Precipitation Management System

The present invention relates to a precipitation management system for a roof and is particularly concerned with inclined roofs, and in particular inclined roofs constructed from corrugated material such as those found on warehouses and industrial units.

Buildings such as warehouses and industrial units often employ inclined roof structures comprising panels constructed from materials such as corrugated steel. Many buildings of this type are used for bulk storage at various goods and equipment and consequently are often very large. The size of the buildings therefore often necessitates the use of multiple roof sections such as those shown in figure 1. hi order to remove rain water that would normally collect between the roof sections, a central gutter is often employed which channels the water along the length of the building until it can be discharged at an appropriate location (e.g. at the end of the building). The gutter is located under the eaves of the roof so that rain water falls off the roof into the gutter (which is mounted below the roof).

Many buildings of this type were designed and erected several years ago, and the gutters were sized appropriate to the rain levels expected at that time. However in recent years it has become apparent that due to global climate change levels of rain in countries such as the UK has increased significantly and is predicted to continue increasing. As a result of this the gutter systems which were installed several years ago based on the known rainfall at that time are unable to cope with the increased rainfall seen at the present day.

Furthermore, deluge type rainfalls are becoming more and more common whereby a large volume of rain falls within a relatively short space of time. In this situation the gutters are unable to cope with the increased flow and the excess rainwater overflows from the gutter often entering the interior of the building and damaging the goods and/or equipment therein.

This is often highly undesirable as the very fact that the goods are inside the warehouse implies that they need to be kept out of contact with water. Furthermore, electrical equipment such as switch gear is often stored below such gutters as this kind of equipment

often needs to be coincident with structural members of the building located where the roof sections meet.

Existing solutions to this problem include overflow systems, gutter linings, extra drainage points and outlets, modification of outlets for greater efficiency, siphonic drainage systems and enlargement of the gutter during roof refurbishment. Although some of these solutions provide an immediate solution there is great risk of further increases in torrential rainfall will overwhelm the modifications. Current weather patterns in countries such as the UK indicate that increases in rainfall will continue to occur. Furthermore many of these solutions are expensive and require a great deal of time and effort to install, possibly affecting the operation of the warehouse.

Traditionally the above mentioned problems are solved by increasing the gutter and/or load capacity of the roof by replacing it or carrying out significant modification. This is often very expensive and can result in the need for vacation of the building whilst the work is being carried out. In buildings which carry a lot of equipment such as warehouses this can prove very expensive and therefore undesirable.

As previously mentioned, many buildings of the type concerned are several years old and may have listed status in the UK, preventing heavy modification due to legal, practical or cost reasons. This said, even modern buildings can be subject to water ingress if the initial design and installation was inadequate, or did not take account of phenomena such as deluge rainfall.

Furthermore, the aforementioned climate change brings about reduction in temperatures seen at certain times of the year. This temperature reduction results in different kinds of precipitation such as snow and sleet which have entirely different characteristics to rain. For example, as snow is substantially solid it tends to accumulate on the roofs of buildings without flowing off (as rainwater would), and if the temperature remains below freezing, a significant amount of snow can collect on the roofs of such buildings. This is undesirable as the load capacity of roofs of this type is limited and has been designed without heavy snow fall in mind in countries where it has not been prevalent in the past. Furthermore

snow or ice may accumulate on the roof, and upon a rise in the ambient temperature it may begin to fall from the roof in large lumps, which is potentially hazardous.

In addition to the above considerations, climate change may lead to long dry periods of weather were no precipitation falls and the average temperature is relatively high. In this situation water reserves become extremely low and in some circumstances stored water has to be rationed.

It is known to collect rainwater in storage facilities such as water butts, however, as mentioned above guttering systems can rarely deal with the type of torrential rainfall that is becoming more prevalent in certain countries such as the UK and as such much of the water flowing into the gutter is wasted before it can even reach the storage facility.

Known gutter systems also exhibit problems when rainwater initially reaches them. The downpipe is normally filled with air, and as such in order for water to escape from the gutter into the downpipe, this air has to escape. As air is of a lower density than water, it will tend to rise through the mouth of the downpipe and through the water filled gutter such that the water flow into the downpipe is inhibited by the rising air. This problem is worsened with torrential rainfall, because as the water flows down the smooth inclined roof, a high speed laminar flow develops under the action of gravity. Therefore a significant flow rate is seen in a very short space of time at the gutter due to the velocity of the water.

