CA1316664C - Waterproofing structure - Google Patents

Abstract

ABSTRACT
WATERPROOFING STRUCTURE
A structure comprising a membrane of a waterproofing pressure sensitive adhesive material with, contiguous thereto, a layer of relatively rigid covering material comprising two walls held spaced apart by a plurality of transverse ribs defining channels between the walls.

Description

'`` ~ 131S6~4 ~``
~ --1--- ~ WATERPROOFING STRUCTURE
This invention relates to waterproofing structures and their use.
Preformed self-adhesive waterproofing structures are known which comprise a sheet like substrate, which typically is of waterproof plastics material, such as polythene or polyethylene, having contiguous therewith a layer of a self adhesive waterproofing material which typically is a bituminous compound such as a mixture of bitumen and rubber.
Such structures are normally supplied in the form of rolls, being flexible, with a release sheet attached to the exposed surface of the self-adhesive compound. The material is applied by unrolling, simultaneously removing the release sheet and brushing the material out 80 that it entirely contacts the surface being covered. Normally, adjacent strips are lapped with the edge of one overlapping the edge of its neighbour.
In some circumstances such structures can be difficult to apply. For instance, application to vertical surfaces can be difficult due to the fact that the adhesive is very tacky and the material heavy and flexible.
Horizontally extending strips of material are often called for on vertical surfaces and the applica~ion of these in particular can pose problems.
As mentioned, the known structures typically have ;a plastic sheet material as the substrate to which the self - 131666~

adhesive membrane is attached. Whether used on horizontal or vertical surfaces these structures, although waterproof, do have mechanical limitations. For instance, in basement construction, the first layer of concrete for the floor is covered with the waterproofing structure. ~owever there may be some time between the application of this covering and subsequently covering the structure with a screed or other flooring substance or with another layer of concrete.
During that period the uppermost plastics substrate needs to be protected because tradesmen require access and so foot traffic must be expected. On vertical walls, the waterproofing structure may be applied to the exterior of a subterranean concrete wall. The space between the ground and the wall is subsequently backfilled and the material used for this may include quite sharp aggregate likely to puncture the plastic sheet substrate. Thus, there is a need to protect the substrate and this may presently be done by using a protecting board attached to the plastic substrate sheet using a curable adhesive. Such boards may comprise bitumen impregnated felts optionally provided with filler such as cork. Alternatively the risk is run that _.~
the plastic substrate, and perhaps the entire structure, will be ruptured, leading to the possibility of moisture penetration in the future.
According to the present invention there is provided a structure comprising a membrane of waterproofing pressure sensitive adhesive material with, contiguous . .

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f ;~ thereto, a layer of relatively rigid covering material ~
comprising two walls held spaced apart by a plurality of transverse ribs defining channels between the walls. ~
By "relatively rigid covering material" we mean that the material is of such stiffness that the structure will not buckle and will not bend very much, under its own weight, for instance if held at one edge, in contrast to the known materials which are easily bent and will droop through a large angle if supported only at the edge. The relatively rigid, covering material has the advantage that it provides, integrally in the waterproofing structure, a stengthening and protecting layer which can withstand satisfactorily foot traffic and the abrasive effects of any backfilling there may be when the material i5 used at an external or subterranean surface. Also there is a continuous skin on the side of the covering adjacent the membrane. In addition, structures of the invention are very easy to apply, the application in fact being easier than with the more flexible rolls of material which lack the rigid layer.
The distance between the two walls in the covering material is preferably about 2 to 10 mm, or more preferably about 4 mm. The spacings between adjacent ribs will normally be similar to the spacing between the walls.
Materials of this type, which are in themselves known and made of plastics material, have a very high strength to weight ratio and are very strong against crushing of the ~`` 13166~ ~

two walls, so that a man may jump upon them without crushing the walls together. If desired, a continuous ~ilm may be applied between the self adhesive membrane and the relatively rigid covering material.
The adhesive membrane may be reinforced with a high tensile strength reinforcing net, for instance of polypropylene, but glass or other fibre reinforcements are other possibilities.
For the pressure sensitive adhesive membrane it is possible to use membranes of adhesive material which enable the structures when pressed by normal hand pressure a~ainst for instance a concrete sur~ace, without any prior treatment of the membrane or the concrete, to remain stuck thereto. Alternatively, adhesives which require prior surface treatment e.g. with a primer, can be used.
Suitably the membrane of adhesive is 0.5 to 3 or 4 mm.
thick but in certain circumstances a thickness down to 0.25 mm thick may be employed. Below that thickness secure adhesion and integrity of the waterproofing membrane may not be maintained.
Bituminous adhesives are generally suitable for the membrane and may be formed of natural or synthetic rubber, virgin or reclaimed, blended into bitumen to provide a smooth mix. The ratio by weight of bitumen to rubber is preferably from 80:20 to 95:5 especially about 90:10. Other types of adhesive composition could be used.
Generally, suitable compositions of adhesive have softening - ~3~6664 ~

