GB2513379A

GB2513379A - Plain tile weather proofing system

Info

Publication number: GB2513379A
Application number: GB1307467.9A
Authority: GB
Inventors: Stephen John Makin
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-04-25
Filing date: 2013-04-25
Publication date: 2014-10-29
Also published as: GB201307467D0; GB2513998B; GB2513998A; GB201406274D0

Abstract

The device E retains the aesthetic appearance of a roof when installed whereby the pitch of the roof is reduced a previously required angle. Preferably the device is an extruded rigid device located between a roof tile and a batten with a perpendicular lip E4 so that the device can be located on a batten. The device may be slightly curved. The device may include two ridges E2, E3 towards the rear to prevent movement of wind driven rain from being driven over the top of the device and entering the roof structure. The device may be used in conjunction with a roof with a secondary underlayment D which holds excessive moisture and is made from three layers including a resilient top layer, a hydrophobic film and a super absorbent polyester fleece on the underside.

Description

PLAIN TILE WEATHER PROOFING SYSTEM

Description

S

A device for improving the weather resistance of plain tiles so they might be used on roofs with a lower pitch.

Background to the invention

Plain tiles are a traditional type of roof covering. The permeable nature of the design of plain tiles mean that they cannot remain weather proof when installed on roofs with a pitch or angle that is below 35 degrees from the horizontal. This is a system for improving the weather proofing and overall performance of the specific type of roof covering known as plain tiles.

Brief description of the drawings.

Figure 1 shows both a longitudal cross section and the underside of a typical plain tile.

Figure 2 shows a lateral cross section of the device.

Figure 3 shows a diagrammatical section of the underlay membrane.

Figure 4 shows a cross section of the build up of a typical plain tiled roof.

Figure 5 shows a cross section as fig 4 but with the device installed.

Figure 6 shows a perspective of a typical roof that is partially constructed.

Figure 7 shows a perspective as fig 6 but with the device installed.

Description of a conventional plain tiled roof that leads to the requirements of device.

Plain tiles (P' Fig. 1) are predominantly flat and square pieces of uniform concrete or clay. When arranged adjacently in regimented horizontal rows they provide a waterproof. durable and aesthetically pleasing external covering known a plain tiled roof (Fig. 6).

Plain tiles (P) are mounted upon timber strips known as roofing battens' (B) that are thus mechanically fixed laterally (usually nailed (N)) in an opposite direction on to the timber rafters'(R). These rafters 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 to form a secondary weather barrier. The whole structure can thus be an arrangement that forms thc roof' of a building.

Most plain tiles are approximately 12mm thick, by 165mm wide by 2ôSnrni long (P' fig. 1). 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 downwards to engage or hang' over the back section of the timber batten (B) on which it rests (fig. 4).

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 is known as being double cambered' S cfig. I).

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 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 (M). On top of this underlay they should then apply strips of wood known as roofing battens' (B), 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 1 00mm apart (BS) and cover the whole of the roof.

The tiles are placed lengthways on the battens (fig. 6) adjacent to each other and form the first course or row' of tiles (Pi). The abutment joint of these tiles is known as the perp' (V) 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. Perp joins are not waterproof and will allow rainwater to pass through them.

On completion of the first row the second row (P2) can now be installed. The length of the tile means that approximately 165mm of this 2' row of tiles covers the tiles on the first row that is positioned below. This is known as the primary lap' (P1)).

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 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 simfiarly in a broken bond with tiles in the second row directly below them. The tiles on the third row (P3) are positioned directly above and in line with the tiles on the first row (P1).

The third row will also overlap the first row by some 65mm and is known as the secondary lap' (PDL), The complete arrangement of plain tiles is known as double lap' tiling. The arrangement of these tiles continues up the roof until it is fully covered in the 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) allowing the water to land on the midsection of the tile below on row 2 (P2). It is therefore imperative that the roof frame is angled to such a degree as to 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 water is further affected by wind and air pressure and general S adverse weather conditions that can displace the water that has permeated the tiles.

Currently when installing a plain tiled roof it is required that the frame of the roof is pitched' at an angle not less than 35 degrees from the horizontal (1-1) so that it might remain watertight and weather proof The loose and irregular abutment of plain tiles allow the free movement of air around and through the tiles, plain tiles are known as an open-air' roof covering. The open-air properties of the plain tiled roof covering can be prone to the adverse affects of wind dnven rain and snow. lii order to further prevent this moisture from entering the building it is normal for a membrane or underlay M) to be installed on top of the rafters (R) and underneath the battens (B' fig. 4,6).

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

Description of the invention

Plain tile should only be installed on roof with an angle in excess of 35 degrees in order to remain water and weather proofing of the roof.

