GB2105614A

GB2105614A - Waterproofing material

Info

Publication number: GB2105614A
Application number: GB08225034A
Authority: GB
Inventors: William Thaddeus Rubel
Original assignee: WR Grace and Co
Current assignee: WR Grace and Co
Priority date: 1981-09-02
Filing date: 1982-09-02
Publication date: 1983-03-30
Also published as: BR8204981A; AU8694382A; KR840001480A; ZA825189B; JPS5845944A

Abstract

A preformed, flexible, sheet-like waterproofing material including a waterproof pressure-sensitive adhesive bituminous membrane with a support sheet superimposed on one surface thereof, the support sheet having a plurality of through holes distributed throughout a margin adjacent one longitudinal edge.

Description

SPECIFICATION Waterproofing material The present invention relates to a waterproofing laminate in the form of a preformed sheet-like structure.

It is known that structural surfaces, such as those formed of concrete, can be sealed in a waterproof manner by forming thereon a continuous membrane of a bituminous composition which is substantially impermeable to moisture. By "bituminous composition" we mean, herein, compositions based on bitumen, tar, asphalt or pitch, with or without added components.

In the past such waterproofing membranes have been formed by in situ application of a hot bituminous composition or of a cold solution or emulsion of bitumen, tar or pitch. However, the formation of the waterproofing membrane in situ tends to be detrimental to uniformity, and is expensive in labour, and on vertical surfaces it is very difficult.

Waterproofing of structural surfaces such as roofs and underground surfaces is increasingly performed using factory made preformed, flexible membranes including waterproofing pressuresensitive adhesives. Examples are disclosed in U.S. Patents 3,741,856; 3,853,682; and 3,900,102; and British Patents 1,230,753 and 1,230,756. These waterproofing materials comprise a sheet-like support member with a membrane of a flexible bituminous composition superimposed thereon and adhered thereto. The bituminous composition may be single or multilayered and has adhesive properties which render it adherent to the support and to the substrate material to which it is applied.Generally, the preformed waterproofing structures in addition have a protective sheet on the free surface of the adhesive membrane which must be removed upon application of the waterproofing structure to the structural surface to be protected.

Formation of a waterproofing system using such membranes can be accomplished by butt joining or overlapping each course or strip of material over that previously laid. Improvement of the waterproof seal between strips can be achieved using the preformed structure disclosed in U.S. Patent 4,172,830 which permits removal of part of the support sheet partially to expose a strip of adhesive on the exposed side, so that on overlap this exposed surface forms an integral waterproofing seal with the adhesive of the next applied course.

The polymeric support sheets used for forming the known preformed, flexible waterproofing membranes have physical properties (such as thermal expansion, etc.) which differ considerably from that of the adhesive. These differences in physical properties tend to cause the edges of any applied strip course to curl, disengage or raise from the adjacent course and/or from the structural surface, thus causing potential for water seepage. Inhibition of this tendency is desired to assure a sound waterproofing system over an extended period of time.

According to the present invention there is provided a preformed, flexible, sheet-like waterproofing material including a waterproof pressure-sensitive adhesive bituminous membrane with a support sheet superimposed on one surface thereof, the support sheet having a plurality of through holes distributed throughout a margin adjacent one longitudinal edge.

With the invention, when adjacent strips of material overlap, contact between the adhesive layers arises through the through holes and this provides a good seal, and it provides anchoring of the polymeric support sheet and of the adhesive in a manner which inhibits raising or curling up of the edges of any strip.

In order that the invention may be more clearly understood, the following description is given, merely by way of example, with reference to the accompanying drawings in which.' Figure 1 is a view in perspective of one embodiment of waterproofing material according to the invention; and Figure 2 is a view in perspective of another embodiment of a waterproofing material according to the invention.

In Figure 1 , the preformed, flexible waterproofing material of the present invention 10 is shown as composed of a support 11 adhering to a waterproof and waterproofing adhesive membrane 12. The support is in the form of a flexible polymeric sheet which has at least one margin adjacent one edge which contains a plurality of uniformly distributed holes 13. The support sheet 11, in combination with the adhesive membrane 12, offers mechanical stability of the material during production, storage, transportation and use while, upon application, it permits exposure of a sufficient portion of the adhesive membrane to achieve good mastic to mastic bonding and to inhibit disengagement of the waterproofing structure from adjacent strips of material and from the structural surface to which it is applied.

