GB2290568A

GB2290568A - Ventilation tile

Info

Publication number: GB2290568A
Application number: GB9512949A
Authority: GB
Inventors: Roger Martin Cooper; Robert Charles Nunn
Original assignee: PHI DESIGN Ltd
Current assignee: PHI DESIGN Ltd
Priority date: 1994-06-25
Filing date: 1995-06-26
Publication date: 1996-01-03
Anticipated expiration: 2015-06-26
Also published as: GB9512949D0; GB2290568B

Abstract

A ventilation tile has a tortuous ventilation passage defined by walls (108) extending inwardly from the outer face and walls (111) extending outwardly from the inner face. The passage opens to the inner face of the tile over substantially the entire length of the tile which is exposed in use in the downward direction. The passage includes apertures (123 - 125) formed in the lower surface of the tile. <IMAGE>

Description

A VENTILATED TILE The present invention relates to a ventilated tile and particularly to a ventilated roof tile.

Roofs of buildings are commonly insulated in order to prevent heat loss from the rooms into the roof space. It has been found desirable to provide ventilation to the roof space in order to prevent undesirable build-up of moisture within the roof cavity. Many house builders specify a minimum ventilation area required per unit length of roof.

A typical local authority specification recommends that at least 10000 mm2 of ventilation area is provided per metre length of roof.

Roof tiles having a ventilation passage therein have been proposed to provide a route for flow of air to and from the roof space. In this specification the term 'tile' should be taken to include slate, shingle or other similar roof covering member. It will also be understood that tiles can be hung vertically, as for example a building feature on a wall, and ventilation may be required to the rear side thereof.

A number of constraints exist concerning the maximum possible ventilation area for a ventilated tile. Firstly, the ventilated tile must have the dimensions and form of the corresponding standard tiles in order to correctly fit therewith. Secondly, the ventilated tile must be designed to prevent ingress of rainwater or the like through the ventilation aperture into the cavity behind the tiles, even under the action of high winds. Thirdly, the ventilated tile will inevitably overlap and be overlapped by surrounding tiles, and will be hung from a batten or similar component of the roof structure. A batten may directly cover part of the tile underside or may form a barrier to a ventilation opening parallel to the plane of the tile.

All these features restrict the surface area of a tile through which a ventilation passage can be formed and thus the maximum ventilation area of a ventilated tile.

It is desirable however to maximise the ventilation area since fewer ventilated tiles per metre length of roof will thus be required, and the cost of ventilation to the property owner will be minimised.

It is also desirable that the tile does not detract unduly from the appearance of the roof. Hence it is generally essential that the tile possesses the same length and breadth dimensions as a single tile with which it is to fit, that it is capable of being hung in the same manner and that it nests with other tiles in the usual manner.

Yet further requirements are that the ventilated tile be inexpensive, relatively easy to produce, have few components and blend aesthetically with standard tiles in an unobtrusive manner.

Thus it is the object of the present invention to provide a tile which meets the requirements noted above, and has a large ventilation area.

According to one aspect of the invention, there is provided a ventilation tile having an outer face, an inner face and a ventilation passage therebetween, the tile including walls extending inwardly from the outer face and outwardly from the inner face to define a tortuous ventilation passage from said outer face to said inner face, said passage opening to -the inner face of the tile over substantially the entire length thereof which is exposed in use in the downward direction.

In a preferred embodiment, said passage opens to the outer face of the tile over substantially the entire length thereof which is exposed in use in the downward direction.

Preferably at least part of the ventilation passage defines a drainage channel for Liquid and/or solid detritus incident on the member in use.

The tile may include a spigot on the underside thereof to receive a tubular member such as a stench pipe or to provide connection to a ventilation unit.

The outlet may be adapted to direct detritus downwardly of a roof, over neighbouring tiles, such that the flow does not directly pass over the junctions between the tiles of a row of tiles directly below the outlet.