Furthermore, a flow of water at high velocity can impart excessive loads on gutter systems, and also "slosh" over the edge of an open gutter. This is undesirable.

It is an object of the present invention to overcome one or more of these problems.

According to a first aspect of the invention there is provided a dam for a roof. Many of the solutions discussed above concentrate on increasing the capacity of, or modifying the gutter system in some way. This is often expensive and time consuming. Contrary to this approach, the present invention seeks to eliminate the problem by forming one or more

reservoirs on the roof itself which can absorb any extra rainwater above the capacity of the gutter and release it at a manageable rate. This is achieved by the use of a dam, behind which water can be stored and released slowly such that the gutter cannot overflow. This is especially useful under conditions of torrential rainfall whereby a large volume of water falls in a short space of time, as the reservoir can continue to discharge its load after the deluge has abated and the gutter is under less stress.

Preferably the roof is separated into a number of smaller roof portions.

Preferably, the dam is constructed from sheet material, and the attachment portion and the dam body portion are defined by a deformation in the sheet material. This feature is ideal for long sections of dam, as they can be roll-formed in great lengths for ease of manufacture.

Also, it is preferable that the dam further comprises a dam blade, the dam blade having a lower edge configured to be proximate the roof. In this manner, the dam blade can be constructed from a different material to the dam body, allowing different surface profiles of roof (such as a corrugated profile) to be formed therein, which could not be achieved from roll-forming sheet material alone.

The dam blade may be removeably mounted to the dam body portion, or in particular the interaction between the dam blade and the dam body may be a snap-fit. This allows both cleaning and replacement of dam blades following damage without the removal of the dam body (which may require the opening of attachment holes in the roof).

According to another aspect of the invention there is provided a dam system comprising an inclined roof and a first dam. Preferably, the first dam defines an inflow region above the dam and an outflow region below the dam, wherein the interaction of the first dam with the inclined roof defines an gap through which fluid is permitted to pass between the inflow region and the outflow region. This interaction is ideally in the form of a clearance between a surface of the dam and the roof, and allows the dam to discharge water at a controlled rate (i.e. a rate at which the gutter can operate comfortably).

As most roofs of this type are constructed from corrugated material, it is preferable in this case that an edge of the first dam is profiled to substantially match the profile of the roof. This enables a constant gap to be defined between the dam and the roof, providing a controlled flow of water.

In one embodiment of the invention, the dam system comprises a further dam. The addition of more than one dam allows the volume of water stored to be increased, and the load distributed more evenly over the roof. Furthermore, dams can also be placed next to each other, to span a very long roof.

According to further aspect of the invention, there is provided a method for controlling the flow of fluid on an inclined roof comprising the steps of:

• providing a roof

• providing a dam for a roof according to the above embodiments,

• positioning the dam between a top edge and a bottom edge of the roof,

• allowing rain to fall onto the roof.

According to still further aspect of the invention, there is provided a method for manufacturing a dam for a roof comprising the steps of:

• providing a piece of sheet material,

• deforming the piece of sheet material to form a blade attachment profile.

In providing a piece of material with only a blade attachment portion formed therein, the dam body can be further formed immediately prior to installation of the dam. This would be achieved by forming appropriate deformations in the sheet in order to give the desired height and shape of the dam after, for example, the roof in question had been analysed in order to predict incident rainfall, and therefore the required capacity of the dam system. This is useful as it would eliminate the need for an installer to store many different sizes of pre-formed dam ready for installation. Rather they would store a variety of blades, and a

number of pieces of sheet material with a blade attachment profile formed therein. Upon completing an analysis of the roof in question, the piece of sheet material may be deformed to the correct shape and the appropriate blade fitted to form the dam, particular to the type of roof in question.

According to a further aspect of the invention there is provided a precipitation collection system comprising a barrier and a vessel, wherein the barrier is configured to be mounted on a roof such that precipitation is guided to the vessel for storage.

