General Concrete Guidelines
For Indoor Synthetic Sports Surfaces
BEYNON SPORTS SURFACES
January 1, 2013
Table of Contents
Table of Contents ......................................................................................................................................... 1
Overview ..................................................................................................................................................... 2
General Guidelines....................................................................................................................................... 2
Testing Procedures ...................................................................................................................................... 3
Moisture Testing .......................................................................................................................................... 3
Synopsis of Other Methods of Evaluating Moisture Conditions of Concrete Floors ................................... 3
Polyethylene Sheet Test ....................................................................................................................... 4
Mat Test ............................................................................................................................................... 4
Electrical Resistance Test...................................................................................................................... 4
Electrical Impedance Test ..................................................................................................................... 5
Preparation of New Concrete Floors ............................................................................................................ 6
Preparation of Existing Concrete Floors........................................................................................................ 6
Use of Adhesive Removers ....................................................................................................................... 6
General Concrete Composition Guidelines ................................................................................................... 7
Water to Cement Ratio ............................................................................................................................ 7
Curing and Drying New Concrete.............................................................................................................. 7
Alkalinity .................................................................................................................................................. 8
Efflorescence ........................................................................................................................................... 8
Moisture Vapor Retarders ........................................................................................................................ 8
Flatness and Levelness of Concrete Floors to Receive Synthetic Flooring ...................................................... 9
Saw-Cut Joints in New Concrete ................................................................................................................... 9
The F-Number System .............................................................................................................................10
Guidelines for F-Number Subfloor Finish Tolerances under Synthetic Floors............................................10
Disclaimer: The information represented here reflects data gathered from literature provided by the Associated
Concrete Institute (ACI) and reviewed by Beynon staff and/or associated subject matter experts. It reflects our best
effort to provide useful indoor concrete information. Use of this information is solely at the user's discretion. It does not
reflect the opinions or policies of Beynon Sports Surfaces or Tarkett Sports. Beynon Sports holds no responsibility for
concrete mix design, installation or application.
1
Overview
The guidelines below discuss the acceptability of a concrete floor for the application of a polyurethane
athletic surface provided by Beynon Sports and includes suggestions for the construction of a concrete floor
to ensure its adequacy for the installation of Beynon Sports’ indoor synthetic sports surfacing systems.
Note that this guideline does not address or represent the following:
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The adequacy of the concrete floor to perform its structural requirements;
The necessary preparation of concrete floors prior to the installation of the Beynon Sports Surfacing indoor
flooring Systems;
All of the safety concerns, if any, associated with its use. It is the responsibility of the user of this guideline to
establish appropriate safety and health practices and determine the applicability of regulatory limitations
prior to use and for specific warning statements.
The values stated in per inch or per pound units are to be regarded as standard. The values in parentheses
are estimated mathematical conversions to SI units and are for information only.
General Guidelines
The installation of a permanent, effective moisture vapor retarder with a minimum thickness of 0.010 in.
and a permeance of 0.1 y, should be required under all on- or below-grade concrete floors.
The use of a moisture vapor retarder, provided that the integrity has not been compromised, reduces
potential severity of water vapor penetration. Every concrete floor slab on- or below-grade to receive
synthetic flooring shall have a water vapor retarder (often improperly called a vapor barrier) installed
directly below the slab.
A concrete design using a sand base between the water vapor retarder and the concrete slab is
unacceptable.
Concrete floors to receive synthetic flooring shall be permanently dry, clean, smooth, and structurally
sound. They shall be free of dust, solvent, paint, wax, oil, grease, residual adhesive, adhesive removers,
film-forming curing compounds, silicate penetrating curing compounds, sealing, hardening, or parting
compounds, alkaline salts, excessive carbonation or laitance, mold, mildew, and other foreign materials
that might prevent adhesive bond.
Surface cracks, grooves, depressions, control joints or other non-moving joints, and other irregularities shall
be filled or smoothed with a single-component polyurethane sealant similar to the Silkaflex concrete fix and
shall be moisture, mildew, and alkali resistant.
Joints such as expansion joints, isolation joints, or other moving joints in concrete slabs cannot be filled
with any cementitious or latex patching compound.
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The surface of the floor must be cleaned of all loose materials, stains and foreign contaminants by scraping,
brushing, vacuuming, or other methods or a combination thereof immediately before commencing
installation of the synthetic floor system.
Sweeping compounds are NOT recommended as most contain chemicals and or oils than can leave
contaminants on the concrete floor.