temperatures measured by the Ring and ~all method of 70 to 130C.
A removable paper or other coating is normally required on structures of the invention to cover the surface of the adhesive membrane remote from the rigid covering sheet. this can be siliconised paper or another release sheet.
When applied to an exterior vertical surface a still further function may be performed by structures according to the invention. This is achieved if the exterior wall of the relatively rigid sheet covering is rendered at least to a small extent perforated, allowing access to drainage passages or parts within the relatively rigid material. This will allow land water to penetrate into this sheet and drain downwards, through the parallel channels, out of contact with the exterior of the wall. To this end, the exterior wall of the twin walled covering sheet can be penetrated at intervals so as to allow access to the parallel channels, the perforations being thermally or mechanically made, the source of heat being electrical or by flame.
With the twin walled parallel channel covering material, impregnation with foam could be employed by an extrusion process.
Adjacent structures of the invention can be lap jointed. To this end, part or all the rigid covering along one on both edges involved in the lap joint can be removed ~ 13~6~6~ ``

so that the lap joint does not stand proud of the remainder. Alternatively double sided adhesive waterproof tape applied in a pattern where the edges of material will be applied can be pre-positioned on the surface to be covered with no need then to provide an edge free of rigid covering. Such a tape can also be used beneath ad~acent sections of structure of the invention which are inclined to each other, e.g. at the bottom of a wall and an adjacent floor. Such tape should be thin in order to avoid bending the rigid covering.
In order that the invention may be more clearly understood the following description is given by way of - example only with reference to the accompanying drawings in which:
Figure 1 is a perspective view of a structure according to the invention;
Figure 2 is a detail of structure edges in a lap joint;
Figure 3 is an illustration of the location of structures of the invention in possible situations of use;
,, Figure 4 is a sectional view of another embodiment;
Figure 5 is a part sectional view of an alternative arrangement where two structures of the invention abut; and Figure 6 is a perspective view of another embodiment including two further optional features of ~ 131~6~

' structures of the invention.
Shown in Figure 1 is a structure 10 having a self-adhesive membrane 20 typically of bituminous rubber material, with a release sheet 21 on one side and a covering layer 22 on the other. The covering layer 22 has upper and lower walls 23 and 24 separated by a plurality o~
parallel transverse walls 25 which define a plurality of parallel channels in the material. The structure can be applied by removing the release sheet 21 and placing it against the surface to be protected in a firm manner.
A suitable twin walled covering material 22 is of polypropylene, 2 to 10 mm and preferably about 4 mm thick.
It is laminated to the bitumen compound which can have a reinforcing mesh within it. This covering material is very strong, it can readily withstand foot traffic and indeed can withstand impact from quite sharp objects without collapsing or puncturing so that the waterproofing function is maintained under all normal circumstances. Application is much easier than with the prior art rolls, as it is more easy to align the structure correctly before placing it in contact with the surface to be covered. A result of the channel formation is that any leakage due to a defect in the membrane does not spread laterally.
A drainage facility can be introduced by perforating the outer wall 23 so as to allow access to the channels between the transverse walls 25. Perforation can be with hot pins to melt material away. This is `"- 13~666~ `

particularly useful in vertical exterior applications.
Such applications are illustrated in Figure 3, which shows a vertical wall 42 and a horizontal blinding layer 43 o~ a basement structure arranged in a dug out portion of the ground. On the exterior of the vertical wall 42 is secured a structure 40 according to the invention which thus has the effects of waterproofing, mechanically protecting and draining land water from the adjacent surface of the concrete. Above the horizontal bottom wall or blinding layer 43 is also applied a structure 41 according to the invention to provide a waterproofing function, while being protected against damage whilst work proceeds before and in preparation for laying a layer of concrete thereon.
Drainage could also be achieved as shown in Figure 4 by removing ~he outer sheet of the covering material at intervals, and covering the resulting gaps by a scrim or mesh 81 ~o keep particles away from the membrane. In this case an optional continuous film 83 such as all embodiments could have is shown between the membrane and rigid covering, with a suitable adhesive system employed to retain the covering material on fi le 83.
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Reverting to Figure 1, on each edge of the structure shown is a margin of reduced thickness 12, where the covering material 22 does not extend to the edge of the membrane. This is to facilitate lap jointing between structures. As shown, lower wall 24 does extend right to the edge, but it need not do so in all embodiments. Such 3 1 6 6 ~ ~ ~

