Roof ventilation

Abstract

 A roof ventilator unit 10 for attachment to a fascia board 28 com­prises 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

[0001] This invention relates to the ventilation of roof spaces and in particular provides a ventilation unit for attachment to a fascia board.

[0002] 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 boards, soffit boards, tiles and the like.

[0003] According to the present invention, we provide a ventilator unit for attachment to a fascia board, the ventilator unit comprising an elongate profiled member adapted to be attached to and spaced apart from a fascia board so that the said unit and board define therebetween a ventilation space, filter means attached to the member substantially to bridge the space, and a plurality of flexible upstanding tooth elements projecting from the upper (in use) side of the elongate member to engage the underside of the external roof covering.

[0004] According to a preferred aspect of the invention, the profiled member overlies and is spaced from the fascia board and the upper or inner-facing (in use) edge of the elongate member is extended to constitute an integral anti-ponding strip, for supporting the lower edge region of roofing felt or other underlay which, in a typical roof construction, underlies the external roof covering, to prevent the formation of puddles or ponds of accumulated rain water in otherwise unsupported marginal regions of roofing felt between the rafters. Furthermore, it is preferred that the lower or outer-facing (in use) region of the profiled strip terminates downwardly in or is constituted by a drip skirt, to direct any rain water impinging thereon preferably towards the centre of the gutter position.

[0005] The elongate profiled member preferably is generally arcuate in cross-section, one longitudinal edge region of which in use over­lies and is spaced apart from the upper edge face of the fascia board and the other longitudinal edge region of which in use is in front of and spaced apart from at least the upper region of the front face of the fascia board, the concave inner arcuate surface generally bounding the front upper edge of the fascia board and being spaced therefrom, whereby ventilation air can flow through the space. The elongate profiled member is supported on or at­tached to the fascia board at intervals by spaced-apart brackets or other fixing means which are preferably integrally formed with the profiled member. The ventilation space is thereby sub-divided into a plurality of apertures defined at their ends by the fixing means, and conveniently the filter means are arranged substan­tially to bridge the apertures between the fixing means.

[0006] The filter means may substantially bridge the ventilation space at any convenient location or plane between the inner surface or the profiled member and the fascia board, and may comprise a mesh screen or other known filter element. However, we prefer to use 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 possibly 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.

[0007] Ventilator units according to the invention may be formed in pre­determined lengths for attaching end to end, to provide in use an uninterrupted length of ventilation over the length of a fascia board. Preferably, lengths of ventilator unit are adapted to over­lap or interengage at their ends with adjacent 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 ventilator unit when the said units are arranged in end-to-end relationship.

[0008] In a preferred aspect, a ventilator unit according to the inven­tion includes an anti-ponding strip and a drip skirt, both formed integrally with the elongate profiled member, spaced-apart brackets being integrally formed at intervals below the concavity of the profiled member to add strength and rigidity thereto and also to act as means for supporting the ventilator unit spaced on a fascia board, the brackets being formed with holes or other apertures for passage therethrough of nails or other suitable fixing means, at least the anti-ponding strip being formed at one end with a tongue extending longitudinally of the member 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, and at least the drip skirt portion of the ventilator unit is 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 which engages with a flange formed beneath the drip skirt portion of the adjacent ventilator unit at the groove end thereof when the said ventilator units are interengaged in end-to-­ 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.

[0009] 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.

[0010] 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 applicaton of any tension in the reverse direction, whereby the clip and hence the tile are effectively locked in position.

[0011] Ventilator units according to the invention may be formed, for example by moulding, from a polyolefin plastics material, prefer­ably a polypropylene or polyethylene.

[0012] 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.

[0013] 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.

[0014] 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).

[0015] 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.

[0016] 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.

[0017] 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) for attachment to a fascia board (28), the ventilator unit comprising an elongate profiled member (11) adapted to be attached to and spaced apart from the fascia board (28) so that the said unit and board define therebetween a ventilation space, characterized in that filter means (21) are attached to the member substantially to extend across the space and a plurality of tooth elements (14) project from the upper side of the elongate member to engage the underside of the external roof covering.

2. A ventilator unit according to claim 1, characterized in that the inner (in use) edge of the profiled member (11) is extended to constitute an anti-ponding strip (12).

3. A ventilator unit according to claim 1 or 2, characterized in that the outer (in use) edge of the profiled member (11) termin­ates in a drip skirt (13).

4. A ventilator unit according to any preceding claim, charac­terized in that the profiled member (11) is generally arcuate in cross-section and adapted so that in use the inner edge region overlies and is spaced from the upper edge face of the fascia board and the outer edge region is in front and spaced from at least the upper region of the front face of the fascia board.

5. A ventilator unit according to any preceding claims, charac­terized in that the profiled member (11) is spaced from the fascia board by brackets (15) which are integrally formed with and spaced at intervals along the profiled member (11).

6. A ventilator unit according to any preceding claim, 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.

7. A ventilator unit according to any preceding claim, charac­terized in that the unit is formed with end means (22, 25, 26) for interengagement with adjacent ventilator units.

8. A ventilator unit according to claim 7, characterized in that the interengagement means comprises a tongue (22) at one end of the profiled member and a groove (25, 26) at the other, whereby the tongue of one ventilator unit is insertable within the groove of another ventilator unit when the said units are arranged in end-to-end relationship.

9. A ventilator unit according to claim 8 as dependent on claims 2 and 3, characterized in that in that the said tongue and groove are respectively formed in the ends of the anti-ponding strip, the upper surface of the tongue (22) being formed with one or more lateral ribs (23) which define a water drainage duct, at least the drip skirt (13) being formed at the tongue end with a lateral channel (24) into which the duct opens, which engages in use with a flange (27) formed beneath the drip skirt of the adjac­ent ventilator unit (10) at the groove end thereof.

10. A ventilator unit according to any of the claims 3 to 9, characterized in that at least an end region of the drip skirt (13) is resiliently deformable about a longitudinal axis of flexion (12a).

11. A 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 to secure a tile engaged by the clip in po­sition with respect to the unit.

Drawing