AU2009292738B2

AU2009292738B2 - Building sheet and method for detecting weatherproofness of structures

Info

Publication number: AU2009292738B2
Application number: AU2009292738A
Authority: AU
Inventors: Kyle Lloyd Herbert
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-09-18
Filing date: 2009-09-16
Publication date: 2016-09-22
Anticipated expiration: 2029-09-16
Also published as: WO2010033040A1; NZ571375A; AU2009292738A1

Abstract

A building sheet which changes a detectable visual characteristic of the sheet when exposed to certain environmental conditions. In a preferred embodiment a hydrochromatic layer is applied to a building sheet and a change in colour or transparency may be detected visually to indicate exposure to water. Use of such a building sheet in a building enables detection of a fault before a structure is enclosed. The building sheet may be formed by applying a detection composition to one or both sides of the sheet in continuous layers or in a desired pattern.

Description

BUILDING SHEET AND METHOD FOR DETECTING WEATHERPROOFNESS OF STRUCTURES

FIELD OF THE INVENTION

This invention relates to a building sheet for detecting the presence of certain environmental conditions (especially moisture) within a'building or the like.

It also relates to visual methods of detection of environmental conditions vyithin a building or the like. '

BACKGROUND OF THE INVENTION

There has been a recent increase in the number of buildings suffering damage due to failure to properly protect buildings from the ingress of water. Typically the problem is only revealed after the building has been completed, requiring expensive remedial actiqn.

It would be desirable to provide a method enabling the easy detection of building faults and a building sheet for use in such a method or to at least provide the public with a useful choice.

EXEMPLARY EMBODIMENTS

According to one exemplary embodiment there is provided a building sheet having a weight of up to 900g/m2 having a hydrochromatic material applied over at least part of the surface thereof which reversibly changes a detectable optical characteristic viewable through the sheet when exposed to water.

According to another exemplary embodiment there is provided a method of testing the weatherproofness of a structure comprising: . i. building at least the shell of a structure; ii. applying a building sheet having a hydrochromic material applied to at least part of the outside facing surface thereof which changes a detectable optical characteristic viewable through the sheet when exposed to water; and iii. visually monitoring the building sheet over time to detect any . change in its optical characteristics. \

According to a further exemplary embodiment there is provided a method of producing a building sheet comprising incorporating or applying a hydrochromatic composition to a building sheet of material having a weight of up to 90pg/m2 which reversibly changes a detectable optical characteristic viewable through the sheet when exposed to Water. ;'

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings which are incorporated in and constitute part of the specification, illustrate embodiments of the invention and, together with the general description of the invention given above, and the detailed description of embodiments given below, serve to explain the principles of the invention.

Figure 1 shows a building sheet according to a first embodiment.

Figure 2 shows a building sheet according to a second embodiment.

Figure 3 shows a building sheet according to a third embodiment.

Figure 4 shows a structure to which a building sheet has been applied to one wall. ‘ .

Figure 5 shows a building sheet according to a further embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

In a first embodiment the building sheet has a detectable visual characteristic which changes in response to certain environmental conditions (for example the ingress .of water into the interior of a structure or the presence of an undesirable chemical composition). The base material of the building sheet may be building paper, building wrap, cladding underlay, roof underlay, ; moisture barrier, sheeting, a fabric etc. The building sheet may be formed of polypropylene, polyethylene, acrylic, polycarbonate, PEVA, PVC, BOPP, polyester, woven and non-woven films etc.. The term "building sheet" is also used in this specification to include a building tape for joining building products together. '

In the embodiment shown in figure 1 the composition 1 having detectable characteristics is applied to sheet 2. In the embodiment shown in figure 2 the composition having detectable characteristics is impregnated into sheet 3. In the embodiment shown in figure 3 the composition having detectable characteristics is applied in layers 4 and 6 to both sides of sheet 5.

