Patent Application
20130084419
The present invention generally relates to a moisture/vapor barrier. More particularly, this invention relates to a moisture/vapor barrier used as an underlayment for a floor covering material. The present invention also relates to a method of making the moisture/vapor barrier. The present invention also relates to a system for installing the moisture/vapor barrier on porous flooring, such as concrete. The present invention also relates to a system for seaming the moisture/vapor barrier.
Floor covering is a broad term used to describe any decorative material applied over a floor to provide a finished surface for walking upon. Floor coverings include, but are not limited to, carpet; carpet tile; area rugs; resilient flooring, such as linoleum or vinyl tile or sheeting; hardwood flooring; engineered wood flooring; ceramic tile; stone; terrazzo and the like. When a floor covering is applied over a porous subflooring, such as concrete, moisture or water vapor may migrate up through the concrete by capillary action and collected between the surface of the concrete and the floor covering. This moisture or water vapor has deleterious effects on adhesives used for holding the floor covering material to the concrete potentially causing debonding, deterioration of the floor covering material and microbial growth.
When a floor covering is to be installed over a concrete surface having potential problems with moisture or water vapor, it is known to install a moisture/water vapor barrier on the surface of the concrete before any floor covering material, or adhesive therefore, is applied. U.S. Pat. No. 6,673,432 and U.S. patent application Publication No. 2011/0173923 (both of which are incorporated herein by reference) discloses such water vapor barriers. These water vapor barriers are not entirely satisfactory because they are relatively expensive to manufacture and relatively difficult and expensive to install. Furthermore, these water vapor barriers of the prior art are not entirely successful at preventing moisture or water vapor from permeating therethrough, particularly at seams.
Therefore, it would be desirable to produce a moisture/vapor barrier system that is relatively inexpensive to manufacture and relatively easy to install. It would also be desirable to provide a moisture/vapor barrier system that is more effective at preventing moisture or water vapor from permeating therethrough.
The present invention satisfies the foregoing needs by providing an improved water vapor barrier. The present invention is relatively easier to manufacture and install than prior art water vapor barriers. And, the present invention provides improved water vapor barrier performance.
In one disclosed embodiment, the present invention comprises a water vapor barrier. The water vapor barrier comprises a water vapor impermeable substrate, the substrate comprises a sheet of polymeric material and the substrate has a width. The water vapor barrier also comprises a first fabric on one side of the substrate, the first fabric having a width less than the width of the substrate such that a portion of the substrate is exposed on both sides of the first fabric. In a further disclosed embodiment, the water vapor barrier also comprises a first water vapor impermeable tape comprising a first water vapor impermeable backing, an adhesive disposed on one surface of the first backing, a first release sheet covering and releasably attached to one portion of the adhesive on the first backing and the other portion of the adhesive on the first backing attached to an exposed portion of the substrate adjacent the first fabric. In a further disclosed embodiment, the water vapor barrier also comprises a second fabric on the side of the substrate opposite the first fabric, the second fabric having a width less than the width of the substrate such that a portion of the substrate is exposed on both sides of the second fabric.
In another disclosed embodiment, the present invention comprises a method. The method comprises applying to a floor a first elongate sheet of a water vapor impermeable membrane comprising a first water vapor impermeable substrate, the first substrate comprising a sheet of polymeric material, the first substrate having a width; a first fabric on one side of the first substrate, the first fabric having a width less than the width of the first substrate such that a portion of the first substrate is exposed on both sides of the first fabric, the exposed portions of the first substrate forming opposed side edges of the first elongate sheet of the water vapor impermeable membrane. The first elongate sheet of a water vapor impermeable membrane also comprises a first water vapor impermeable tape comprising a first water vapor impermeable backing; an adhesive disposed on one surface of the first backing; a first release sheet covering and releasably attached to one portion of the adhesive on the first backing; and the other portion of the adhesive on the first backing attached to the exposed portion of the first substrate adjacent one of the edges of the first elongate sheet of a water vapor impermeable membrane. The method further comprises applying to a floor a second elongate sheet of a water vapor impermeable membrane comprising a second water vapor impermeable substrate, the second substrate comprising a sheet of polymeric material, the second substrate having a width; a first fabric on one side of the second substrate, the first fabric having a width less than the width of the second substrate such that a portion of the second substrate is exposed on both sides of the first fabric, the exposed portions of the second substrate forming opposed side edges of the second elongate sheet of a water vapor impermeable membrane. The method also comprises aligning the edges of the first and second elongate sheets of a water vapor impermeable membrane in abutting relationship; removing the first release sheet; and placing the exposed edge portion of the second substrate on the portion of the exposed adhesive of the first water vapor impermeable tape thereby adhering the second elongate sheet of water vapor impermeable membrane thereto.