A grille or mesh may be provided over the opening of the passage into the outer face of the tile.

Means to suspend the tile from a batten or the like of a roof structure may be provided.

According to another aspect of the invention there is provided a ventilation tile comprising an outer face, an underside and a ventilation passage therebetween, the tile having a slot in the outer face thereof, said slot being open at the lower edge of the tile and otherwise bounded by a depending wall, and the underside constituting a bottom to the slot, and having an upstanding wall overlapping and surrounding said depending wall and one or more openings therein around said upstanding wall, said slot, walls and opening defining said ventilation passage.

In a preferred embodiment the slot is rectangul-ar, the long side thereof being aligned to the downward direction of the tile in use. The opening or openings around the upstanding wall may be substantially continuous. In one embodiment, the depending wall at the upper end thereof is immediately adjacent the upstanding wall.

In the preferred embodiment said opening extends only over the portion of the underside which is in use exposed.

The plane of the underside may diverge from the plane of the tile from the lower exposed edge of the underside in use. In such an arrangement the portion of the underside which overlies the next succeeding lower tile in use lies at a steeper angle than the remaining portion. The divergence angle must not be so great as to permit the upper (remaining) portion to approach closely to horizontal in use, since effective drainage of rain water would not be possible. Preferably the divergence angle is in the range 20 -30 but is in any event dependent on the minimum recommended angle at which the corresponding standard tile will shed water efficiently.

In the preferred embodiment said slot extends over the portion of the outer face which is in use exposed.

Preferably-the open end of said slot does not lie on the centreline of the tile in the downward direction. This arrangement has the advantage that water leaving the slot does not impinge immediately on a vertical join of identical neighbouring lower tiles.

Preferably said tile includes two substantially parallel slots having respective depending walls and upstanding walls. A plurality of openings may be provided one each extending along the sides of said upstanding walls.

Preferably the openings between said slots are substantially co-extensive.

In a preferred embodiment the upstanding and depending wall are separated laterally by at least one half of the width of said slot. Preferably the minimum cross sectional area of said ventilation passage in the flow direction is not less than the lateral spacing of said walls.

The underside portion of the tile which defines the bottom of the slot defines together with the adjacent upstanding wall a drainage channel for the tile open at the lower end of said slot. In one embodiment the upper surface of the tile and underside thereof are constituted by two members manufactured or fixed together to form a unitary whole. Preferably the ventilation tile is moulded in plastic material.

In a preferred embodiment the slot is closed on the outward side thereof by a grille, the purpose of which is to exclude solid matter such as leaves or moss.

The ventilated tile of the invention permits ventilation over substantially the entire length of the exposed underside in the downward direction and thus makes good use of the available ventilation area. Parallel ventilation passages may be provided over substantially the entire width of the tile, thus making maximum use of the exposed area for ventilation. Such a tile may provide at least 15000 mm2 of ventilation area per metre length of roof.

Other features of the invention will be apparent from the following description of a preferred embodiment shown by way of example only in the accompanying schematic drawings, in which: Figure 1 is a perspective view of a prior art ventilated roof tile from the side and front, a near side wall having been omitted for clarity; Figure 2 is a side elevation of the tile of Figure 1.

Fig. 3 is a perspective view of a ventilated roof tile according to the invention; Fig. 4 is a cross section of the roof tile of Fig. 3 along line IV - IV; Fig. 5 is a front elevation of the roof tile of Fig. 3; Fig. 6 is a side elevation of the roof tile of Fig. 3; Fig. 7 is a view on the underside of the roof tile of Fig. 3; and Fig. 8 is a cross section of a tiled roof along a line of maximum slope of the roof including a ventilated roof tile of the specific embodiment.

