Recommendations for Maintenance and Other Treatments
of
Existing Flooring for Optimum Slip Resistance
Summary
The objective of these recommendations is to reduce
the human and financial costs of slips and falls on all types of flooring
materials, particularly in commercial, industrial and public properties.
Such accidents cause some 1200 deaths, and in the workplace alone about
$4 billion in lost productivity and compensation costs, in the United
States each year.
Benefits of maintaining good slip resistance can
include reduction in injuries and suffering; reduced insurance premiums
from lower three-year losses; reduced risk of lawsuits from visitors
to the property; reduced costs from employee falls or slip-related
ergonomic injuries; and increased customer traffic, particularly from
elderly or pregnant customers who are more aware of flooring hazards.
To maintain good slip resistance and to minimize
your potential liability, select flooring carefully for its planned
use. Modify the flooring with chemical or mechanical treatment if necessary
to increase wet slip resistance. Use matting where necessary to exclude
water and other contaminants. Clean the flooring as required for appearance and safety, without leaving a slippery
residue. Warn pedestrians when there’s a hazard they must avoid. Document
your maintenance practices and training. Have your floors tested periodically
for slip resistance, take action to solve any problems the tests may
reveal, and keep records of your test results and remedial actions.
Introduction
The Slip Resistance Committee of the Ceramic Tile
Institute of America (“the Committee”) is tasked to advance and disseminate
scientific knowledge of slip and fall issues in order to improve safety
of walkway surfaces in the built environment, including floors, stairs,
and pedestrian ramps.
Pedestrian slips occur from an unfavorable combination
of the person involved, the activity in which the person is involved,
the environment, the footwear (if any), and the flooring. Most slip
accidents occur when the footwear or bare feet and/or the flooring
are wet or otherwise lubricated by oil, grease, dust, foodstuffs, etc.
Slips can lead not only to falls, but to ergonomic
injuries without falls. Slips when pushing a heavy wheelchair, gurney,
or other object are particularly likely to lead to injuries.
Switching floor surfaces to carpet does not necessarily
eliminate problems. Carpet can be a growth medium for bacteria and
molds, a collector for allergens, and can make it more difficult to
push wheelchairs, gurneys, etc.
On September 19, 2001 the Committee approved “Endorsement
of Improved Test Methods and Slip Prevention Standards for New Flooring,” which
recommended a laboratory test method for rating slip resistance of
new flooring as well as slip-resistance safety standards for some 150
situations. On December 3, 2001 the Committee approved “Endorsement
of Portable Test Methods and Slip Prevention Standards for Existing
Flooring.” These two publications are available from the Ceramic Tile
Institute of America (CTIOA, telephone 1-310-574-7800).
The recommendations here supplement those in the
two documents named above. The objective here is to give an introduction
to maintenance and other treatments of flooring that will help obtain
and preserve the optimum slip resistance for that particular flooring.
The focus is primarily on commercial and industrial properties. A domestic
floor is typically used by a relatively small number of people, who
become familiar with its slip resistance (or lack of it) or can be
warned individually by residents when entering the premises with water,
snow or ice on their shoes, for instance.
An important step well before maintenance starts
is proper selection of flooring for its planned use. If you’re planning
a new building or renovating an existing one, use CTIOA’s guidelines
for new flooring (see above) to help select flooring based on safety.
If you’re taking over an existing building, have a testing service
survey the flooring for wet slip resistance, preferably before you
make your offer to buy. This will help you assess what problems you
may have when the responsibility for safety in the building is yours.
You should consider these potential problems during your price negotiations
when you offer to buy a building.
Benefits of Good Slip Resistance
Ensuring good slip resistance of your flooring
can have a number of benefits. They include
· Reduction in injuries and suffering
· Reduced insurance premiums from lower three-year
losses
· Lower risk of lawsuits from visitors
· Reduced direct and indirect costs from employee
falls or slip-related ergonomic injuries
· Increased
customer traffic, particularly from elderly or pregnant customerswho are more aware of flooring hazards
In lawsuits from non-employees, damage awards from
a single case sometimes exceed a million dollars. Direct costs of employee
injuries are lower on average because certain damages are not covered.
