AU698272B2

AU698272B2 - Building construction material

Info

Publication number: AU698272B2
Application number: AU31232/95A
Authority: AU
Inventors: Saing Heng Ing
Original assignee: CONSOLIDATED ALLOYS N Z LIMITE
Current assignee: Consolidated Alloys (nz) Ltd
Priority date: 1994-08-24
Filing date: 1995-08-10
Publication date: 1998-10-29
Anticipated expiration: 2015-08-10
Also published as: AU3123295A; WO1996006245A1

Description

BUILDING CONSTRUCTION MATERIAL BACKGROUND OF THE INVENTION

The invention relates to construction material and/ or a method of manufacture and, in particular, a weather proofing material, such as a roof flashing and the like.

In conventional roofing construction a roof flashing is often used at the juncture between the ridge portion or abutting wall and the roofing material extending from beneath the ridge or wall. Such roof flashings have traditionally been made from lead so that the malleable properties of the lead can be used to form the roof flashing into the corrugations and other deformations in the roofing material.

Roofing manufacturers have sometimes applied coatings to their roofing materials. Such coatings have included both aluminium and zinc which may be incompatible with the lead roof flashings and can cause or promote corrosion.

As a result, some manufacturers have resorted to the use of aluminium sheet as a roof flashing. However, aluminium sheet is not very malleable and does not allow the expansion necessary for it deforming into the corrugations without shortening in length or it at least requires a substantial effort to enable deforming to occur, making installation difficult.

Therefore, it is an object of the present invention to provide construction material and/or method of manufacture which will overcome or at least obviate some of these disadvantages or will at least provide the public with a useful choice.

BRIEF SUMMARY OF THE INVENTION

In a first aspect, the invention may broadly be said to consist in construction material comprising: a substantially planar sheet of material; a plurality of substantially transverse deformations or perforations provided in said sheet to increase the malleability and expandability of said planar sheet such that, in use, said planar sheet may be expanded longitudinally to conform with a non-planar surface against which said construction material is required to fit; an expandable waterproofing layer being provided at least on one side of said planar sheet, which said one side would in use be positioned against said non-planar surface. In one embodiment said deformations or perforations comprise a plurality of substantially transverse perforations extending through the planar sheet.

In one embodiment said perforations comprise lines of spaced apart perforations over the whole area or a substantial portion of the area of said planar sheet and wherein said lines of perforations themselves are substantially parallel and spaced apart.

In one embodiment said waterproofing layer comprises a material containing bitumen or synthetic rubber.

In one embodiment said waterproofing layer comprises polyisobutylene.

In one embodiment said construction material may include a layer of polyethylene soft paper, expandable woven fabric, or other non-adhering material.

In one embodiment said planar sheet of material is a planar sheet of aluminium.

In a second aspect, the invention may broadly be said to consist in a method of manufacturing construction material comprising the steps of: providing a substantially planar sheet of material; forming a plurality of substantially transverse deformations or perforations in said planar sheet of material to increase the longitudinal malleability and expandability of said planar sheet, and further including the step of providing an expandable waterproofing layer for at least one side of said planar sheet .

In one embodiment said step of forming a plurality of deformations or perforations comprises the step of providing a plurality of spaced apart substantially parallel lines of spaced apart perforations over at least a substantial portion of the area of said planar sheet .

Further aspects of the invention, which should be considered in all its novel aspects, will become apparent to those skilled in the art from reading the description of possible embodiments of the invention which will now be described with reference to the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a plan, very diagrammatic, view of one embodiment of a construction material; Figure 2 is a cross section through an embodiment of the invention in accordance with Figure 1;

Figure 3 is a very diagrammatic cross section through a roof showing the embodiment of Figure 1 in use; and

Figure 4 is a very diagrammatic plan view of an embodiment of the present invention in use on a roof .

