ROOF VENTILATION

Abstract: A roof ventilator unit 10 for attachment to a fascia board 28 com­ prises an elongate profiled member 11 for attachment to a fascia board 28 with a ventilation gap therebetween, filter means 21 which extend across the gap and upstanding tooth elements 14 to engage the underside of tiles or other external roof covering. The unit may also include an integral anti-ponding strip 12 and drip skirt 13. Tiles may be retained in position by means of a tile-­ engaging clip 32 which is anchorable on a selected tooth element 14.

Description: This invention is concerned with improvements to a roof ventilator unit as set forth in the preamble of the accompanying main claim. It is highly desirable and now a legal requirement according to UK building regulations for roof voids to be provided with means for allowing ventilation by the inflow and circulation of fresh air, thus preventing condensation occurring within the roof space. Equally, however, it is desirable to prevent access, through any ventilation apertures, of rain, snow and birds. To this end, various designs of ventilator have been proposed for fitting to or incorporating in particular roofing components such as fascia board, soffit boards, tiles and the like. An example of a roof ventilator unit as set forth in the preamble of the accompanying main claim is described in FR-A-2 551 123, wherein this prior art roof ventilator unit is not supplied with an integrally formed anti-ponding strip to prevent the formation of a water trap behind the fascia board. The anti-ponding strip shown in that prior publication is a separate element. In order to obtain an adequate drainage of water it is necessary to have the anti-ponding strip arranged in a right position with regard to the roof ventilator unit, however the mutual position of said strip and said unit varies because the roof ventilator unit and the anti-ponding strip are two independent members as shown in said French publication. Moreover it is a disadvantage that the production and mounting of the two separate members requires more effort. Furthermore does the filter means in this prior art roof ventilator have the shape of a horizontal portion with a plurality of ventilation slots, one side of this portion being integrally linked to a horizontal securing portion for attaching the roof ventilator unit on the top of the fascia board, and the other side of this ventilation portion being integrally linked to the lower end of upstanding tooth elements so that these tooth elements in use are positioned at a distance to and on the same level as the top of the fascia board, resulting in that the tooth elements by pushing against the roof covering, exert a toppling force on the roof ventilator unit. The invention contemplates a new and improved roof ventilator unit which is characterized by the features in the characterizing portion of the accompanying main claim in order to provide a mutual right position of the anti-ponding strip and the drip skirt and in order to eliminate a toppling force on the roof ventilator unit. Because according to the invention the anti-ponding strip is integrally formed with the other portions of the roof ventilator unit, the anti-ponding strip is always joined to the drip skirt in a waterproof way, so that water underneath the roof covering is collected by the anti-ponding strip and is removed by the drip skirt over the fascia board into the roof guttering. Moreover, the invented roof ventilator unit having the anti-ponding strip integrally formed thereon, is cheaper to produce and easier to attach than the prior art roof ventilator unit and a separate anti-ponding strip. Furthermore, the tooth elements of the invented roof ventilator unit in use are positioned substantially straight over the top of the fascia board, so that the tooth elements pressing against the roof covering do not exert a toppling force on the roof ventilator unit. The filter means preferably is an array of pins which depend from the upper edge region of the profiled member in a generally downwards direction towards the fascia board, the pins defining slots therebetween through which birds and flying insects cannot pass. Preferably, the array of pins is arranged in a double or multiple row, pins in each row being offset to alternate with respect to pins in the other row or rows. Roof ventilator units according to the invention may be formed in predetermined lengths for mutually attaching units end to end, to provide in use an uninterrupted length of ventilation over the length of a fascia board. Preferably, lengths of roof ventilator unit are adapted to overlap or interenagage at their ends with adjacent roof ventilator units. Interengagement may be provided by a tongue-and-groove arrangement, for example, in which a tongue is formed at the one end of the profiled roof section and a groove is formed at the other end, whereby the tongue of a first ventilator unit is insertable within the groove in a second roof ventilator unit when the said units are arranged in end-to-end relationship. In a preferred aspect, at least the anti-ponding strip is formed at one end with a tongue extending longitudinally of the unit and at the other end with a groove defined between upper and lower lips. In such an arrangement, the upper surface of the tongue is preferably formed with one or more transversely extending ribs for strengthening purposes and to define a water-drainage duct. The drip skirt portion of the ventilator unit is preferably formed at the tongue end thereof with a transversely extending channel into which the duct