The use of a barrier on a roof provides an alternative channel for precipitation such as rainwater to flow along to a collection point where it can be guided into the storage vessel. This is advantageous over the prior art gutter systems as the flow of water along the barrier significantly reduces the amount of water flowing into the gutter and therefore overflowing is reduced. It should be noted that installation of a higher capacity gutter system is extremely difficult in many circumstances and as such the present invention offers a convenient solution.

Inclined roofs comprise an upper edge (the ridge) and lower edge (the eaves). The barrier acts to separate the roof into a series of smaller roof sections by guiding water towards the vessel before the water can reach the roof eaves. As such, instead of rainwater accumulating as it flows down the entire roof, the flow is diverted before such flow can reach a significant level. In this manner, the accumulated flow at the eaves is reduced.

Furthermore, the barrier acts as a temporary storage area for rainwater such that deluge rainfall can be more easily managed. Temporary storage of deluge rainfall reduces the flow rate experienced into the gutter and / or storage vessel and effectively converts a short term, high flow of water into a longer term, lower flow.

The use of barriers also interrupts and disrupts the initial flow of rainwater down the roof. The fast, laminar flow is made turbulent by the barriers disrupting the flow and as such the initial flow rate reaching the gutter is reduced as the water flow is interrupted. This allows

the flow into the gutter to build more gradually and alleviates the aforementioned problem of the downpipe flow being inhibited by rising air causing the gutter to overflow.

Furthermore, the velocity of the water as it flows down the roof is prevented from reaching significant levels as the barriers cause turbulent eddies to form, dissipating the kinetic energy of the flow of water. This is beneficial as the amount of "sloshing" as the water arrives at the gutter is reduced, as is the impact loading on the gutter as the impinging water has a lower overall velocity.

According to a still further aspect of the invention there is provided a precipitation management barrier comprising a barrier body and heating means wherein the barrier is configured to be mounted on a roof such that solid precipitation proximate the barrier is heated by the heating means.

Such a barrier may be used to direct water to an alternative location (such as the storage vessel described above) or alternatively the barrier may be a dam configured to allow a controlled flow of water through, which then flows towards the gutter. The advantage of having a heating means is that any solid precipitation such as snow or ice that falls onto the roof will be melted and be able to flow away one of the ways mentioned above as opposed to prior art roofs in which the snow slowly builds until the ambient temperature increases to a point at which it could melt and potentially fall from the roof. Therefore the loading on the roof is reduced and the requirement for reinforcement of the roof is eliminated.

The present invention will now be described in detail with reference to the accompanying drawings in which:-

Figure 1 is an end section of a warehouse and known gutter,

Figure Ia is a side section of the gutter of figure 1 operating under normal rainfall conditions,

Figure Ib is a side section of the gutter of figure 1 operating under deluge rainfall conditions,

Figure 2 is a side section of a dam system for a roof including several dams for a roof according to the present invention in accordance with the current invention,

Figure 3 is a perspective view of a dam for a roof in accordance with the present invention, Figure 4 is a side section of the dam of figure 3, rotated by angle α,

Figure 5 is a perspective view of a dam for a roof in accordance with a second embodiment of the present invention;

Figure 6 is a side section view of the dam of figure 5, rotated by angle α, Figure 7 is a side section view of a dam in accordance with a third embodiment of the present invention, rotated by angle α,

Figure 7a is a side section view of part of the assembly sequence of the dam of figure 7. Figure 8 is a side section view of the dam in accordance with a fourth embodiment of the present invention, rotated by angle α,

Figure 8a is a side section view of part of the assembly sequence of the dam of figure 8. Figure 9 is a perspective view of a dam for a roof in accordance with a fifth embodiment of the present invention,

Figure 10 is a side section view of the dam of figure 9, Figure 11 is a perspective view of a known water collection system,

Figure 12 shows a precipitation management system in accordance with the current invention installed on a roof,

Figure 13 is a perspective view of additional sealing componentary installed on a roof, Figure 14 is a side section view of a precipitation management system in accordance with the present invention,

Figure 15 is a perspective view of the part of a precipitation management system of figure 14,

Figure 15a is a plan view of the precipitation management system of figure 14, Figure 15b is a side section view of the precipitation management system of figure 14 installed on a roof at a first angle,

