Is there a wood-floor finish
that will hold up to all the sand that inevitably seems to be a
part of life at the shore? It's really taking a toll on the
polyurethane finished strip flooring we installed less than a year
Flooring contractor Michael
Purser, owner of The Rosebud Co. based in Atlanta, Ga.,
responds: Abrasion is an issue with any finish on any wood
floor. But abrasion from beach sand is especially acute: Sand is
essentially silica carbide, which is the same compound that's on
sandpaper — the very stuff we use to remove an old finish. So
there's only so much you can do with the finish itself when
refinishing an existing wood floor. Yes, there are some finishes
that will be stronger than others, but the ultimate solution is
best solved with design solutions and material choices.
The very best way to deal with this problem is at the design phase,
either for a new property or an existing property, by trying to
keep as much sand out of the house as possible. Use exterior
walkways and create entrance hallways that force people coming
inside to "run the gauntlet" before they get to the wood floor
surface. The goal is to get people to knock the sand off their feet
before they enter the house by treading over decking, stone,
unglazed tile, or other surfaces that aren't as vulnerable to the
abrasive effects of sand. This will work only so well to keep beach
sand at bay, however. At the beach, sand comes in anyway — on
feet, shoes, clothes, pets, towels, and so forth. It's a given that
sand will eventually get on the wood floor.
Some help can come from the type of flooring you select.
Prefinished or engineered flooring typically relies on a composite
core like plywood, covered by a solid-wood veneer, making it
inherently more stable. These floors are available with either an
aluminum oxide or a UV-cured coating. Either choice will be the
hardest surface you can get on a wood flooring material, and it
will have the best chance of resisting abrasion. Because the finish
is applied in a highly controllable setting, temperature and
humidity at the site will not become limiting factors.
Engineered "floating" floors come prefinished with either an
aluminum oxide or a UV-cured coating — both finishes that
provide the hardest surface available on a wood flooring
However, having the best clear coat possible is a double-edged
sword. Homeowners tend to drop their guard and think, "Why should I
worry? I have the hardest finish possible." They not only don't
take precautions to control sand, but they also feel it's
unnecessary to put felt pads beneath furniture legs or to rely on
throw rugs to protect high-traffic areas. No matter where I install
or finish a floor, I find it's critical to educate the owner. Every
wood surface is vulnerable, and clients must be informed about how
to care for their investment.
Prefinished engineered floorings typically are not meant to be
refinished. To begin with, the wear layer is usually thin and can't
sustain much sanding. In addition, an aluminum oxide or UV-cured
coating cannot be reapplied on site. However, Basic Coatings
(800-441-1934; http://www.basiccoatings.com) does have a system now
that uses a bonding agent that gets applied over the existing
finish, which allows a new top coat to adhere. This TyKote system
can be used over any existing finish without sanding.
A prefinished floor makes a logical choice for a beach property
that will be rented or leased at least part of the time, if only
because it will be much easier to replace. Renters rarely take care
of a home as if it were their own, so relying on the occupants to
take care of a glossy finish is setting yourself up for heartbreak.
In this case, you might consider treating the wood flooring as an
expendable surface, recoat it using the TyKote system every few
rental seasons, and plan to replace the floor when it becomes too
There are several different urethanes that can be used for
refinishing strip wood flooring, some of which are more suitable
for high-abrasion situations than others. In the end, however, it's
the degree to which a homeowner is willing to maintain the finish
that will depend on how well it survives.
• Moisture-cured finishes are supposed to be
the hardest but have not been popular, primarily because they
contain xylene or toluene solvents, which are extremely volatile.
There has been more than one case of a house being blown off its
foundations when the vapors settle to the basement and ignite as
they reach the water heater's pilot light. I would never apply this
type of finish when a homeowner is occupying the house.
• Oil-modified urethanes are by far the most
commonly used urethanes, mainly because they are the easiest to
apply. They are as susceptible to wear as any other finish, but
they may be suitable if well maintained.
• Waterborne urethanes are gaining in
popularity. They've been around long enough that they have a good
track record of performance, and if properly applied they will
outperform oil-modified urethanes. However, flooring contractors
are often very reluctant to use them because the learning curve for
being able to apply them successfully is so steep. While strong and
durable, they will show wear like any other urethane and must be
protected from abrasion.
Waterborne finishes have a good track record of performance
and, if properly applied, will outperform oil-modified urethanes.