opens, to convey water in the duct into the roof guttering, and in which engages a flange formed beneath the drip skirt portion of the adjacent roof ventilator unit at the groove end thereof when the said ventilator units are interengaged in end-to-end end relationship. At least the flanged end region of the drip skirt portion may be resiliently deformable about a longitudinal axis of flexion to allow it to be lifted, for the purpose of positioning the flange in the channel of the adjacent ventilator unit, after interengagement of the respective tongue and groove. The flexible upstanding tooth elements, which constitute a filler element to engage the underside of overlying tiles or slates to exclude for example birds from the space between the tiles or slates and the underlay, are preferably all of substantially the same height, rather than being pre-formed to match the under-side of a particular design of tile. Provided that the length is sufficient to reach from the upper side of the profiled member to the highest point on the under-side of any available tile or slate, the gap therebetween will be substantially covered and any undulations in the underside of the tile or slate will be accommodated by the flexibility of the tooth elements and hence the angle which they are constrained to adapt, according to the shape of the tile and the pitch angle of the roof. Advantageously, and particularly where the external roof covering comprises profiled tiles, individual tooth elements can be used to maintain a tile-engaging clip in position, for the purpose of securing said tile to the eaves. For example, a clip may be formed to engage in the drip edge of a tile, the clip including a downwardly-directed limb including a slot defined by angled opposed gripping members between which a selected tooth element can be inserted from below and passed therethrough until under tension, the members acting together to clamp on the tooth element on the application of any tension in the reverse direction, whereby the clip and hence the tile are effectively locked in position. Ventilator units according to the invention may be formed, for example by moulding, from a polyolefin plastics material, preferably a polypropylene or polyethylene. Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, of which: Figure 1 is a plan view, with parts cut away to avoid undue repetition, of a ventilator unit according to the invention; Figure 2 is a front elevation of the unit of Figure 1; Figure 3 is a cross section through the line III-III of Figure 1; Figures 4 (a) and (b) show how ventilator units according to the invention are arranged in use with steep-pitched and shallow-pitched roofs, respectively; Figure 5 is a diagrammatic perspective view showing the use of a ventilator unit with a tile clip; and Figures 6 (a) to (f) show an installation sequence of ventilator units according to the invention in roof construction. Referring firstly to Figure 1, a ventilator unit is shown generally at 10 and includes an elongate profiled member 11 having an arcuate cross section (see Figure 3), the upper edge region of which is formed integrally with an anti-ponding strip 12 and the lower edge region of which terminates in a drip skirt 13. The thickness of the anti-ponding strip is less than that of the profiled member 11, such that the former is flexible for accommodation of different pitch angles of roofs, while retaining sufficient rigidity to support the roofing felt without distortion or depression. At 12a furthermore a longitudinal zone of flexion is provided to permit the profiled member to bend relative to the anti-ponding strip, for example for inter-engaging ventilator units in end-to-end relationship (see Figure 6). A row of upstanding comb-like tooth elements 14 are integrally formed at the upper rear edge of the profiled member 11 and support brackets 15 are formed below the profiled member at intervals, the brackets in cluding surfaces 16 and 17 for engaging a fascia board 28. Preferably brackets have apertures 18 terminating at their upper ends in slots 19 having a raised edge formation 20, for the purpose of receiving the heads of nails or screws for fixing to the fascia board. A double row of alternating pins 21 is also formed integrally with the underside of the profiled member 11, the pins depending in a generally downwards direction towards the surface 16. The right-hand end (in Figure 1) of the anti-ponding strip 12 is formed with a longitudinally-extending tongue 22 having lateral ribs 23, and the water drainage ducts formed thereby lead to a lateral channels 24 formed at the righ-hand end of the drip skirt 13. At the left-hand end of the anti-ponding strip 12 is formed a groove defined by upper and lower lips 25, 26, into which the tongue 22 of an adjacent ventilator unit can engage. The left-hand end of the drip skirt 13 is formed with a depending flange 27 which can engage with the channel 24 of the said adjacent ventilator unit (see Figures 6b and 6c). Referring to Figures 4a and 4b, a fascia board 28 is indicated in cross-section and attached thereto is shown a support bracket 15 of a ventilator unit. The concave arcuate surface of the profiled member 11 of this ventilator unit is held spaced from the fascia board and generally bounding the front upper edge 29 thereof. It is seen in Figure 4a how, with a slate-covered roof set at a steep pitch angle, the teeth 14 are directed upwardly to engage the underside of the slates whereas, with a tiled roof set at a shallow pitch angle and as seen in Figure 4b, the teeth are directed downwardly. As tile 31 has