The waterproofing adhesive membrane 12 is preferably of the self-adhesive bituminous type described in the aforementioned patents, and can comprise a mixture of a bituminous material and natural or synthetic polymer preferably a rubber or other elastomeric polymer. The amount of polymer employed can be anything from about 1 to 100% but is preferably about 20 to 50 percent by weight of the bituminous material. The membrane may be reinforced with fibres and/or particulate fillers. The adhesive composition may also contain a conventional extender component such as mineral oil. Suitable polymers include thermoplastic polymers such as polyethylene. The preferred polymer component is rubber which may be a virgin rubber, a synthetic rubber, or reclaimed rubber which is blended into the bitumen, preferably with an extender oil at elevated temperature to form a smooth mix.Suitable adhesive compositions generally have softening points (measures by the Ring and Ball method) of 700 to 1200C, preferably 750 to 100"C, and penetration values of 50 to 400, preferably 50 to 100dmm.at250C(150g/5-ASTM D217), and are thermoplastic in nature.

In order to give optimum sealing and waterproofing performance the adhesive layer should be at least 0.025 cms thick and preferably in the range of about 0.06 to about 0.5 cms thick.

The adhesive membrane can include one or more layers of bituminous adhesive, not necessarily of the same composition, to give an adhesive membrane within the overall aforementioned thickness range. Further, the adhesive membrane can have a reinforcement such as an open weave fabric, gauze, scrim or the like located therein to strengthen it. The adhesive membrane 12, at least at its surface remote from support 11, is pressuresensitive and tacky at normal ambient temperature in order that it be self-adhesive to the substrate. The bituminous adhesive layer serves to form a continuous waterproofing covering which is elastic and self-sealing against punctures at high and low temperature.

The support 11 serves as a strength imparting and supporting member in the laminate and may also serve as a further barrier to prevent moisture vapour transmission through the laminate. Thus while of less thickness than that of the adhesive 12, the support 11 should be of sufficient thickness to impart additional tear and puncture resistance to the laminate. The support 11 suitably has a thickness in the range of from about 0.005 to about 0.06 cms, preferably from about 0.010 to about 0.025 cms, and may comprise a single layer of sheet material or several such layers bonded together.

The preferred sheet materials for use as support 11 are films of synthetic organic polymers such as polyethylene, polypropylene or another polyolefin; polyamide, polyester, e.g. polyethylene terephthalate, polyurethane, polyvinyl chloride, a copolymer of vinyl chloride and vinylidene chloride, synthetic rubbers such as polychloroprene or butyl rubber as well as metal films or foils such as aluminium, copper or zinc. It is desirable that the uppermost surface of support 11 for certain applications should have optimum weatherability. Thus polymeric films rendered opaque, for example by the incorporation therein of a material such as carbon black to render the film non-translucent, may be desirable.Protective coatings and films such as thin pigmented coatings and films also can be applied in the factory to the surfaces of the support 11 to be exposed to the weather.

Cross-laminated polymeric films and biaxiallyoriented polymeric films are desirable synthetic polymer films for use as or in the support 11 As discussed in Canadian Patent 1,008,738, such films are more dimensionally stable when laminated to bituminous adhesives of the type used in the present invention. Any film-forming synthetic polymer or copolymer which can be oriented (biaxialiy or cross-laminated) is useful.

Biaxially oriented films of such polymers as polyolefins, e.g. high and low density polyethylene, vinylidene chloride, polystyrene, polyvinyl chloride, rubber hydrochloride, polyethylene terephthalate, etc., are commercially available. Especially useful films are biaxially oriented polyolefin and cross-laminated polyolefins. Preferred polymeric films for use as or in the support 11 are cross-laminated high density polyethylene films and biaxially oriented polyesters such as polyethylene terephthalate, desirably containing a filler such as carbon black to render the film opaque. Metal films or foils having, e.g. a thickness of about 0.0006 to about 0.010 cms may be used.

The support 11 can be in the form of a single support sheet which extends from one edge to the other of the adhesive membrane, as shown in Fig. 1. The surface of the suDport sheet in Fig. 1 can be viewed as being subdivided into one major surface area and at least one minor surface area or margin, with each margin being adjacent an edge.

The or each margin has a plurality of through holes 13, of which the dimensions and shape are not critical. The holes should be substantially uniformly distributed throughout the margin. Each margin may be about 0.75 to about 12 cms, preferably 2.5 to about 1 5 cms in width. The total width of the margins should be less than about one-third of the total support sheet width.