Concrete floors shall be smooth to prevent irregularities, roughness, or other defects from telegraphing
through the new synthetic flooring. The surface of concrete floors shall be flat to within the equivalent of
1/8 inch in a 10-foot radius. FF and FL numbers alone are not acceptable for final flatness results; however,
per Beynon’s specification, a FF 50/FL 30 result will achieve a close proximity to these tolerances.
Testing Procedures
Concrete floors designed to receive synthetic flooring shall be free of dust, solvent, paint, wax, oil, grease,
residual adhesive, adhesive removers, sealers, coatings, finishes, dirt, film forming curing compounds,
silicate penetrating curing compounds, hardening or parting compounds, alkaline salts, excessive
carbonation or laitance, mold, mildew, and other foreign materials. These may affect the rate of moisture
dissipation from the concrete or the adhesion of synthetic flooring to the concrete.
Non-chemical methods for removal, such as abrasive cleaning, ‘bead-blasting’ or ‘shot blasting,’ can be
used on existing slabs with deleterious residues to achieve an appropriate state for testing. Cleaning shall
take place a minimum of 24 hours before testing.
Warning: Hydraulic cement used in concrete construction may contain trace amounts of free crystalline silica.
Prolonged exposure to airborne free crystalline silica may be a health hazard. Avoid actions that cause dust to become
airborne. Use local or general ventilation to control exposures below applicable exposure limits.
Moisture Testing
All concrete slabs must be tested for moisture regardless of age or grade level.
Beynon Sports Surfaces recommends the use of Calcium Chloride testing in conjunction with RH probes
placed in the slab as per manufacturers’ recommendations.
Permanent HVAC must be in operation for a minimum of seven (7) days prior to testing of the slabs.
Synopsis of Other Methods of Evaluating Moisture Conditions of Concrete Floors
This guideline describes four (4) procedures, commonly referred to as “tests,” or “practices” used in the
construction industry to provide an indication of the presence of moisture.
These procedures are non-mandatory. They may assist in screening for potential moisture issues.
Unless otherwise indicated, these practices are applicable to slabs on grade, slabs below grade, and slabs
above grade.
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Polyethylene Sheet Test
Summary of Method
Materials
Procedure
Calculation and
Interpretation of
Results
This method uses a vapor retardant plastic sheet sealed to the floor as a vapor trap to
determine if excessive moisture is present. Although developed for coating systems
preparation, it is also sometimes used in the flooring industry.
Transparent polyethylene sheet minimum 4 mils (0.1 mm) thick. Adhesive tape that
will adhere to the floor and the sheet, such as duct tape, 2 inch (50 mm) wide.
1. Tape a plastic sheet approximately 18 by 18 in. (460 by 460 mm) tightly to the
concrete surface making sure all edges are sealed.
2. After a minimum of 16 hours, remove the plastic sheet and inspect the underside of
the sheet and the concrete surface for presence of moisture.
Presence of visible liquid water indicates concrete is insufficiently dry for application of
finishes. However, lack of visible liquid water does not ensure that the concrete is
sufficiently dry for the application of finishes. Quantitative testing must be performed.
Mat Test
Summary of Method
Materials
Procedure
Calculation and
Interpretation of
Results
This method uses a sample of vapor retardant floor finish material and a water-based
adhesive to predict the behavior of resilient floor covering adhesives over a limited
time. A variation of this procedure (known as the short-term “bond” test) beyond the
scope of this document can be used to test for bond between substrate and synthetic
floor coverings.
Latex multipurpose or water-soluble adhesive intended for use with resilient flooring
products. It is not necessary to use the type of floor finish product intended for
application in this procedure, since the sheet product simply provides a vapor-retardant
surface that has sufficient rigidity and weight to remain in place during the procedure.
Sheet vinyl or similar resilient vapor-retardant resilient flooring sheet product.
Adhesive tape that will adhere to the floor and the sheet, such as duct tape, 2 in. (50
mm) wide.
1. Prepare number of mats as required approximately 24 by 24 in. (600 by 600 mm).
2. Apply adhesive to an area 24 by 24 in. (600 by 600 mm). While the adhesive is wet,
place the mat, surface or face down, immediately into the adhesive. Seal the
perimeter edges using tape. The face is placed down to avoid absorption of water
in the adhesive by the backing.
After 72 hours, make a visual inspection to determine the condition of the adhesive. If
the adhesive is partially or completely dissolved, is still wet, or has little bond, there is
too much moisture present to proceed with the installation of flooring material. If the
mat is firmly bonded or removal of the mat reveals the adhesive to be stringy and with
good adhesion, the level of moisture present may be low enough that quantification of
moisture level is in order.
