GB2513998A

GB2513998A - Roofing system

Info

Publication number: GB2513998A
Application number: GB1406274.9A
Authority: GB
Inventors: Stephen John Makin
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-04-25
Filing date: 2014-04-08
Publication date: 2014-11-12
Anticipated expiration: 2034-04-08
Also published as: GB2513379A; GB2513998B; GB201307467D0; GB201406274D0

Abstract

A cambered plate E is located between plain roof tiles P. The plate is suspended by a hook at its upper end from a batten B of. At its lower end it sits on the upper surface of one of the cambered tiles. The plate is positioned between adjacent tiles such that rain passing through the gap between them is deflected by the plate and prevented from entering the roof (H). In use, the plate permits a breathable open-air roof space with increased impermeability. The plate preferably has two ridges extending across its width to prevent ingress of wind-driven rain and a seal may be incorporated into its underside. It may be made from PVC, GRP or Aluminium. The plate may be used with a membrane comprising layers of polypropylene and polyester, the polyester absorbing water condensate from the roof space and releasing it via the outermost polypropylene. In use the plate permits the roof tiles to be spaced father apart which lowers the weight and cost of the roof and results in a roof with increased freedom of pitch angles. A plate per se is also claimed.

Description

ROOFING SYSTEM

BACKGROUND

The roofing system of this appiioation, hereinafter the Easy plain' , is a system for improving the weather proofing and overall performance of the specific type of traditional roofing covering tiles known as Plain Tiles' (P) Plain tiles are predominantly flat and sguare pieces of uniform concrete or clay that, when arranged adjacently regimented horizontal rows and provide a waterproof, durable and aesthetically pleasing external covering known a plain tiled roof (Fig 4) L5 Plain tiles (P) are mounted upon timber strips known as roofing battens' (8) that are thus mechanically fixed (usually nailed (N) ) laterally in an opposite direction on to the timber rafters' (P4 that are used to form the roof structure, A membrane known as a tile underlay' (D) is laid on top of the rafters and underneath the battens as to form a secondary weather barrier, the whole structure can thus be an arrangement that forms the roof of a building.

Most plain tiles are approxiirately 12mm thick, by 165mm wide by 2 65mm long (F) The top of the tile is usually shaped so that a small part of the top section of the tile commonly known as the nib' (Pn) protrudes downward as to engage or hang' over the back section of the timber batten (B) on which it rests.

Concrete plain tiles are machine made and incorporate a slight curve along the length of the tile so that the tile rises slightly upwards in the mid section (approx. 5mm), this curve is known as the camber' (Pc) . In some cases the tiles can also incorporate a similar curve from side to side and in this case the tile is known as being double cambered' Plain tiles that are made using clay can be either machine or hand made and are then heat fired in a Kiln so as to remain hard and durable. They can be flat, cambered or double cambered according to the mould in which they are formed. Hand made tiles tend to be slightly irregular in size and shape, this being mainly as a result of the manufacturing process.

In order to arrange the tiles on the roof frames (R) the installer should first apply a secondary waterproofing membrane layer known as an underlay (D) . On top of this underlay they should then apply strips of wood known as roofing!battens! (13), they are fixed (N) in a horizontal position laterally on top of the underlay and across the roofing frames or rafters (R) . These battens are spaced parallel and approximately 100mm apart (Es) and cover the whole of the roof.

The tiles are place lengthways upon these battens (fig 2 and 4) as to be adjacent to each other and thus form the first course or row' of tiles (El) . The abutment joint of these tiles is known as the!perpT (17) that being a perpendicular or vertical join that remains visible upon the roof. This perp join can be closed or open with the gap ranging from 0- 5mm in width, these perp joins are not waterproof and will allow rainwater to pass through them.