Figure 15c is a side section view of the precipitation management system of figure 14 installed on a roof at a second angle,

Figure 16 is a perspective view of additional sealing componentary in accordance with the present invention,

Figure 17 is a plan view of a precipitation management system in accordance with the present invention,

Figure 17a is a perspective view of a part of the precipitation management system of figure

17 under normal operating conditions,

Figure 17b is a perspective view of a part of the precipitation management system of figure

17 under high flow conditions,

Figure 18 is a side section view of a first embodiment of a precipitation management barrier in accordance with the present invention,

Figure 19 is a side section view of a second embodiment of a precipitation management barrier in accordance with the present invention.

A warehouse 10 of known type is shown in figure 1.

The warehouse 10 comprises side walls 12 supporting roof 13. Warehouse 10 further encloses warehouse contents 20 which may be, for example, stored goods or electrical equipment.

The roof 13 comprises two external inclined roof sections 14 and two internal inclined roof sections 16 constructed from corrugated steel. The incline roof sections 14, 16 form an "M" shape, with roof ridges 2 at the peaks and eaves 15 at the trough, below which is a gutter 18. The gutter 18 is substantially U-shaped in cross section and runs the length of the warehouse 10 with a drainage means, such as a down-pipe (not shown) at least one end acting to dispose of any water flowing into the gutter 18.

When the warehouse 10 is exposed to rain 22, some of the water will typically run off the external inclined roof sections 14 into external gutters (not shown) on the exterior of the building. However, the rain that impinges on the internal inclined roof section 16 will tend to flow towards the trough of the "M", flow over the eaves 15 and collect in the gutter 18 which is positioned below the eaves 15. Under design rainfall conditions, gutter 18 will transport the water to the drainage means at the end of the building (not shown).

The gutter 18, operating under design rainfall conditions, is shown in figure Ia whereby the water level is well below the top of the gutter 18.

However, under deluge rainfall conditions, the water running down internal inclined roof section 16 enters the gutter 18 at a rate higher than that of the drainage means capacity, causing the gutter to fill and overflow as depicted in figure Ib. This overflowing water will then enter the interior of the warehouse, contacting the warehouse contents 20 and possibly causing damage to stored goods or resulting in failure or damage of electrical equipment.

In figure 2 the warehouse 10 has been installed with a precipitation management system in the form of two sets of dams 24 each comprising an upper dam 26 a middle dam 28 and a lower dam 30. Each dam is attached to the roof and extends longitudinally along its length in a manner which will be described below.

Each dam 26, 28, 30 comprises at least one portion projecting from the internal inclined roof section 16 such that a reservoir of water 32 maybe formed behind it. Furthermore each dam 26, 28, 30 permits the flow of water through it at a known rate determined by a passage in the form of an orifice in the dam or preferably a clearance gap between the dam and the roof as will be described below.

If the rain 22 is light then the rain will simply pass through the orifices or gaps in the set of dams 24 into the gutter 18 where it will flow to the drainage means (not shown).

If the rain 22 exceeds the flow that the gutter 18 is designed for (e.g. from a deluge of rain), the orifices or gaps reach a condition at which no further water may flow through them (hereinafter referred to as the 'choked' condition) resulting in the reservoirs 32 starting to fill. The flow permitted through the set of dams 24 is designed to be less than the maximum design capacity of the gutter 18 such that it cannot overflow, and hence the reservoirs 32 begin to fill.

As the deluge rainfall 22 begins to abate, the flow through the set of dams 24 will be greater than the flow into the reservoirs 32 and consequently the level of the reservoirs 32 will begin to drop. Therefore the gutter 18 will continue to experience the same manageable flow rate as was felt during the initial deluge and can expel the water via the drainage means (not shown).

Eventually the reservoirs will empty and all of the water will have been drained away. In this manner, rather than the gutter 18 experiencing an extremely large water ingress causing overflowing; it experiences a manageable water ingress over a longer period of time thus eliminating the possibility of overflow and damage to warehouse contents 20.

The number and size of the dams making up the set of dams 24 can be varied according to the size of the building, the geographical location of the building (and therefore predicted rainfall) and the capacity of the gutter 18.