Electrical Resistance Test
Summary of Method
Apparatus
Determines the relative moisture content by measuring the electrical conductivity of
concrete between the meter probes. Conductivity varies in proportion to moisture
content. This procedure uses proprietary meters and interpretive methods provided by
meter manufacturers. This procedure provides a relatively quick way to obtain an
approximation of the relative moisture content of concrete.
Suitable instrument to measure the conductivity between two electrodes which are
placed in contact with the concrete floor surface or placed into two pre-drilled holes 1
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Preparation,
Calibration and
Standardization of
Apparatus
Calculation and
Interpretation of
Results
inch (25 mm) deep into the concrete floor.
To use one type of instrument, it is necessary to drill holes in the slab to receive pins.
Another type can be used with or without drilling holes, but the readings will be more
accurate if holes are drilled and the pins are driven into the holes. Care shall be taken to
avoid contact between the probes and any metal incorporated into the slab.
Generic data to correlate measured electrical resistance to acceptable moisture
conditions are not available at this time; however, instrument manufacturers generally
publish guides for this purpose specific to the instruments they manufacture. When
results indicate potential high moisture level, quantify results. Although a high reading
(good conductance) typically indicates high relative moisture content, a low reading
(poor conductance) does not necessarily indicate more than surface dryness, as the
concrete may have a higher relative moisture content below the surface. Conversely, a
concrete with low relative moisture content but containing metal fibers could cause a
high reading. Confirmation measurements can be made by taking readings at a number
of locations which are then covered by a vapor retarder material such as polyethylene
sheeting, then taking subsequent readings 24 h later after removing the covers. Where
the second reading significantly exceeds the first, it indicates that the concrete may
have a high MVER.
Electrical Impedance Test
Summary of Method
Apparatus
Preparation,
Calibration and
Standardization of
Apparatus
Calculation and
Interpretation of
Results
Uses proprietary meters and interpretive methods provided by meter manufacturers to
determine the relative moisture content of concrete by measuring both conductance
and capacitance. A non-destructive way to determine the potential relative moisture
content of concrete is by measuring the electrical AC impedance. Impedance is an
alternating current measurement combining both resistance and capacitance while at
the same time overcoming the separate limitations of each (single-line measurement
with resistance and shallow depth of penetration of signal with capacitance).
With impedance measurement, a field is set up consisting of an area under the footprint
of the instrument electrodes. The depth of the signal penetration will vary depending
on the material content of the slab and the relative moisture content, generally varying
from 0.75 in. (20 mm) to 2.0 in. (50 mm).
An electrical impedance meter specifically developed and calibrated for concrete
moisture measurement.
Typically, the meter is placed on the concrete slab with its electrodes pressed in direct
contact with the surface. When the meter is switched on, low frequency signals are
transmitted into the slab, measuring the change in impedance brought about by
potential moisture. The impedance is converted to a moisture reading displayed on the
instrument dial. Holes in the slab are typically not required.
See instrument manufacturer’s instructions. Instructions for calibration of instruments
are provided by instrument manufacturers typically indicate presence of moisture.
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Preparation of New Concrete Floors
New concrete slabs must be properly cured, dried or treated before the installation of synthetic surfacing.
The precise drying time before concrete slabs are ready for moisture testing will vary depending on both
atmospheric conditions and mix design. Concrete floors containing lightweight aggregate or excess water,
and those which are allowed to dry from only one (1) side, such as concrete over a moisture vapor retarder
or concrete on metal deck construction, may require a longer drying time. These floors should not be
covered with synthetic flooring unless the moisture-vapor emission rate or the percentage of internal
relative humidity meets Beynon Sports Surfaces installation specifications.
Preparation of Existing Concrete Floors
Beynon Sports should be consulted regarding the necessity of removing of old resilient flooring, adhesive
residue, paint, or other surface contaminants. If old resilient flooring, paint, or adhesive residue is to be
removed, Beynon Sports recommends removal via mechanical means (i.e. grinding and/or ‘bead-blasting’
or ‘shot blasting’).
Warning: Do not sand, dry sweep, dry scrape, drill, saw, bead blast, or mechanically chip or pulverize
existing resilient flooring, backing, lining felt, paint, asphaltic cutback adhesives, or other adhesives.
