Installation Instructions

Test the subfloor. Set the meter to the type of subfloor. Obtain an average by meter testing the
subfloor (10 locations per every 500sqft). Test around exterior doorways, near plumbing and
foundation walls and in the center of the room. On average, the subfloor moisture range must not
exceed 12%.
Test the new flooring. Set the meter to the proper wood species. Obtain an average reading by
testing (20 boards out of every 500sqft) of new flooring. The flooring can have acceptable moisture
range between 4%-8%, with no more than 5% of total material containing a variance up to 10%. After
thoroughly testing both the subfloor and the flooring, be sure that the average moisture content of both
doesn’t differ by more than 4% for strip flooring (boards 2 ½” or less) and 2% for plank flooring (3” or
wider). If high moisture readings are found in either the new floor or subfloor identify the moisture
source and correct. Extend acclimation time. Postpone the installation until the proper conditions have
been met. It is recommended to document moisture test results with notes should future questions
arise; include a record of the customer’s name, the order number and digital pictures showing the
meter used, including the time and date.
WOOD SUBFLOORS
All wood subfloor components must not exceed 12 percent moisture content.
Do not install flooring directly over floor joist without subflooring. Subfloors provide strength and a proper nailing base.
• Install subflooring sealed-side down. Square-edged or non-tongue and grooved panels used as a subfloor will require a
minimum 1/8˝ (3 mm) expansion space placed between all plywood seams. Panels must meet minimum CD grade
Exposure 1 and US Voluntary Product Standard PS1-95, PS2-04 or Canadian performance standard CAN/CSA 0325-0-
92 for construction sheathing. Check panel/supplier for codes.
• Solid board planks used for subflooring should be ¾” x 5 1/2” (1” x 6” nominal), Group 1 dense softwoods, No. 2 Common
• Particleboard, Luan or Masonite: is not recommended for nailing solid wood, remove and replace with minimum
recommended subfloor material to meet minimum thickness requirements or cover with 3/8” plywood underlayment.
• Minimum of 3/8˝CD panel thickness is recommended when used as an underlayment when needed.
• Avoid pressure treated plywood for interior use. These can have elevated moisture or latent with rot resistant chemicals.
Note that joist spacing determines minimum subfloor thickness.
• Joist spacing 16” (oc) on center or less
Plywood: Minimum of (5/8˝, 19/32) Oriented Strand Board (OSB): minimum (3/4˝, 23/32”) Advantech minimum (3/4˝,
23/32”)
• Joist spacing 16” up to 19.2” (oc)
Plywood: Minimum of (3/4˝, 23/32”) Oriented Strand Board (OSB): minimum of (3/4˝, 23/32”)
• Joist spacing over 19.2”up to maximum 24” (oc)
Plywood: Minimum of (7/8”) Oriented Strand Board (OSB): Minimum of (1”) or two layers of subflooring, or brace between
truss/joists in accordance with local building codes.
Wood floor orientation
• Nail wood flooring perpendicular to the floor joist.
• Nailing wood flooring parallel to the floor joist is an option using a combination of plywood, OSB, Advantech or similar
approved subfloors. Floor joist (16” to 19.2 oc) The total subfloor thickness minimum must be 1-1/4”
Floor joist (19.2 to 24”oc) The total subfloor thickness minimum must be 1-7/16”
When nailing over existing solid wood tongue and groove flooring, install over an additional 3/8” plywood or run the new
floor perpendicular or at a 45 degree angle to the direction of the existing flooring.