an arrangement is possible at each edge, or just two edges on each structure of the invention. In Figure 2 is shown on an e~larged scale a lap joint between the edges of adjacently laid structures of the invention. In the left hand structure the upper wall 23 of the membrane is terminated a short distance from the edge of the self adhesive membrane although the lower wall 24 of the membrane continues right up to that edge. The edge of the right hand structure laps over, and is similar in construction.
The invention extends to methods of waterproofing a surface by applying a covering of a plurality of st-ructures according to the invention, with or without lap jointing between them.
Figure 5 shows use of a double sided adhesive strip 90 on a concrete surface 91 where adjacent structures of the invention meet. Such structures in this case do not have edges free of covering material.
To assist in detailing at complicated places a liquid applied waterproofing compound can be used.
As an alternative to the above arrangement where the channels in the relatively rigid material are transverse to the length of the structure, embodiments o~
the invention may provide the channels parallel to that length. Thus, as shown in Figure ~R~there is a structure of the invention comprising a self adhesive bituminous substrate 100 and, contiguous thereto, a layer of rigid 1316~6~

material 101 which has channels 102 defined between side walls, which channels are parallel to the length of the structure. The embodiment also illustriates another feature of the invention, which is that the fold lines between adjacent segments of the material 101 are provided by compressing the material, e.g. with a nip-roller or the like, rather than by cutting. Such nip-folding can be performed either transverse to or longitudinally of the channels where the relative rigid material is of the channel structure shown. C
Embodiments such as that of Figure ~ can also include, where applicable, features of other embodiments described above.
Embodiments with the channels extending longitudinally have the advantages that continuous length manufacture may be easier, water is not drained from the channels into the main, longitudinal, lap joints, interchange of liquid floor between channels is easier at the fold lines, and with vertical surfaces, vertical positioning of the structures gives vertical channels, as is of course desired for drainage.
It is possible for structure of the invention to be assembled on site rather than be factory made. Thus, a separate membrane having perhaps a substrate of plastics material can, in certain cases, be applied first to a surface to be protected and the remainder of the structure can be applied as a separate item subsequently and be adhered in place, for instance by an adhesive which it carries.

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Claims (14)

1. A structure comprising a membrane of a waterproofing pressure sensitive adhesive material with, contiguous thereto, a layer of relatively rigid covering material comprising two walls held spaced apart by a plurality of transverse ribs defining channels between the walls.

2. A structure according to claim 1 wherein the channels are parallel to the length of the structure.

3. A structure according to claim 1 wherein the channels are transverse to the length of the structure.

4. A structure according to claim 1, 2 or 3 wherein the outer wall of the covering material is perforated.

5. A structure according to claim 1, 2 or 3 wherein sections of the outer wall of the covering material are removed and the resulting gaps covered with scrim or mesh.

6. A structure according to claim 1, 2 or 3 wherein the channels contain foam.

7. A structure according to claim 1, 2 or 3 wherein the covering material is 2 to 10 mm thick.

8. A structure according to claim 7 wherein the covering material is about 4 mm thick.

9. A structure according to claim 1, 2, 3 or 8 wherein the adhesive membrane is reinforced.

10. A structure according to claim 1, 2, 3 or 8 wherein the membrane is of a bituminous composition.

11. A structure according to claim 1, 2, 3 or 8 wherein the covering material is of reduced thickness along two or all edges such that lap joints may be made with adjacent structures.

12. A structure according to claim 1, 2, 3 or 8 wherein there is a film between the membrane and segments.

13. A waterproofing membrane structure, comprising:
a self-adhesive waterproofing layer operative for adhesion to a surface; and a cover layer having a lower wall parallel with and contacting said self-adhesive waterproofing layer, an upper wall spaced apart from and parallel to said lower wall, and a plurality of transverse walls connecting said lower wall to said upper wall, whereby channels are formed between said lower and upper walls.

14. A method of waterproofing a surface by applying thereto a plurality of structures according to claim 1, 2, 3 or 8.