In another disclosed embodiment, the present invention comprises a method. The method comprises applying to a floor a first elongate sheet of a water vapor impermeable membrane; applying to the floor a second elongate sheet of a water vapor impermeable membrane; aligning adjacent edges of the first and second elongate sheets of a water vapor impermeable membrane in abutting relationship; and adhering the abutting edge of the second elongate sheet of a water vapor impermeable membrane to a portion of a water vapor impermeable adhesive tape, a portion of which is adhered to the abutting edge of the first elongate sheet of water vapor impermeable membrane.
In another disclosed embodiment, the present invention comprises a method. The method comprises applying to a floor a first sheet of a water vapor impermeable membrane; applying to the floor a second sheet of a water vapor impermeable membrane; aligning adjacent edges of the first and second sheets of water vapor impermeable membrane in abutting relationship and such that the edge of the second sheet of water vapor impermeable membrane overlays a release sheet on an adhesive portion of a water vapor impermeable adhesive tape adhered to the abutting edge of the first sheet of water vapor impermeable membrane; removing the release sheet from the adhesive portion of the water vapor impermeable adhesive tape; and adhering the abutting edge of the second sheet of a water vapor impermeable membrane to the adhesive portion of the water vapor impermeable adhesive tape.
In another disclosed embodiment, the present invention comprises an article. The article comprises an elongate layer of a water vapor impermeable polymeric material; a layer of adhesive on one side of the layer of polymeric material; and a release sheet removably adhered to the adhesive layer, the release sheet being cut or perforated along a longitudinal center of the release sheet so that a portion of the release sheet can be removed from the adhesive layer while another portion of the release sheet remains.
In another disclosed embodiment, the present invention comprises a method. The method comprises applying to a floor a water vapor impermeable adhesive tape comprising a layer of a water vapor impermeable polymeric material; a layer of adhesive on one side of the layer of polymeric material; and a release sheet removably adhered to the adhesive layer, the release sheet being at least partially cut so that a portion of the release sheet can be removed from a portion of the adhesive layer while another portion of the release sheet remains. The method further comprises applying to the floor a first sheet of a water vapor impermeable membrane; removing a portion of the release sheet to expose a portion of the adhesive layer; adhering to the exposed portion of the adhesive layer an edge of the first sheet of water vapor impermeable membrane; applying to the floor a second sheet of a water vapor impermeable membrane; aligning an adjacent edge of the second sheet of water vapor impermeable membrane in butting relationship with the edge of the first sheet of water vapor impermeable membrane and overlaying the remaining portion of the release sheet; removing the remaining portion of the release sheet to expose the remaining portion of the adhesive layer; and adhering the abutting edge of the second sheet of water vapor impermeable membrane to the remaining portion of the adhesive layer.
Accordingly, it is an object of the present invention to provide an improved moisture/water vapor barrier.
Another object of the present invention is to provide an improved method of applying a moisture/water vapor barrier to a porous floor, especially concrete.
A further object of the present invention is to provide an improved moisture/water vapor impermeable tape for joining adjacent sheets of a moisture/water vapor impermeable membrane.
Another object of the present invention is to provide an improved method of joining adjacent sheets of a moisture/water vapor impermeable membrane.
