Common Wood Floor Failures
By Frederick M. Hueston
Natural wood floors add special warmth to a space and can
increase the value of a home or business. However, with that said, wood floors
are not flawless, and problems can arise that distract from their beauty. Some
of these problems can result in long-term damage. All wood floors eventually
deteriorate, but if they show signs of deterioration after just a few years,
then it is likely that either something went wrong during the installation or
that the floor was not properly maintained. This article is a brief guide to
some of the most common issues with wood flooring and how to avoid or repair
them.
Improper Prep Before and During Finish Application
Before a finish is placed, the floor must be properly sanded
and cleaned to receive the finish. If not, the finish tends to peel. In
addition, the finish must be abraded and cleaned in between coats, and adequate
drying time allowed before a topcoat is applied. Failure to do any of these
things can result in the finish peeling.
Improper Wood Floor Sanding
Improperly sanded floors have sanding grooves that are
problematic to finish application. Wood floor finish settles at the bottom of
these sanding grooves, but the tops of the grooves receive little to no finish.
Consequently, surface deteriorates when the floor is exposed to foot traffic.
To avoid this problem, try sanding bare boards to either 100 or 120 grit,
depending on the finish.
Pay attention to the sanding materials you use in between
coats of finish. Old abrasive screens or sanding pads can cause unattractive
scratches that resemble spider webs on a wood floor. Additional finishes can
accentuate these flaws. By the time you finish the job, poor sanding will be
very obvious. To eliminate these scratches, the finish must be sanded past the
coat where the scratches were first produced. Unfortunately, it can be
challenging or even impossible to determine which coat of finish is scratched,
so your best bet would be to start over and completely refinish the floor.
For proper wood floor sanding, sand between each finish
application with high-quality abrasive pads that produce smaller, less
apparent, and more numerous scratches. A suitable scratch pattern can greatly
improve adhesion between finish applications. When sanding oil-based
polyurethanes, use 150- to 180-grit pads, and when sanding between applications
of water-based finishes, use 220-grit pads.
For the best finish, use the best sandpaper.
Inadequate Wood Floor Finish Drying Time
If coats of finish are added too quickly, the finish could
take up to six months to cure. The result will be a wood floor with an aged
appearance. Be sure to allow adequate drying time between finish applications.
Improper Wood Floor Maintenance
Thoroughly polished and sanded wood floors will need
periodic professional services in order to maintain a pristine, welcoming
appearance. Damage to the finish can happen in numerous ways. Grit on wood
floors behaves like sandpaper with foot traffic. Unprotected furniture feet or
unclipped pet nails can severely damage a finish, as well. Sometimes re-coating
a slightly worn floor without completely removing the original finish can
dramatically improve the appearance of the floor. On the other hand, it is
better to sand down a floor to bare wood and refinish it if it has significant
wear and severe scratches.
Other Common Problems
Other common problems with wood floors include peeling, grit
and foreign particles in the finish, finish droplets, stains, gaps, cupping,
buckling/sagging, and cracks. Let's take a look at each of them.
Peeling
The most frequent source of peeling is excess stain that is
not removed from the floor before applying finish. Remove excess stain no later
than three minutes after it has been applied and allow the floor to completely
dry before applying the finish to avoid a buildup of stain residue. Don't use several
applications of stain too quickly. Allow it to dry.
Other causes of peeling include using finishes that are
incompatible with each other or applying finishes to burnished wood, that is,
wood that has become too smooth because of high-grit over-sanding.
When a floor peels, the best solution is to sand the floor
down to the bare wood and start over. The issue might not be resolved by simply
abrading the floor and applying a fresh topcoat, because furniture polishes,
waxes, and oils used to clean wood floors can soak into the pores of the finish
and may hinder new finish from successfully adhering.
Grit and Foreign Particles
Wet paint functions like a sizable piece of flypaper. Once
the finish is complete, any dust or animal hair that gets inside of it will be
more noticeable. Clean every surface in the room, including light fixtures and
walls, before finishing the floor to keep debris from damaging the finish.
Sweep the floor and wipe it down with a tack cloth, but never use tack cloths
made for use on automobiles. They can have silicone in them, which jeopardizes
the finish.
Line your applicator tray with an inside-out garbage bag.
Strain the finish before being pouring it into the applicator. Finally,
carefully wash and vacuum the applicator to eliminate any remaining loose
fibers.
In the event that some debris penetrates the finish, make
repairs by sanding the floor between applications of finish and then painting
the floor with a fresh topcoat.
Finish Droplets
Moisture is always to blame when tiny polyurethane droplets
collect around the borders of each floorboard. The polyurethane that flows into
the spaces between the floorboards as the floor moves is what causes the
droplets. This issue typically arises when a floor is being finished during the
transition between dry and humid seasons. The boards expand as they acclimatize
to the weather, pushing any uncured polyurethane out of the gap.