Currently and in general, building design and application is legislated through the planning process. This is applied through local authorities who might place restrictions upon the style and design of buildings i.e. 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. The width of a building when incorporating a roof with a pitch of not less than 35 degrees, will 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. This generates a greater load upon the structure of the building. Ultimately, a greater load and the additional quantity of tiles can further increase the costs of constructing the building.

ffi order to allow a lower angle of rooting when using plain tiles, it is necessary S to improve the normal weather and water proofing properties of these plain tiles (P).

The application of the device (fig. 5 and 7(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.

The device (E) should be installed in addition to these tiles to run between and along the length of each row (fig. 5 and 7). This will improve the weather proofing performance of the tiles to such a degree that the angle of the roof (H) might be considerably lowered. Due to the specific design of the device there will be 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 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 aLo 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.

Modern construction methods have air and draft sealed buildings that have resulted in the increased occurrence of condensation (C) in the roof space. It can therefore be considered a fortuitous part of the design of a conventional roof (fig. 4 and 6) that the standard plain roof tile aho allows a consideraNe 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 considering dispersing the build up of condensation especially as the movement of air is traditionally the best way to clear this condensation to the atmosphere (S). Should this moisture not be cleared from the roof space. 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 (M) are used in order to h&p disperse this condensation of water molecules (C) into the atmosphere. Should the device 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 or conventional membranes (M) would not be a sufficient method of coping with these further levels of condensation and additional methods should be employed.

A membrane (fig 3 D') that is made from a 3 layered spunbond polypropylene top layer (Dl) that incorporates a Polyester fleece that is adhered to the underside (D3).

A functional film (D2) is sandwiched and protected between both of these resilient

S

layers. It is constructed in such a way as to absorb the additional levels of condensation that might build up during high moisture times that exist in a dwelling (fig. 5 and 7) The fleece will collect the condensation and allow it to be released in a S controlled manner throughout the day. The multi-layered construction incorporates a functional film that will protect the home from interstitial condensation that can form on both top and underneath of the membrane. The 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 device should therefore also be used in conjunction with the super absorbent underlay membrane (D).

Claims

CLAIMS1) A device (F Fig 2) that is specifically designed for improving the weather and water proofing performance of plain roofing tiles whilst retaining the aesthetic S appearance of the roof when installed on the roofs of buildings whereby the pitch of the roof is reduced below a previously required angle.

2) A device as described in claim I that can be extruded or formed from a weather resistant material with a life span that will complement the expected lifespan of the intended plain tile roof covering such as rigid PVC, GRP or formed aluminium.

3) A device as described in claim I 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 as well as incorporating a front edge that is reduced in thickness as to follow the contour of the front edge of the tiles and forming a more effective weather seal (Ei).

4) A device as described in dairn I that incorporates 2 ridges towards the rear (E2,3) that prevent the movement of wind driven rain from being driven over the top of the rear of the device and thus entering the roof structure.

5) A device as described in claim 1 that has a top lip that is perpendicular to the devise (E4) so that the device can be easily, accurately and securely located upon the battens (B).

6) A device as described in claim 1 that 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 to negate and remove the capillary action of the rain water (ES).

7) A device as described in claim I that incorporates a slight upward curve (P6) to add gravitational strength when located into position in addition to accommodating the camber of the plain tiles.

8) A device as described in claim 2 that should be sufficiently simple to cut and install so that the devise might be side lapped and sealed at the edge to create a weather proof seal along the row of tiles whilst not compromising the general structure or aesthetic appeal of the finished roof.

9) A device as described in claims I and 2 that is compatible with standard fixing methods that are associated with the installation of the plain tiles in that it is sufficiently angled to be laid flat upon the batten and would not be distorted when being pierced by the fixing method of the plain tfles (F' fig. 7).

10) A device as described in claim 1 that allows a reduction in the lap (P1' and PDL' fig. 5) of the tiles so that the overall number of tiles placed upon the roof can be reduced whereby the reduction in the number of the tiles on the roof has the advantage of reducing the overall weight and cost of the roof 11) A device as described in claim 1 that acts as a secondary underlayment (if fig 3,5 and 7) that will complement and on its own maintain the waterproofing and overall well being of the roof when the free air movement has been restricted on a plain tiled roof.

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12) A device as described in claim 11 that is constructed in 3 layers and in such a way as to utilise a resilient top layer (Dl) that will remain watertight above and encapsulating a hydrophobic film (D2) above a layer of a super absorbent p&yester fleece to the underside (D3).

13) A device as described in claim II (fig. 7) that is a membrane that is specifically constructed to hold excessive moisture that is generated within the loft space of a dwelling. The super absorbent layer will prevent any moisture from dripping and running on the underside of the membrane and is designed specifically to protect the structure of the roof when installed with the device as described in claim I. 14) A device as described iii claim 12 is a membrane that wUl ailow the gradual release of captured moisture into the atmosphere that is held within the fleece (D3) and transmitted through the roof space so as to maintain the requirements of claims 1 and 11.