IE55710B1

IE55710B1 - Roof space ventilation

Info

Publication number: IE55710B1
Application number: IE257684A
Authority: IE
Original assignee: Anchor Building Products Ltd
Priority date: 1983-10-10
Filing date: 1984-10-09
Publication date: 1990-12-19
Also published as: EP0138561A3; GB8327067D0; EP0138561B1; IE842576L; GB8425493D0; GB2147992A; DE3481853D1; GB2147992B; EP0138561A2

Description

- 2 - - 2 -SS7 i Ο 1 This invention relates to the ventilation of pitched roof spaces and more particularly to high-level roof ventilation.

Roof ventilation is essential in pitched roof 5 spaces in order to control condensation which, if permitted to occur, can result in mould growth, rot and distortion of roof timbers, metal corrosion, ceiling damage and reduced thermal insulation. In principal, the most effective way of ventilating a 10 pitched roof space is known as eaves to ridge ventilation which involves a flow of air into the roof space from the low level of the eaves to the high level of the ridge. The object of eaves to ridge ventilation is to achieve adequate ventilation 15 whatever the wind direction, convectional ventilation in windless conditions, satisfactory mixing of air throughout the roof space and uniform outflow of air from the roof space.

It is an object of the present invention to 20 provide an improved system for high-level pitched roof space ventilation.

From one aspect, the present invention consists in a ventilation member for use in the ventilation of a pitched roof space, said ventilation member 25 being adapted to rest on and extend transversely of the upper surface of a roof covering, and having an upper wall for supporting at least a portion of a longitudinal side edge of a ridge covering}an open-bottom, a front wall depending from the upper wall and defining an elongate ventilation area which is 3 1 disposed to extend transversely of the roof covering and which comprises a plurality of ventilation apertures having a size to prevent the entry of large insects into the ventilation member and thus into a 5 roof space and yet permit a sufficient volume of air to pass therethrough, a baffle depending from the upper wall and spaced from said front wall and said open bottom, for creating a reduction in pressure of any wind blowing into the ventilation member through the 10 ventilation apertures and for precipitating wind driven water through said open bottom and onto said roof covering, and a ventilation opening located above said open bottom and behind said baffle for permitting a flow of air from the roof space into the ventilation 15 member, around said baffle and out through said ventilation apertures.

By means of the invention, a substantially continuous area of ventilation along the length of a roof ridge is achieved, ensuring sufficient volume 20 of air flow through and out of the roof space whatever the wind direction and in windless conditions, the apertures of the elongate ventilation area are of such a size as to prevent the entry of large insects into the roof space yet ensure adequate air flow and the 25 baffle reduces any wind pressure'. The ventilation member constructed according to the present invention can be made in one-piece e.g. a one-piece plastics moulding, and is simple to fit in that it can accommodate variations in the laying of the tiles.

The ventilation area preferably has the configuration 30 4 1 of a grille, with the apertures being elongate in form and extending transversely of the direction of the grille.

In a preferred embodiment, the front wall has 5 a lower edge having the general shape of the nib of the particular roofing tile with which the ventilation member is to be used in the case of contoured roofing tiles or is flat or straight in the case of plain tiles. By making the ventilation member with a front 10 wall of such shape, there is no difficulty in fitting them to a roof where the tilers have not kept the fixing of each line of tiles the same.

Advantageously, there is a rear wall depending from the upper wall behind the baffle and defining 15 therewith an open-bottomed rear chamber portion with which the ventilation opening is in communication. Preferably, the rear wall extends downwardly for a greater distance than the front wall so as to engage -against the top edge of a roofing tile of the upper-20 most tile course to hold the ventilation member thereon. If desired the rear wall could be extended still further to permit the tiling member to be nailed to the top tiling batten through the further extension to prevent it being blown inwards by strong 25 winds and/or stop a flow of air into the tiling member from between the roof felt and roofing tiles. Conveniently, the lower edge of the rear wall has a shape which is generally the same as the lower edge of the front wall.

In a preferred embodiment, the rear chamber 5 1 portion has a greater size than that of an open-bottomed front chamber portion defined by the upper wall;the front wall and the baffle which extends downwardly for a lesser distance than the front wall 5 to permit a flow of air around the baffle and out of the ventilation apertures.