Furthermore, the longitudinal course of these set of dams 24 may be angled such that they are not horizontal in order to channel water from the reservoirs 32 to a more desirable location such as the end of the building where it can be discharged.

It should be understood that roofs of this type are often designed to withstand the load imposed by conditions such as heavy snow fall and therefore will be more than capable of carrying the load imposed by the reservoirs of water 32.

Figures 3 and 4 are detailed views of a precipitation management system in the form of a dam 100 in accordance with the present invention mounted on a corrugated roof 102. It should be noted that figure 4 has been rotated by angle α, and the true horizontal and vertical directions are denoted by arrows 'h' and V respectively.

Corrugated roof 102 is inclined such that it comprises a lower edge 104 and an upper edge in a direction indicated by 106. It is constructed from a corrugated material such as steel and comprises trough sections 108, peak sections 110 and wall sections 112. A gutter (not shown) is located beneath the lower edge 104. Such a roof section may make up one of the internal inclined roof sections 16 at Figure 2. The surface profile of the corrugated roof 102 could take many forms, from completely flat to corrugated as described herein.

The dam 100 comprises dam body 114 and blade 116.

Dam body 114 is constructed from a single piece of sheet metal such as aluminium or steel. The sheet metal of the dam body 114 is plastically deformed either manually or by an automated process such as roll forming into several flat sections.

Roll forming is a well-known operation whereby a sheet metal work piece is continuously fed through sequential sets of rollers, which progressively deform the sheet into a desired profile. It is widely applied where constant cross-section components are required.

The flat sections resulting from the deformations are; an attachment section 118, a downstream wall 120, a top section 122, an upstream wall 124 and a blade attachment profile 126. The blade attachment profile 126 comprises a return flange 128 and an inverted U-section 130.

The blade 116 is constructed from a mouldable material such as plastic or rubber and comprises a blade body 132 and a blade head 134. The blade body 132 tapers from a lower edge 136 to become wider at the blade head 134. Furthermore, the blade body 132 is profiled along the lower edge 136 to match the profile of the corrugated roof 102. The lower edge 136 does not abut the corrugated roof 102 but is suspended above it by a predetermined gap of width denoted by arrows W.

The blade head 134 is significantly wider in cross section than the blade body 132 and is formed to define an inverted U-shaped recess 138 into which the inverted U-section 130 of the blade attachment profile 126 fits. The blade 116 may be engaged with the dam body 114 by sliding the blade attachment profile 126 into the inverted U-shaped recess 138 longitudinally (i.e. in a direction perpendicular to the section of figure 3) such that the blade 116 is suspended and supported by the dam body 114.

The attachment section 118 of the dam body 114 rests on the peaks 110 of the corrugated roof 102 and is attached thereto by rivets 140, self-tapping screws, self drilling screws or any other appropriate attachment means.

The gap W between the lower edge 136 of the blade body 132 and the corrugated roof 102 is such that any water passing from the upper edge 106 to the lower edge 104 of the corrugated roof 102 that is within the design capacity of the gutter (not shown) may pass unhindered by the dam 100. The water will simply pass through the gap between the lower edge 136 and the corrugated roof 102 and then beneath the attachment section 118 in the trough sections 108 of the corrugated roof 102.

If the flow of water exceeds the capacity of the gutter, the gap between the lower edge 136 of the corrugated roof 102 denoted by W is designed such that it will become choked and water will begin to build up behind the dam 100 against the blade body 132. As the rain continues to form, the water will continue to build up behind the dam 100 which will only release a flow of water within the capacity of the gutter. The height H of the dam 100 is designed such that an appropriate amount of water may be stored for the conditions expected, bearing in mind the predicted rainfall on the building.

It is envisaged that several dams of this type may be used together on a single roof section as is shown in figure 2. In order to adjust the location and amount of loading on the roof imposed by the reservoirs of water, it may be necessary to vary the size of each dam depending on roof structure building location and gutter capacity. Therefore it is advantageous for the dams 100 to be adaptable in terms of height H and also the gap represented by W.

