Method of creating barrier to fluid flow under concrete surface coat of concrete floor

A barrier to fluid passage is embedded within, instead of atop, porous material to retain the durability of the surface of the porous material. In one embodiment, a thin set mortar is applied to a concrete slab. A pleated metal foil is pressed into the wet mortar and a bond is established. The mortar is allowed to set and a top, or finish, section of concrete is then poured over the foil and finished conventionally. Provisions are made for sealing expansion joints in concrete slab floors and at the juncture of floor and wall. The foil may be provided in multiple layers to provide a mechanical bond via mortar oozing through perforations or along pleats in each of the top and bottoms layers, while providing a solid layer through which a fluid will not pass, at least in one direction.

BACKGROUND

U.S. Pat. No. 6,286,279, Method for Attaching Fabric and Floor Covering Materials to Concrete, to Bean et al., Sep. 11, 2001, and incorporated herein by reference, teaches bonding a thin metal plate or metal foil to a concrete surface to effect a barrier to water vapor transfer. The configuration of the '279 patent improves the maintenance of the bond between a concrete surface and various types of floor coverings. The '279 patent teaches two systems for implementing the barrier: one uses a single-layered thin metal plate or metal foil that is folded to produce recesses much like corrugated sheet metal. One side of the foil is attached to the concrete surface using a Portland cement-based thin set grout. A second embodiment employs a two-part thin metal plate or foil. A first lower part is perforated (or slit and expanded) and attached to a second solid upper part. The lower perforated part is embedded in a layer of thin set mortar on the concrete to anchor it to the concrete. The thin set mortar that oozes through the perforations also serves as a mechanical bond, a “cementitious rivet,” supplementing the chemical bond made along the contact surface.

A preferred embodiment of the present invention is an improvement on the '279 patent in that it allows the thin metal plate or metal foil to be embedded just below the surface of the underlayment, concrete in the case of a “poured slab,” so that there is a layer, e.g., concrete, both above and below the thin metal plate or metal foil. That is, a robust “finish” surface, e.g., concrete, is placed above the thin metal plate or metal foil, thus presenting a durable surface of conventional appearance. One advantage of this design is the ability of the surface to resist moisture flow from without while accommodating typical use, e.g., that of hard-wheeled vehicles that would otherwise damage vinyl or carpet floor coverings.

SUMMARY

A fluid, or vapor, barrier is encapsulated within a durable structure to preclude passage of fluid in at least one direction while retaining the durability of a surface of a structure that conventionally does not contain such a barrier.

A first preferred embodiment of the present invention employs a two-part folded thin metal (or composite) plate or metal (or composite) solid (un-perforated) foil such as provided in the '279 patent, but embedded just below the top surface of a durable surface such as an underlayment, typically a concrete “slab” or floor.

Alternatively, a second preferred embodiment of the present invention employs a two-part thin metal plate or metal foil differing from that of the '279 patent in that the second or top layer of metal is a perforated thin plate or metal foil. The perforations on the top side of the second (top) layer serve to facilitate the formation of a mechanical bond via the concrete oozing through the perforations and acting as a “cementitious rivet” between the top side of the second layer and the bottom side of the surface of the underlayment above this second (top) layer. This mechanical bond acts in addition to any chemical bond formed between the bottom side of the underlayment surface and the remainder of the upper surface of this second (top) perforated layer. This second preferred embodiment must employ a solid thin metal plate or metal foil as a first (bottom) layer to block passage of moisture through the path provided by the underlayment material, typically concrete, that, upon installation, oozed through the perforations in the second (top) layer of perforated thin metal plate or metal foil. That is, if a perforated second (top) layer of a two-part thin metal plate or metal foil is used to achieve a better bond, then the first (bottom) layer must be solid, and conversely, if a perforated first (bottom) layer is used, then the second (top) layer must be solid.