In order to provide for the option of having a secondary water check in the form of a water proof 10 membrane passed over the ridge batten and onto the upper wall portion, where the longitudinal ridge of a ridge tile would rest on the membrane, the ventilation opening opens into the rear chamber portion from the upper wall and has a hood or cowl to prevent the 15 membrane closing the ventilation opening. Alternatively, the ventilation opening could be in the rear wall behind the baffle.

Additionally or instead of the further extension of the rear wall, the upper wall may have a plurality 20 of spaced apart stops or projections extending along its front edge to guard against the possibility of the ventilation member being blown inwards by strong winds.

Preferably, the ventilation member has support 25 elements extending transversely thereof and in the direction of a roofing tile when laid thereon and which engage with, and further support, the ventilation member on the upper surface of a roofing tile and 6 1 ensure that the ventilation members adequately support the ridge tiles, particularly in the case of contoured roofing tiles having shallow pans and with plain tiles.

In the case of contoured roofing tiles of the bold roll type which have deep pans, the apertured ventilation area preferably lies substantially in the pan when the ventilation member is laid thereon but, in the case of shallow panned contoured roofing 10 tiles and plain roofing tiles the ventilation area preferably lies above the pan and the top surface of the roofing tile.

From another aspect the present invention consists in a pitched roof structure comprising a 15 plurality of roofing tiles laid in courses on roof battens, and a plurality of any of the ventilation members as defined hereinabove resting on roofing tiles of the or each uppermost course with the apertured ventilation area facing outwards.

In dual pitch and mono-pitch roof structures, the roof structure includes a plurality of ridge tiles arranged in end to end relationship along the roof ridge with the longitudinal side edges of the ridge tiles resting on the upper 25 portions of the ventilation members on opposite sides of the roof apex with dual pitch roofs, and with mono-pitch roofs the ridge tiles are halfridge tiles and one of their longitudinal side edges rests on the upper walls of the ventilation 30 members. 7 1 In the case of roof structures terminating at an abutment wall, ridge tiles are not used and the ventilation members will be at the top of the roof and can easily be held in position by a clip and/or 5 flashing and/or by nailing the further extension of the rear wall , if provided.

In order that the invention may be more readily understood, some embodiments thereof will now' be described, by way of example, with reference to the 10 accompanying drawings, in which:- Figure 1 is a front elevation of one embodiment of ventilation member constituted by a tiling member constructed in accordance with the invention, Figures 2 and 3 are a cross-section and a plan 15 view respectively of the tiling member of Figure 1, Figure 4 is a perspective view of a part of a tiled roof structure showing the tiling members of the embodiment of Figures 1 to 3 -in position.

Figure 5 is a cross-section through the ridge 20 of the tiled roof of Fig. 4.

Figure 6 is a front elevation of another embodiment, Figures 7 and 8 are a cross-section and a plan view respectively of Figure 6, 25 Figures 9 and 10 are cross-sections of modifications of the embodiments of 1 and 6 respectively.

In the. drawings, the same reference characters are used to designate the same or similar parts.

Referring to Figs. 1 to 3 of the drawings, a tiling member which is generally indicated at 1 may be made of any suitable material such as plastics, metal or a cementitious material but is preferably δ 1 a one-piece plastics moulding, conveniently of polyethylene or polyvinyl chloride, and comprises an upper wall 2 forming a platform. Depending generally perpendicularly from the platform 2 are parallely extend-5 ing front and rear walls 3 and 4 which, with the platform define an open-bottomed chamber 5. The front wall is formed with an elongate apertured ventilation area 6 which can extend up to the entire length of the front wall 3 and comprising a 10 plurality of vertically arranged transversely extending ventilation apertures 7 to form a ventilation grill. In order to reduce the pressure of air flow due to wind into the tiling member 1 and thus into the roof space, and also to guard against the entry of wind driven 15 water into the roof space, the chamber 5 is divided into front and rear portions 5a and 5b respectively by a baffle 8 depending from the platform 2 and extending parallel to the walls 3 and 4 behind the aper tured ventilation area 6.

