AU2004100461B4 - Insulation system - Google Patents

Description

P/00/009A Section 29

AUSTRALIA

Patents Act 1990 INNOVATION PATENT SPECIFICATION Invention Title: INSULATION SYSTEM Applicant: Sisalation Pty Ltd The invention is described in the following statement: INSULATION SYSTEM Field of the Invention The present invention relates to insulation, more particularly to thermal insulation for building. It will be convenient to describe the invention with particular reference to insulation for domestic housing but the invention may have wider application.

Background of the Invention Thermal insulation of domestic housing has been mandatory in some states of Australia for many years. Local and Australia-wide building codes and regulations specify minimum insulation specification in various climate zones for different parts of houses, roof/ceiling, wall and in some cases floors. Ever increasing energy costs and demand on energy resources makes energy efficiency of domestic housing an important issue.

There are many different arrangements of different types of insulation products in buildings which meet or exceed the different regulatory requirements. These utilize either bulk insulation or reflective insulation, or a combination of these. Bulk insulation resists the transfer of conducted and convected heat by relying on the insulation effect of still, trapped air within its structure, while reflective insulation resists radiant heat flow by reflecting infrared radiation and offering low emissivity (ability to store and re-radiate heat).

Conventional teaching dictates that an air gap of at least 25 mm is required adjacent to the reflective surface of reflective insulation for it to be effective.

There are a number of problems associated with many of the known insulation systems. First, reflective foils installed directly underneath metal or tiled roofs beneath battens may suffer from "foil-flap" a condition where air currently created by wind blowing through gaps in the roofing material cause the W:ErnnMPS'Spedces\722397.doc 12.JA.205 14:28 PHILLIPS ORMONDE 96141B67 NO, B59'1 P. 4 2 o foil to flap and beat against the roofing material, rafters or battens. This creates Ci noise, particularly in high winds, which can be very annoying for the householder and neighbours, Secondly the costs of installing various types of insulation systems can add significantly to the building project, and ever increasing cost pressures on builders may case them to adopt alternative insulation arrangements which, while meeting the minimum regulatory requirements, may not necessarily give the best overall insulation result.

Thirdly, some insulation methods such as installation of bulk installation over o ceilings may lead to higher incidents of rectification problems, primarily when an installer may accidentally put their foot through the plaster ceiling, leading to Sadded cost to the builder to have the damage repaired. Further, it would be Cdesirable for installation of insulation to be done by other tradesmen during their particular job, rather than having to rely on one further trade, which may otherwise hold up completion of construction and hand-over to the client.

Objects of the Invention It is an object of the present invention to provide an insulation system which is economical to install, and which meets the necessary regulatory requirements, at least in certain climate zones. It is another object of the invention to provide an insulation system which reduces or eliminates the occurrence of foil-flap.

Summary of the Invention According to one aspect of the invention there is provided an insulation system for a roof having a roofing material fixed to battens and battens fixed to rafters, the system including a foil layer positioned over the rafters and secured in place by and located to which the roofing material is fixed beneath the battens; and a bulk insulation layer located over said foil layer and beneath said roofing material, and between adjacent battens.

COMS ID No: SBM-010735D5 Received by IP Australia: Time 15:35 Date 2005-01-12 12. JAN. 2105 14:28 PHILLIPS ORMONDE 96'41867 NO. 859' P. 3 o In another aspect of the Invention there is provided a method of Cl insulating the roof of a building comprising the steps of; S- overlaying rafters with a layer of insulating foil fixing battens to said rafters at desired spacings to secure said foil positioning a layer of bulk insulation over said foil between said battens fixing a roofing material to said battens.

SThe foil may be any suitable sarking material which has a reflective foil layer and is preferably water-resistant and acts as a vapour barrier. Preferably O the foil is a multilayer laminate sarking which includes a reflective foil layer tC made from aluminium foil or the like. To achieve the optimal total thermal value of the insulation system, the reflective foil layer faces downwardly Into the airspace of the roof cavity, i.e. the reflective foil layer is on the under side facing downwardly and thus lies over the rafters. Preferably the foil also includes a non-reflective or glare reducing upper layer which faces upwardly. The nonreflective surface thus protects the installer of the insulation from glare and reflected heat during installation which may otherwise present an occupationa health and safety hazard.