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawings, one embodiment of the construction material 1 of the present invention is shown in Figure 1. The material 1 comprises a planar sheet 2 of material, suitably a metal. Although a variety of metals may be used, a preferred embodiment of this invention uses aluminium. In selecting the metal to be used, consideration of its possible end use on roofs in conjunction with an aluminium and zinc coating should be given; ie. the metal of sheet 2 should be non- reactive and compatible with any coatings or other materials with which it may be used.

The malleability and expandability of the sheet^' of material 2 is increased in its longitudinal direction through the provision of a plurality of transverse deformations or perforations 3 suitably throughout the sheet. Again, a number of varying sizes and/or directions of perforations or deformations could be used. However, with the material 1 being used as a roof flashing over corrugations and the like in roofing steel, an ability for longitudinal expansion is desired and, therefore, the preferred form of this invention provides a plurality of transverse perforations 3.

The terms "longitudinal" and "transverse" are used throughout this specification, including the claims, merely to indicate axes which are substantially, or relatively, orthogonal or at or towards 90° towards one another.

As can be seen in Figure 1, the perforations 3 may be arranged in substantial parallel lines of perforations .

Again, in the use as a roof flashing for this particular sheet, the principal direction in which expansion is required is longitudinally. Therefore, an arrangement of substantially transverse perforations is preferred to allow the expansion in the longitudinal direction. Of course, in alternative uses, expansion may be required transverse of the sheet of material and the perforations may be redirected substantially longitudinally accordingly. The preferred form of this invention arranges the perforations at substantially right angles to the desired direction of expansion. However, expansion or malleability can be achieved when the perforations are at an angle of less than 90° to the required direction for the expansion or malleability.

A roof flashing as shown in Figure 1 when provided with perforations which will expand to fit over corrugations in a roofing profile would allow the passage of rain through the perforations. Therefore, to provide weather proofing of the material 1, a waterproof layer at least on one side of the sheet 2 provides the necessary degree of weather proofing. As shown in Figure 2, this waterproof layer comprises an expandable material such as a layer of polyisobutylene 4. Other expandable and resilient waterproof coatings or thicknesses of material (s) may also be used. For example, bitumen based products or synthetic rubber or plastic layers or coatings could be used.

In the use of polyisobutylene, the polyisobutylene 4 itself is somewhat adherent in its natural state. Therefore, the layer of polyisobutylene 4 will adhere to the sheet of aluminium or similar metal 2. To create an ease of handling and to inhibit the adherence of the polyisobutylene 4 during transportation or use, a further layer 5 of non adherent material or coating such as polyethylene, soft tissue paper, expandible woven fabric or any other non-adherent but expandable and resilient material, may be provided on an opposite side of the polyisobutylene 4 from the metal sheet 2.

If other substitute materials are used rather than the polyisobutylene 4, it may be necessary to adhere such materials to the sheet 2 with a suitable adhesive or other process. Additionally, the layer or coating 5 may be redundant particularly if a non or less adherent substance used as a waterproof material for the layer 4.

Also shown in Figure 2 is a portion 6 of the sheet 2 which is formed and turned into the conventional edge used to engage the ridge of a conventional roof. This may not always be necessary in other weather proofing products using the same invention.

In an alternative form to that shown in Figure 2, the waterproof layer of polyisobutylene or other material 4 and the layer or coating 5 could run the entire width of the sheet 2 including the turned edge 6.

Figure 3 shows a roof having a ridge portion 7, rafters 8, purlins 9 and roofing material 10 in accordance with a conventional roof. It can be seen that the weather proofing material 1 may be provided as a flashing, to engage an edge 11 of the ridge member 7 and seal against the roofing material 10. When the roofing material 10 includes corrugations, the flashing 1 must be deformed to correspond with the corrugations at least adjacent to its edge distant from the ridge member 7 to stop the driving of water or other materials or wind into the roof cavity in the hollows of the corrugations.

To manufacture the material 1, the metal sheet 2 may be formed using, for example, 0.3mm aluminium sheet. This itself may be primed or painted or not depending on the customer's requirements.

The deformations or perforations 3 may be formed through pressing or the use of a die cut process or rolled into the material.