This embodiment is for use with contoured roofing tiles of double channelled configuration with shallow pans. The bottom edge 9 of the front wall 3is contoured to match generally the shape of the tile nib (not shown) to that the tiling member 25 can fit loosely into the tile pan areas and thus accommodate variations in the laying of the roofing tiles. The bottom edge of the rear wall 4 is also contoured to be of similar shape and projects downwardly for a greater distance than 30 the front wall 3 to provide a holding portion 1 10 which engages with the upper edge of the roofing tile when laid thereon and prevents the tiling member from slipping down the roof. The front and rear wall 3 and 4 are joined by transversely 5 extending support members in the form of strips 11 having straight bottom edges which engage with the top surface of the contoured roofing tile to ensure that the tiling member takes the weight of the ridge tiles. Alternatively, the transversely extending support 10 members could be in the form of rows of projections or pegs. The support members 11 are of particular importance with plan or flat tiles for preventing collapse of the tiling member.

Air from the roof space flows into the tiling 15 member 1 through an elongate entry opening 12, in and extending lengthwise of, the platform 2 and opens into the rear portion 5b of the chamber 5. The opening 12 is provided with a cowl or hood 13 for a purpose to be described. A row of ridge tile stops 20 14 constituted by projections or pegs project upwardly from the platform 2 along its front edge for guarding against the possibility of the tiling member being blown inwards for a sufficient distance to prevent it being weatherproof.

Referring now to Figs. 4 and 5, the ridge portion of a tiled dual pitch roof structure comprises spaced apart pairs of wooden rafters 15 to which are secured roof battens 16 with roofing felt 16a laid therebetween. Figures 4 and 5 show the upper courses of concrete roof tiles 17 laid on the battens 16 with the nibs at their upper edges fitted over the battens. At the apex of the rafters 15 are 30 ( -ΙΟ Ι secured, at spaced apart intervals, supporting brackets such as 18 for a ridge batten 19 to which the ridge tiles such as 20 are nailed by nails (not shown). The opposed ends of the ridge tiles 20 may 5 be joined by concrete, or, preferably, (not shown) opposed ends of the ridge tiles are secured together by fixing or jointing members such as are described in the specification of our co-pending Irish Patent Application No. 1498/84 to form a "dry" ridge system. The 10 roofing tiles 17 are of double-channelled configuration with shallow pans and interlock along their side edges. As will be more readily apparent from Figure 5, the tiling members 1 are laid in position on the upper surfaces of the upper portions of the roofing 15 tiles 17, one for each roofing tile, with the contoured lower edges of the front wal-l 3 engaging with the pan and top surfaces of the roofing tiles' with their holding portions 10 engaging with the upper edges of the top courses of the roofing 20 tiles to hold the tiling members in position.' The ridge tiles 20 are then laid over the ridge so that their longitudinal side edges engage with the platform 2 of the tiling members 1 on opposite sides respectively of the ridge between the hoods 13 25 and the ridge tile stops 14. As will be apparent from Figure 4, the support members 11 rest on the flat top surface of the roofing tiles 17. As the ridge tiles are laid in position, the fixing members can be fitted onto the adjacent ridge tile ends 30 and the ridge tiles 20 are nailed onto the ridge 11 - 1 batten 19.

Referring to Figures 2, 4 and 5, the tiling members 1 provide for high-level ventilation of the roof space 21 such that there is a flow of air as 5 indicated by the dashed line 22 in the direction of the indicated arrows out through the gaps between apex of the rafters 15 and upper edges of the roofing tiles 17, through the entry openings 12 of the chamber 5 around the baffle 8 and out through the 10 apertured ventilation area 6. The wind pressure on the right hand side of the tiled structure as illustrated in Figure 5 will produce a low pressure area on the left hand side of the roof which induces a flow of air out through the tiling members 1 on 15 the left hand side of the roof structure as indicated by the dashed line 22.