These products may contain asbestos fibers or crystalline silica and preparations must be made to avoid
creating dust. Inhalation of such dust is a dangerous and respiratory tract hazard and should be avoided at
all costs. Smoking by individuals exposed to asbestos fibers greatly increases the risk of serious bodily
harm. Unless positively certain that the product is a non-asbestos-containing material, presume that it
contains asbestos. Regulations may require that the material be tested to determine asbestos content. The
Resilient Floor Covering Institute’s (http://www.rfci.com/) recommended work practices for removal of
existing resilient floor coverings should be consulted for a defined set of instructions addressed to the task
of removing all resilient floor covering structures.
Warning: Certain flooring paints may contain lead. Exposure to excessive amounts of lead dust presents a
serious health hazard. Others must refer to applicable federal, state, and local laws and guidelines for
hazard identification and abatement of lead-based paint published by the U.S. Department of Housing and
Urban Development regarding the appropriate methods for identifying lead-based paint and removing such
paint, as well as any licensing, certification, and training requirements for persons performing lead
abatement work.
Use of Adhesive Removers
There are commercial adhesive removers that will properly remove adhesive residue from a subfloor;
however, there are concerns that these products may adversely affect the new adhesive or new floor
covering. The Resilient Floor Covering Institute’s (http://www.rfci.com/) recommended work practices for
removal of existing resilient floor surfaces should be reviewed in detail. If chemicals are used for the
removal of contaminants, the floor should then be ‘shot-blasted’ to ensure no residues exist prior to
installation of the new synthetic floor.
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General Concrete Composition Guidelines
Below is a brief and non-comprehensive information on concrete composition and practices is provided to
help specifiers, synthetic flooring installers, and contractors understand the general properties of concrete.
A concrete slab is not an inert substrate. A concrete slab is a complex mixture of organic and inorganic
substances whose properties and condition will affect the performance of a floor covering placed on its
surface. Surface flatness, strength, joints, alkalinity, permeability, and many other concrete properties will
have a significant effect on the long-term appearance and performance of the synthetic athletic surface.
Concrete used for most floors is a mixture of hydraulic cement, fine aggregate (sand), coarse aggregate
(stone), water and admixtures. In addition to these batch ingredients, chemical admixtures can be used to
control the setting time, rate of strength development, workability, air entrapment, and other properties of
concrete. For example, water-reducing admixtures can increase the slump of fresh concrete without
adding additional water. Pozzolanic admixtures such as fly ash or ground granulated blast furnace slag are
sometimes present as a partial replacement for the cement.
Lightweight concrete, less than 115 per lb. per cubic foot (1841 per kg per cubic meter), may have such low
compressive strength that it is unsuitable for covering with synthetic flooring unless 1 in. (25 mm) or more
of standard weight concrete, generally 140 per lb. per cubic foot (2241 per kg per cubic meter) or more, is
used as a topping.
Water to Cement Ratio
The most important factor affecting concrete properties is the water to cement ratio. This is the ratio of the
mass of water to the mass of cement in a standard volume of concrete. For a given concrete mix design, as
the water to cement ratio is increased, most concrete properties are negatively affected. Of special
interest to the floor covering industry, compressive and flexural strengths are decreased, permeability is
increased, and drying times are lengthened.
Moderate to low water to cement ratios (0.40 to 0.45) are used to produce floor slabs that can easily be
placed, finished, and dried, and which will have acceptable permeability to moisture. Floor slabs with water
to cement ratios above take an exceedingly long time to dry and can cause adhesives and/or floor coverings
to fail due to high moisture permeability.
Curing and Drying New Concrete
Concrete sets, cures and gains strength by the chemical reaction of water with the silicate and aluminate
materials in the cement. As long as water is available during the planned curing period, the concrete will
continue to gain strength and decrease its permeability. Various ways concrete is cured include cover
curing with paper or plastic sheets or other methods that aid in retaining some moisture in the concrete,
thus retarding the rate of drying. Synthetic flooring and adhesive manufacturer’s specifications often
prohibit the use of membrane forming curing compounds as they can interfere with the bond of the
adhesive to the concrete.
