AU2011204990A1 - Roof flashing - Google Patents

Abstract

A roof flashing 10 for mounting on a roof, including an opening 11 through which a conduit can extend, an upstanding lip 12 extending fully about the opening 11 and 5 including an engagement portion 30 for engaging side walls of a conduit. A flange 16, 17 extends fully about the opening 11. The flange 16, 17 is substantially planar and extends from the lip 12 away from the opening 11. The flashing is formed in two substantially identical flashing parts 14, 15, with the flashing parts being formed to overlap along portions of the flashing 10 which in use form opposite side portions 19, 0 20 of the flashing 10 with the overlap on each side portion 19, 20 being between portions of the flange 16, 17 of each of the two flashing parts 14, 15 and portions of the lip 12 of each of the two flashing parts 14, 15. p '|7

Description

P/00/011 Regulation 3.2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title: ROOF FLASHING Applicant: Tonna Ducted Heating Services Pty Ltd The following statement is a full description of this invention, including the best method of performing it known to me: 1 8087 SYC 2 ROOF FLASHING FIELD OF THE INVENTION The present invention relates to roof flashing for providing a weather seal between a 5 conduit that extends through the roof of a building and the adjacent roof surface. The flashing is principally provided to prevent rain from entering the roof of a building through an opening which is provided for passage of a conduit through the roof, although it can also resist ingress of wind as well. The present invention has been developed principally for sealing a conduit, typically known as a "dropper box", that 10 extends from an evaporative air cooling unit above the roof, into the roof cavity. It will therefore be convenient to describe the invention in relation to that application, however it is to be appreciated that the invention can have alternative application, such as to skylights or other roof mounted objects. 15 BACKGROUND OF THE INVENTION A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims. 20 Dropper boxers for evaporative air coolers are one form of conduit that require a roof flashing for weather sealing purposes. Dropper boxes typically are square or rectangular in cross-section and form a passage for cooled air to enter a building through the roof from the air cooler. Dropper boxes usually extend through a roof 25 either vertically at an angle to the slope or pitch of the roof, or perpendicular to the slope or pitch of the roof. Many dropper boxes in use in Australia are of a standard size, so that manufacturers of roof flashing can manufacture the flashing to suit a variety of different dropper 30 boxes from different manufacturers. However, some manufacturers employee non standard sized dropper boxes and for those boxes, customised roof flashing is required.

