Installation & Assembly

Engineered T&G – Installation Guidelines
Please contact your local dealer for questions and further information
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that is installed on non-conforming sub-floors will be
greatly compromised and will void all warranties.
The owner and/or installer is responsible for ensuring that
the proper installation conditions and appropriate sub
floors meet or exceed all NWFA industry standards. The
sub floor must be clean, flat, dry and structurally sound.
Proper installation can be affected by adverse moisture
content in the product, humidity at the job site, acclimation
of flooring to local site conditions, preparation of job site,
preparation of the sub floor, and flooring layout.
§ Subfloors must be completely clean – free of wax,
paint, oil, sealers, adhesives, curing compounds,
dirt, and other debris.
§ Subfloors must be structurally sound. Replace any
water-damaged, swollen, or delaminated
subflooring or underlayment. Any problems caused
by inadequate substructures or improper
preparation of substructures void all warranties.
§ Subfloors must be dry. An appropriate moisture
content test using a pin-type moisture meter must
be done and documented. For concrete floors, the
slab must be cured for a minimum of 30 days
before the moisture test.
§ The subfloor must be flat, meeting a minimum of
3/16” within 10” (5 mm in 3 m) or 1/8” in 6’ (3 mm
in 2 m). For concrete subfloors, sand high areas or
joints, or fill all low spots with a cement-based
leveling material (with a minimum compressive
strength of 3000 psi). Leveling compounds must
also be cured for a minimum or 30 days before the
moisture test.
Preferred Plywood Sub Floor: Use 4'x 8' sheets of 5/8
CDX grade Ply- wood underlayment or 23/32" OSB
underlayment with joist spacing 16" on center or 19.2 on
with floor truss system. If joists are spaced over 16" on
center or floor truss system over 19.2" on center, an
additional layer of 1/2" CDX laid diagonal or perpendicular
with 1/8" spacing will be required between sheets of
underlay. Particle board is not an approved subfloor for
nail down or glue down applications.
Minimum Plywood Sub flooring Requirements: 4 'x 8"
sheets of 5/8" CDX grade underlayment with a maximum
16" on center joist construction. If joist system is spaced
over 16" on center an additional layer of 1/2" CDX
Plywood underlayment, laid diagonal or perpendicular,
will be required.
* Minimum specified materials at maximum span and
spacing may result in movement, gaps, and noises.
Solid Board Sub flooring: Should be 3/4"x 5 1/2" Group
1 dense soft- woods, No.2 Common, Kiln dried less than
15% MC.
Concrete: Solid Hardwood Floors can be laid on concrete
provided an appropriate sub floor and moisture barriers
are installed over concrete.
1. Make sure concrete is clean, flat, dry and structurally
sound.
2. Floor should be flat to within 3/16” in 10'.
3. Substrate should be flattened to tolerance.
4. Always use a 6 mil poly moisture barrier when installing
over concrete (Floating installation).
5. If a concrete sub floor is lightweight (less than 100 lb.)
rule of thumb: Draw a nail across the top of concrete and
if it leaves an indentation, it is probably lightweight
concrete and cannot be installed using the glue down
method. With light weight concrete you must float the
wood flooring.
Moisture testing for material and wood subfloors:
Using a pin-style meter, test wood for moisture content.
Wood should be between 6% - 9% moisture content prior
to installation. The subfloor should be within 2%
difference of the hardwood, with the moisture content of
the subfloor not to exceed 11%.
Crawl spaces must be cross-ventilated (1.5% of the total
sq. ft.). 6-8 mil black poly covering 100% of the ground
and a minimum of 24” from the ground to the bottom of
the joists.
Test concrete for moisture using one of the following
methods:
Calcium chloride test: Follow test manufacturer's
directions, performing 3 tests for the first 1,000 s/f and one
additional test for every subsequent 1,000 s/f. Moisture
emission rate should not exceed 3 lbs. per 1,000 s/f.
Insitu test: Relative humidity probes should read 75%
relative humidity or less in all areas.
For further information on moisture testing, follow the
guidelines published by the National Wood Flooring
Association, www.nwfa.org.
Additional Sub Floor Notes
Sub floor surface must be clean, flat, dry and structurally
sound. Manufacturer will not be responsible for any