Alternatively, a third preferred embodiment of the present invention employs a three-part thin metal plate or metal foil differing from that of the '279 patent in that a solid center foil or thin metal plate has an expanded metal foil or thin metal plate, e.g., pleated foil, applied to both sides. Application of the top and bottom pleated foils or thin pleated metal plates may be by way of spot welding in one embodiment. This results in a three-layered system that provides opportunity for the adhesive, e.g., thin-set mortar, to infiltrate slots in the lower foil (or thin metal plate) positioned over the adhesive immediately applied to an existing slab, while the expanded foil (or thin metal plate) attached to the top of this three-layer version establishes a similar mechanical and chemical bond to the overlaid concrete that forms a surface, e.g., concrete flooring. This particular embodiment also aids in resisting “curling” of an overlaid concrete layer that provides a durable surface for use by hard-wheeled vehicles.

A preferred method of applying a first preferred embodiment of the present invention to an existing porous surface, such as cured concrete, comprises:applying a layer of adhesive, such as thin set mortar, to the existing surface;placing a folded or pleated thin metal plate or folded or pleated metal foil on the layer of adhesive, e.g., thin set mortar;embedding the bottom of the thin metal plate or metal foil into the adhesive, e.g., thin set mortar;covering the top of the folded or pleated thin metal plate or folded or pleated metal foil with a thin layer of durable material, such as concrete;permitting the adhesive to cure; andfinishing and curing the thin layer of durable material, e.g., concrete, as needed.

Note that if concrete is used as a finish layer, consolidation of this covering concrete must be done with care to avoid loosening the foil bonded to the adhesive, e.g., thin set mortar.

As an alternative, seams between the pieces (sheets) of the folded or pleated thin metal plate or folded or pleated metal foil may be sealed with flexible commercially available room temperature vulcanizing (RTV) products appropriate for use in alkaline environments. As a further alternative, employing accordion-style pleats at edges of the thin metal plate or metal foil accommodates panel movement while avoiding tearing or breaking the folded thin metal plate or folded metal foil should the installed surface move under load. Of course, this method is not limited to existing installations but may be employed upon initial installation of an underlayment or wall.

In installing a second preferred embodiment, the above method of installation may be applied using a two-part thin metal plate or metal foil having a first (bottom) layer and a second (top) layer, instead of a single folded thin metal plate or folded metal foil.

In another method of installing the second preferred embodiment a two-part thin metal plate or two-part metal foil is used in which the second (top) layer incorporates perforations and the first (bottom) layer is solid.

In yet another method of installing the second preferred embodiment, the immediately above method of installation may be applied using a two-part thin metal plate or two-part metal foil in which the first (bottom) layer incorporates perforations and the second (top) layer is solid.

Finally, the above method of installation may be applied using the third preferred embodiment, a three-layer sandwich comprising top and bottom layers of perforated, folded or pleated foil or thin metal covering a solid middle layer of foil or thin metal. The top and bottom layers may be joined to the solid center layer by any of a number of suitable processes, e.g., tack welding.

Embodiments of the present invention are not limited to underlayments but may be used on vertical or slanted surfaces where protection from fluid intrusion is desired. Further, a “one-way” vapor barrier may be installed to prevent intrusion of fluids while permitting expulsion of the same fluids or vapors. Instead of a metal foil or thin metal plate, a special “breathing” material such as those marketed under the trademark GORETEX® (liquid impermeable, moisture vapor transmissive material) may be used in place of metal. This would have particular application in below grade applications such as basement floors or walls and in environments of high humidity such as kitchens or bathroom floors or walls that otherwise “sweat.” In addition to embedding the GORETEX® (liquid impermeable, moisture vapor transmissive material) lining in concrete on a slab, it could be embedded just beneath a porous outer stucco or similar coating to achieve the same effect as the metal barrier does in the underlayment while also permitting “out gassing” of vapors from within the room.

Embodiments of the present invention may be used in any application where it is necessary to prevent the movement of fluids (liquid or gas) through porous material, such as concrete. Specifically, embodiments may be used to block the movement of water vapor and will be equally effective in preventing the movement of stable gases, such as radon, through porous material, such as concrete.

The “embedded barrier” of the present invention, in all of its preferred embodiments, is unique in its implementation. For example, conventionally, a concrete slab has been “sealed” by pre-placing a polymer membrane under the slab prior to placing the new concrete. Once the concrete slab had been installed, the slab could be further sealed only at its top surface. This sealing of the top surface has been accomplished conventionally by using epoxy, fiberglass or combinations of fiberglass and epoxy, leaving a surface that was less durable than a concrete surface.