Layers 1, 4 and 6 may consist of multiple layers. Where sheet 2 or 5 has poor adherence a primer layer may be applied before the active composition is applied. ' (

The composition may be applied over an entire sheet or in a predetermined pattern such as in stripes, in the form of an advertising logo or as a combination of patterns. Applying the composition as a pattern may reduce the usage of the composition required as well as providing additional advertising. . .

The building sheet preferably has a weight of up to 900 g/m2, more . preferably 50 to 170 g/m2 and most preferably 60 to 120 g/m2. In One embodiment the detectable characteristic of the composition may be an optical characteristic. In one embodiment this may be colour or transparency. Colour or transparency changes in the composition may be permanent or reversible depending upon the application.

In one embodiment the composition may be a hydrochromatic composition that is activated by water to produce a colour or transparency change. Water may cause· the colour or transparency of the sheet to change or the surface contour to change. Alternatively, the composition may be thermochromic and change in dependence upon temperature. A change in temperature may reveal the presence of water on the sheet and so may provide an indication as to the presence of water. Hydrochromatic and thermochromic materials may provide reversible colour or transparency change. Hydrochromatic .compositions may react with water to provide a permanent detectable change. Compositions may also react in the presence of other chemicals. For example, the presence of arsenic may activate the composition. This allows the presence of undesirable compositions to be detected. The sheet will preferably have a thickness of less than 1 mm.

Example

In one preferred embodiment shown in figure.5 a transparent plastic building sheet 13 having a weight of 60 to 150 g/m2 has a transparent primer layer 14 applied thereto to facilitate adherence of a hydrochromatic layer 15. A primer such as Kamthane S-1801 may be used with a density of about 1 g/m2 to bind the hydrochromatic layer 15 to the sheet 13. Where the building sheet has suitable adherence the primer layer may not be required. The hydrochromatic ink is an ink that is opaque when dry and transparent when wet (such as Binder B-0821 or Neo Flex J-10) which may be applied at a density of about 35 g/m2. A coloured layer 16 is applied over the hydrochromatic layer 15 so that when the hydrochromatic ink turns transparent when wet the coloured layer 16. is clearly visible through the building sheet. A suitable coloured ink may be applied at a density of about 10 g/m2. The coloured layer 16 could be omitted and the change in transparency/opacity used to detect the presence of water but the coloured layer is preferred as this gives a clear visual indication of the presence of water.

The layers 14 to 16 may be applied to the.entire sheet 13 or selected portions (stripes, designs, advertising etc.). The layers 14 to 16 may be applied using screen printing, flexographic printing, offset printing or other suitable printing methods or by spraying, rolling or be incorporated during manufacture.

According to another embodiment a hydrochromatic sheet may be secured to a building sheet by welding or gluing etc. This enables the method to be used with a non-transparent sheet. In another embodiment, the substrate may be a building tape for joining building sheets together. Such tape may provide visual indication of leaks etc. where standard building sheets are employed. ' .

Referring now to figure 4, walls 7 and 8 of a structure are shown. Building sheets 9, 10 and 11 have been applied to the interior of wall 8 which has had cladding applied to the exterior wall. In this example the building sheets are shown applied to the interior of the framing for. clarity - it will be appreciated that normally the building sheets will be applied between the framing and the external cladding. In this embodiment the colour or surface contour of a region 12 appears visibly different to the rest of sheets 9, 10 and 11. In this case water has penetrated the exterior cladding and region 12 indicates that there has been water penetration. During the period before internal linings are applied to a structure the use of this building sheet provides a useful method to identify the ingress of water through external cladding so that it may be remedied before internal linings are applied. Rather than waiting for certain environmental conditions to occur the exterior cladding may be tested by hosing or water blasting the exterior. It will be appreciated that the same method may be employed for cladding or roof underlay to detect leaks etc. in roofing. ' . · · ' C · ' . - .

The invention thus provides a range of methods for detecting exposure to certain environmental conditions. The use of a detectable sheet incorporates detection capabilities into a standard building material making it easy and cost effective to implement.

While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus and. method, ahd. illustrative examples shown and · described. Accordingly, departures may be made from such details without departure from the spirit Or scope of the Applicants general inventive concept.