This can be achieved by initially roll forming the blade attachment profile 126 into the dam body 114 and storing the result of this operation (i.e. a flat panel with a blade attachment profile 126 on one edge). Therefore the dam profile can be created at a specialist manufacturing facility (such as a roll-former's) in bulk, before delivery to the supplier (who need not possess such specialist manufacturing equipment).

When a dam is required, the supplier may then deform the panel to form attachment section 118, downstream wall 120, top section 122 and upstream wall 124 as he sees fit dependent on the application. This operation is a simple one, requiring folding or bending deformations in the panel, which can be carried out on a simple jig. In this way, dams can

be quickly created for individual applications, without the lead time of a roll-forming operation for every application.

Complimentary to this, a number of blade bodies 132 of various heights may be carried by the supplier. Alternatively, the blade body 132 could be constructed from a material that is easy to cut or shape to fit the profile of the roof section and consequently the dam 100 can be customised for an individual application at the same time as the dam body. The size of the gap between the lower edge 136 and the corrugated roof 102 may be varied by varying the length of the upstream wall 124 during fabrication.

Therefore the system described above is highly flexible and may either be manufactured in advance or alternatively at short notice. This is desirable as the corrugated profile of roofs tends to vary between buildings, and holding many of the same simple, adaptable components is preferable to holding a few components each of the many different roof types that exist. In this manner, the required storage space is significantly reduced.

Figures 5 and 6 show that a second embodiment of a precipitation management system in the form of a dam 200 in accordance with the current invention, similar to the embodiment shown in figures 3 and 4. It should be noted that figure 6 has been rotated by angle α, and the true horizontal and vertical directions are denoted by arrows 'h' and V respectively.

The dam 200 is installed on a corrugated roof 102 with a lower edge 104, an upper edge in the direction of 106, trough section 108, peak sections 110 and wall sections 112. Dam 200 comprises a dam body 202 and a blade 204.

Dam body 202 is constructed from a piece of sheet metal such as aluminium or steel, plastically deformed to form attachment section 206, downstream wall 208, upstream wall 210 and blade attachment profile 212.

The blade attachment profile 212 comprises upper section 214 and upstream section 216 at right angles to each other and projecting from the upstream wall 210 such that an inverted

U-channel is made with downstream wall 208. The bottom edge 218 of upstream section 216 does not extend downwards as far as the attachment section 206.

The blade 204 is constructed from a known profiled foam rubber/plastics filler that is normally used to close an upper and lower corrugated profile on roof sheets. These filler sections are already produced for several known types of corrugated roof section. The blade 204 can be inserted into the inverted U section formed by the blade attachment profile and glued into position.

The blade 204 is therefore supported by the dam body 202 in a similar way to the previous embodiment of the invention described in figures 3 and 4.

The attachment section 206 is attached to the corrugated roof 102 by screws 220.

The height of the dam, H', can be adjusted to vary the distance between a lower edge 222 of the blade 204 and corrugated roof 102 in order to allow water to pass through.

Therefore the dam can operate in much the same way as previously described but instead of custom manufacturing the blades 116, an appropriate filler material can be purchased and used as blade 204.

Furthermore, the blade attachment profile 212 can be pre-rolled into the sheet material for the dam body 202 and supplied to the installer who can then make appropriate deformations to create the correct size of dam and height of gap W.

Figure 7 shows a precipitation management system in the form of a dam 300 in accordance with a third embodiment of the invention. Dam 300 is similar to dam 100 of figure 4 comprising dam body 302 and blade 304. It should be noted that figure 7 has been rotated by angle α, and the true horizontal and vertical directions are denoted by arrows 'h' and 'v' respectively.

In this instance the shape of the blade attachment profile 306 forms the shape of a rotated T. The blade attachment profile 306 comprises first upper surface 308, first vertical surface 310, second upper surface 312, second vertical surface 314, first lower surface 316, third vertical surface 318, second lower surface 320 and flange 322.