Wind tests have been carried out by the Applicants with simulated wind speeds of up to 60 mph (96.54 kmh) and it has been found that when air 20 flows through the ventilation apertures 7 in the direction indicated by the arrowed dashed line 23 (see Fig. 2), the baffle 8 acts to reduce the pressure due to wind in the rear chamber portion 5b as evidenced by pressure readings taken therein.

Moreover, when water was entrained in the air flow in such tests, the baffle 8 prevented the entry of such wind driven water, not only into the chamber portion 5b but also into the roof space 21.

The hood 13 serves to prevent closing of the opening 12 in the event of using a secondary water 30 12 1 check, as indicated by the dashed lines 23a in Figure 5. This water check 23a consists of a waterproof membrane and passes over the ridge batten 19 and underneath the longitudinal side edges of the 5 ridge tiles 20 where they rest between the tile stops 14 and the hood 13. The hood 13 also serves to deflect the air flow from the roof space into the tiling member. By providing the entry opening 12 in the platform 2 the effect of the baffle 8 is 10 enhanced.

It is a simple matter to adapt the embodiment of Figs. 1 to 3 for use with flat or plain roofing tiles by making the bottom edge of the front wall 3 of the tiling member 1 straight as indicated by the 15 chain lines 24 (Fig. 1) instead of contoured. In such a case the bottom edge of the rear wall 4 is also conveniently made straight as indicated by the chain lines 25 in Fig·. 1.

The embodiment of Figs. 6 to 8 differs from 20 that of Figs. 1 to 3 in that the tiling member la is specially adapted for a deep pan bold roll contoured roofing tile and has front and rear wall walls 3 and 4 of greater depth (compare Figs. 2 and 7) to accommodate the deeper pan with the 25 apertured ventilation area 6 being disposed in the pan between the roofing tile rolls when positioned thereon, whereas in Figs. 1 to 3 the ventilation area 6 is disposed above the pans and top surface of the roofing tiles as will be apparent from Fig. 4. The requisite volume of air flow from the roof 13 - 1 space is provided by increasing the length of ventilation apertures 7. Other differences are that two support members 11 only are provided which rest against the tile pan and which are cut away as 5 indicated at 11a to provide a facility for accommodating a transverse raised barrier on the upper end portion of a roofing tile. The support members 11 in this embodiment could, however, be dispensed with.

In the modifications of Figures 9 and 10, a 10 substantial part of the upper wall 2a is of arcuate, outwardly curved, configuration as viewed in cross-section and extends upwardly and rearwardly at an angle of greater than 90° from the front wall 3 (unlike the upper wall 2 which is 15 at an angle of about 90® to the front wall 3) and stops short of the rear wall 4 so that the ventilation opening is defined between the rear edge of the upper wall . 2a and front edge of the remaining flat portion 2b of the upper wall 20 2 which extends at an angle of about 90“ to the rear wall 4. Alternatively, the upper wall 2a is flat. Such modifications are particularly suitable for tapered ridge tiles. By modifying the tiling members 1 and la in this way the upper 25 wall 2a also serves the function of the cowl or hood 13. Preferably, as shown, an additional baffle 8a depends from the upper wall 2a for facilitating the flow of air into the tiling member and for preventing blow through from the exterior. Referring again to Figure 5, tiling members 30 - 14 1 constructed in accordance with the invention also provide for a flow of ventilating air from between the roofing felt 16a and the roofing tiles 17 and into the tiling members 1, (la) as shown in arrowed 5 dashed lines 30. if desired the rear wall 4 may be extended still further so that its bottom edge engages with the roofing felt 16a to stop this flow of air. The further extension of the rear wall also or instead permits nailing of the tiling member to 10 the top tiling batten 16.

In other embodiments-which are not illustrated, the tiling members such as previously described instead of being in one piece may be made in two or more elongate elements which are positioned in correct 15 relationship to one another in situ on the roof or are fitted together either in situ or before laying e.g. by means of interengaging members such as projections and apertures or recesses, to form the complete tiling member. In such embodiments, the elongate 20 elements may extend over one or preferably several roofing tiles, and be as long, for example, as 3 metres. In one form of tiling member made of three such elements, these elements could comprise the upper wall , the rear wall and the front wall 25 In such embodiments the elongate apertured ventilation area could be continuous.

