the tongue. Fasten a minimum of two staples into every plank shorter than 10”.

Adjusting the head of the fastener tool and/or air pressure will ensure the fastener is not set too deep or too high in the tongue. Failing to do so will create a loose, squeaky floor. Be careful not to break the tongue. If the tongue is broken during installation, replace the plank.

When nailing/stapling down wood flooring, leave at least a 1/2” expansion gap around every row end, and a 1/2” expansion gap around the row widths.

Working off the longest straight wall, snap a chalk line parallel with the wall that is equal to the width of the wood flooring, plus enough room for the expansion gap. Use blocks of the flooring to maintain the proper expansion gap around all vertical objects coming off the floor (including walls). Keeping the tongue facing out, nail/staple down the first row while using the snapped line as a guide. This will ensure a solid and straight platform to install the next rows against. Once the wood floor installation is complete, remove all spacers or blocks that were used to maintain the expansion gap.

Clean and adjust the nailer/stapler base plate regularly to ensure it does not damage the finish of the flooring.

GLUE DOWN WITH NAIL ASSIST

Solid wood flooring CANNOT be installed over concrete or gypcrete substrates unless it is marked approved for concrete substrates. It is the job site/ homeowner and installer’s responsibility to check with the manufacturer for a current list of approved wood products that are warranted for concrete or gypcrete installations.

ALL BOND AND MOISTURE WARRANTIES COME SOLELY FROM ADHESIVE AND SEALANT MANUFACTURERS. THIS INSTALLATION METHOD SHOULD ONLY BE PERFORMED BY EXPERIENCED WOOD FLOORING INSTALLERS.

USE ONLY URETHANE-BASED ADHESIVES APPROVED FOR SOLID WOOD FLOORING. NEVER USE ANY WATER-BASED ADHESIVES.

Approved adhesives: TuffGrip 90, TuffGrip Unlimited, and TuffGrip WGA Glue Assist. All adhesive bond warranties come solely from the adhesive manufacturer. Be sure to follow all adhesive manufacturer guidelines, trowel sizes, and suggestions. Most flooring manufacturers require that the adhesive is adhered to a minimum of 100% of the bottom of the wood flooring. Periodically check to make sure the trowel notches are clean and are not worn out.

Verify with the adhesive manufacturer to make sure the job site/home substrate is approved with their adhesives.

When gluing down wood flooring over wood sub-floors, remove any paint, dust, or drywall compounds.

During the wood installation, roll the new floor with a soft 100-150lb. roller while the adhesive is still active and again within 45-60 minutes.

Leave at least a 1/2” expansion gap around every row end and a 1/2” expansion gap around the row widths.

When nailing and gluing the hardwood in place, the adhesive should cover 100% of the back of the plank. To have nail assistance, follow the nailing schedule in Section A “Nail/Staple-Down Method.”

Working off the longest straight wall (this is usually an outside wall), snap a chalk line parallel with the wall that is equal to the width of the wood flooring, plus enough room for the expansion gap. Use blocks of the flooring to maintain the proper expansion gap around all vertical objects coming off the floor (including walls). Keep the tongue facing out and glue 3-5 rows down while using the snapped line as a guide. Keep the planks tight with a clamp system and/or green/blue 3M/Scotch Tape model #2080 (it has an orange core). Clean all adhesive residue off the wood floor before it dries. Allow the first rows to dry for a minimum of one hour before installing additional rows. This will ensure a solid and straight platform to install the next rows against. Once the wood floor installation is complete, remove all spacers or blocks that were used to maintain the expansion gap.

Clean all adhesive residue off the wood floor before it dries. Removing dried adhesive from the top of the wood surface may damage the finish. Be sure to follow the manufacturer’s guidelines on adhesive removers.

[10] INSTALLATION TIPS FOR HOW TO IMPROVE THE LOOK OF YOUR WOOD FLOOR

Important: Install your wood floor under good lighting conditions. Examine each plank carefully. Contact the dealer immediately if the material is not acceptable. Materials installed with visible defects are not covered under warranty. The manufacturer will not assume any responsibility for installed materials.

Before installation begins, use a jamb saw to undercut all door casings and vertical objects coming off the floor. To achieve the correct height, combine a piece of the underlayment padding and wood flooring to use as a guide for the saw. Be sure to clean out all debris from under the jambs. This will allow the flooring to slide underneath the object for a clean professional look.

When installing wood floors, try to avoid installing short boards in the middle of the floor. Use these boards for closets, under appliances, and starter/end cuts.

When ready to install, open up and work with at least five boxes at a time. Check for any defects and thoroughly mix the planks to avoid groupings of similar colors, sizes, and graining. Be sure to stack the planks on a flat surface to reduce plank warping.

Planks generally show fewer seams and imperfections if it is installed lengthwise into the light.

Avoid “H-Seams” in the wood flooring for cosmetic and structural reasons. “H-Seams” are when two wood flooring end joints are laid parallel to each other within three rows.

Stagger end joints more than 6” from each other for both cosmetic and structural reasons.

The room will seem longer whichever direction the wood flooring is laid lengthwise.

To avoid trims not matching the shade or graining of the floor, match wood planks up to the trims before installation begins and set those pieces aside. Install these trims up against the matching wood planks.