The polyisobutylene 4 can be extruded directly onto the metal sheet 2 or can be obtained in coils including a release paper and the release paper can be removed as the polyisobutylene is layered onto the metal sheet 2.

The non-adherent layer 5 may, if required, then be applied to complete the composite material 1. Of course, this may be done in an alternative arrangement of the steps .

It should be noted that, in use, where the waterproof coating or material 4 is polyisobutylene or a similar such material, this may be sensitive to ultra violet light. Therefore, the provision of the metal sheet 2 over the waterproof coating 4 allows for protection against the ultra violet light while the expandable waterproof coating or material itself protects against the passage of water or other materials through the small apertures of the deformations or perforations 3 formed in the sheet 2.

With regard to the materials for the sheet 2, aluminium or soft zinc sheets or suitable alloys are all possible suitable materials.

Referring now more specifically to figure 4, the metal sheet 2 is shown providing a roof flashing extending downwardly from a roof edge 11 and over a roofing profile 10 having a profile for corrugation 13. The perforations of the metal sheet 2 are shown enabling the metal sheet to expand in a longitudinal direction forming the expanded area 12 with its plurality of opened out apertures 3A formed from the perforations'. In this way the expanded perforations 3A are able to extend over a distance "X" corresponding with the width of the profile 10 from an unexpanded longitudinal width of metal "Y" .

Thus it can be seen that the invention provides a roofing material and/or a method of manufacture of same which in a roof flashing allows for the substitution of existing lead flashings with other materials which are less malleable or expandable in their natural state. This allows for the use of suitable materials to coincide with a variety of varying roofing materials, some of which may not be compatible with lead due to potential corrosion or other problems.

Where in the foregoing description, reference has been made to specific components or integers of the invention having known equivalents, then such equivalents are herein incorporated as if individually set forth.

Although this invention has been described by way of example and with reference to possible embodiments thereof, it is to be understood that modifications or improvements may be made thereto without departing from the scope of the invention as defined in the appended claims .

Claims

Construction material comprising:

(a) a substantially planar sheet of material;

(b) a plurality of substantially transverse deformations or perforations provided in said sheet to increase the malleability and expandability of said planar sheet such that, in use, said planar sheet may be expanded longitudinally to conform with a non-planar surface against which said construction material is required to fit,

(c) an expandable waterproofing layer being provided at least on one side of said planar sheet, which said one side would in use be positioned against said non-planar surface.

2. Construction material as claimed in claim 1 having a plurality of substantially transverse said perforations extending through the planar sheet.

3. Construction material as claimed in claim 2 wherein said perforations are spaced apart in lines extending over at least a substantial proportion of the area of said planar sheet .

4. Construction material as claimed in claim 3 wherein said lines of perforations are substantially parallel with one another.

5. Construction material as claimed in any one of the preceding claims wherein said waterproofing layer comprises a self-adhering material which will adhere to said planar sheet.

6. Construction material as claimed in claim 5 wherein said self adhering waterproofing material comprises polyisobutylene.

7. Construction material as claimed in claim 5 or claim 6 and further including a layer of a non- adhering material provided for said self-adhering waterproofing material on the side opposite from said planar sheet.

8. Construction material as claimed in any one of the preceding claims wherein said planar sheet is of aluminium.

9. Construction material substantially as herein described with reference to the accompanying drawings.

10. A roof flashing comprising a construction material according to any one of the preceding claims.

11. A method of manufacturing construction material comprising the steps of:

(a) providing a substantially planar sheet of a material;

(b) forming a plurality of substantially transverse deformations or perforations in the said planar sheet of material to increase the longitudinal malleability and expandability of said planar sheet;

(c) and further including the step of providing an expandable waterproofing layer for at least one side of said planar sheet.

12. A method of manufacturing construction material as claimed in claim 11 including the steps of providing, a plurality of spaced apart perforations over at least a substantial portion of the area of said planar sheet, said waterproofing layer as an application of polyisobutylene, and a non-adhering material on an opposite side of said waterproofing material .