Membrane forming curing compounds, in many cases, form a surface film of oil, wax, resins, or a
combination thereof, that tend to lengthen the drying time of the concrete, obstruct the bond between the
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concrete surface and the adhesive and/or the patching or underlayment compound to the concrete. In
addition, they may trap moisture in the concrete which may be released at a future date causing adhesive
failure or other problems related to excess water vapor between the flooring and the slab. In all cases
where curing compounds have been used Beynon Sports Surfaces should be consulted. Excess water is
always present beyond the amount of water required for cement hydration. As the cement continues to
hydrate, excess water must be permitted to flow out of the concrete, generally by evaporation at the top
surface, during a planned drying period following curing. A typical 4 inch (100 mm) thick slab, allowed to
dry from only one side, batched at a water-cement ratio of 0.45, typically requires approximately 90 to 120
days to achieve a moisture vapor emission rate (MVER) of 3 lb./1000 square foot (170 μg/square meter) per
24 hours (the resilient flooring industry standard MVER). The importance of using a moderate to low
water-cement ratio for floors to receive resilient flooring cannot be overemphasized.
Alkalinity
As Portland cement hydrates, calcium hydroxide and other alkaline hydroxides form. The pH of wet
concrete is extremely alkaline, typically around a pH 12 to 13. The surface of a concrete slab will naturally
react with atmospheric carbon dioxide to produce calcium carbonate in the hydraulic cement paste, which
reduces the pH of the surface. Results in the range of a pH 8 to 10 are typical for a floor with at least a thin
layer of carbonation (approximately 0.04 inch (1 mm)).
Abrasive removal (shot blasting, sanding, or grinding) of a thin layer of concrete can remove this
carbonated layer and expose the more highly alkaline concrete below. Additional pH tests, waiting time,
the application of a patching compound or underlayment, or a combination thereof, might be required
after abrasive removal of the concrete surface. If the carbonated layer is removed and the pH of the
concrete surface is still above 10, please consult Beynon Sports for additional recommendation.
Efflorescence
Accumulation of salts on a concrete slab can be due to moisture movement vertically through the slab from
bottom to top or horizontally inward from exposed edges of slabs on or below grade. Such salts can cause
problems by destroying adhesive bond, displacing floor coverings, and staining. The most common
efflorescence is a white powdery deposit of calcium carbonate that has a pH of close to neutral (7.0).
Sulfate compounds can accumulate due to moisture migration, especially in parts of California. These
compounds are not deleterious themselves but indicate that excessive moisture may be moving through
the slab and should be addressed before installing a Beynon Sports Surfaces floor system.
Moisture Vapor Retarders
The installation of a permanent, effective moisture vapor retarder with a minimum thickness of 0.010
inches, and a permeability of 0.1y, as described in Specification E 1745 is required under all on- or belowgrade concrete floors. The use of such a moisture vapor retarder, provided its integrity has not been
compromised, reduces the potential severity of water vapor penetration. Every concrete floor slab on- or
below-grade to receive synthetic flooring should have a water vapor retarder (often improperly called a
vapor barrier) installed directly below the slab.
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Slab curling problems can arise when a slab dries at a differential rate – faster at the top while remaining
wet at its lower surface. Curling is exacerbated by conditions such as hot, dry, windy weather following
placement, inadequate curing, and excessively high water-cement ratio. Differential stresses due to
shrinkage at the top and restraint at the bottom can cause upward curling of the slab leading to
uncontrolled cracking. Placing concrete directly on top of a moisture retarder reduces the possibility of
outflow of excess batch water at the bottom of the slab, perhaps increasing the possibility of curling.
Measurement of slab curling is not reflected in FF and FL measurements. See ACI 302.1R-06 for specific
slab curling measuring techniques.
Flatness and Levelness of Concrete Floors to Receive Synthetic Flooring
For over 50 years, concrete floor surface tolerances were typically measured and described by the
maximum gap allowed under a ten (10) foot (3 meter) long straightedge placed anywhere on the floor. This
manual method was difficult, especially for large areas, and often the results were deceptive, too stringent,
and not reproducible.
During the 1970’s and 1980’s, more sophisticated instruments were developed to measure floor flatness,
particularly in response to the need for producing extremely flat floors to control the sway of moving
forklifts in warehouses with high storage racks and narrow aisles. There are two (2) accepted measurement
methods using such instruments today - Test Method E 1155 and Test Method E 1486.
Saw-Cut Joints in New Concrete
On large flat concrete surfaces, rather than hand-tooling joints, it can be more convenient to cut joints with
an electric or gasoline-driven power saw fitted with an abrasive or diamond blade, and using one of the
following three types of saws: conventional wet-cut; conventional dry-cut; or early-entry dry-cut. The depth
of saw cut using a conventional saw should be at least 1/4 of the slab depth or a minimum of 1 in. (25 mm),
whichever is greater. The depth of saw cut using an early-entry dry-cut saw should be 1 in. (25 mm)
minimum, unless experience has shown that a shallower saw cut is sufficient. This recommendation
assumes that the early-entry dry-cut saw is used within the time constraints noted above.