3 Roof flashing for dropper boxes typically is formed from single piece out of metal, such as tin or lead. The roof flashing is typically fitted first to the roof and thereafter the dropper box is inserted through the flashing and into the roof cavity. The drawback with a single piece roof flashing is that where the dimensions of a dropper 5 box differs through normal manufacturing tolerances, often the fit between the dropper box and the roof flashing is loose, so that sealing of the flashing to the dropper box can be more difficult and time consuming and sometimes less reliable in the long term. In addition, the necessity to fit the dropper box through the roof flashing means that it is not possible to fit the dropper box first and thereafter apply 0 the roof flashing. The present invention has recognised problems with existing single piece roof flashing for dropper boxes, and therefore seeks to overcome or at least alleviate one or more disadvantages with that type of flashing. 15 SUMMARY OF THE INVENTION The present invention provides a roof flashing for mounting on a roof, including: a square or rectangular opening through which a conduit can extend, an upstanding lip extending fully about the opening and including an engagement portion for engaging 20 side walls of a conduit which extends through the opening, a flange extending fully about the opening, the flange being substantially planar and extending from the lip away from the opening, the flashing being formed in two substantially identical flashing parts, with the flashing parts being formed to overlap along portions of the flashing which in use form opposite side portions of the flashing with the overlap on 25 each side portion being between portions of the flange of each of the two flashing parts and portions of the lip of each of the two flashing parts. By virtue or providing the roof flashing in a two-part form, the roof flashing can be fitted to the roof either before the dropper box has been installed in the roof, or after 30 that installation has taken place. This provides flexibility with installation of the roof flashing which is not available with existing single piece roof flashing. In addition, the two-part construction of the roof flashing of the invention, with overlapping portions provided at each side portion of the flashing, allows flexibility in 4 sizing of the opening through which the dropper box is to extend through. Thus, while only minor adjustments are envisaged to be necessary, this ability to adjust one dimension of the opening can make the fit between the dropper box and the roof flashing more precise and thus more easy to seal and more reliable in the longer 5 term. A further advantage provided by roof flashing of the present invention, is that the roof flashing can be formed for fitting to dropper boxes of different dimensions. In the Australian industry, standard sized dropper boxes are formed in various external 0 dimensions, with two sizes from example being 550mm x 550mm and 550mm x 600mm. Thus, in this example, the width dimension across the top and bottom of the dropper box with respect to the slope or pitch of the roof to which the box is fitted, remains constant, while the length dimension in the direction of the incline of the roof, differs by 50mm. With a roof flashing according to the invention, the overlap of the 15 opposite side portions of the flashing can accommodate this difference in size between one dropper box and the next. This has significant advantages for flashing manufacturers, by allowing them to produce a single set of flashing parts, which can be used over a range of dropper box ?0 dimensions. This has advantages in relation to storage or parts, manufacture of parts (requiring a single die rather than a plurality of differ sized dies), while further advantages are provided for assembly personnel, who do not need to select the correct flashing from a stock of flashings, but simply have to take enough flashing parts for the number of dropper boxes required. This latter advantage is significant, 25 when it is understood that the difference in size of the opening of a roof flashing between two different sets of flashings might be as little as 50mm (as in the example given above), which is a difference not readily apparent to the eye. Accordingly, assembly personnel can be required to measure the opening if the flashing is otherwise unmarked to ensure that the correct flashings have been selected for a 30 particular size of dropper box. The invention has the further advantage that once the two parts of the roof flashing have been selected and positioned, installation of the flashing can take place substantially in accordance with the assembly technique for a single piece flashing.

5 Accordingly, while the roof flashing of the invention is formed in two parts, assembly personnel who are familiar with single piece flashing will readily understand how the roof flashing of the invention is to be assembled and therefore greater expertise is not required. 5 The opening of the roof flashing is square or rectangular. As indicated above, by providing the roof flashing as a two part instruction, the dimensions of the opening can be varied to suit the conduit to which the roof flashing is to be applied. Thus, by varying the extent to which the two parts of the roof flashing overlap, the size of the 0 opening which is provided in the roof flashing can be increased or decreased. The upstanding lip which extends fully about the opening can engage side walls of the conduit in any suitable manner, although in respect of a dropper box, the engagement is expected to be by way of a silicone sealant and screws. Thus, the lip can be fixed 5 to the side walls of the dropper box by screws, and thereafter a silicone sealant can be applied to the edge of the lip and the facing surface of the dropper box to seal any gaps between the lip and the dropper box against ingress of rain past the lip. Each flashing part of the flashing includes a lip portion and a flange portion. With the ?0 flashing parts assembled together, the lip extends fully about the opening. Each flashing part includes a full lip portion that in use extends across the slope or pitch of the roof and a pair of part lip portions that extend perpendicular to the full lip portion and in use extend in the direction of the inclination of the roof. The part lip portions overlap when the flashing parts are fitted together. In each flashing part, the junction 25 between the full lip portion and the part lip portions can be continuous or discontinuous. For example, if the roof flashing is formed from metal, the junction could be discontinuous and require a seal, such as a silicone seal. Alternatively, if the roof flashing is formed from plastic, the junction could be 30 continuous even though the lip portions extend at right angles to each other. It will be apparent from the above discussion, that the roof flashing of the invention can be manufactured from metal or plastic, or other materials such as fibreglass. However, by forming the roof flashing in plastic, the flashing can be moulded so that 6 the requirement for sealing at the junctions of the lip portions can be eliminated. In addition, once dies for the roof flashing have been produced, manufacture of plastic parts for the roof flashing is more cost effective than manufacturing the flashing from metal which usually involves stamping the flashing into shape. 5 The flange also extends fully about the opening and forms a substantially planar section of the flashing. The flange typically will be square or rectangular and will have an upper section and a lower section, which reside on opposite sides of the conduit relative to the slope or pitch of a roof to which the flashing is fixed, and a pair of 0 opposite side portions. The portions of the lip that extend from the upper and lower flange portions preferably extend towards a conduit which the roof flashing is provided for, at an angle of between 900 to 00. However, the angle of inclination is more preferably between 90* and 450, such as between 80* and 50* or 70* and 60*. One preferred angle is about 230 from vertical. 15 The portions of the lip which are disposed in use on opposite sides of a conduit which extends through the flashing can extend at 90* to the flange, or they can extend at an inclination of the kind described above in relation to the lip portions which extend from the upper and lower portions of the flashing. In practice, the side lip portions can extend at 90* to the side flange portions to sit flush against side walls of a dropper box, while the lip portions at the upper and lower flange portions extend at an angle towards the dropper box adjacent upper and lower flange portions of less than 90*. 25 The pair of flashing parts which form the roof flashing of the present invention can be substantially identical. In fact, the parts can be formed from the same die so that, putting aside moulding tolerance differences, the parts are effectively identical. As indicated above, this means that a single die is required to produce the two parts of 30 the roof flashing, and this has advantages in relation to storage and installation, manufacture and assembly. The present invention thus also provides individual flashing parts for a roof flashing of the aforementioned kind.