Upon completion of the first row the second row (P2) can now be installed. The length of the tile means that approximately 165mm of this 2nd row of tiles covers the tiles on the first row that is positioned below and this is known as the primary lap' (P1)), that being said the result of this lap is that 100mm of the bottom end of the tile as well as 100mm of its perp join is now and will remain exposed to the elements, this exposed area of tile is called the tile margin (PM) . The tiles on the second row (P2) are positioned so that the perp join (V2) is placed over the centre point of the tile on the first row that is below (P1) . The result of this is that the centre of the tile above is covering the upper part of the perp join below in an arrangement known as broken bond' Upon completion of the second row the third row (P3) is installed similarly in a broken bond with tiles in the second row directly below them. The position of the tiles on the third row (P3) is therefcre consequently directly above and in line with the tiles on the first row (P1) . The length of the tiles mean that the third row will also overlap the first row by some 65mm and is thus known as the secondary lap' (Pdl), this arrangement of plain tiles is thus known as double lap' tiling. The arrangement of these tiles continues up the roof to its ultimate conclusion whereby said roof is fully covered in these tiles.

The double lap of plain tiles is the method by which the plain tiles provide a weather proof covering to the roof. By this arrangement water can permeate through the visible and exposed perp joins on the third row (V3) with the result that this water will land on the midsection of the tile below on row 2 (P2) . The flow of water being controlled by gravity it is therefore imperative that the roof frame is angled to such a degree as tc ensure that water will exit the space between the third and second tile before the water is able to reach the upper part of the perp join of the second tile and might thus be able to enter or permeate' through the roof covering.

The flow of this this water is further affected by wind and air pressure and general adverse weather conditions that can displace the water that has permeated the tiles. The result of this type of tile is that currently when installing a plain tiled roof it is reguired that the frame of the roof is pitched' at an angle not less than 35 degrees from the horizontal (H) It is known that because of the loose and irregular abutment of plain tiles then this will allow the free movement of air around and through the tiles so that plain tiles are known as an open air' roof covering. The open air properties of the plain tiled roof covering also means it can also be prone to the adverse affects of wind driven rain and snow.

In order to further prevent this moisture from entering the building it is normal for a membrane or underlay (D) to be installed on top of the rafters (R) and underneath the battens (3) Traditionally these membranes consisted of a string re-enforced bitumen material that formed a durable yet flexible waterproof underlay covering to the roof structure. Modern technology has utilised vapour open membranes that have the additional advantage of helping to control water vapour that can build up within the roof space of a modern dwelling (C).

These membranes allow this water vapour to escape by passing through them and thus into the atmosphere (5) . These membranes therefore work best when they are used with air open roof coverings that allcw the free movement of this vapour such as plain tiles.

Currently and in general, building design and application is legislated through the planning process and this is applied through local authorities who might place restrictions upon the style and design of buildings insofar as the height, inclination or aesthetic appearance of the roof, these planning laws often require the use of local and traditionally used materials such as plain tiles especially when they are sympathetic to the local area.

The use of plain tiles can therefore place restrictions upon the designer when confronted with a specific size of building insofar as; the width of a building when incorporating a roof with a pitch of not less than 35 degrees will thus decide the height of the roof and therefore it could prevail that the total height might exceed the maximum allowed by a local authority. Another example of the type of restriction on the angle of the roof might be when an upper floor window restricts the pitch of the plain tiled roof below when a ground floor extension is built.

A roof that utilises a steeper angle of roof has a greater surface area of those tiles placed upon the roof and thus the roof is heavier and this generates a greater load upon the structure of the building. Ultimately, a greater load and the additional quantity cf tiles can further increase the costs of constructing the building.

In order to allow a lower angle of roofing when using plain tiles it is necessary therefcre to improve the normal weather and water proofing properties of these plain tiles (2) . The application (Fig 5) of the Plain Easy System (Fig 3 and 6(E)) will do this by preventing the usual passage of water that would normally pass through the marginal perp joins in these tiles at lower roof angles. :is

SUMMARY OF THE INVENTION

According to the present invention, there is provided a roof structure according to claim 1.

Also provided is a plate for a roof structure according to claim 10.

DETAILED DESCRIPTION

The Plain Easy System (E) shculd be installed in addition to these tiles to run between and along the length of each row (fig 3 and 5) and will thus improve the weather proofing performance of these tiles tc such a degree that the angle of the roof (H) might be considerably lowered. Because of the specific design of the Plain Easy System it will have little or no visual impact on the general aesthetic of the roof and will thus satisfy the requirements of both the designer and local authority. Because of the double lap of the Plain Easy it is therefore also possible to increase the length of the traditional lap of the tiles (P1 and Pdl) and thus offer an increased reduction in the weight of the roof and quantity of tiles that might be required.