To summarize some of the salient advantages of preferred embodiments of the present invention:it permits modifying existing installations, e.g., addition of concrete above the metal barrier on existing slabs;it allows a trafficked surface above a vapor barrier to be made of durable castable material such as concrete or asphalt concrete;it provides a continuous sheet of metal foil that also serves to reinforce an underlayment, such as a concrete slab;it reduces the opportunity for cracking that occurs on one side of a structure to propagate to the other side;it reduces the opportunity for fractures that exist in the lower part of an underlayment, e.g., a concrete slab, to widen or propagate laterally;in a preferred embodiment it prevents curling of a top surface of concrete that has been applied to an existing concrete slab; andin an alternative embodiment, it accommodates joints between panels of structure, such as an underlayment, by employing a pleated barrier joining section thus permitting movement without compromising the integrity of the barrier.

Further advantages of the present invention will be apparent from the description below with reference to the accompanying drawings, in which like numbers indicate like elements.

DETAILED DESCRIPTION

Refer toFIGS. 1,3A,3B, and6A. Provided is a method of implementing a fluid barrier within porous material such as concrete. In a preferred embodiment, a barrier panel100, in one embodiment including pleats101and having pleated edges102, is placed between a “base”311of porous material, such as a concrete slab, and an emplaced topmost section313of durable material, such as concrete, thus creating a topmost surface suitable for use by wheeled traffic. A single layer600plate or foil with pleats101and related spacings601between the pleats101may be used as an embedded fluid barrier such as shown at310. Also shown at310are depictions315of the adhesive312as it forms in the valleys between pleats101and the formation of anchoring portions314of the initially “flowable” top layer313as it is placed on the surface103of a pleated single layer panel100of the configuration at310.

Refer toFIGS. 3A,3B and7. Also provided in a preferred embodiment of the present invention is a configuration310such as shown inFIG. 3Aor the configuration320shown inFIG. 3Bimplementing a barrier to fluid flow in at least one direction and enclosed within porous material. Either configuration310,320uses a durable top section313applied over the barrier panel100placed upon adhesive312coated on a first section311of the porous material. Either configuration310,320is thus made suitable for routine use by wheeled traffic. Both configurations comprise:at least one layer of adhesive312applied to a top surface of the porous material comprising a base311, e.g., thin set mortar applied to a concrete slab;panels100of non-porous material having edges102suitable for overlapping, e.g., pleated edges, as shown at701ofFIG. 7, affixed to a topmost layer of adhesive312so as to completely cover the adhesive312,a flexible sealant as shown at702ofFIG. 7applied between the overlapping edges as shown at701ofFIG. 7; andthe topmost section313emplaced upon the panels100so as to completely cover all said panels100, the topmost section313incorporating the top surface suitable for routine use by wheeled traffic.

In a preferred embodiment of the configuration, the barrier is a vapor barrier embedded, i.e., completely enclosed, in porous material. The non-porous material used for the panels100may be selected from: a metal, a metal alloy, a steel alloy, a stainless steel, a composite material, a composite material containing at least some metal, and combinations thereof.

In a preferred embodiment of the configuration, the non-porous material comprises at least one metal and the porous material comprises at least some concrete. Further, the adhesive312may be a thin set mortar applied to a thickness of about 6 mm (¼ inch). In a preferred embodiment of the configuration in which the porous material at least partially comprises concrete, the topmost section may comprise concrete applied to a thickness of about 2.5 cm (1 inch) or more.

Refer toFIG. 7. In a preferred embodiment of the configuration, a seal702comprises a continuous bead of a flexible sealant applied along the entire length between all overlapped edges701of the panels160. A preferred embodiment of flexible sealant is a RTV sealant.