7 The present invention also provides an installation on a roof, which comprises a roof flashing of the above described kind and a conduit extending through the flashing. The conduit can connect an appliance, such as an evaporative air cooler from outside the roof to inside the roof cavity. 5 BRIEF DESCRIPTION OF THE DRAWINGS With reference to Figure 1, a two-part roof flashing 10 is illustrated which includes an opening 11, an upstanding lip 12 and a flange 13. 0 The flashing 10 is a two-piece flashing, comprising upper flashing portion 14 and lower flashing portion 15. Designation of upper and lower in relation to the flashing portions 14 and 15 is made on the basis of the positioning of the portions 14 and 15 on an inclined roof. In practice, while not shown, the upper flange portion 16 of the upper flashing portion 14 would underlie the roof covering, e.g. roofing tiles or 15 corrugated iron, while the lower flange portion 17 of the lower flashing portion 15 would overlie the roof covering. In this manner, water flowing onto the flashing 10 would flow from the upper flashing portion 14 onto the lower flashing portion 15 and then onto the roof covering below the flashing portion 15. ?0 The flashing portions 14 and 15 are of identical shape, and nest together as shown when installed in a roof structure. Accordingly, while the flashing portions 14 and 15 have been designated upper and lower portions respectively, these portions are identical and could be substituted for one another without affecting the operation of the flashing 10. What is important, is that the flashing portion 14 overlie the flashing 25 portion 15 as shown in the side portions 19 and 20 thereof. Extending from the upper and lower flange portions 16 and 17 are the side portions 19 and 20. In the upper flashing portion 14, the side portion 19 is shown to the left hand side, while the side portion 20 is shown to the right hand side. In the lower 30 flashing portion 15, the side portions 19 and 20 are reversed. This illustrates, that if the lower flashing portion 15 was rotated through 1800, it would have an identical construction to the upper flashing portion 14.