A prior art ventilated roof tile is shown in Figures 1 and 2. The tile 10 has an upper face 12 which resembles a conventional roofing slate. Beneath this upper face 12, there is provided a ventilation chamber 13, defined by base 14, which in use is sloped generally towards an output chute 15, a substantially upright back wall 16, and two side walls (not shown). The upper face extends beyond the back wall 16 to allow attachment of tile by for example nails to a batten 17 or the like of a roof structure (not shown). An outer aperture 20 is provided in the upper face 12, through which air may pass between the ventilation chamber 13 and the exterior. The aperture 20 inevitably permits rain water to enter the ventilation chamber 13.

An inner aperture 22 is provided in the back wall 16, which allows flow of air between the interior of a roof and the ventilation chamber 13. A depending baffle 23 shields the inner aperture 22 and defines a tortuous passage for ventilation air. Water carried through outer aperture 20 strikes the base 14, or a baffle 23, and flows therefrom to the output chute 15 which overlies the neighbouring lower tile or tiles; water is thus discharged over the roof, and cannot enter the roof space through the inner aperture 22.

It will be understood that the air flow through the ventilated tile may be in either direction, depending on the relative air pressures on either side of the tile.

The ventilation capability of such a device depends on the minimum cross-sectional area of ventilation path. It follows that by maximising the ventilation area and that of each aperture, the ventilation throughput may be increased, and therefore the number of ventilated tiles required to give adequate ventilation to a roof cavity may be reduced.

This prior art design illustrates some of the difficulties in obtaining an optimum design. The inner aperture 22 cannot be positioned so low that rainwater could flow through it into the roof cavity. The inner aperture cannot be so high that it is occluded by the batten.

Accordingly the size of the inner aperture is restricted, and as a consequence the maximum ventilation area per tile is limited.

With reference to Figures 3-8 of the drawings, there is provided a ventilated roof tile 100, comprising an upper member 102 and a lower member 103. The members 102,103 are of plastics, and are preferably injection moulded. In the figures, the thicknesses of the members 102,103 has been exaggerated for reasons of clarity, and edge formations which permit engagement with adjacent tiles have been omitted.

The upper member 102 is substantially rectangular, and may have a profile moulded into its outer face 104 to resemble a standard roof tile. Two parallel slots 105,106 extend from the lower edge 107 of the member 102 almost to the upper edge 118 thereof. These slots 105,106 are substantially rectangular and parallel, and are symmetrical about the approximate centreline of the upper member 102.

Thus, the upper member 102 has three downwardly extending limbs.

The edges of the slots 105,106 have depending walls 108, at right angles to the upper surface 104 of the upper member 102.

At the lower end of the upper member 102, depending end walls 109 are provided at right angles to the upper surface 104 for each limb; end walls 109 close the lower edge of the tile against water ingress. A depending wall 122 (not shown in Fig. 3) is provided around the remainder of the periphery of the ventilation tile to prevent water ingress and in order that the tile be of the same thickness as a corresponding standard tile. The lower member 103 has two channels 110,112 and three ridges 113,114,115. Each channel 110,112 is constituted by upstanding walls 111 and aligns with and corresponds to a respective slot 105,106 of the upper member 102, the depending walls 108 being surrounded by the upstanding walls 111 as illustrated in Fig. 4. Conversely, the ridges are bounded by the depending walls 108.Apertures 123,124,125 are provided in the ridges of the lower member 103, over substantially the whole length of the lower member in the downward direction of use. As shown in Figure 4, the slots 105,106 are approximately the same width as the central aperture 124, which is approximately twice as wide as the two side apertures 123,125.

A lower portion 119 of the lower member 103 is provided into which the apertures 123,124,125 do not extend, this lower portion 119 being the portion which, in use, overlaps the next succeeding lower row in use.

The bottom of each channel above the lower portion 119, diverges from the plane of the upper member 102, from the upper boundary of the lower portion 119 as illustrated in Figs. 3 and 6. The depending walls 108 and side walls 111 are consequently divergent towards the upper end of the ventilation tile.

The plane of the lower portion 119 is substantially parallel to the plane of the upper member 102 in order to effectively overlap with a lower tile, or tiles, on a roof.

