1.7.2 Mohawk Hardwood Installation Guide
some of these products may have the necessary qualifications of underlayment for wood flooring installations,
others do not.
To test for lightweight concrete, scrape a coin or key across the surface of the subfloor. If the surface
powders easily or has a dry density of 100 pounds or less per cubic foot, do not install Mohawk hardwood.
Concrete sub-floors must be dry, smooth (level with 3/16” in a 10 foot radius – 1/8” in 6”) and free of
structural defects. Hand scrape or sand with a 20 grit #3 _ open face paper to remove loose, flaky concrete.
Grind high spots in concrete and fill low spots with a Portland based leveling compound (minimum 3000
PSI). Concrete must be free of paint, oil, existing adhesives, wax, grease, dirt and curing compounds.
These may be removed chemically or mechanically, but do not use solvent based strippers under any
circumstances. The use of residual solvents can prohibit the satisfactory bond of flooring adhesives. It is
important to ensure a proper bond between the adhesive and the concrete, and planks or strips. Mohawk
Engineered Hardwood Flooring may be installed on grade, above grade, as well as below grade where
moisture conditions do not exist.
➡ To ensure a long lasting bond, make sure that the perimeter of the foundation has adequate drainage
and vapor barriers.
Wood Sub-Floors
Wood sub-floors need to be well nailed or secured with screws. Nails should be ring shanks and screws
need to be counter sunk. The wood subfloor needs to be structurally sound and dry. They should not
exceed 14% moisture prior to installation. If the sub-floor is single layer, less than 3/4” thick, add a single
cross layer for strength and stability (minimum 5/16” thick for a total 1” thickness). This is to reduce the
possibility of squeaking. Wood sub-floors must be free of paint, oil, existing adhesives, wax, grease, dirt
and urethane, varnish etc. Underlayment grade OSB (not the wax side) is also a suitable sub-floor.
Particleboard is not an acceptable sub-floor for staple or nail down installations but can be used as a sub-
floor in glue down installations. When installing over existing wood flooring, install at right angles to the
existing floor.
Sub-Floor Moisture Check
Mohawk Hardwood Flooring Adhesive may be used for above, on and below grade applications and on all
common substrates. On and below grade applications are susceptible to moisture and should be tested for
moisture prior to installation in several locations within the installation area. Acceptable conditions for an
above, on and below grade applications are:
✔ Less than 3 lbs./1000 sq. ft./24 hrs. on a calcium chloride test.
✔ Less than a reading of 5.0 on a Tramex Concrete Moisture Encounter (moisture meter).
✔ Wood substrates must have a moisture reading of less than 14% when using a Tramex or Delmhorst
or equivalent moisture meter.
To correct any subfloor problems concerning moisture, either wait until the subfloor dries to meet
specifications or use and appropriate moisture barrier. For more information concerning moisture conditions,
call Mohawk’s Technical Department at 1-888-6MOHAWK (1-888-666-4295).
Sub-Floors Other than Wood or Concrete
➡ Note: Perimeter glued resilient vinyl and rubber tiles are unacceptable underlayments and must be
removed.
Terrazzo, tile and any other hard surfaces that are dry, structurally sound and level, as described above, are