8 An overlapping region 0 is formed by the side portions 19 and 20 of the flashing portion 14 overlapping the respective side portions 20 and 19 of the flashing portion 15. The extent of the overlapping region 0 can be varied to vary the dimension D of the opening 11. It is anticipated that in some forms of the invention, the allowable 5 variation in the dimension D will be in the order of 150mm to 300mm. The lip 12 is comprised of upper and lower lip portions 25 and 26, and side lip portions 27. The side lip portions 27 are formed from subportions 28 and 29 of each of flashing portions 14 and 15, and as indicated above, the length of the side lip 0 portions 27 can vary depending on the extent of the overlapping region 0. The upper and lower lip portions 25 are formed at an angle to the flange 13. This is shown in cross-section in Figure 2, which shows the lip portions 25 and 26 disposed at an angle a of approximately 650. Because the flashing portion 14 is identical to 5 flashing portion 15, the angle at which the lip portions 25 and 26 extend relative to the flange 13, is the same. The side lip portions 27 extend perpendicular to the flange 13. Thus, while the lip portions 25 and 26 extend at an angle to the flange 13, the side lip portions 27 are ?0 formed perpendicular to the flange 13. The lip portions 27 are intended for flush engagement against side walls of a dropper box which extends through the opening 11 (shown in broken outline in Figure 1), while the lip portions 25 and 26 are intended for line engagement with such a dropper box. The reason for line engagement with the lip portions 25 and 26 is to accommodate differences in roof slope or pitch to 25 which the flashing 10 is applied. By arranging line contact, the flashing 10 can accommodate installations on roofs with low slope or pitch, such as 15*, to high slope or pitch such as 600. For secure engagement of the lip 12 with surfaces of a conduit extending through the 30 opening 11, the lip 12 can include a flexible end region, which can be brought into flush engagement with the surface of the conduit for fixing thereto. Figure 2 illustrates a lip end portion 30 which can flex relative to the remaining lip portions 25 and 26 of Figure 2 and by this arrangement, not only can a secure connection be made between the lip portions 25 and 26 to the surface of the conduit, tolerance variations 9 in the size of a conduit can be accommodated. The lip end portions 30 can be provided easily in relation to flashing portions 14 and 15 that are formed from moulded plastic, as the junction between the lip end portions 30 and the remaining lip 12, such as the lip portions 25 and 26, can be grooved to provide a hinge region. In 5 that case, the lip end portions 30 can be bent into parallel configuration with the side surfaces of a conduit, while the remaining lip portions 25 and 26 remain at the angle shown in Figures 1 and 2. The lip end portions 30 can accommodate fasteners such as screw fasteners, and can be covered in silicone sealant for final sealing. 0 The upper and lower flange portions 16 and 17 can be formed to include an upstanding barrier (not shown), which extends from one side edge 32 to the other side edge 33. The barrier can be formed in the upper flashing portion 14 for the purpose of resisting ingress of rain which might be blown upwardly along the flange portion 16 and over the upper edge 34. Because the upper and lower flashing 5 portions 14 and 15 are identical, the same barrier will also appear in the lower flashing portion 15, but the barrier is not required in the lower portion 15 (it would resist flow of water off the flange portion 17) and rather is preferably removed. For this, a groove 35 can be provided adjacent the barrier 31 and which forms a line for severing the barrier 31 from the lower flashing portion 15, such as by a knife. !0 Accordingly, when installing the flashing 10 on a roof, the installation personnel would install the upper flashing portion 14 with the barrier, but either sever the barrier from the lower flashing portion 15 prior to installing that portion relative to the portion 14, or make the installation and sever the barrier 31 afterwards. 25 As an alternative to the above arrangement, slots could be provided in the barrier so that where it forms part of the lower flashing portion 15, the slots can allow any rain water build-up to pass through the barrier. While this would mean that there would also be slots in the barrier of the upper flashing portion 14, the number of slots and their spacing could be such as to prevent the majority of water which might otherwise 30 escape over the upper edge 34 of the upper flashing portion 14 to be resisted with only a minor and thus insubstantial amount of water flowing past the barrier of the upper flashing portion 14.