The upstanding wall 121 of the lower member which defines the upper edge of the channel does not meet to the upper edge of the tile, the plain portion 116 resulting therefrom being provided to allow the ventilated tile 100 to be fitted to a batten 201. A moulded hook 117 is provided, extending substantially at right angles from the upper edge 118 of the upper member 102, by which the tile 100 may be hung from the batten 201. Holes for fixing nails, may also be provided in the plain portion 116.

The upstanding walls 111 extend, parallel to the depending walls 108 and are spaced therefrom by clearance 130 through which ventilation air may flow. Clearance 130 is approximately the same width as a side aperture 123,125.

Air thus flows through the slots 105,106, passes through the clearance 130 between the depending walls 108 and the side walls 111, underneath the limbs of the upper member 102 and out through the apertures 123,124,125. The divergence of the upper portion of the lower member 103 maximises the effective area of this ventilation path at the upper end thereof. The degree of overlap of the upstanding and depending walls can thus be optimised without restricting the ventilation path or risking ingress of water.

At the lower end of the ventilation path the height of the upstanding wall may restrict the ventilation opening, the wall necessarily being of a minimum height which will prevent passage of water. The divergence of the upper portion of the lower member permits an increased opening to compensate for the reduced opening at the lower end whilst retaining an upstanding wall of effective height. This arrangement also has the effect of directing air incident on the ventilated tile through the tile and towards the upper end thereof, which causes a preferred flow pattern in a roof cavity. However rainwater will strike the bottom of the channels 110,112, and drain therefrom towards the lower edge 107 of the tile 100.It is usual for tiles to be placed on a roof in a staggered formation, so that a join between two adjacent tiles will align with the centreline of a tile on the row above on the roof. This embodiment of the invention has the added advantage that the two channels direct rainwater either side of the join between the adjacent lower tiles. This avoids excessive flow of rainwater over the join, which is a potential point of leakage on the roof.

Hence, rain incident on the ventilated roof tile will be retained by the baffles provided by the side walls 111 of the channels and the depending walls 108 of the upper member. The water will drain downwardly of the roof, and air will vent through the ventilated roof tile, and into the roof cavity.

Fig. 8 illustrates that the ventilation apertures 123,124,125 of the present invention are not occluded by fixing battens 201, and thus the ventilation tile may be relatively slim.

The particular advantage of the ventilation passage opening to the underside over the entire exposed length in the downward direction is that the width and number of channels may be optimised across the width of the ventilated tile to give a very high ventilation area.

Claims

CLAIMS:

1. A ventilation tile having an outer -face, an inner face and a ventilation passage therebetween, the tile including walls extending inwardly from the outer face and outwardly from the inner face to define a tortuous ventilation passage from said outer face to said inner face, said passage opening to the inner face of the tile over substantially the entire length thereof which is exposed in use in the downward direction.

2. The tile of claim 1 wherein the passage opens to the outer face of the tile over substantially the entire length thereof which is exposed in use in the downward direction.

3. The tile of claim 1 or claim 2 wherein at least part of the ventilation passage defines a drainage channel for material incident on the tile in use.

4. The tile of claim 3 wherein said channel is adapted to direct flow in use between the junctions of neighbouring lower tiles.

5. The tile of any preceding claim further comprising a protective grille over the opening of the ventilation passage into the outer face of the tile.

6. The tile of claim 5 wherein said grille and said outer face are co-planar.

7. The tile of any preceding claim wherein the ventilation passage opens to the outer face via a slot, said slot being open at the lower edge of the tile and otherwise bounded by depending walls extending inwardly of said outer face, upstanding walls extending outwardly of the inner face and overlapping and surrounding said depending walls.

8. The tile of claim 7 wherein the slot is rectangular, the long side of the slot being parallel to the downward dimension of the tile.

9. The tile of claim 8 wherein the tile is rectangular in plan, the long side of the slot being perpendicular to the lower edge of the tile.