In order for the plain easy to work efficiently it must prevent the water from entering the structure of the roof through the perp joins whilst simultaneously allowing the water to freely drain off the roof. It must also prevent wind driven rain from being driven up and underneath the tiles whilst eliminating any capillary action that would transmit the water through the layers of the tiles. L5

Modern construction methods have air and draft sealed the buildings with the effect that the occurrence of condensation (C) in the roof space has considerably increased. It can therefore be considered a fortuitous part of the design of a conventional roof (fig 2 and 4) that the standard plain roof tile also allows a considerable amount of free air to circulate around the tiles so that they are considered as an open-air roof covering.

This free air is advantageous when dispersing the build up of condensation is to be considered especially as the movement of air is traditionally the best way to clear this condensation to the atmosphere (5) . Should this moisture not be cleared from the roof space then it would condensate on the underside of the membrane in such a quantity as to run down the inside of the membrane and damage the structure of the roof.

Modern underlays utilise technology that allows the membrane to breath and these breathable membranes are used in order to help disperse this condensation of water molecules (0) into the atmosphere. Should the plain easy roof system be installed on a conventional plain tiled roof then it would thus restrict the movement of this free air. It is therefore imperative that the well being of the roof is maintained.

Ordinary breathable membranes would not be a sufficient method of coping with these further levels of condensation and additional methods should be employed.

The Dryroof membrane (fig 7 (D) ) is made from a 3 layered spunbond polypropylene top layer (Dl) that incorporates a Polyester fleece that is adhered to the underside (P3) . A functional film is sandwiched and protected between both of these resilient layers (D2) It is constructed in such a way as to absorb the additional levels of condensation that might build up during high mcisture times that exist in a dwelling The fleece will collect this condensation so that it can be released in a controlled manner throughout the day. The multi-layered construction incorporates a functional film that will prctect the home from interstitial condensation that can form on both top and underneath of the membrane. The Dryroof membrane is sufficiently strong to maintain its structure and performance so that the weather proofing integrity of the roof is maintained for the lifespan of the roof structure. The Plain Easy should therefore also be used in conjunction the Dryroof super absorbent underlay membrane (D) The Plain Easy System is a specifically designed for improving the weather and water proofing performance of plain roofing tiles when installed on the roofs of dwellings whereby the pitch of the roof is reduced.

The Plain Easy device can be extruded or formed from a weather resistant material that should have a life span that will complement the expected lifespan of the intended plain tile roof covering such as rigid PVC, CRP or formed aluminium.

Plain Easy is a devise that is sufficiently thin in construction so that it is harmonised within the normal installation of the plain tiles as not to affect the aesthetic appeal of the finished roof covering. The front edge being reduced in thickness as to follow the contour of the front edge of the tiles and thus form a more effective weather seal (El) The Plain easy device incorpcrates 2 ridges towards the rear (E2,3) that prevent the movement of wind driven rain as to prevent that moisture from being driven over the top of the rear of the device and thus entering the roof structure.

The Plain Easy has top lip that is angle perpendicular to the devise (E4) so that the Plain easy can be easily, accurately and securely located upon the battens (B) The Plain Easy devise is angled in such a way that it fits squarely onto the roofing batten and thus creates a gap between the tile and the devise so as to negate and remove the capillary action of the rain water (ES) -10 -The Plain Easy devise should incorporate a slight upward curve (E6) so as to add gravitational strength when located into position in addition to accommodating the camber of the plain tiles.

The Plain Easy devise should be sufficiently simple to cut and install so that the devise might he side lapped and sealed at the edge in order to create a weather proof seal along the row of tiles whilst not compromising the general structure or aesthetic appeal of the finished roof.