10 While the flashing 10 can be made of metal, as indicated above, the invention is particularly advantageous when applied to moulded plastic. With moulded plastic components, the junctions 36 between the side lip portions 27 and the respective upper and lower lip portions 25 and 26 is an integral junction. That is, the respective 5 lip portions continue integrally through the junctions 36 and thus form a barrier to entry of water past those junctions. This differs from an arrangement in which the flashing 10 is made from metal, whereby the junctions 36 would be formed by a meeting of the edges of the respective lip portions 25 and 27 and 26 and 27. To seal those junctions, a silicone sealant, or tape or solder or the like would be required. 0 The present invention also provides advantages in respect of the weight of the flashing, which in a moulded plastic would be less than if the flashing was made from metal while the cost of the flashing in moulded plastic is likely to be significantly less than metal. The malleability of plastic is also likely to provide advantages when 5 installing the flashing 10, particularly given that the dimensions of dropper boxes for which the flashing 10 has been principally designed, can vary to the extent that the respective lip portions 25, 26 and 27 need to be flexible to accommodate boxes having smaller or greater dimensions than specified. 0 The lip 12 is connected to the conduit in any suitable manner but with dropper boxes, the connection is envisaged to by screws, such as those known as "Tec" screws driven through the lip and through the wall of the dropper box. A sealant would then be applied. Where the lip is not a perfect fit against the surface of the dropper box, the lip can be bent or deformed to engage the dropper box wall. This is particularly 25 the case with a plastic flashing. Throughout the description of this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives or components or integers. 30 The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the spirit and scope of the present disclosure. 35

Claims (15)

1. A roof flashing for mounting on a roof, including: a square or rectangular opening through which a conduit can extend, 5 an upstanding lip extending fully about the opening and including an engagement portion for engaging side walls of a conduit which extends through the opening, a flange extending fully about the opening, the flange being substantially planar and extending from the lip away from the opening, 0 the flashing being formed in two substantially identical flashing parts, with the flashing parts being formed to overlap along portions of the flashing which in use form opposite side portions of the flashing with the overlap on each side portion being between portions of the flange of each of the two flashing parts and portions of the lip of each of the two flashing parts. 5

2. A roof flashing according to claim 1, the extent of overlap enabling the size of the opening to be varied.

3. A roof flashing according to claim 1 or 2, each flashing part includes a full lip ?0 portion that in use extends across the slope or pitch of the roof and a pair of part lip portions that extend perpendicular to the full lip portion and in use extend in the direction of the inclination of the roof, the part lip portions of respective flashing parts overlapping when the flashing parts are fitted together. . 25

4. A roof flashing according to claim 3, the junction between the full lip portion and the part lip portions of each flashing part being continuous

5. A roof flashing according to claim 3, the junction between the full lip portion and the part lip portions of each flashing part being discontinuous. 30

6. A roof flashing according to any one of claims 1 to 5, the flashing parts being formed from moulded plastic. 12

7. A roof flashing according to any one of claims 1 to 6, the flange being square or rectangular and having an upper section and a lower section, which reside on opposite sides of the conduit relative to the slope or pitch of a roof to which the roof flashing is fixed, and a pair of opposite side portions. 5

8. A roof flashing according to claim 7, wherein portions of the lip extend from the upper and lower flange portions in use towards a conduit which extends through the roof flashing at an angle of between 900 to 00. 0

9. A roof flashing according to claim 7, wherein portions of the lip extend from the upper and lower flange portions in use towards a conduit which extends through the roof flashing at an angle of between 80* and 50'.

10. A roof flashing according to claim 7, wherein portions of the lip extend from the 5 upper and lower flange portions in use towards a conduit which extends through the roof flashing at an angle of between 70* and 600.

11. A roof flashing according to any one of claims 7 to 10, wherein portions of the lip extend from the pair of opposite side portions of the flange at an angle of ?0 approximately 90*.

12. A flashing part for use in a roof flashing according to any one of claims 1 to 11.

13. A roof installation including a roof flashing according to any one of claims 1 to 25 11.

14. A roof installation according to claim 13, the installation further including an air cooling unit and a dropper box, the dropper box extending through the roof flashing. 30

15. A roof installation according to claim 14, the air cooling unit being an evaporative air cooling unit.