The open area within the margins is preferably from about 5 percent to about 50 percent and preferably from about 10 to about 30 percent of the area of the margin. Due to the flow properties of the adhesive membrane the adhesive of adjacent strips will have sufficient intimate contact through the holes 1 3 to form agood seal therewith. Further, it has been found that the support sheet and such overlapping adhesive membranes are integrally bound within the margin by the adhesive to adhesive contact of adjacent strips to cause good anchoring of the support sheet material and adhesive at the overlap and thereby inhibit the laminate from curling at its edges.

Although Fig. 1 shows a support with only one perforated margin, two similarly perforated longitudinal margins can be used. This permits the application of the waterproofing structure onto a structural surface without the need first to note the location of the margin prior to application.

The waterproof structure of the invention can be formed with a support sheet 11 of a width which is less than the width of the adhesive membrane 12 (Fig. 2). The difference between the width of the support sheet 11 and that of the membrane produces a zone 1 6 of exposed adhesive adjacent at least one of the edges of the adhesive membrane. Each such zone may be up to about 5 cms wide although greater dimensions may be used where deemed applicable. The exposed adhesive 1 6 may be covered with an additional, readily removable, marginal sheet 1 5 of a material such as described in U.S. Patent 4,172,830.The waterproof structure as shown in Fig. 2 thus has a support formed of a first, major, part 12 having at least one margin which contains a plurality of uniformly distributed holes 1 3 therethrough as described above. Adjacent to one edge as shown, but alternatively adjacent to both edges of the first part, may be a second support sheet part 15 covering the remainder of the adhesive membrane. This second part 1 5 is preferably readily removable, having nonadherent properties, in order to be readily removed at the job site. Such a waterproofing structure permits the formation of overlapping seams which provide superior anchoring of the support sheet due to the integral adhesive to adhesive contact, and further provides for a uniform continuous adhesive to adhesive contact and, therefore, a superior waterproofing seal.

In both embodiments the other surface of the adhesive membrane can have a protective sheet 14 thereon which is removed prior to application of the waterproofing structure to a structural surface to be protected. This protective sheet permits rolling up of the waterproofing structure into rolls for storage and delivery. The protective sheet can be formed of any conventional material such as, for example, paper which has been treated to be substantially nonadherent with respect to the adhesive composition. Obviously, second, minor, support sheet 1 5 can also comprise such a material.

The surface of the support sheet 11 which is not in face to face contact with the adhesive composition 12 can be made nonadherent with respect to the adhesive membrane by known techniques. For example, a commercial release coating can be applied in a conventional manner to the surface of the support sheet such as by the application of a dispersion of silicon compound which is cured with the aid of catalyst and/or heat and forced ventilation. Known release agents such as, for example, poly(dimethylsiloxane) and certain polymers having a fraction of the methyl groups replaced by hydrogen, a higher alkyl or phenyl group are also known to give good nonadherent properties. The use of such a coating upon sheet 11 avoids the use of a protective sheet 14.

The material of the invention is useful in providing a waterproofing barrier on a surface of any structure. Such a waterproofing barrier is formed by applying the exposed surface of the adhesive membrane 12 to the structure surface.

Rolls of material can be unrolled with the exposed surface of the membrane applied to the structural surface to be sealed. The applied waterproofing laminate structure then has the support 11 exposed. Application of an adjacent strip of waterproofing structure is then performed with the second strip overlapping the perforated margin and, if provided, the exposed surface area of the previously applied strip. The overlap thus produces an adhesive to adhesive contact which readily assures bonding, a waterproof seal and anchorage of the support sheet material. The process can thus be repeated to produce a continuous waterproof seal over the entire structural surface.

The width "w" of the overall material is selected depending upon the intended use.

Generally, widths of from about 10 cms to about 1 metre and greater can be used. Obviously the greater the width, the fewer seams and overlaps are needed to cover an expanse of surface.

The novel structure of the subject invention can be formed without difficulty by known techniques.

The use of adhesives of the aforementioned bituminous types which are not solvent based and can be formed from hot compositions are preferred. Thus such adhesives can be applied hot, with the aid of a suitable device to ensure uniform thickness, to a substrate-forming material which may or may not be removed at the end of the manufacturing process. The support described above is superimposed on the formed layer of adhesive membrane in accordance with the orientation described hereinabove. Other conventional techniques may be used to form the present novel structure.

The following examples are for illustrative purposes. All parts and percentages are by weight except where otherwise indicated.