Refer toFIGS. 2A,2B, and3B. In a preferred embodiment of the configuration, the panels100are plates of a total thickness less than about 6 mm (¼ inch). In an alternate preferred embodiment, the panel100comprises a first perforated plate210in contact with a second solid plate220, i.e., a two-layer panel100, each of the first210and second220plates being of a total thickness of less than about 3 mm (⅛ inch). A preferred configuration places a first perforated plate210“layer” immediately adjacent the bottom side of the topmost section313, e.g., the finish layer of concrete. A generic two-layer configuration321,322representing this preferred configuration is shown inFIG. 3B. The first perforated plate210would be placed at321inFIG. 3Band the second solid plate220at322inFIG. 3B.

Refer toFIGS. 2A,2B, and3B. In an alternate preferred embodiment of the configuration, the panels100comprise a multi-layer foil of a thickness less than about 2 mm (0.08 inch) and preferably in the range of about 0.5-1.5 mm (20-60 mils), and may be represented as inFIG. 3Bas a perforated foil (such as depicted inFIG. 2Aat210) at321and a solid foil (such as depicted inFIG. 2Bat220) at322. Each of the foil layers210,220in a two-layer foil321,322used in a preferred embodiment of the present invention has a total thickness of less than about 1 mm (0.04 inch) and preferably in the range of about 0.25-0.76 mm (10-30 mils).

Refer toFIGS. 1,3A,6A and6B. In yet another preferred embodiment, the configuration employs panels100comprising three-layers, two identical configurations as shown at600, and a single flat configuration as shown at610. InFIG. 6A, the adhesive602is shown as it oozes into the folds of the foil or thin metal from the layers of porous material (not shown separately inFIG. 6A) above and below the foil or thin metal configuration600. InFIG. 6B, by contrast, the adhesive620is emplaced to adhere to the portion of the thin foil or thin metal configuration600in direct contact with a separate middle layer610as described immediately below. These configurations600,610may be metal (or composite) foil or thin metal (or composite) sheets or plates. The top600and bottom600layers of the three-layer panel600,610may be perforated, a solid that is folded or pleated, and combinations thereof, while the middle layer610must be solid if both the top and bottom layers600are perforated. As foils, the layers600,610each may be of a thickness less than 1.0 mm (40 mils) and more preferably less than about 0.76 mm (30 mils) and most preferably in a range of thickness from about 0.25-0.76 mm (10-30 mils).A preferred method of implementing an embedded barrier comprises:applying at least one layer312of adhesive, such as a thin set mortar, to an entire first surface of the porous material of the base311, e.g., a concrete slab, prior to emplacing the topmost section313, e.g., a finish layer of concrete;placing panels100of non-porous material, such as a metal or composite plate or metal or composite foil, upon a topmost layer312of adhesive (if more than one layer of adhesive is used), overlapping edges102of each panel100with edges of any panels100placed adjacent thereto in the same plane along the topmost layer312of adhesive such as shown at701inFIG. 7, andcompletely covering the topmost adhesive layer312with the overlapping panels100;establishing a seal702as shown inFIG. 7between all the overlapped panel edges701; andemplacing at least one layer of material comprising a topmost section313upon the panels100such that each panel100is confined below the topmost section313and above a topmost layer312of adhesive.

Employing this method, i.e., providing one or more adhesive layers312upon a surface of a base311of porous material, placing “barrier” panels100of one or more layers such as layers depicted at210,220,600,610upon the topmost layer312of adhesive, establishing a seal702between the overlapped edges701of the panels100and emplacing a topmost section313to encapsulate the panels100, implements a fluid barrier within porous material, preferably durable porous material such as concrete.

Refer toFIG. 3A. In one preferred method, the adhesive312may then be allowed to “set” or cure prior to installing a finish layer313over the plate (or foil)100. Not all methods may require curing of the adhesive312prior to the finish step, however. The finish layer313may be a poured fluid, such as concrete, such that the concrete oozes into the spaces between the channels101as shown at314, thus facilitating a strong bond between the plate (or foil)100and the finish layer313. For those underlayments311that are exposed to heavy traffic, including hard-wheeled vehicles, for example, the finish layer313may be relatively thick concrete. In one preferred embodiment, the result is a multi-layered configuration310that achieves an effective moisture and vapor barrier to fluid ingress from beneath the underlayment311, while permitting heavy traffic on its concrete finished surface313.