The foil may include reinforcement such as fibers or filaments which assist the foil in resisting puncturing or penetration and may prevent a person from falling through the foil by accident. Suitable foils include Sisalaton 466 and Proguard sarking (both trademarks of Sisalation Pty Ltd) although other foils and sarking products may be suitable.

The foil may be laid over rafters in a series of strips running substantially perpendicular to the rafters, in the conventional manner as is known in the art.

The strips preferably overlap to reduce heat leakage.

Battens are then laid over the rafters and fixed using any suitable means known in the art. In the process of securing the battens, which will generally run substantially perpendicular to the rafters, the foil will thus be fixed in position by being held by the batten overlying the rafter. Adjacent battens are spaced at COMS ID No SBMI-01073505 Reccived by IP Australia: Time 15:35 Date 2005-01 -12 specified centres depending upon the roofing material to be fixed to the battens.

For example, where the roofing material is roofing tiles, the battens, may be spaced at 300 mm centres. For other forms of roofing material such as metal decking battens may be spaced according to the specification of the roofing manufacturer.

The battens preferably have a depth of about 40mm. (but may vary from to Between each adjacent pair of battens, a layer of bulk insulation is then laid lying directly on top of the foil layer. In a preferred embodiment the bulk insulation is supplied having a width corresponding to the width of the gap between adjacent battens, i.e. the spacing of the centres of the battens less the width of a typical batten. In this preferred embodiment the bulk insulation is provided as an elongated blanket which is of substantially the same thickness as the depth of the battens, i.e. preferably about 40-45 mm. The foil is generally draped between the rafters often resulting in the spacing between the foil and the top of the batten being greater than the depth of the batten. Typically this can allow up to an extra 30mm insulation between the foil and the top of the batten. Preferably the bulk insulation is glass wool insulation and has a thermal resistance rating of about RI1.0 if the insulation is about 40 mm thick. Other forms of bulk insulation may be suitable such as rock wool, polystyrene or polyester.

Preferably the bulk insulation is water resistant and does not degrade if it becomes wet for a period of time. Accordingly, wood based bulk insulation such as cellulose is not considered to be suitable for the present invention, and sheep's wool may also be unsuitable.

Once the bulk insulation has been positioned the roofing material can be fixed in the conventional manner. For example, roofing tiles can be laid directly over the battens and optionally wired in position. Other forms of roofing material such as metal decking or corrugated iron may be nailed or screwed or otherwise fixed with position using known methods. Preferably the bulk W:ElinW\MPS\Speces\722397.doc insulation is not compressed to any significant degree when the roofing material is laid over it.

It will be appreciated that by providing a layer of bulk insulation in the space created beneath the roofing material and above the foil, and bordered by the battens, the air gap which would otherwise be present is now filled.

Surprisingly, the applicant has found that this particular arrangement can achieve thermal resistance ratings necessary to satisfy the regulatory requirements in a number of climate zones. For example, with a bulk insulation thickness of about 40 mm and using one of its proprietary foils, ratings in excess of R2.2 can be achieved.

It will now be convenient to describe the invention with reference to the preferred embodiment shown in the accompanying drawings. It is to be understood that the drawings and following description related to a preferred embodiment only and are not intended to limit the scope of the present invention.

Figure 1 shows a top view of a roof without the roofing material applied showing part of the roof covered with bulk insulation.

Figure 2 shows a transverse section of part of the roof of Figure 1.

In Figure 1 roof 1 has a plurality of rafters 3a, b, c, d running parallel. As will be appreciated rafters 3a-d are spaced at equal centres where convenient.

Overlying rafters 3a-d is a layer of sarking 5 which has a reflective surface 4 (now shown in Figure 1) facing downwards and a non-glare surface 7 facing upwards relative to the rafters and the roof in general. Sarking 5 is laid over the rafters 3a-b simply by unrolling the roll of sarking 5 perpendicular to rafters 3ad. Adjacent runs of sarking should be overlapped according to manufacturers' recommendations or regulatory requirements. Battens 9a, b, c, and d, are then fixed to rafters 3a-d at points of intersection typically shown in I1 la, b, c, and d, most preferably by nailing.