Claims

CLAIMS: ,

1. A building sheet having a weight of up to 900g/m2 having a ' · · ' · . ‘ t . _ hydrochromatic material applied over at least part of the surface , thereof which reversibly changes a detectable optical characteristic viewable through the sheet vvhen exposed to water. • . - · .·./·' '
2. A building sheet as claimed in claim 1 wherein the sheet has a weight of 50 to 170g/m2. .
3. A building sheet as claimed in claim 1 wherein the sheet has a weight of 60 to120g/m2.
4. A building sheet as claimed in any one of the preceding claims wherein the sheet has a thickness of less than 1 mm.
5. A building sheet as claimed in anyone of the preceding claims wherein the optical characteristic is coldur or transparency.
6. A building sheet as claimed in any one of the preceding claims ' wherein the hydrochromatic layer is applied by printing, spraying or rolling.
7. A building sheet as claimed in claim 6 wherein a primer is applied to the sheet before the hydrochromatic layer is applied.
8. A building sheet as claimed in claim 6 or claim 7 wherein a coloured layer is applied over the hydrochromatic layer. . 9. A building sheet as claimed in any one of the preceding claims wherein a composition exhibiting the detectable characteristic is applied to one side of the sheet.
10. A building sheet as claimed in any one of claims 1 to 9 wherein a composition exhibiting the detectable characteristic is applied to both sides of the sheet * -
11. A building sheet as claimed in claim 9 or 10 wherein the composition is applied in a predetermined pattern.
12. A building sheet as claimed in claim 11 wherein the pattern is stripes.
13. A building sheet as claimed in claim 1.1 wherein the pattern is advertising.
14. A building sheet as claimed in claim 11 wherein the pattern is a combination of patterns.
15. A building sheet as claimed in any one of the preceding claims wherein the sheet is building paper. ·
16. A building sheet as claimed in any one of claims 1 to 14 wherein the . sheet is building wrap.
17. A building sheet as claimed in any one of claims 1 to 14 wherein the sheet is a fabric.
18. A building sheet as claimed in any one of claims 1 to 14 wherein the sheet is cladding underlay or roof underlay.
19. A building sheet as claimed in any one of claims 1 to 14 wherein the ' sheet is sheathing.
20. A building sheet as claimed in any one of claims 1 to 14 wherein the building sheet is a moisture barrier.
21. A building sheet as claimed in any one of claims 1 to 14wherein the building sheet is a building tape. .
22. A building sheet as claimed in any one of claims 1 to 14 wherein the building sheet is jointing tape.
23. A building sheet as claimed in any one of claims 1 to 14 wherein the building sheet is transparent. .
24. A method of testing the weatherproofness of a structure comprising: i. building at least the shell of a structure; ii. applying a building sheet having a hydrochromic material applied to at least part of the outside facing surface thereof which changes a detectable optical characteristic viewable through the sheet when exposed to water; and iii. visually monitoring the building sheet over time to detect any change in its optical characteristics.
25. A method as claimed in claim 24 wherein the building sheet is a building sheet as claimed in any one of claims 1 to 23.
26. A method of producing a building sheet comprising incorporating or applying a hydrochromatic composition to a building sheet of material having a weight of up to 900g/m2 which reversibly changes a detectable optical characteristic viewable through the sheet when exposed to water.
27. A method as claimed in claim 26 wherein a primer layer is applied before the hydrochromatic layer is applied.
28. A method as claimed in claim 26 or 27 wherein a coloured layer is applied over the hydrochromatic layer.
29. A method as claimed in claim 26 wherein the hydrochromatic composition changes colour or transparency in the presence of water.
30. A method as claimed in any one of claims 26 to 29 wherein the ; composition is applied to both sides of the sheet.
31. A method as claimed in any one of claims 26 to 29 wherein the composition is applied to one side of the sheet.
32. A method as claimed in any one of claims 26 to 31 wherein the composition is applied by printing, spraying or rolling.