Installation InstructionSolid Wood Flooring

This is only a guide. Follow the National Wood Flooring Association’s installation guidelines and recommendations when installing FERMA branded products.


A. General Information:

  • It is recommended that installation by experienced professionals who subscribe to installation standards as set forth by NOFMA, NWFA.
  • Use of approved products during installation as described in this installation instruction is required to validate all warranty.
  • Installing solid wood flooring over radiant-heated sub-floor is not recommended and will void the warranty.
  • Sawing, sanding or machining of wood flooring can cause respiratory, eye and skin irritation. The International Agency for Research on Cancer has classified wood dust as a nasal carcinogenic in humans. If using power tools, a dust collector is recommended, as is a dust masks NIOSH approved. Avoid contact with the eyes or skin when in proximity to wood dust. Use of a protective device for the eyes is also recommended.

B. Responsibilities of Purchaser/Installer:

  • The purchaser/installer should inspect all of the flooring before installation. Being a natural product, hardwood rarely will be perfect. Industry standards of manufacture allow for grading deficiencies up to 5%. This 5% may be composed of natural or manufacturing deficiencies. The purchaser/installer should carefully examine the flooring for color quality and finish. If there is any product discrepancy or not acceptable, DO NOT INSTALL it. Seller should be contacted immediately. Installation of flooring denotes installer and owner accepts the materials, even if owner is absent at time of installation.
  • It is noted that stain-putty filler is an accepted part of the installation procedure throughout the industry.
  • It is the purchaser/installer’s responsibility to determine the suitability of the job site environment and sub-surfaces involved. Installation must follow recommendations of the construction industry and the material’s manufacturer as well as local codes. Reference is made to NWFA requirement for minimum job site conditions and substrate requirements.
  • FERMA declines any responsibility for job failure or non-acceptability from or associated with sub-floor/substrates or job site environmental deficiencies.

C. Pre-Installation:

  • Unlike unfinished flooring, extra caution is needed during installation of pre-finished wood flooring to prevent scratch and damage.
  • Solid wood flooring must be installed on grade or above grade. Below grade installation is not recommended for solid wood flooring.
  • The building, where the installation takes place should be completed to an environmental control level, whereas doors and windows are in place and paint and masonry work is dry.
  • Basements and crawlspaces must be dry and well ventilated. Crawlspaces must be a minimum of 24” from the ground to bottom of joists. A ground cover of 6-8mil poly should cover the soil in the crawlspace 100%. Seams lapped at least 12” and sealed. Edges should be lapped up the perimeter walls 3”-6” to divert moisture to the outside. This vapor barrier is REQUIRED.
  • Perimeter venting is necessary to provide for cross ventilation. Minimum combined venting should be equal to at least 1.5% square feet of the crawlspace or exceed where applicable. Local codes prevail. No dead walls allowed impeding cross flow of air movement.
  • The installation site should have at or near environmental living conditions 68F – 72F temperature, 40%-60% relative humidity, prior to, during installation and or until site is occupied. These conditions will allow for acclimation of wood to the proper environmental conditions. Moisture testing is still necessary.
  • Exterior grading must drop at least 3” in 10 feet or according to local codes. All gutters and downspouts must be in place and divert run-off away from structure.
  • Flooring must be stored in a clear dry environment. Do not deliver materials to a site that is not environmentally controlled. This means building must be closed in, windows and doors on, all wet work complete, heat air or equivalent environmental controls functioning, temporarily or permanently. Moisture control is necessary for at least 7 days prior to delivery.
  • The wood sub-floor must NOT exceed 12% moisture content. The difference in moisture content between the sub-floor and wood flooring must NOT exceed 4%, preferably 2% for exotic and larger plank. A reliable moisture meter should be used to measure and determine accurate moisture contents.
  • Acclimation is to allow wood flooring to acclimate to sub-floor with no more than 4% difference in moisture contents (2% is preferred). Acclimation time for solid wood flooring is determined by the moisture content of the sub-floor and the wood at time of delivery, but at least 5-7 days acclimation is needed prior to installation.
  • Exotic woods such as Brazilian Cherry (JATOBA) may need longer acclimation period.