an undulating shape in horizontal direction as seen in Figure 5, the teeth 14 are bent to various extents with respect to one another against the tile 31, the theeth thus barring the access along the undersides of the tiles. Both in Figures 4a and 4b, the drip skirt 13 terminates above the bottom of the eaves guttering 30. Figure 5 illustrates the use of a tile clip secured to the fascia board 28 via one of the teeth 14 of the ventilator unit 10. In the drawing, the drainage edge of a tile 31 is engaged by a pre-formed metallic clip 32 including uni-directional self-locking gripper jaws 33 between which is passed a tooth 14 of the filler element. The sequence of steps shown in Figures 6(a) to (f) are as follows: a) A roof rafter 35 has secured to it a fascia board 28. b) A first ventilator unit 10 is secured to the fascia board and a second ventilator unit 38 is partially interengaged at an angle therewith, the tongue 22 of unit 11 being partially inserted within the groove and beneath the overhanging lip 25 of unit 38. c) The unit 38 is in alignment with the unit 10, the tongue 2 being fully engaged within the groove. The unit 38 is supported on the fascia board 28 and the drip skirt 13 and profiled section 11 of unit 38 are temporarily raised by hand about a flexion axis between the profiled section and the anti-ponding strip 12, in order to allow the flange 27 of unit 38 to engage in the drainage channel 24 of unit 10. d) Unit 38 is secured to the fascia board. e) Roofing felt 44 is laid in position, the lower edge of which lies adjacent the base of the teeth 14. f) The tiles are placed in position, tile 31 being secured via clip 32 and the tooth 14 of the ventilator unit 10 to the eaves, as shown more fully in the enlarged insert, by means of the self-locking gripper jaws 33.

Claims: 1. A roof ventilator unit (10) in the shape of an elongate profiled member (11) having integrally formed spacers (15) and adapted to be mounted on a fascia board (28) so that the said unit and board define therebetween a ventilation space, the said unit comprising filter means (21) being integrally formed with the member (11) substantially to extend across the ventilation space, a plurality of tooth elements (14) projecting from the upper side of and integrally formed with the elongate member (11) to engage (in use) the underside of an external roof covering (31), and a dripskirt (13) constituted by the extended outer (in use) edge of the profiled member (11), characterized in that the inner (in use) edge region of the profiled member (11) is extended to constitute an anti-ponding strip (12), and in that the profiled member (11) is generally angular in cross-section and adapted so that in use the said tooth elements (14) carrying portion of its inner edge region overlies and is spaced from the upper edge face of the fascia board (28) and its outer edge region is in front and spaced from at least the upper portion of the front face of the fascia board (28), said spacers (15) being spaced at intervals along the profiled member (11). 2. A roof ventilator unit according to claim 1, characterized in that the filter means comprises an array of pins (21) which depend from the upper edge region of the profiled member (11) in a generally downwards direction towards the fascia board (28). 3. A roof ventilator unit according to claim 1 or 2, characterized in that the unit is formed with end means (22, 2 5, 26) for interengagement with adjacent ventilator units (10). 4. A roof ventilator unit according to claim 3, characterized in that the interengagement means comprises a tongue (22) at one end of the anti-ponding strip (12) and a groove (25, 26) at the other, whereby the tongue of one ventilator unit (10) is insertable into the groove of another ventilator unit (10) when the said units are arranged in end-to-end relationship. 5. A roof ventilator unit according to claim 4, characterized in that the upper surface of the tongue (22) is being formed with one or more lateral ribs (23) which define a water drainage duct. 6. A roof ventilator unit according to claim 4 or 5, characterized in that the drip skirt (13) is formed with a lateral channel (24) into which the tongue (22) opens, said channel serving to receive a flange (27) formed at the drip skirt (13) of the adjacent roof ventilator unit (10) at the groove end thereof. 7. A roof ventilator unit according to any of the claims 2 to 6 inclusive, characterized in that at least an end region of the drip skirt (13) is resiliently deformable about a longitudinal axis of flexion (12a). 8. A roof ventilator unit according to any preceding claim, characterized in that the said unit is in combination with a tile-engaging clip (32) which is interlockable with a selected tooth element (14) of the unit (10) to secure a tile (31) engaged by the clip in position with respect to the unit, said clip (32) comprising two integrally formed jaws (33) for gripping the selected tooth element (14), each jaw (33) being positioned at one side of both sides of the tooth element and being an extension of a clip portion having a slot through which the tooth element is passed, said slotted clip portion being connected with a hook shaped clip portion for engaging a tile (31). 9. A roof ventilator unit according to any preceding claim, characterized by raised edge formations (20) around the apertures (19) for receiving nails or screws for fixing the unit (10) to the fascial board (28).

Inventors: VAN SCHELLEBEEK, DIRK JOHANNES
Applicants: UBBINK NEDERLAND B.V.
Application year: 1989
Main classification: E04D13
IPC codes: E04D1, E04D13