The blade 304 is tapered from a thin lower edge 324 up to a head 326 which is T-shaped in profile with the leg of the T being perpendicular to the body of the blade 304.

hi order to assemble the blade 304 to the blade body 302 the blade 304 must be inserted at an oblique angle and twisted into position as shown in figure 7a. The distance between upper surface 312 first lower surface 316 is greater than the height of the widest part of the head 326 of the blade 304 therefore facilitating an easy "snap fit" and removal. When in situe, as shown in figure 7, the blade head 326 is held in position by the neck formed by first upper surface 308 and second lower surface 320 such that any force acting on the body of the blade 304 will be reacted by either the second vertical surface 314 or the first and third vertical surfaces 310, 318.

Furthermore loading during use will act in the direction of arrow F in figure 7 (i.e. the load of the water) causing the body of the blade 304 to react against flange 322. Removal of the blade 304 requires a force in the direction opposite to that of force F which would not normally occur during use, only when the blade needs to be removed.

This configuration allows easy installation of the blade and furthermore facilitates subsequent removal which would be necessary if, for example, the blade needed cleaning, if debris became lodged on the roof behind it, it became damaged or furthermore if the flow characteristics between the lower edge 324 and the corrugated roof 102 require adjustment.

Figure 8 shows a precipitation management system in the form of a dam 400 in accordance with a fourth embodiment of the invention. It should be noted that figure 8 has been rotated by angle α, and the true horizontal and vertical directions are denoted by arrows 'h' and 'v' respectively.

The dam 400 comprises dam body 402 and blade 404. Dam body 402 comprises blade attachment profile 406.

In this instance blade attachment profile 406 forms the male portion of the joint between the dam body 402 and the blade 404. The blade attachment portion 406 forms recess 408, trapezoidal section 410 and flange 412.

A head 414 of the blade 404 forms an opposite profile with a protruding section 416, and a trapezoidal recess 418 connected to a blade body 420.

In order to fit the blade 404 to the dam body 402, it needs to be twisted in as demonstrated in figure 8 a. The resilience in both components causes the protruding section 416 to enter the recess 408 and the trapezoidal section 410 to enter the trapezoidal recess 418 locking the blade 404 in position.

In a similar manner to the aspect of the invention shown in figure 7, forces during use will act in the direction indicated by arrow F resulting in the blade reacting against flange 412. No force experienced during normal use would act to act in an opposite direction to arrow F and therefore the blade 404 cannot easily become detached.

The embodiment depicted in figures 9 and 10 is a simpler version of a precipitation management system in the form of a dam 500 in accordance with the present invention. A single piece construction is used which is formed from a flat piece of metal sheet 502 with tabs 504 deformed at 90 degrees to the metal sheet 502 and mounted on peaks 506 of the corrugated steel roof 508. The tabs 504 are mounted via rivets 505.

Downward facing portions 510 of the metal sheet 502 are sized to define a gap, denoted by W, through which water may flow. Water may also flow between the sides of the downward facing portions 510 and the corrugated steel roof 508.

Alternatively, the downward facing portions 510 may contact troughs 512 of the corrugated steel roof 508 (i.e. not forming gap W) such that flow is only permitted between the sides of the downward facing portions 510 and the corrugated steel roof 508.

Numerous changes may be made within the scope of the present invention. All of the embodiments discussed above involve a two piece assembly comprising a dam body and a blade. This arrangement simply facilitates manufacture and assembly as it is easier to roll form long sections of the dam body and mould short sections of the blade making a modular construction necessary.

The rolled sections discussed above could be modified such that the upstream wall 124 in figure 4 could be extended downwards to meet the corrugated roof 102 and profiled appropriately to leave a gap between it and the roof. In this instance the requirement for a blade is negated.

Various materials may be used for the construction of the dam, for example sheet metal such as steels and alloys or even plastics material which can be heat treated to form the appropriate deformations.

As the length of warehouses are typically 70 metres but may be up to 1.5 kilometres it is often impractical to dam the length of a roof using a single component. Rather, a sequence of adjacent dams of 3 to 5 metres in length could be used. In this instance it is possible, but not necessary, to seal the gaps between the dams to prevent excess water running down the roof.

The number of dams on the roof can be varied to match the requirements of the specific case. For example, a more even load distribution requirement may require a high number of small dams (i.e. 2 or more) whereby the existence of a load bearing member at the centre of the roof panel may give rise to a single large dam located there. The number and size of dams can be calculated taking into account the size of the gutter, the incident rainfall on the roof, the projected future rainfall on the roof and the size of the roof. These factors can be

combined in such a way that the appropriate height of and flow through the dam can be designed.