D. Recommended Sub-Floor Surface:

  • Following is requirement of the recommended sub-floor surface:
    Joist spacing 24” o.c. 7/8” plywood.
    Joist spacing 19.2”o.c 3/4” plywood preferred
    Joist spacing 19.2” o.c. 23/32” OSB acceptable (Exposure 1)
    Joist spacing 16” o.c. 3/4” plywood preferred
    Joist spacing 16” o.c. 5/8” plywood minimum
  • Exterior grade rated panels preferred. Exposure I for OSB rated panels is acceptable. For plywood, CDX APA rated is minimum acceptable.
  • Use of minimum standards will result in minimum performance of flooring.
  • Do not install solid wood flooring over particle board, wafer board, pressed wood or fiber board. These products do not have adequate nail holding capacity. Installation over inadequate sub-floor will result in poor performance and will void any warranties.
  • Sub-floors must meet industry standards for flatness. Standards are 1/8” in 6' or 3/16” in 10'.

E. Over Concrete Installation:

  • It is not recommend gluing down of solid wood flooring on concrete. If glued directly to concrete substrates FERMA, warranty is void.
  • Plywood sub-floor systems that are attached to concrete must be secured and installed per industry standards.
  • Plywood sub-floor floating systems are acceptable: minimum 2 layers 5/8” installed at right angles to each other.
  • Screed system is acceptable. (For further details, consult NWFA or NOFMA).
  • A moisture barrier is always recommended over concrete when installing sub floor, for use with solid wood flooring installations.
  • Moisture testing is necessary. A Calcium chloride test is recommended. A result of 3 lbs per 1000sf. in 24 hours is the acceptable, maximum allowable level.
  • PH testing should also be done. PH 5-9 is satisfactory, 7 is neutral as reading above 9 requires corrective action.
  • Purchaser and installer are solely and jointly responsible for pre-installation sub-floor moisture level check and must ensure that all conditions are/or specifications listed in this guide have been thoroughly met prior to installation of hardwood floor.

F. Installation:

  • If installing with manual fastening machine, be sure proper adapter plate is used as well as proper length fasteners.
  • If using pneumatic fastening machines, be sure to use the proper adapters as well as fasteners. Air pressure settings may have to be adjusted to properly set the fastener used. Failure to observe and regulate pressure could result in severe damage to the flooring tongues.
  • 15lb roofing felt tar paper is recommended to be used as a buffer between the sub-floor and hardwood flooring.
  • Remove any molding, base, thresholds and reinstall after floor has been installed.
  • Installation of wood should be perpendicular to joist system. This will assist in maintaining dimensional stability.
  • End joints of adjacent rows should be staggered at least 6” minimum for pleasing appearance.
  • Nailing schedule should fasten boards 6-8” apart with minimum 2 nails per board. Ends to be nailed 1”-3” from each end.
  • Last 2 rows may need to be cut to size and face nailed.
  • Putty filling of nail holes is an acceptable part of the installation of hardwood flooring.
  • Replacing molding, base, and threshold.
  • If covering the floor is needed after installation, it is recommended to cover the floor completely to avoid color changing, since some species are light-sensitive. All covering material should be taped to each other’s overlapping layers and should not be taped directly to finished flooring.

G. Molding:

Finish installations with following choices of moldings that will enhance the appearance of any installation. Refer to the illustrations and descriptions below for the proper use of each molding.

Molding / Trim


F. Further Information:

FERMA FLOORING is a member of National Wood Flooring Association (NWFA). FERMA recommends installation by experienced professionals who subscribe to installation standards as set forth by NOFMA, NWFA. For further information about the installation of solid wood flooring, please refer to related instruction by NWFA as follows:

SOLID STRIP AND PLANK INSTALLATION:
http://www.nwfa.org/member/pdf/InstallG/Chap9.pdf

For more technical information about the installation, please also refer to other associated instructions by NWFA as follow:

JOBSITE CHECKLIST:
http://www.nwfa.org/member/pdf/InstallG/AppenM.pdf

JOBSITE CONDITIONS:
http://www.nwfa.org/member/pdf/InstallG/Chap1.PDF

ACCLIMATION:
http://www.nwfa.org/member/pdf/InstallG/Chap2.PDF

MOISTURE TESTING :
http://www.nwfa.org/member/pdf/InstallG/Chap3.PDF

WOOD SUBFLOOR GUIDE:
http://www.nwfa.org/member/pdf/InstallG/Chap4.pdf

INSTALLING A SUBFLOOR:
http://www.nwfa.org/member/pdf/InstallG/Chap6.pdf

INSTALLATION OVER EXISTING FLOORS:
http://www.nwfa.org/member/pdf/InstallG/Chap10.pdf

GLOSSARY OF WOOD FLOORING TERMS:

http://www.nwfa.org/member/pdf/InstallG/Glossary.pdf