The method of emplacing a fluid barrier within porous material extends to establishing a vapor barrier in porous material. The vapor barrier may be a one-way barrier such that the configuration is permitted to “breathe” or “outgas” in one direction while establishing and maintaining a fluid barrier in the opposite direction.

In a preferred embodiment of a method of implementation of the present invention, the method employs non-porous material comprising at least one metal and the porous material comprises at least some concrete. Further, the topmost adhesive layer312may be a thin set mortar applied to a thickness of about 6 mm (0.25 inch). In a preferred embodiment in which the porous material at least partially comprises concrete, the topmost section may comprise concrete applied to a thickness of about 2.5 cm (1.0 inch) or more.

Refer toFIGS. 3A,3B, and7. In a preferred embodiment of a method of implementing the present invention, a seal702may be established, at least in part, by applying a continuous bead of a flexible sealant along the entire length between all overlapped edges701of the panels100. A preferred embodiment of flexible sealant is a RTV sealant. In applications where concrete is to be applied as a finishing layer313, the RTV sealant should be suitable for use in alkaline environments.

Refer toFIGS. 1,2A,2B and3B. In a preferred method of implementing the present invention, the panels100comprise multiple layers321,322of plates of a total thickness less than about 6 mm (0.25 inch). In an alternate preferred method, the panels100comprise a perforated plate210as a first layer321, the perforated plate210having evenly spaced perforations212on its interior surface211and abutted about its entire surface area to a second solid plate220as a second layer322, the solid plate having a solid interior surface221, and each of the first210and second220plates being of a total thickness of less than about 3 mm (0.125 inch). A preferred method is to place the first perforated plate220immediately adjacent the bottom side of the topmost section313as shown at321in the configuration320ofFIG. 3B.

Refer toFIGS. 2A,2B, and3B. In an alternate preferred method, the method employs panels100comprising multi-layer foil of a thickness less than about 4 mm (0.16 inch), and more preferably less than about 2.5 mm (100 mils), and most preferably about 0.5 mm to 1.5 mm (20-60 mils). In yet another alternate preferred method, the panels100comprise a first perforated foil210as a first layer321of a two-layer foil321,322, the second layer322being a solid foil220. Each of the first and second foil layers321,322has a total thickness of less than about 2 mm (80 mils), and more preferably less than about 0.76 mm (30 mils), and most preferably about 0.25 mm to 0.76 mm (10-30 mils). In a preferred embodiment, the first perforated foil210is placed immediately adjacent the bottom side of the topmost section313as shown at321.

Refer toFIGS. 1,3A,6A and6B. In yet another preferred embodiment, the method employs panels100comprising three-layers, two identical configurations as shown at600, and a single flat configuration as shown at610. These may be metal (or composite) foil or thin metal (or composite) sheets or plates. The three layers600,610are bonded together by any of a number of suitable means, such as by gluing, heating, applying pressure, soldering, tack welding, or combinations of the above. The top600and bottom600layers of the three-layer panel600,610may be perforated, a solid that is folded or pleated, and combinations thereof, while the middle layer610must be solid if both the top and bottom layers600are perforated. As foils, the layers600,610each may be provided in a thickness less than 1.0 mm (40 mils) and more preferably less than about 0.76 mm (30 mils) and most preferably in a range in thickness from about 0.25-0.76 mm (10-30 mils).

Refer toFIG. 4. Some installations400of underlayments311, such as a concrete slab, applied over a prepared base404, such as an aggregate, incorporate embedded expansion joints. A preferred embodiment of the present invention incorporates a sealed expansion joint401between each of the overlaid top sections313and a corresponding portion of the underlayment311. This sealed expansion joint401comprises a pleated non-porous strip402that is placed over the adhesive312at the expansion joint401to overlap the entire length of each side of the expansion joint401below the installed panels100(that may be thin metal or composite plates or foil layers), each overlap of a width less than about 5.0 cm (2.0 inches). The strip402is then sealed with an appropriate sealant as shown at403along each longitudinal edge of the strip402between the top surface of the edge of the strip402and the bottom of each panel100abutting the expansion joint401. A preferred embodiment employs a continuous bead403of flexible sealant, such as an RTV, applied along the entire length of the expansion joint401.

