Karlson Hardwood Floors, LLC Approved Maintenance Instructions


National Wood Flooring Association Installation Instructions

Before installation of Karlson Hardwood Floors, your installation professional should follow the installation guidelines set by the NWFA.  These are industry standards and any questions or concerns can be addressed by calling the NWFA at 1-800-422-4556.

 Before Installation:

  • Prior to installation, any and all concerns regarding the grade or milling of this product should be directed with the manufacturer.
  • Both the installer and the home owner are responsible for inspecting all wood flooring prior to and during the installation process.
  • It is the responsibility of the installer to protect the home owner from installation of any damaged or questionable product: any damaged or questionable material must be returned to Karlson Hardwood Floors in its original state in order to receive credit for material.
  • Any noticeable question in color, sheen or grade of material must be presented to the manufacturer prior to installation.
  • All responsibility to resolve any issues regarding product quality or manufacturer defects must be directed to the manufacturer prior to installation or the manufacturer will not be liable for any costs of product or replacement.
  • After completion of the installation, the customer is responsible for the care and maintenance of their hardwood floors.


Job Site Conditions:

All Karlson Hardwood Floors should be placed in a climate controlled environment that is well ventilated no less than 72 hours prior to installation or until moisture testing confirms the subfloor and wood flooring is within normal approved moisture content range.  NEVER INSTALL WOOD FLOORING ON A WOODEN SUBFLOOR THAT EXCEEDS 12% MOISTURE CONTENT. 

  • Temperatures should be kept at occupancy levels prior to, during and after installation to ensure a sound installation (between 60 and 80 degrees Fahrenheit).
  • Product should not be exposed to high humidity or moisture content in any room or building in which hardwood flooring is installed.
  • Average sub-floor moisture content should be within 2% (3 ¼” and wider) or 4% (strip 3” or less) of the moisture content of the flooring before installation, but the subfloor should not exceed 10% moisture content to ensure a sound installation and prevent moisture related issues such as cupping.
  • It is recommended that heating and cooling systems are installed and running for a minimum of  2 weeks prior to installation the wood flooring.
  • It is important that the residential or commercial job site be able to maintain a relative humidity of 35 to 55 percent at all times for the life of the wood floor.  To test the relative humidity and ensure the relative humidity requirements are met, contact your heating and cooling service contractor for installation of humidifiers and/or dehumidifiers for your heating and cooling system.
  • It is important that the installer and home owner check all crawl space and basement moisture content prior to installation.  All homes with a crawl space must maintain 18 inches of clearance and must be covered with a 6 mil plastic with NO OPEN SEEMS and an approved vapor barrier for the subfloor.


Sub-floors, grade and preparations for ¾” solid hardwood flooring:

  • Karlson Hardwood Floors can be installed over any APA approved plywood 5/8” or ¾” and ¾” OSB substrate.
  • ¾” solid hardwood flooring is not recommended or approved by Karlson Hardwood Floors to be glued down on any concrete substrate; this will void any and all manufacturer warranties.
  • Karlson Hardwood Floors are recommended to be installed on or above grade with a sub-floor vapor retardant/moisture barrier placed on top of sub-floor prior to installation (15 lb. asphalt felt or rosin paper is an acceptable moisture barrier).


  • After moisture barrier has been placed on sub-floor and overlapped 2 to 4 inches, the flooring strips or planks should be positioned at right angles to the floor joists.
  • A 2” barbed flooring cleat should be used for installation of the solid wood flooring to the sub-floor.  Recommended spacing between nails should be 6” to 8” apart, with a minimum of 2 nails per 12” board.
  • All end joints should be staggered at least 6” apart with a nail within 2” of the end joint of each board.
  • An expansion gap of ¾” is should be left around all walls.

After Installation Maintenance and Care Instructions

Maintenance Instructions: 

  • Karlson Hardwood Floors are easily cared for with routine maintenance.  Simply vacuum and/or use a dust mop often to keep grit and any abrasive debris off the floor.  Hardwood floors can be maintained with a terry cloth cover on the bottom of a DRY MOP.
  • Always wipe up any spills as they occur and use a spray solution of hardwood floor cleaner for maintenance (available at your hardwood flooring dealer).
  • DO NOT USE a wax or oiled based soap cleaners!!!

High Heels and Pets:

All species of wood floors can be severely damaged by high heel shoes or boots.  To best protect against damage to your wood floor associated with high heels, follow the following guidelines:

  • Remove high heel shoes/boots upon entering your home.
  • High traffic areas of your home can be covered with area rugs to prevent damage caused by gritty debris and stiletto shoes and boots.

Pets are like our children and more often than not, they are in our homes more than they are outside.  To protect your wood floor from damage caused by pets, follow these guidelines:

  • Make sure you regularly clip your pet’s nails; if they can be heard taping on the floor, they need to be clipped.
  • Pet urine and vomit are very acidic and can be very damaging to the finish of your hardwood floor.  It is very important that you clean up any accidents your pet may have as soon as possible.
  • If you keep your pets water and food bowls on the wood floor, make sure that the bottoms of the bowls have protective covers  to prevent damage to the wood floor and ALL water bowls should be kept on protective water proof risers or mats designed for wood floors.

For more information please refer to the NWFA Instruction Manual or contact the NWFA at 1-800-422-4556.

Limited Structural Integrity Warranty

Karlson Hardwood Floors, LLC warrants its products to be free from defects in milling, grading and dimension from the factory.  Karlson Hardwood Floors will remain free from these structural defects for a period of 50 years provided they are installed in accordance with NWFA Installation Guidelines and are maintained in a climate controlled environment with a relative humidity between 35 and 55 percent maintained at all times.  This warranty is extended to the original purchaser of the goods and is not transferable to any other party.

25 Year Finish Warranty

Karlson Hardwood Floors, LLC warrants to the original purchaser that the factory applied finish will not wear through, peel, or separate from the floors for a full 25 years from the date of purchase, when used under normal residential traffic conditions.  This warranty excludes any indentations, scratches or surface damages caused by lack of proper maintenance, misuse, negligence, water damage or abrasives.  This warranty is extended to the original purchaser of the goods and is not transferable to any other party.  Wood is a natural material that will expand and contract with changes in moisture conditions due to the extremes of each season.  During seasonal changes some minor separation could occur; this is not a manufacturing defect and is not covered under any manufacturer’s warranty.

Warranty Exclusions

Karlson Hardwood Floors warranties do not cover structural damage that results from products installed in uncontrolled environments or in extreme moisture conditions.  Specifically dry environments can damage the structural integrity of the flooring (refer back to installation section on relative humidity for information on preventative solutions).  Karlson Hardwood Floors does not warranty against improper installation or any structural damage due to install errors.  Karlson Hardwood Floors warranties do not cover scratches, indentations, damages or defects that have occurred due to negligence.  The installation specialist is the final inspector, along with the purchaser (consumer) of the wood flooring.  All concerns over color, shade variation, grade or any manufacturing defects must be addressed prior to the installation for warranty claims to be valid.  The installer is the final inspector of the product and Karlson Hardwood Floors is not responsible for any labor costs associated with the replacement of any visibly defective planks after installation is complete.  It is the responsibility of the installer and the flooring dealer to ensure your hardwood floor is installed with the National Wood Flooring Association standard guidelines/rules.  If these industry guidelines are not followed, all claims will be rejected.