Yet another object of the present invention is to provide a moisture/water vapor barrier that can be used over chemically abated concrete floors.
Another object of the present invention is to provide a moisture/water vapor barrier that can be used over concrete floors experiencing alkali silica reactions.
These and other objects, features and advantages of the present invention will become apparent after a review of the following detailed description of the disclosed embodiments and the appended drawing and claims.
As used herein, the term “water vapor impermeable” shall mean having a water vapor transmission rating below 0.3 as measured by ASTM E96 and having no increase in relative humidity above the water vapor membrane as measured by ASTM 2420-05.
Referring now to the drawing in which like numbers indicate like elements throughout the several views, there is shown in
As can be clearly seen in
The particular polymer from which the first sheet of water vapor impermeable polymeric material 16 is made is not critical to the present invention, except that it must be water vapor impermeable, lay flat on a flat surface; i.e., have no or virtually no memory, and be pliable and stable at temperatures ranging from about 0 to about 40° C. The first sheet of water vapor impermeable polymeric material 16 is preferably made from a thermoplastic including, but not limited to, ethylene methyl acrylate, polyethylene, polypropylene, acrylonitrile butadiene styrene, cellulose acetate, ethylene-vinyl acetate, polyacrylate, polyacrylonitrile, polyamide, polybutadiene, polybutylene, polybutylene terephthalate, polycaprolactone, polyethylene terephthalate, polycarbonate, polyester, polystyrene, polyurea, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, styrene-acrylonitrile, ethyl butyl acrylate or mixtures thereof. Post consumer recycled turf can also be used for the first sheet of water vapor impermeable polymeric material 16. Recycled turf is typically made of polyethylene face fibers, polypropylene primary backing and a polyurethane or latex back coat. Pellets of recycled synthetic turf are commercially available under the designation ThermoTex 1311A from the ThermoTex Division of Textile Rubber and Chemical Company, Inc., Cartersville, GA. Mixtures of virgin polymer and recycled turf can also be used in any proportion. The first sheet of water vapor impermeable polymeric material 16 can be any thickness that is water vapor impermeable and is suitable for use as an underlayment for floor covering; preferably, approximately 0.002 to approximately 0.075 inches thick, especially approximately 0.035 inches thick.
The polymeric formulation from which the first sheet of water vapor impermeable polymeric material 16 is made may also optionally include typical polymer additives, including but not limited to, plasticizers; fillers; extenders; anti-microbials or biocides, such as mildewcides, bactericides or fungicides; deodorizers; antioxidants; antiseptic agents; antistatic agents; stabilizers; fire retardants; colorants and the like. Up to 50% by weight (based on the weight of the polymer) additives can be used in the present invention; preferably, up to 25% by weight. While fillers may be used in the formulation for the first sheet of water vapor impermeable polymeric material 16, the more filler that is added, the less water vapor impermeable the sheet becomes. In accordance with the present invention, it has been discovered that up to 50% by weight (based on the weight of the polymer) can be used successfully in the present invention; preferably, 0% to approximately 50% by weight; especially, approximately 25% by weight. Fillers useful in the present invention include, but are not limited to, post consumer recycled minerals, calcium carbonate, barium sulfate, clays, magnesium hydroxide, alumina trihydrate, talc, Portland cement, feldspar, glass cullet, fly ash, gypsum, and mixtures thereof.
The top and bottom layers of fabric 18, 20 can be the same or different; however, they are preferably the same. The top and bottom layers of fabric 18, 20 can be a woven or a nonwoven fabric. The top and bottom layers of fabric 18, 20 are preferably made from synthetic fibers, such as polyester, polyamide, polypropylene, cotton, wool, polylactic acid, polybutylene terephthalate, polyvinyl alcohol, polyvinyl chloride, polyethylene, polyurethane or acrylic. The top and bottom layers of fabric 18, 20 are preferably a nonwoven polyester point bond fabric, having a weight of approximately 50 grams per cubic meter. A nonwoven polyester point bond fabric having these properties is commercially available from Oxco, Inc. of Charlotte, N.C.