W:Ern\MPSSpecies%722397.doc 1 6 The spacing 13 of battens is dictated by the type of roofing material (not shown) to be used. With tiled roofing, the spacing may be about 300 mm.

Blankets 15a and 15b are then laid directly over the non-glare surface 7 of sarking 5 between battens 9a and 9b and 9b and 9c. Blankets 15a and are supplied in a width corresponding to width 17, which is the width of spacing 13 less the width of a batten 9. Blankets 15a and 15b thus fit snugly in this space to prevent air currents.

Preferably blankets 15a and 15b are supplied in an elongate roll and are simply rolled out in the direction of the batten 9a-d.

In another embodiment the blanket may be supplied with a width corresponding to a multiple of two or more widths 17 and is provided with perforation which allow the blanket to be rolled out in the direction of the batten 9a-d, then separated along perforations into individual widths corresponding to width 17.

As can be seen in Figure 2, the thickness of blankets 15a and 15b is roughly the same as the depth of battens 9a, b, and c, although the thickness of blankets 15a and 15b may be slightly more or less than the depth of the battens. It will be appreciated that the thickness of battens and/or blanket may vary due to irregularities inherent in the products but this will not affect the functioning of the invention.

Once all sarking is overlaid with blanket material, roofing elements such as tiles, sheet metal or decking or the like can be overlaid and fixed to battens 9a d in a suitable manner. With some roofing materials such as tiles, there may be a small air gap between the underside of the tile and the top of the blanket 15. With tiled roofs in particular rain or moisture may penetrate beneath the tiles, especially in cases of heavy, driven rain. With the present insulation system, it is permissible for the bulk insulation to be wet to a limited degree on occasion without jeopardizing the integrity of the insulation. Surprisingly, the applicant has found that limited wetting is reversible without permanent degradation of the thermal resistance of the insulation systems.

W:AErdnWPS\SpeCies\722397doc The insulation system of the present invention may be more suitable to warm humid, hot humid or hot dry-warm winter climates if it is the exclusive insulation system to be used in the building roof or ceiling. This is due to the fact that the R-rating achievable may to a fair degree depend upon the thickness of the battens, which determines the greatest allowable thickness of bulk insulation in most cases. The system of the present invention may equally be used in temperate, hot dry-cold winter, and cool temperature climate zones, preferably if used in conjunction with other insulation such as ceiling bulk insulation.

The bulk insulation occupying the space between the foil and roofing material provides a buffer against foil flap, thus enhancing homeowners' acoustic requirements as well as thermal requirements. It can be seen that the insulation system of the present invention can economically be installed by the relevant tradespeople who install the roofing material. In most cases this would be the roof tiler. The installation can thus be done when the roof is being installed, which is relatively early in the construction process, so delays on hand-over due to unavailability of insulation installers can be avoided.

It is to be understood that various alterations, modifications and/or additions may be introduced with the arrangements and components previously described without departing from the spirit of the invention as described.

W:Ern\MPS\Speces\722397.doc

Claims (1)

11.JAN-2005 14:29 PHILLIPS ORMONDE 96141867 NUO. 859' P, 6 8 o CLAIMS 0 1. An insulation system for a roof having a roofing material fixed to battens and battens fixed to rafters, the system including a foil layer positioned over the rafters and secured in place by and located beneath the battens to which the roofing material is fixed; and a bulk insulation layer located over said foil layer and beneath said O roofing material, and between adjacent battens. O 2. An insulation system for a roof according to claim 1, wherein the width of Sthe bulk insulation corresponds to the width of the gap between adjacent Sbattens. 3. An insulation system for a roof according to claim 1 or 2 wherein said bulk insulation is contained within the space between the battens, the foil layer and the roofing. 4. An insulation system according to any one of claims 1 to 3, wherein the thermal resistance rating of the bulk Insulation and the foil combined is R 2.2 or greater. A method of insulating the roof of a building comprising the steps of: overlaying rafters with a layer of insulating foil; fixing battens to said rafters at desired spacings to secure said foil; positioning a layer of bulk insulation over said foil between said battens; fixing a roofing material to said battens. Date: 12 January, 2005 Phillips Ornnonde Fitzpatrick Attoreys For: Sisaration Pty Ltd COMS ID No SBMI-01073505 Received by IP Australia Time 15:35 Date 2005-01-12