However, the learning curve for installing them correctly is
Controlling heat and humidity. Regardless of
the finish you choose, it's critical to control the job-site
environment. The ideal range for drying and curing coatings is
between 45% and 75% relative humidity at 65° to 85°F. Be
sure to monitor the indoor temperature and humidity levels, using a
hygrometer to measure the relative humidity. Also check the
moisture level of the flooring and the subfloor periodically
throughout the job — when the flooring is received, as it
acclimates to indoor conditions, as it is installed, and prior to
finishing. It's critical that the moisture content be below 12%
before installing and finishing. A good moisture meter is worth
every penny. If the cost seems high ($200 to $300), just think how
much you'll lose going back to correct mistakes.
The best way to control the temperature and humidity conditions is
to have all HVAC systems operational and running three to four
weeks before any finishing work begins.
In summer, when outside temperatures and humidity are high, crank
up the A/C to dry the air and keep the temperature cool and even.
High temperatures (above 85°F) cause the finish to dry so
quickly that it doesn't flow and level as well. If there's no air
conditioner, apply the finish early in the morning when the
temperature is lower.
In winter, keep the heat on. If a forced-air heating system is
being used, the general contractor or homeowner may object to using
the heating system while construction is underway because they want
to keep dust out of the ductwork. I use a paper-towel prefilter
over the air return vents and change the furnace filters regularly
during sanding and screening operations; I have never stressed a
heating system yet.
By now, most contractors have gotten the message that torpedo
heaters are not a good source of heat, because they dump so much
moisture into the air from combustion. Much better to use if the
HVAC system is not active is an oil-filled electric radiator. This
won't provide the gratifying blast of heat for the crew on a cold
morning, but it can maintain the air temperature at a higher level
to keep indoor conditions stable. A simple dehumidifier on the job
will also help remove the moisture that a combustion heater
introduces. This dehumidifier should be in place when the flooring
is brought to the job and installed. Unfinished wood flooring acts
like a sponge; it will absorb any excess moisture when humidity
levels are high.
Curing time. The curing of a floor finish
is like the curing of concrete: It's a chemical process that
continues for days after the finish is dry to the touch. Until it
reaches maximum hardness, the finish is especially susceptible to
scratching, abrasion, and chemical damage. All activity on the
floor during this time should be minimized. Depending on the
product, the drying time can vary from two to eight hours. However,
curing can take from five to thirty days. Read the instructions and
keep in mind the times given are when indoor conditions are ideal.
As the conditions become less than ideal, the curing times will be
Recoating. All three of types of
urethanes can be recoated as they wear, but you don't want to get
to the point of having to sand down the floor completely. When a
coating gets thin, it is much more likely to let moisture penetrate
the wood, which then rapidly accelerates the deterioration of the
coating. It's far better to recoat frequently, screening lightly
first and reapplying the top coat. For most beachfront properties
where keeping a glossy floor finish looking impeccable is desired,
frequent refinishing may be the best option of all.
Any glossy clear coat will get scratched, so one option is to avoid
the glossy surface and opt for a penetrating oil instead. Most of
these are tung-oil products. These soak into the wood without much
buildup and can be refurbished easily. They will produce a matte
finish that simply won't show fine scratches. They are also very
easy to reapply. The existing oil dissolves with the freshly
applied coat, bonding the old and new finishes without
But just because you don't see the scratches doesn't mean the wood
is not getting chewed up. In restoration work, this leads to what's
often referred to a "loss of original material" — it's not a
goal you want to strive for if you really care about the long-term
durability of the flooring itself.
An exception that is only now becoming available in the U.S. market
is a European-style oil finish from Trip Trap of Denmark (available
from Special Hardwood Products, 800-242-8160; http://www.specialhardwood.com). This finish contains
cold-pressed vegetable oils and aromatic hardening oils that both
penetrate and harden, creating a reasonably wear-resistant finish
that can still be easily applied and maintained.
The primary drawback to any penetrating oil is that it provides
limited protection from food, beverages, and grease, which can pass
through the finish and permanently stain the wood. I would not
recommend such a finish in a food-preparation area.
Another potential drawback, which all penetrating oils share, is
the disappointment that may arise from a nonglossy surface. In my
experience with ocean properties, there is frequently a design
emphasis on using large windows to bring in light and views, and a
trend toward enhancing reflective surfaces with glossy finishes.
The look of a matte finish is often a letdown. The owners must be
made aware of what they are getting.