But indirect, non-insured costs to employers can be significant due
to loss of key people, overtime costs, replacement training costs,
failure to meet deadlines, etc.
Surface Treatments
and Slip Resistance
There are four types of surface “treatments” that
affect slip resistance of existing floors:
· Cleaning
· Coatings applied on-site
· Mechanical alteration
· Chemical alteration
Slip resistance of flooring is most influenced
by the surface actually walked on, which in some cases might be a floor
finish (“wax”) rather than the underlying flooring. The underlying
flooring might have an effect, though, if its roughness (under the
finish, for instance) affects the roughness of the walked-on surface.
Some flooring should not have finish applied, since the finish could
destroy the wet slip-resistance of the flooring. Consider safety as
well as cosmetics and cost when deciding whether to apply finish. Always
check the appearance and slip resistance of a small test area before
treating the entire floor.
By “maintenance” we mean routine periodic work
done on the floor, such as washing, coating with floor finish, buffing
(150–300 rpm), high-speed burnishing (1500–2000 rpm), or polishing.
Mechanical or chemical alteration is typically only done a few times
during the lifetime of a floor.
Variables in Maintenance
The key variables in routine floor maintenance
are
· Chemicals
· Frequency and other procedures
· Agitation and soiling collection methods
Agitation and collection of soiling are variously done
by mops with buckets or wet vacuums, or by scrubbing machines with
brushes or pads.
An autoscrubber can be a very effective
cleaning machine. It applies cleaning solution to the floor, agitates
it with a pad or brush, and vacuums up the dirty water between two
squeegees into a separate tank. A very
soft brush, such as a white carpet shampoo brush, is often the
best choice for cleaning with an autoscrubber. Stiff bristles on hard
brushes tend to skid over the wet floor on their tips without making
contact over greater bristle length that promotes good washing. Pads collect
soil, which can then scratch glossy finishes to the detriment of the
floor’s appearance. If you use a pad, clean or replace it frequently.
String mops are popular, but in practice are often
just a method of spreading soil and grease to make the floor uniform
in appearance rather than clean and safe. Mops can also cause ergonomic
problems for people who spend large amounts of time mopping.
When using mops, consider dedicated mops for specific
areas so that the mopping doesn’t transfer contaminants such as grease
from one area to the other. Color-coding the mops can help keep mops
in their designated areas. Picking up mop solution with a wet vacuum
can be much more effective than rinsing the dirty mop in dirty water.
Using a two-bucket system makes it possible to rinse a mop in clean
rinse water rather than dirty, soapy water.
Clean and/or replace mops frequently so that they
are not effective carriers of soil, grease and bacteria. In some situations
three mops are used to separate the washing, rinsing, and drying processes.
Wood floor sweepers using terry cloth can supplement mops as an aid
in rapid, uniform drying of the floor. Different areas of a property
(e.g. restaurant kitchen and dining room) might need dedicated mops
to prevent cross-contamination. For less transfer of contaminants,
consider using sponge mops rather than string mops — sponge mops can
be cleaned and rinsed more thoroughly. Some floors even act as washboards,
scrubbing dirt out of the mop rather than the mop cleaning the floor.
In the absence of an autoscrubber, wet vacuums
can be effective in lifting dirty and/or greasy water after mopping
a floor. When mopping leaves the floor wet, be sure to exclude pedestrians
from the area until the floor dries. Leave a dry, obvious path for
pedestrians to use to avoid the wet zone. Place “wet floor” signs around
wet areas, but don’t leave the area unattended — and pedestrians unwarned — while
you go to get signs. For spills, consider storing warning signs inside
trash-can containers so the signs are available at a moment’s notice.
Chemicals include sealers, cleaning agents, strippers,
waxes and other floor finishes. Sealers can fill pores in pervious
floors so that soil and staining materials are excluded, and material
below the surface stays below rather than rising to the top and forming
deposits. Penetrating/impregnating sealers are intended to fill pores
in grout and pervious flooring and are not necessarily intended to
form a continuous barrier on the top of the flooring. Check the manufacturer’s
instructions to see if excess sealer should be removed from the surface
before it dries.