Poly droplets can be eliminated with a razor blade, a rag,
and floor cleaner if they are discovered in time. If a mess has already been
formed, either from walking on the droplets or from allowing them to dry, then
each droplet must be manually removed with a razor blade from the floor before
the entire surface is abraded in order to prepare for a new topcoat.
Stains
The most common cause of wood floor stains is pet accidents,
although water can also be very destructive. A wood-floor cleanser can
typically remove stains that have accumulated on a floor finish, but stains
that have penetrated the wood surface must be sanded off. Stains that seep into
the wood fibers are the most challenging to remove.
Two-part wood bleach can be used to restore the surface of a
stained wood floor. Bleach the entire floor, not just a portion of it. (This
requires a lot more work but results in a floor with a uniform gloss and hue.)
After a couple of hours, neutralize the floor, and once it has dried, it can be
sanded and refinished. Deeply soiled floorboards, particularly those that have
been affected by pet urine, are typically replaced. However, removing stains
with two-part wood bleach can also work.
This stain removal method comes with some negative aspects.
The tendency of bleach to break down wood fibers can make wood more prone to
denting. Additionally, there is no guarantee that the bleach will completely
remove the stains from the wood, so wood flooring or floorboards may still need
to be replaced.
Gaps
Wood flooring is susceptible to shifting. Properly installed
floorboards will hold tightly together during the humid seasons of the year and
may show gaps during the dry seasons. The installation of flooring in overly
dry places can also result in abnormal gaps, which are typically caused by the
flooring being too moist when it is put in place. Examples include regions that
receive a lot of sunlight, floorboards installed directly over heating ducts,
and houses heated by wood stoves, which produce a dry indoor environment.
Gaps can be an aesthetic problem and should be fixed anytime
they detract from the appearance of the entire floor. Fix abnormal gaps during
the wettest season of the year when gaps are the smallest. Closing gaps when
they are at their widest could result in a floor that buckles due to
insufficient space for expansion.
Finally, never fill gaps with wood filler. Instead, use wood
glue to attach small pieces of wood to the floorboard borders to create a
repair. To avoid gluing any boards together, take care to just apply glue to
one side of the sliver.
Cupping
A board's edges cup when the bottom is wetter than the top.
The most frequent cause of cupping is the installation of flooring over a damp
basement or crawlspace. Although cupping is more likely to occur on wide plank
flooring, it can also occur on strip flooring.
Vapor retarders can improve the situation by reducing the
rate of moisture migration but should not be considered a long-term fix for
moisture issues. For strip flooring laid over traditionally constructed floors,
use a vapor retarder. On floors over slabs, install broad plank flooring, or
install radiant heating.
Once moisture problems have been resolved, some cupped
floors flatten while others will remain irreversibly distorted. When the
moisture content of the top and bottom of the boards is within 1%, a floor that
does not lie flat will need to be sanded. To inspect the board bottoms, drill a
moisture meter through the subfloor. Do not sand the peaked edges of a floor
that has been cupped too soon, or you will risk having crowned boards once the
wood is completely dry.
Buckling and Sagging
Too much moisture can cause wood flooring to expand to the
point that it rises off the subfloor, causing shifts to door frames and
separation of floor trim from walls. A floor may sag because of a flood, a
moist basement, or from being installed when it was too dry. In any event,
moisture is the primary cause of buckling and sagging.
Proper fastening can help prevent buckling and sagging.
Nails should be the right size and spaced correctly. Using the proper size
trowel during glue-down installations can help ensure a strong bond between the
floors and the subfloor. Poor fastening can make buckling and sagging problems
worse.
Some buckled floorboards can be refastened, but some need to
be taken out. When feasible, reuse floorboards, but if the tongues and grooves
are broken or the boards are damaged, you must replace them. Do not attempt to
restore buckled flooring until moisture problems have been resolved and the
moisture content of the floorboards and subfloor is at the proper level.
Cracks
Compared to other types of flooring, factory-finished wood
floors have more cracks, and a wood flooring nailer can easily ruin the finish
on these boards. Most manufacturers produce adapters for their nailers that
prevent the force of the nailer from concentrating on the surface of the
floorboards.
Boards with a severely damaged edges should be immediately
replaced during installation.
The faces of floorboards, whether factory-finished or
normal, can develop cracks. Checks in the wood are usually to blame for this
damage. Some species of wood are more prone checking and cracking than others.
Manufacturers can also cause cracking if the kiln dries the
wood too soon. A manufacturer repair kit, which normally consists of wood
filler, colored marker, and a bottle of finish, can be used to fix
factory-finished boards. To ensure that
the colors, tones, and sheen are exactly matched, replace the board, or fix the
crack with wood filler before applying a layer of finish to the entire floor.
Follow these suggestions to resolve problems that diminish
the beauty of wood floors or cause long-term damage. A properly installed and
maintained wood floor can last a lifetime.