While the top and bottom layers of fabric 18, 20 can be attached to the first sheet of water vapor impermeable polymeric material 16 by any practical means known in the art, such as by an adhesive, it is preferred that the top and bottom layers of fabric be melt bonded to the first sheet of water vapor impermeable plastic.
The polymer formulation; i.e., polymer(s) and any desired additives, for forming the sheet of water vapor impermeable polymeric material 16 is fed into the extruder 42 which both melts and mixes the plastic formulation and deposits the molten material onto the fabrics 38, 40 just as they pass between the nip rolls 32, 34. The nip rolls 32, 34 squeeze the molten plastic formulation between the two sheets of fabric 38, 40 as they pass between the nip rolls. This process forms the molten plastic formulation into a flat sheet of a desired thickness and simultaneously forces some of the molten plastic formulation into the opposed sheets of fabric 38, 40. The nip roll 34 is chilled with cold water so that as the molten plastic formulation passes between the nip rolls 32, 34 it is cooled, so that when the laminated composite structure 44 exits the nip rolls, the molten plastic formulation is solidified, or almost solidified. The solidification of the plastic formulation bonds the two sheets of fabric 38, 40 to the opposite sides of the sheet of water vapor impermeable polymeric material 16. The laminated composite structure 44 therefore comprises a first layer of fabric melt bonded to a layer of water vapor impermeable polymeric material and a second layer of fabric melt bonded to the opposite side of the layer of water vapor impermeable polymeric material. This laminated composite structure 44 corresponds to the laminated structure of the water vapor impermeable membrane 10 shown in
Optionally, before the laminated composite structure 44 is rolled up on the take-up roll 48, an adhesive tape 50 is applied to an edge portion, such as the edge portion 28, of the water vapor impermeable membrane 10. The adhesive tape preferably comprises a water vapor impermeable backing layer 52 and a water-proof or water-resistant adhesive layer 54 on one surface thereof. The backing layer 52 can be made from any water vapor impermeable material, including but not limited to, polyester, ethylene methyl acrylate, polyethylene, polypropylene, acrylonitrile butadiene styrene, cellulose acetate, ethylene-vinyl acetate, polyacrylate, polyacrylonitrile, polyamide, polybutadiene, polybutylene, polybutylene terephthalate, polycaprolactone, polyethylene terephthalate, polycarbonate, polystyrene, polyurea, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, styrene-acrylonitrile, ethyl butyl acrylate or mixtures thereof, and the like. The adhesive can be any suitable adhesive, such as pressure sensitive adhesives, contact adhesives, UV-curable adhesives, RF-curable adhesives, thermosetting adhesives and the like. In the presently disclosed embodiment, a water-vapor impermeable adhesive tape useful in the present invention having a low permeance high-density polyethylene film backing and a pressure-sensitive adhesive is commercially available under the designation Stego Tape from Stego Industries, LLC. San Clemente, Calif. Covering one-half of the adhesive layer 54 is a release sheet 56 (
Use of the water vapor impermeable membrane 10 will now be considered. The water vapor impermeable membrane 10 is preferably in a roll, such as the roll 48 shown in
It has been discovered as a part of the present invention that moisture or water vapor may penetrate horizontally up to 1 inch through the adhesive bond, such as the adhesive bond used to attach the adhesive tape 50 to the first and second water vapor impermeable membranes 10, 10′, due to water or water vapor seeping under the lateral edges of the adhesive tape. As stated above, the adhesive tape 50 is preferably 4 inches wide. Thus, there are approximately 2 inches of overlap between the adhesive tape 50 and each of the edge portions 28, 26′ of the first and second water vapor impermeable membranes 10, 10′. Therefore, if any moisture or water vapor penetrates under the lateral edges of the adhesive layer 54 of the adhesive tape 50, it will not penetrate to the joint 64 between the first and second water vapor impermeable membranes 10, 10′ because that joint is more than one inch way from the lateral edges of the adhesive tape. Thus, the present invention prevents, or substantially reduces, the penetration of moisture or water vapor between the adhesive tape 50 and the first and second water vapor impermeable membranes 10, 10′. Also, since the tape 50 is placed on the bottom of the first and second water vapor impermeable membranes 10, 10′, instead of on the top, as done in the prior art, the tape further reduces the possibility of moisture or water vapor penetrating through the joint 64 between the first and second water vapor impermeable membranes 10, 10′.