For steel-fiber-reinforced slabs, the saw cut using the conventional saw should be1/3 of the slab depth.
Typically, experience has shown that when timely cutting is done with an early-entry saw, the depth can be
the same as for plain concrete. See ACI 302.8.3.12 for specific details.
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The above chart can be used as a reference for determining joint spacing. See ACI 360R.06:5.1.3 for more details.
The F-Number System
The American Concrete Institute now recommends that flatness and levelness be described using the FNumber System as outlined in ACI 302.1R-06 and ACI 117R. This system identifies two (2) numbers: FF
controls local surface bumpiness (or waviness) by limiting the magnitude of successive 1-foot (300 mm)
slope changes. FL controls overall levelness (or pitch) by limiting differences in the average of 10-foot (3meter) elevations along sample measurement lines.
The ACI 117R (commentary) states, “None of the conventional concrete placement techniques in use today
can adequately compensate for form or structure deflections that occur during the concrete placement
and, for this reason, it is inappropriate to specify levelness tolerances on unshored floor construction.” For
concrete slabs receiving resilient floor covering, therefore, it is most important to describe limits of floor
flatness.
As stated in ACI 302.1R-06, “In practice, FF and FL values generally fall between 12 and 45. The scale is
linear, so that relative flatness/levelness of two different floors will be in proportion to the ratio of their Fnumbers. For example, an FF 30/FL 24 floor is exactly twice as flat and twice as level as an FF 15/FL 12
floor.” While there is no direct equivalent between F-numbers and straightedge tolerances, ACI 117R does
give a rough correlation between the two systems.
Guidelines for F-Number Subfloor Finish Tolerances under Synthetic Floors
ACI 302.1R gives F-number results that can be achieved by following various slab construction procedures.
It recommends that concrete slabs to receive thin-set flooring with moderate or heavy traffic have
10
composite flatness and levelness of FF 35/FL 25. However, it also advises that the selections of the proper
FF /FL tolerances for a new project be best made by the measurement of a similar satisfactory existing
floor.
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MASTERSPEC Guide Spec Section 03300, Evaluations, presents a guide to floor flatness and
levelness tolerances for various floor use categories. It recommends a minimum FF 20/FL 17 for
subfloors receiving thin coverings that will not mask the subfloor condition. Smooth, glossy,
resilient flooring may require higher FF/FL values to minimize potential telegraphing.
·
Guide Spec Section 03346 includes appropriate options for slabs under various floor finishes as
well. It recommends a minimum FF 75/FL 50 under glossy resilient finishes, and a maximum
variation using a straightedge of 1⁄8 inch (3.2 mm) to 1⁄4 inch (6.4 mm) under resilient flooring.
(These F-numbers are much higher than other industry guidelines and may be too expensive to
accomplish and unnecessary where thin floor coverings are to be applied.)
·
Remedial Measures—ACI 302.1R-06 identifies precautions, influencing factors, construction
environment, and measurement timeliness relative to maintaining flatness and levelness
tolerances. It suggests: “Remedial measures for slabs on ground might include grinding, planing,
surface repair, re-topping, or removal and replacement. For suspended slabs, remedial measures
are generally limited to grinding or use of an underlayment or topping material. Contract
documents should clearly identify the acceptable corrective methods(s) to be used.”
Thin, applied synthetic floor coverings can exhibit show-through of very small subfloor irregularities
and roughness.
Methods that indicate surface flatness by measuring elevations at 12 inch (300-mm) or larger
increments cannot reflect surface imperfections that occur at smaller intervals. Only visual
inspection will show surface defects such as concrete trowel marks, small protrusions, or pits.
Resilient flooring finishing techniques and products that give increased glossiness will accentuate
the telegraphing of such subfloor unevenness or texture. Therefore, specifications for slabs to
receive resilient flooring should address the issue of small-scale smoothness, even if only from a
qualitative point of view.
Disclaimer: The information represented here reflects data gathered from literature provided by
the Associated Concrete Institute (ACI) and reviewed by Beynon staff and/or associated subject
matter experts. It reflects our best effort to provide useful indoor concrete information. Use of this
information is solely at the user's discretion. It does not reflect the opinions or policies of Beynon
Sports Surfaces or Tarkett Sports. Beynon Sports holds no responsibility for concrete mix design,
installation or application.
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