Cleaning chemicals help to thoroughly wet, lift,
and suspend soil or grease in the wash water. Using either measuring
cups or proportional flow control, measure dilution carefully according
to directions — don’t guess. Overdosing with cleaner doesn’t necessarily
improve cleaning, but adds unnecessary cost and can leave a film that
becomes slippery under spills or wet shoes. Some cleaners leave residues
that are more slippery than others.
Neutral cleaners (that is, neither acid nor alkaline)
are best for most situations, but alkaline detergents may be more effective
in removing animal fats. Some situations, e.g. certain cleaning agents
in kitchens — may require hot water. Never use a powered laundry detergent
on a floor — it can leave a slippery calcite residue.
Applied floor finishes may have a fairly wide range
of traction properties when dry, but most are slippery when wet. They
are not permanent, but must be maintained and/or stripped and reapplied.
Make sure at a minimum that the slip resistance of the finish you use
complies with American Society for Testing and Materials (ASTM) standard
D 2047 for dry slip resistance. This is a laboratory
test conducted by the manufacturer to establish that the slip resistance
is adequate when the finish is dry and clean. It applies to the finish
only, not to your flooring with the finish on it. Most important, it
applies to ideal laboratory conditions, not real-world conditions.
The test has no relevance to wet conditions.
Before applying a finish to a large floor area,
it’s best to test it on a smaller area for at least several weeks to
check for appearance and potential problems. Disinfectants and highly-alkaline
or solvent-based cleaners affect some floor finishes adversely.
Most finishes are slippery when wet unless professionally
treated chemically after application to create wet slip resistance.
The slip resistance of the floor finish is not
constant, but is affected by what happens to the finish after it’s
applied. Buffing or burnishing may reduce or increase slip resistance,
and it’s important to follow correct procedures as specified by the
reputable manufacturer. Also, make sure that dust particles of finish
don’t remain on the floor after buffing; these can create a slippery
situation even when dry. To detect this dust in subdued light, place
a lighted flashlight on the floor, so that its beam is parallel to
the floor. This will usually make the dust easy to see.
Procedures covers not only the temperature, agitation and
collection methods, and chemicals used, but also the frequency of their
use and the practices of the people who implement them. Floor-care
staffs often have annual turnover rates far exceeding one hundred percent.
In such a situation, constant training and supervision are necessary.
The training and supervision must make clear that safety of the floor
is as important as its appearance and the direct cost of maintenance.
(Indirect costs of inappropriate maintenance
include the costs of injuries to employees and visitors.)
Physical Modification of Flooring for Slip Resistance
Scarification of the surface by sandblasting or
grinding may be one way of increasing wet slip resistance for some
floors — namely, those that will not suffer much by losing their surface
layer. Use only qualified professionals to conduct this process. Unlike
coating, scarification is non-reversible — the effect on the floor
surface is permanent. Dust created by the process can be damaging to
other materials or to health — especially when lead glazes, silica,
or asbestos are disturbed. Under no circumstances should you sand or
scarify linoleum floors that may contain asbestos. Contact environmental
professionals if you need an assessment of asbestos content.
Scarification usually results in increased maintenance
requirements — pores in tile and grout, once opened, become hard to
clean. The floor may lose its visual appeal too.
Chemical Modification
Chemical alteration to increase wet slip resistance
involves either coating or etching the surface. As in scarification,
qualified professionals must carry out these processes. Generally the
processes are non-reversible. There is little effect on dry slip resistance
(which usually is adequate anyway if the floor is clean), but there
can be a dramatic improvement in wet slip resistance and a significant
reduction in the difference between dry and wet slip resistance.
Chemicals based on strong acids or their derivatives
operate by dissolving the surface of tile or stone and creating a surface
that includes millions of tiny pits or suction cups. The suction force
supplements friction force and can improve traction. Usually the flooring
becomes somewhat more difficult to clean, and soiling eventually reduces
the effectiveness of the treatment, which must be repeated to maintain
slip resistance. These “chemical etching” processes are not applicable
to resilient or wood floors or floors covered by waxes or finishes.
Technology in this area is changing, with products
that can produce the slip resistance with less damage to the floor.