The foregoing describes the joining of adjacent sheets of the water vapor impermeable membrane in side-by-side relationship. However, it is often necessary to join multiple sheets of the water vapor impermeable membrane in end-to-end relationship in order to obtain a sheet of a longer desired length. The leading or trailing edge of a sheet of the water vapor impermeable membrane, such as the leading edge 66 of the first water vapor impermeable membrane 10 (
The leading and trailing edge of two sheets of the water vapor impermeable membrane are joined together, as shown in
The following examples are illustrative of selected embodiments of the present invention and are not intended to limit the scope of the invention.
The following test was performed on four test samples of the water vapor impermeable membrane as described above. For these tests, the fabric layers were omitted from the water vapor impermeable membrane. The four water vapor impermeable membranes were made from different thermoplastic polymers and different combinations of polymers. The purpose of the test was to determine whether those test samples were water vapor impermeable. The tests were performed in accordance with ASTM E96 and ASTM F2420 for the determination of water vapor transmission and permeance.
Test Dish
The test dish was made from a non-corroding material, impermeable to water or water vapor. The mouth of the dish was 3.875 in2. The desiccant or water area the same as the mouth area.
Test Chamber
The cabinet where the assembled test dishes were placed had controlled temperature and relative humidity. The relative humidity was maintained at 50%. Both temperature and relative humidity were measured frequently. Air was continuously circulated throughout the chamber, with a velocity sufficient to maintain uniform conditions at all test locations. The air velocity over the specimen was 0.1 ft/s. Racks were provided on which to place the test dishes within the test chamber.
Balance and Weights
The balance was sensitive to a change smaller than 1% of the weight change during the period when a steady state was considered to exist. The weights used were accurate to 1% of the weight change during the stead-state period.
Thickness-Measuring Gage
The nominal thickness of the specimen was determined using a thickness-measuring gage with an accuracy of 0.00005 in.
The test dish was filled with desiccant within ¼ in. (6 mm) of the specimen. The specimen was attached to the dish and placed in the controlled chamber, specimen up, weighing it at once. The dish was weighed every 24 hours.
Numerical Analysis
The water vapor transmission and permeance were calculated as follows:
Water Vapor Transmission:
WVT=G/tA=G/t/A
Where:
In inch-pound units:
G=weight change, grains (from the straight line),
t=time during which G occurred, h,
G/t=slope of the straight line, grains/h,
A=test area (cup mouth area), ft2, and
Permeance:
WVT/Dp=WVT/S(R1−R2)
Where:
In inch-pound units:
Dp=vapor pressure difference, inches Hg,
S=saturation vapor pressure at test temperature, inches Hg,
R1=relative humidity at the source expressed as a fraction (the test chamber for desiccant method; in the dish or water method), and
R2=relative humidity at the vapor sink expressed as a fraction.
A) 100% Recycled Synthetic Turf having a polyethylene face fiber, polypropylene primary and polyurethane back coat.
B) 100% ethyl methyl acrylate (Westlake SP2207).
C) 75% ethyl methyl acrylate (Westlake SP2207)+25% Recycled
Synthetic Turf.
D) 75% ethyl methyl acrylate (Westlake SP2207)+25% recycled mineral filler (Cimbar RMF75).
A water vapor transmission of 0.3 grains/hr/ft2 is considered to be water vapor impermeable. Similarly, a permeance of less than 0.3 is considered to be water vapor impermeable. Therefore, the foregoing tests demonstrate that all four samples were water vapor impermeable.
It should be understood, of course, that the foregoing relates only to certain disclosed embodiments of the present invention and that numerous modifications or alterations may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims.