It should be understood that the term tiling member is used herein in a generic sense to cover a ventilation member which can be used with all types 30 of pitched roof coverings which need not necessarily 15 1 be ridge and roofing tiles. For example, the ridge covering could be say a plastics elongate ridge covering extending over several normal tile widths and the roof covering instead of being of roofing tiles could 5 be of shingles, slates or of panels e.g. of a suitable metal such as aluminium which may be coated, or of asbestos,and which may be flat, corrugated, or contoured to give an appearance of contoured roofing tiles.

Such panels may be 3 x 6 metres, for example. Thus, 10 "ridge tiles" and "roofing tiles" are used herein in a generic sense to cover all kinds of ridge and roof coverings used for pitched roofs.

Although particular embodiments have been described, it should be appreciated that various 15 modifications may be made without departing from the scope of the invention. For example, the elongate ventilation apertured area can extend for any suitabl'e distance up to the full width of a 'roofing tile. Instead of the vertically arranged 20 apertures 7, the ventilation apertures may be in the form of elongated narrow slots or slits arranged one above the other and extending lengthwise of the ventilation area 6.

Particularly in the case of flat or plain roofing 25 tiles, the tiling members may extend over at least two roofing tile widths.

Claims

1. 1. A ventilation member for use in the ventilation of a pitched roof space, said ventilation member being adapted to rest on and extend transversely of the upper surface of a roof covering, and having 'an 5 upper wall for supporting at least a portion of a longitudinal side edge of a ridge covering,an open-bottom, a front wall depending from the upper wall and defining an elongate ventilation area which is disposed to extend transversely of the roof covering 10 and which comprises a plurality of ventilation apertures having a size to prevent the entry of large insects into the ventilation member and thus into a roof space and yet permit a sufficient volume of air to pass therethrough, a baffle depending from the upper wall 15 and spaced· from said front wall and said open bottom, for creating a -reduction in pressure of any wind blowing into the ventilation member through the ventilation apertures and for precipitating wind driven water through said open bottom and onto said 20 roof covering, and a ventilation opening located above said open bottom and behind said baffle for permitting a flow of air from the roof space into the ventilation member, around said baffle and out through said ventilation apertures. 25 2. A ventilation member as claimed in claim 1, wherein the elongate ventilation area has the configuration of a grille with the ventilation apertures being elongate in form and extending transversely of the direction of the grille. 30 3. a ventilation member as claimed in claim 1 or 2, wherein the front wall has a lower edge having the - 17 1 general shape of the nib of a contoured roofing tile with which the ventilation member is to be used or the lower edge of the ventilation member is flat or straight for use with flat or plain tiles.

2. 54. A ventilation member as claimed in any one of claims 1 to 3, and having a rear wall depending from the upper wall behind said baffle and defining therewith an open-bottomed rear chamber portion with which said ventilation opening is in commun-10 ication.

3. 5. A ventilation member as claimed in claim 4, wherein the rear chamber portion has a greater size than that of an open-bottomed front chamber portion defined by said upper wall, said front wall and said baffle. 15 6. A ventilation member as claimed in claim 4 or 5, wherein said ventilation opening is located in said rear wall.

4. 7. A ventilation member as claimed in claim 4 or 5, wherein said ventilation opening is located in said 20 upper wall.

5. 8. A ventilation member as claimed in claim 7, wherein said ventilation opening is provided with a hood or cowl.

6. 9. A ventilation member as claimed in claim 8, 25 wherein the hood or cowl is integral with the upper wall and extends upwardly and over said ventilation opening.

7. 10. A ventilation member as claimed in any one of claims 4 to 9, wherein the rear wall extends down-30 wardly for a greater distance than the front wall so as to be engageable against the top edge of a roofing tile of the uppermost tile course to hold the ventilation member thereon.

8. 11. A ventilation member as claimed in claim 10, - 18 - X wherein the rear wall is extended still further to permit the ventilation member to be nailed to the top tiling batten through the further extension and/or to enable a flow of air into the ventilation member 5 from between roofing felt and'the roofing tiles to be stopped.

