Nail down installations are regarded as the traditional way to
install hardwood flooring. This type of installation works with
both solid and engineered flooring. Solid ¾" flooring is fastened
to the wood sub floor using cleats (nails) or staples. Engineered
flooring is mostly stapled down depending on the thickness of the
flooring. Suitable sub floors for a common ¾" solid hardwood floor
would be:
- 3/4" CDX grade plywood
- 3/4" (23/32") OSB PS2 rated underlayment
- Minimum 5/8" CDX grade plywood
- Existing solid wood flooring
- Screeds
- Tongue and groove wood sub flooring
Glue down installations comprise a large segment of the hardwood
flooring business. They are often
used in situations where concrete sub floors are king in
residential and high-rise applications. Most glue down applications
use the engineered type of flooring. FloorWorks does not recommend
gluing down any solid flooring more than ½" in thickness. Some
items to consider for glue down applications are sensitivity to the
adhesives used. The types used today are greatly improved
from those of only five years ago when trichlohydrates were
commonly used; a strong lingering odor that would sometimes
take weeks to dissipate. Now the more common types are
urethane and acrylic based that don't pose the reactions
of older ones. Some of the premium types would be Bostiks,
Taylor, Franklin, and Dritac.
Floating floors are installed over a thin pad called underlayment.
The floor is not fastened or adhered to the sub floor, and in
essence "floats" on the underlayment. If the sub floor is concrete,
a moisture barrier is installed before the underlayment is
installed. This is usually a 6-mil polyethylene sheet.
The flooring usually has a locking tongue and groove or the tongue
is glued into the groove. These floors will expand and contract
with temperature and humidity changes from season to season (i.e.;
summer to winter). Expansion zones around the perimeter allow this
expansion. Usually a ¼" expansion is acceptable in a residential
application. All laminate floors are installed using this method
and some hardwood floors can also be installed using this
method.