A new class of chemicals originally developed in England deposits a
chemically-bonded, transparent “honeycomb” structure on top of the
surface, also forming millions of suction cups. These coatings, which
are not sealers, are said to preserve the aesthetic appearance and
the cleanability of the flooring. They are applicable to most types
of flooring, not just tile and stone. Again, qualified professionals
must apply them.
Contact CTIOA (telephone 1-310-574-7800) for chemical
treatment vendor contacts. For either type of chemical modification,
periodic documented testing is necessary to confirm that the process
is initially successful and continues to be effective. Soil, detergent
film, or wear can defeat the effectiveness of the chemical processes
unless monitoring leads to detection and correction of cleaning problems.
Ceramic Tile Institute of America (CTIOA) endorses the Tortus test
method, or (particularly for areas where some pedestrians are likely
to be running, such as airports or subway stations) the pendulum method.
Contact CTIOA for further details on these methods.
Other Precautions
When you know a floor to be slippery under some
or all of its conditions of use, you must take precautions to prevent
accidents. Post warnings when and where appropriate, remembering to
provide for the visually-impaired. Use mats, rugs, or abrasive tapes
in sensitive areas. Trap rain, mud, snow, and dust at the entrance.
(We recommend at least fifteen feet of absorbent matting to dry shoes
before stepping on to a floor that’s slippery when wet.) Offer plastic
bags at entrances when it’s raining or snowing for pedestrians to stow
their umbrellas without dripping water throughout the building. Be
aware that water and other contaminants from drinking fountains, coffee
spills, etc. can be tracked in by shoes.
Your Program to Prevent Slips
The best way of preventing slips is to specify
flooring and/or floor treatment that is slip-resistant when wet. Find
out how the supplier recommends cleaning the flooring; some flooring
that’s slip-resistant when wet is rough and takes more energy to clean
than slippery flooring. See CTIOA’s “Endorsement of Portable Test Methods
and Slip Prevention Standards for Existing Flooring” for further information
about on-site slip-resistance tests.
If a flooring surface is not slip-resistant as
manufactured (after any potentially slippery protective coating or
mold-release or grout-release compound is removed), proper maintenance
in itself will not render the surface slip-resistant. By definition,
the goal of “maintenance” is maintaining the like-new condition to
the extent feasible. For existing surfaces that are slippery when wet,
chemical treatment is the best alternative.
To reduce risk exposure, agents and owners of large
commercial or industrial properties should have their flooring tested
periodically for slip resistance. This will help verify that you are
maintaining the optimum slip resistance for that flooring. The CTIOA
paper, “Endorsement of Portable Test Methods and Slip Prevention Standards
for Existing Flooring,” provides information on recommended portable
test methods. Telephone Gray LaFortune at CTIOA for referrals to testing
services.
For some properties, quarterly testing is appropriate,
while for others an annual test is adequate. Many variables go into
deciding frequency. They include number of pedestrians using the floors
(with added consideration for the aged or disabled), turnover rate
of maintenance personnel, and other factors affecting risk.
Have a qualified testing service conduct the testing
and submit a written report that you maintain on file. This has the
advantage of giving added credibility to your safety program. Correct
problems that the test results may expose.
Keep records of your maintenance practices, and
document your maintenance training. This helps establish reliably good
procedures, and can aid in your defense when an alleged accident occurs.
You must also be alert to complaints about slippery
floors. These not only can help you identify problems, but legally
they provide notice to you
that there is a problem you must solve so that you can avoid being
found negligent if an alleged accident occurs.
In summary, to maintain good slip resistance and
to minimize your potential liability, select flooring carefully for its planned
use; modify it with chemical
or mechanical treatment if necessary to get good slip resistance with
cleanability; use matting where
necessary to exclude water and other contaminants; clean the flooring frequently, without
leaving a slippery residue; warn pedestrians
when there’s a hazard they must avoid; and document your maintenance practices and
training and your slip-resistance test results.
If the flooring as installed provides good slip
resistance, proper maintenance can be effective in preserving safety.
If the flooring as installed is slippery under some conditions, good
maintenance can help minimize the risk. Consider chemical or mechanical
treatment of the surface in areas where the existing risk is unacceptable.
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