IAWFP
MEMBER ARTICLES
Disturbing the Peace
By
Mickey Moore
Wood Flooring Advisors (WFA)
The Problem
A colleague and I
were called to inspect wood flooring
in four homes in a new upscale
subdivision in Virginia. The
factory-finished solid strip oak
flooring was making squeaking,
popping and crackling noises.
The Procedure
The homes all had
crawlspaces; the flooring had been
stapled to a 3.4-inch OSB subfloor
over wood joists that were 16 inches
o.c. in most areas and 19.2 o.c. in
others. Some of the wood flooring
squeaked right away after occupancy,
while other areas started making
noises three to four months after
occupancy. Later, it was noticed
there was an issue with the
springiness of the subfloor
involving the spans and joist
spacing, so the builder had done
some retrofit work to stiffen the
subfloor system. In addition, some
areas of the wood floor had
been replaced and others were
face-nailed to address the noises,
but these actions did not fix the
problems.
The Cause
Upon walking
into the homes, it was apparent
there were humps in the flooring
every 4 feet, which were from edge
swell of the OSB panels. There were
noises throughout the flooring; some
boards would make the noise as many
times as they were stepped on, while
others would stop making the noise.
The flooring itself was basically
flat and together. Measurements of
20 runs of boards were within
1.16
inch plus or
minus, so the flooring had been
installed on size and remained that
way. The flooring was at 8.5 to 9
percent moisture content (MC), while
the subfloor averaged 13 to 14
percent. One house had a subfloor MC
of 15 percent, and in two homes
there was evidence of mildew on the
subfloor when looking from
underneath. We took up sections of
the flooring and the subfloor about
48 inches long and 24 to 30 inches
wide. The fasteners were seated
correctly, the fastener schedule was
correct, and the tongue and groove
configuration was correct. We did
pull tests with testing machines to
determine the fastener holding power
in the OSB, and it did not perform
as well as the industry testing that
had been done previously regarding
OSB and wood flooring fasteners.
Cases such as
this demonstrate that in most cases,
there is no black and white, only
gray. The OSB wasn’t holding the
wood flooring fasteners, even though
OSB is an approved subfloor for wood
flooring and some of the OSB used
involved higher-end, brand-name
products from three manufacturers.
There was evidence of previous
moisture in the homes that
contributed to the subfloor issues
(the moisture caused thickness swell
and movement, affecting the way
fasteners were held in the
flooring). There was no evidence
that there were moisture problems at
the time of the flooring
installation, however.
How to Fix the Floor
As always, one
option was to live with the issues,
but that was not acceptable in this
case. Other options were to replace
the flooring by installing a minimum
5.8-inch
plywood over the OSB before a new
floor or to install a new floor by
nailing and gluing. Most contractors
opt for gluing and nailing, as it’s
the more cost-effective method.
In the Future
We found no
evidence that the installer in this
case did anything wrong. However,
it’s always best to address any
concerns about the job site with the
builder and owners in a written note
before the flooring is installed,
whether it’s an indication of
moisture problems or movement in the
entire subfloor system. That way,
when things don’t perform as
expected, it’s easier to re-identify
the problems associated with
previously mentioned site
inadequacies.
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