9. 12. A ventilation member as claimed in claim 3 or any claim dependent thereon, wherein the lower edge of the rear wall has a shape which is generally the 10 same as the lower edge of the front wall.

10. 13. A ventilation member as claimed in any one of claims 1 to 12, wherein the upper wall is disposed at an angle of about 90° with respect to the front wall. 15 14. A ventilation member as claimed in any one of claims 1 to 13, wherein the upper wall has a plurality of spaced apart stops or projections extending along its front edge to guard against the possibility of the ventilation member being blown inwards by 20 strong winds.

11. 15. A ventilation member as claimed in any one of claims 1 to 14, and having support elements extending transversely thereof and in the direction of a roofing tile when laid thereon and which engage 25 with, and further support, the ventilation member on the upper surface of the roofing tile.

12. 16. A ventilation member as claimed in claim 4 and any claim dependent thereon, wherein a substantial part of the upper wall is inclined at an angle of 30 more than 90° with respect to the front wall and 19 1 extends upwardly and rearwardly from the front wall towards the rear wall.

13. 17. A ventilation member as claimed in claim 16, wherein a substantial part of the upper wall is 5 of outwardly curved form.

14. 18. A ventilation member as claimed in claim 16 or 17, wherein an additional baffle depends from the upper wall at a location which is behind, and spaced from, the said baffle. lO 19. A ventilation member as claimed in any one of claims 1 to 18, and made of at least two elongate elements which can be positioned or fitted together. 20. A ventilation member as claimed in claim 19 and which extends over several tile widths. 15 21. A ventilation member as claimed in claim 19 or 20., wherein the elongate elements are fitted together by means of interengaging projections and apertures or recesses.

15. 22. A ventilation member for use in the ventilation 20 of a pitched roof space, substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings.

16. 23. A ventilation member for use in the ventilation of a pitched roof space, substantially 25 as hereinbefore described with reference to Figures 6 to 8 of the accompanying drawings.

17. 24. A ventilation member for use in the ventilation of a pitched roof space, substantially as hereinbefore described with reference to Figures 1 to 3 as modified by Figure 9 of the accompanying 30 - 20 - 1 drawings. 2 5. A ventilation member for use in the ventilation of a pitched roof space , substantially as hereinbefore described with reference to Figures 5 6 to 8 as modified by Figure 10 of the accompanying drawings.

18. 26. A pitched roof structure comprising a plurality of roofing tiles laid in courses on roof battens, and wherein one or a plurality of ventilation members 10 as claimed in any one of claims 1 to 25 rest on the roofing tiles of the or each uppermost course with the apertured ventilation areas facing outwards.

19. 22. A pitched roof structure as claimed in claim 26, wherein the roofing tiles have 15 pans and the apertured ventilation area of the or each ventilation member lies substantially in the respective pan. 28. a pitched roof structure'as claimed in claim 26, wherein the roofing tiles have pans 20 or are plain or flat tiles and wherein the apertured ventilation area of the or each ventilation member lies above the pans and/or the top surfaces of the roofing tiles.

20. 29· A pitched roof structure as claimed in any 25 one of claims 26 to 26’, wherein at least a portion of a longitudinal side edge of the ridge covering is supported on the upper wall of the or each ventilation member.

21. 30. A pitched roof structure as claimed in any 30 one of claims 26 to 28, and terminating in an abutment - 21 - 1 wall, wherein the or each ventilation member is positioned at the top of the roof covering and is held in position thereon.

22. 31. A pitched roof structure substantially 5 as hereinbefore described with reference to Figures 1 to 5 of the accompanying drawings.

23. 32. A pitched roof structure substantially as hereinbefore described with reference to Figures 1 to 5 as modified by Figure 9 of the accompanying 10 drawings.. '33. A pitched roof structure substantially as hereinbefore described with reference to Figures 4 and 5 as modified by Figures 6 to 8 of the accompanying drawings. 15 34. A pitched roof structure substantially as hereinbefore described with reference to Figures 4 and 5 as modified by Figures 6 to 8 as modified by Figure 10 of the accompanying drawings. MACLACHLAN & DONALDSON Applicants' Agents 47 Merrion Square Dublin 2.