The Plain Easy device is compatible with standard fixing methods that are associated with the installation of the plain tiles and is sufficiently angled as to be laid flat upon the batten and would not be thus distorted when being pierced by the fixing of the plain tiles (F) The Plain Easy System allows a reduction in the lap (P1 and Pdl) of the tiles so that the overall number of tiles placed upon the roof can be reduced. The reduction in the number of the tiles on the roof has the advantage of reducing the overall weight of the roof.

The Plain Easy System incorpcrates a secondary Dryroof underlayment for the control of the additional condensation that is generated when the free air movement is removed from plain tiles.

The Dryroof (fig 7) membrane is specifically constructed as to hold excessive moisture that is thus generated within the loft space of a dwelling. The super absorbent layer will -11 -prevent any moisture from dripping and running on the underside of the membrane and is thus designed specifically to protect the structure of the roof when installed with the Plain Easy devise.

The Dryroof membrane will allow the gradual release of this moisture into the atmosphere that is held within the fleece and transmitted through the roof space.

The Dryroof Membrane is constructed with the addition of a super absorbent Polyester fleece to the underside.

Claims

-12 -CLAIMS1. A double lapped roof structure comprising: a lower batten; an intermediary batten; and an upper batten, a cambered lower roof tile suspended by its upper end from the lower batten; a first and second cambered intermediary tile each suspended by its upper end from the intermediary batten and each supported at its opposite end on an upper surface of the lower roof tile, wherein the first intermediary roof tile is adjacent to the second intermediary roof tile; an upper cambered roof tile suspended by its upper end from the upper batten and supported at its opposite end on an upper surface of each of the first and second intermediary roof tiles, such that a portion of each of the first and second intermediary tiles is sandwiched between a portion of each of the lower and upper tiles; a plate located between the intermediary roof tiles and the lower roof tile, suspended by its upper end from the intermediary roof batten, and supported at its opposite end on the upper surface of the lower roof tile, wherein the plate is cambered to fit with the cambered tiles, such that rain passing between the first and second intermediary roof tiles is deflected by the plate onto the lower roof tile.
2. A roof structure according to claim 1 wherein the plate comprises a first ridge which is located on the side of the plate nearest the intermediary roof tiles and which extends across the width of the plate for inhibiting wind driven rain from being driven up between the lower and intermediary roof tiles.

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3. A roof structure according to claim 2 wherein the plate comprises a second ridge which is located on the side of the plate nearest the intermediary roof tiles and which extends across the width of the plate for inhibiting wind driven rain from being driven up between the lower and intermediary roof tiles.
4. A roof structure or plate according to any preceding claim wherein the thickness of the plate decreases from the upper end to the opposite end.
5. A roof structure according to any preceding claim wherein the plate is hooked around the outer surface of the intermediary batten.
6. A roof structure according to any preceding claim wherein the opposite end of the plate comprises a seal located along a width of the plate for engaging the lower and/or intermediary roof tiles.
7. A roof structure according to any preceding claim wherein the plate is made of at least one of PVC, GRP or formed aluminium.
8. A roof structure according to any preceding claim wherein the plate is less than 265mm long.
9. A roof structure according to any preceding claim further comprising a water absorbent multi-layer membrane which is locatable underneath the tiles and battens, the membrane comprising a polyprcpylene layer and a polyester -14 -layer, wherein the polyester layer is operable to collect water condensate in air located on the interior side of the roof, and release this condensate towards the exterior side of the roof via the polypropylene layer.
10. A plate for a double lapped roof structure, the plate comprising: a first end and an opposite end to the first end; a hook shaped portion at the first end for securing the plate on a roof batten in the roof structure; wherein the plate is positionable between a cambered lower roof tile and a first cambered and second cambered intermediary roof tile from the roof structure such that the plate inhibits wind driven rain from being driven up between the lower and the intermediary cambered roof tiles; and wherein the plate is cantered to fit with the cambered tiles.
11. A double lapped roof structure as substantially hereinbefore described and with reference to the accompanying drawings.
12. A water absorbent multi-layer membrane as substantially hereinbefore described and with reference to the accompanying drawings.
13. A plate for use in a double lapped roof structure as substantially hereinbefore described and with reference to the accompanying drawings.-15 -
14. A method of forming a double lapped roof as substantially hereinbefore described and with reference to the accompanying drawings.