EXAMPLE I A flexible waterproofing laminate product is formed by applying a coating of a self-adhesive hot bituminous composition 12 comprising about 10 parts by weight styrene-butadiene rubber and 90 parts by weight asphalt and oil on a paper 14 first coated with a commercial silicon release agent.

The paper 14 may be supported by a moving continuous belt. The asphaltic composition is made about 0.15 cms thick and about 1 metre wide. A support sheet 11 formed of polyethylene film having a width the same as that of the adhesive is applied to the formed adhesive membrane so as fully to extend from edge to edge of the membrane. Prior to its application to the membrane, the support sheet is perforated with holes along a margin about 10 cms wide at each of its edges. The margins occupy approximately 15 percent of the area of the support 11 and are substantially uniformly distributed within the margins. The laminate structure of the adhesive membrane with the perforated support sheet on one surface and release coated paper protective sheet on the other surface is removed from the continuous belt and formed into rolls for shipment and subsequent application.

The roll of laminate structure may be applied over e.g. a concrete deck by unrolling the laminate structure, removing the protective sheet and applying the free adhesive surface to the concrete.

After application of one laminate structure the next laminate structure is applied with overlapping of the exposed margins having the preformed holes therein.

EXAMPLE II A flexible waterproofing material as shown in Fig. 2 can be formed in the same manner as described in Example I, except that the support sheet material is composed of two elements, a major one having a width of about 1 metre less about 5 cms and a minor one having a width of about 5 cms. The major support element is superimposed onto the adhesive membrane so that one edge of the membrane and one edge of the major support sheet are coextensive. Adjacent the other edge of the major support sheet is a margin with holes punched therein to a width of approximately 10 cms from the edge. Part of the adhesive membrane not covered by the major support sheet is covered by the minor support which has been previously coated e.g. with a poly(dimethylsiloxane) having 3 percent of the methyl groups substituted by hydrogen.

The roll of laminate structure of this Example is applied over a substrate by unrolling, removing the protective sheet and applying the free adhesive surface adjacent to the substrate. After application of one strip the minor support sheet 1 5 is removed exposing the membrane. The next strip is then applied overlapping the exposed membrane surface and also over the perforated margin to form a waterproofing seal for the substrate and to further anchor the support sheet thereon.

Claims

CLAIM

1. A preformed, flexible, sheet-like waterproofing material including a waterproof pressure-sensitive adhesive bituminous membrane with a support sheet superimposed on one surface thereof, the support sheet having a plurality of through holes distributed throughout a margin adjacent one longitudinal edge.

2. A structure according to claim 1, wherein said support sheet has the same width as the adhesive membrane.

3. A structure according to claim 2, wherein the support sheet comprises a first, major, part having said plurality of through holes at a margin adjacent one longitudinal edge thereof and at least one second, minor, part adjacent to said margin.

4. A structure according to claim 3, wherein the second part is substantially non-adherent to the membrane and is less wide than the first part.

5. A structure according to claim 3 or 4, wherein the first and second parts abut.

6. A structure according to claim 2, 3, 4 or 5, wherein a said plurality of through holes is provided in margins adjacent each edge of said sheet or said first part.

7. A structure according to any preceding claim, wherein said plurality of through holes are uniformly distributed and occupy between 5 and 50 percent of the margin.

8. A structure according to any preceding claim, wherein each margin extends inwards for from about 1.25 cms to about 20 cms from one sheet edge towards the other sheet edge.

9. A structure according to any preceding claim, wherein the adhesive membrane includes some rubber or synthetic resin or both.

10. A structure according to any preceding claim, wherein the support sheet is in the form of a film or a woven or unwoven fabric.

11. A structure according to any preceding claim, wherein the support sheet has a first face attached to the adhesive membrane and a second face having the property of being substantially non-adherent to the adhesive membrane.

12. A structure according to claim 11, wherein the non-adherent face of the support sheet has a release composition coated thereon.

1 3. A preformed waterproofing material substantially as hereinbefore described with reference to and as illustrated in Fig. 1 or Fig. 2 of the accompanying drawings.

14. A preformed waterproofing material substantially as described in either Example herein.

1 5. A method of providing a waterproof layer on a structural surface including the steps of applying to the structural surface a strip of preformed, waterproofing material according to any preceding claim, applying a further strip of said material with a portion of the free surface of the adhesive membrane thereof superimposed on the holes in said support sheet of the first strip, and repeating the procedure.