AU2011100379A4 - Leaf screen mesh - Google Patents

Description

2 5 Field of Invention This invention relates to gutter guards, as a means for preventing the entry of leaves, debris and vermin into the open gutter, which may cause blockages to the gutter system. 10 Background of the Invention Most buildings incorporate a gutter system in their design to assist in the diversion of rainwater from the roof surface. Essentially this prevents flooding and undermining of the foundations and also provides a means for channeling rainwater to a catchment facility. As rainwater is becoming an increasingly valuable resource the harvesting and re-use of 15 rainwater from the roofs of buildings is desirable both for its environmental and economical benefits. Australia's well publicized bushfire threat in populated regions is another area of major concern. Airborne embers from bushfires may ignite 'dry-leaf build up' in guttering, thereby creating a significant fire hazard. 20 In the past the use of many forms of extruded plastic mesh inserted into the gutter has been a popular choice due to its low cost and ease of installation, however these plastic products have proven inadequate in most instances especially where a fire resistant product is required to meet council regulations. Also, due to the way some mesh is rolled concave / convex to fit into the gutter it tends to act as a barrier accumulating leaf and 25 debris. The unnecessarily large hole sizes used in many of these meshes also tend to entrap the leaf stem and twigs creating both an unacceptable appearance and potential fire hazard. In recent times several perforated, expanded and woven metal products have appeared on the market, however many of these have retained inadequacies of the plastic mesh (i.e. unnecessarily large hole sizes). As previously stated leaves and twigs are easily 30 entrapped in large mesh openings, encouraging the build-up of leaf mulch. If left unattended this leaf mulch may promote premature breakdown of the metal mesh and guttering and reduce the overall effectiveness of the system. Whilst steel mesh may prove significantly more fire resistant than plastic, It is however subject to atmospheric degradation, especially in coastal locations. Protective coatings 35 such as painting and powder coating are generally employed to combat this problem, but due to some manufacturing processes many of these metal meshes are perforated and expanded after being coated and some woven mesh is coated after weaving, thereby rendering some areas of the mesh unprotected.

3 5 This inability to treat the total surface area of the mesh may lead to rust problems, once again reducing mesh performance and life expectancy, and possibly creating an adverse reaction with the roof surface. The size of the openings and shape of the mesh dramatically effect the way the system 10 performs. Flattened / smooth metal mesh whether perforated or expanded provides minimal resistance as water flows across it, therefore relatively large openings are required to break this water flow and direct water through the mesh. Also as wet leaves dry they have a tendency to stick to flat surfaces creating a 'snag' for other debris. 15 Systems that fit inside the gutter generally fail as they tend to sit higher than the gutter tile bottom edge and create a barrier, conversely the mesh fits too low in the gutter sometimes sloping in the wrong direction (back towards the fascia) also the leading edge of the mesh is sometimes fitted into the roll of the gutter lip thereby creating a 10mm barrier, again accumulating debris 20 25 30 35 4 5 Summary of the Invention In a first broad form the present invention provides a mesh filter for preventing the ingress of leaf and debris into a gutter or the like. The gutter mesh filter comprises a flexible length (or preferably a roll) of woven metal 10 mesh (preferably aluminium). Having typically square @ or rectangular uniformly shaped openings / apertures which produce a 'dimpled' non-smooth surface. The edges of the mesh comprise of a folded / double thickness selvedge (B) on both sides 15 of the length of mesh establishing improved strength and durability (when compared to prior art woven mesh). This added strength significantly reduces the possibility of tearing and fraying of the mesh at stress locations such as screw points on metal roofs and gutters and excessive tension points on tiled roofs when tiles are pushed down on the mesh to form to tile profile, 20 The use of a malleable aluminum mesh also allows the mesh to be more easily moulded to form to tile and metal profiles and is also much lighter and easier to work with when compared to steel woven mesh. Aluminium is highly regarded as a non-flammable material ideally suited in bushfire risk zones and is also compatible with colorbond metal 25 roof sheeting and will not rust. The application of a quality powder coating (A) significantly reduces the likelihood of corrosion to the mesh and allows for colour matching to a wide range of popular roof colours. Metal Roof 30 Using corresponding profile saddles the mesh is fixed (screwed / riveted) through the mesh to the high point of the corrugated roof profile securing and forming the mesh to the roof. The outer gutter edge of the mesh is fitted to the top edge of the gutter lip / roll using screws or rivets or 90 degree angle cover trims. 35 Tiled Roof To fit the present invention to a tiled roof the mesh is firstly fixed to the gutter edge in the same manner as with a metal roof.

5 5 To fit the roof side the mesh is installed across the gutter opening extending across the first row of tiles then tucked under the second row of tiles which are pressed down firmly to form the mesh to the profile of the roof tile. Mesh has been cut, shaped and fixed in many forms when attaching to the roof surface 10 and gutter edge, however, some prior art examples have not worked very affectively. Some attachment systems use double sided tape which does not generally perform long term being highly dependant on the diligence of the installer to adhere to strict installation guidelines. On metal roofs mechanical fixing is the most widely accepted method of attaching the mesh by screwing profile shaped saddles and metal angle trims to 15 the metal roofing and guttering. However, on some woven mesh the strands tend to pull away (fray) from fixing screws creating holes in the mesh greatly reducing its effectiveness. When fitting gutter mesh to a tiled roof some systems are fixed to the outer gutter edge, across the first row of tiles and fixed under the second row of tiles. In most cases this 20 system works quite effectively however, when the second row tile is pressed down onto the mesh to mould and form to the tile profile most expanded or fine meshes have a tendency to tear under this tension, significantly reducing the effectiveness of the leafsereening system. This present invention seeks to alleviate at least one of the problems associated with prior 25 art and provide a substantial contribution to the working of such prior art 30 35

Claims (5)

1. An arrangement for preventing the ingress of leaves and debris into a gutter or the like, said arrangement comprising a length of substantially flexible woven metal mesh preferably aluminium having folded / double edge selvedged extending the full length of 10 said mesh

2. An arrangement as claimed in claim 1. where said mesh comprises a folded/double edge selvedged extending the full length of said mesh on both outer edges of said mesh.

3. An arrangement as claimed in claims 1 & 2 where said mesh is powder coated

4. An arrangement as claimed in claims 1, 2 & 3 where said mesh arrangement comprises 15 uniformly square shaped apertures as herein described with reference to an accompanying drawing.

5. An arrangement as claimed in claims 1, 2, 3 &4 where said mesh arrangement comprises uniformly rectangular shaped apetures. 20 25 30