10. The tile of any one of claims 7 to 9 having a plurality of said slots.

11. A tile according- to claim 10 having two substantially parallel slots.

12. The tile of any one of claims 7 to 11 wherein the depending walls at the upper end thereof are immediately adjacent the upstanding walls.

13. The tile of any preceding claim including suspension means for suspending the tile from a structure.

14. The tile of any preceding claim wherein said passage opens to the inner face only over the length thereof which is in use exposed.

15. The tile of any preceding claim wherein said outer face is planar and the portion of the inner face which is exposed in use is planar, the plane of said portion diverging from the plane of said outer face towards the upper edge of the tile.

16. The tile-of claim 15 wherein the plane of said portion and the plane of said outer face diverge at an angle in the range 200;300,

17. The tile of any preceding claim wherein the minimum cross sectional area of said ventilation passage in the flow direction is not less than the lateral spacing of said walls.

18. The tile of any preceding claim wherein said outer and inner faces of the tile are respectively defined by two members fixed together to form a unitary whole.

19. A ventilaXion tile substantially as described herein with reference to Figures 3 to 8 of the accompanyng drawings.

19. The ventilation tile of any preceding claim including a spigot of the inner face adapted to receive a tubular outlet vent.

20. A ventilation tile substantially as described herein with reference to Figures 3 to 8 of the drawings.

Amendments to the claims have been filed as follows CLAIMS: 1. A ventilation tile having an outer face, an inner face and a ventilat on passage therebetween, the tile including depending walls extending inwardly from the outer face and upstanding walls extending outwardly from the inner face to define a tortuous ventilation passage from said outer face to said inner face, said passage opening to the loner face of the tile over substantially the entire length thereof which is exposed in use in the downward direection, and at least part of said ver.tilation passage defining a drainage channel for material incident on the tile in use, said channel being bounded by said upstanding walls.

2. The tile of claim 1 wherein the passage opens to the outer face of the tile over substantally the entire length thereof which is exposed ifl use In the downward direction.

3. The tile of claim 1 or claim 2 wherein said channel is adapted to direct flow in use between the junctions of neighbouring lower tiles 4. The tile of any preceding claim further comprising a protective grille over the opening of the ',entilation passage into the outer face of the tile.

5. The tile of claim 4 wherein said grille and said outer face are co-planar.

6. The tile of any preceding cai wherein the ventilation passage opens to the outer face via a slot, said slot being open at the lower edge of the tile and otherwise bounded by said depending walls, said upstanding walls overlapping and surrounding said depending walls.

7. The tile of claim 6 wherein the slot is rectangular, the log side of the slot being parallel to the downward dimension of the tile.

8. The tile of claim 7 wherein the tile is rectangular in plan, the long side of the slot being perpendicular to the lower edge of the tile.

9. The tile of any one of claims 6 to 8 having a plurality of said slots.

10. A tile according to claim 9 having two substantially parallel slots.

ii. The tile of any one of claims 6 to 10 wherein the depending walls at the upper end thereof are immediately adjacent the upstanding walls.

12. The tile of any preceding claim including suspension means for suspendir.g the tile from a structure.

13. The tile of any preceding rlair, whereon said passage opens to the inner face only over the length thereof which is in use exposed.

14. The tile of any preceding claim wherein said outer face is planar and the portion of the inner face which is exposed in use is planar, the plane of said portion diverging from the plane of said outer face towards the upper edge of the tile.

15. The tile of claim 14 wherein the plane of said portion and the plane of said outer face diverge at an angle in the range 20 - 300.

16. The tile of any preceding claim where; the minimum cross sectional area of said ventilation passage in the flow direction is not less that the lateral spacing of said walls.

17. The tile of any preceding claim wherein said outer and inner faces of the tile are respectively defined by two members fixed together to form a unitary whole.

18. The ventilation tile of any preceding claim including a spigot of the inner face adapted to receive a tubular vent.