Refer toFIGS. 2A,2B and3B.FIG. 2Adepicts the perforated piece210of a two-piece thin metal plate (or foil) structure shown installed inFIG. 3Bat321,322. The perforations212in the main part211of this perforated piece210facilitate bonding of the metal plate (or foil) structure to either the adhesive layer312or the overlaying finish layer313as shown in the resultant multi-layered structure320ofFIG. 3B. The solid piece220of the two-piece thin metal plate (or foil) is shown installed as one of the layers inFIG. 3Bat321,322. The configuration320ofFIG. 3Bfacilitates additional mechanical bonding of the two-piece plate321,322, to either the adhesive layer312or the finish layer313, but not both while providing a solid interface to prevent moisture or vapor flow from beneath the underlayment311. A preferred method of installation is to mount the perforated piece210against the finish layer313and the solid piece220against the adhesive layer312. In the case of a concrete finish layer313, this provides protection for the mechanical bond developed by the concrete as it oozes into the perforations212in the perforated piece210since no moisture or vapor passes through the solid piece220mounted next to the adhesive layer312, for example, thin set mortar in the case of a concrete underlayment311. Although the perforations212are shown as circular holes inFIG. 2A, other means of perforation may be used. For example, the perforated piece210may comprise metal screen material very similar to that used in screening windows to prevent insect ingress, a wire mesh, or combinations of types of perforations. Also shown inFIGS. 2A and 2Bare alternative edges102that facilitate flexion of the installed two-piece plate (or foil)210,220in much the same manner as described above for the one-piece configuration100ofFIG. 1. The two pieces210,220may be joined together prior to installation by any of a number of means such as application of adhesive to parts of their adjoining surfaces, mechanically pressing edges together, soldering, welding, and combinations of these means. Further, the two pieces210,220may be installed separately and either joined as would be done in methods described above for joining prior to installation or simply placed one above the other as part of the installation with the weight of the finish layer313and the adhesion of the adhesive layer312serving to maintain proper alignment. Adjacent two-piece plates (or foils)210,220may be connected in the same manner as for the one-piece plates (or foils)100as described above.

Refer toFIG. 4. Expansion joints401provide for movement of underlayment311in many cases. A preferred embodiment400of the present invention provides for bridging these joints401while sealing the joint401from moisture or vapor and avoiding tearing the underlying metal plate (or foil)100,210,220,321,322. In a preferred embodiment of the present invention, a separate flexible and expandable “bridge”402is provided for bridging expansion joints in underlayments311above a sub-grade404. This bridge402may be a long narrow section of thin metal plate (or foil) similar to that used as the moisture and vapor barrier. The longitudinal edges are flat while the center section is accordion-shaped or pleated to permit movement. These bridges402are installed over, and bond to, the adhesive layer312at the expansion joint401prior to installation of the thin metal plate (or foil)100,210,220,321,322. The bridges402are then bonded to the thin metal plate (or foil)100,210,220,321,322via any of a number of suitable means such as the application of a continuous bead403of a flexible sealant, e.g., any of various commercial RTV sealants suited to the application.

Refer toFIG. 5. In much the same way as expansion joints401are provided for in underlayments311, the joint501between a floor and a wall504is also subject to movement and a preferred embodiment500of the present invention provides for addressing this joint501also. The bridge502used in this application is affixed at one end to the underlayment in the same manner as for the in-floor expansion joint401. The bridge502is bent at a right angle to permit installation along the adjoining wall504to a point just above the top of the finish layer313. A bead503of suitable flexible sealant, such as any of a number of commercial RTV sealants, is applied along the entire length of the bridge502at the wall504.

The abstract of the disclosure is provided to comply with the rules requiring an abstract that will allow a searcher to quickly ascertain the subject matter of the technical disclosure of any patent issued from this disclosure. 37 CFR § 1.72(b). Any advantages and benefits described may not apply to all embodiments of the invention.

While the invention has been described in terms of its preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the appended claims. For example, although the system is described in specific examples related to concrete structure, it may be adapted to other porous construction materials, such as drywall, chipboard, wood, tile, composites, and combinations thereof. Thus, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting, and the invention should be defined only in accordance with the following claims and their equivalents.