The attachment means may also vary in nature. Rivets may be used, or alternatively screws in order to attach the dam to the roof. Sealing means may be employed such as rubber O-rings to prevent water ingress through the holes that the attachment means require. However, it is important to note that preferentially, the dam is attached to the roof at the peaks as the water will tend to flow down the troughs, therefore water ingress will be minimised at these holes.

The blade of figure 5 and 6 comprising the filler section may be attached, as discussed, via adhesive or alternatively mechanical attachment means such as dowel pins extending through upstream section 216 may be employed. Alternatively, screw type means through upper section 214 would also suffice.

The dams are not limited in application to the internal inclined roof sections 16 (figure 2), but may be equally applied to the external inclined roof sections 14. Often, external gutters (not shown) are also present at the top of side walls 12, and could potentially overflow under deluge rainfall conditions. This may be undesirable for different reasons (e.g. flooding of doorways), but the invention decried above could equally be applied to external inclined roof sections in order to alleviate the problem.

The dam need not allow the passage of water via a gap W. It is also within the scope of the invention for no gap to exist between the dam and the roof, and instead for the dam, or dam blade to contain an orifice through which water may pass. This may be advantageous if any debris washed from the roof tends to sink to the base of the dam blades, blocking the gaps. Positioning an orifice part way up the dam would alleviate this problem. Alternatively a combination of these features may be used.

The gap W need not be uniform. If extra support is required, the blade could contact the roof in the trough sections and the gap could only be defined in the sloping sections, or vice-versa.

Furthermore, the dams need not be uniformally distributed over the roof. A single section of roof may contain dams where another does not, depending on the desired location of flow.

Similarly, only a single internal inclined roof section may comprise a dam or dam system. It is within the scope of this invention to provide a dam system for a single roof section, if the desired reduction in flow can be achieved. In this case, a benefit is gained as less installation work is necessary and furthermore only one side of the roof will have to be modified.

Further, the dam blade may be manufactured in more than one stage. The blade head 134 may be preformed into a "blank" blade containing no profile at the lower edge 136; e.g. the lower edge could be straight. In this instance, the installer would form the necessary profile at the lower edge 136 by removing material in order to create a lower edge profile by operations such as punching.

Figure 11 shows the edge of a building 800 having a roof ridge 801, eaves 815 and an angled roof section 802 constructed from corrugated material. In a similar manner to warehouse 10 inclined roof section 802 channels water into a gutter 804. The flow of rainwater is depicted by arrows A.

The gutter 804 then channels water into a down pipe 806 via a hopper 805. Down pipe 806 then transfers to a water storage 808 which may be, for example, a water butt or other known storage tank which can be utilized to store water and use it at a later date.

A problem with the device shown in figure 11 is that the gutter 804 is of a limited capacity. Therefore if excessive deluge rainfall occurs the gutter 804 will overflow and the water will be lost as shown by arrows B. Apart from potentially creating damage as discussed above, this overflowed water will not be stored in water storage vessel 808 and therefore cannot be

used at a later date. Therefore the water collection system shown in figure 11 is not efficient at deluge rainfall conditions.

Figure 12 shows a precipitation management system in the form of a precipitation collection system 820 in accordance with the present invention. Precipitation collection system 820 is installed on a roof 822 of known type (having an upper edge, or ridge 801 and a lower edge, or eaves 815) comprising inclined roof section 824. A number of barriers 826 (to be described below) are mounted flat on the inclined roof section 824 but at a slight angle from the horizontal shown at reference numeral 828 in order to direct the flow of water. The barriers 826 are located between the ridge 801 and eaves 815.

At an edge 830 of the inclined roof section 824 there is a drainage channel 832, which takes the form of a channel open at its top and lower end faces. At the lower end of drainage channel 832 is hopper 834 which is fluidly connected to down pipe 836 which in turn is fluidly connected to water storage vessel 838 which may take the form of a water butt, storage tank or the like.

Referring to figure 14 barrier 826 is shown in section along the line IV-IV of figure 12. Figure 15 shows a perspective view of a barrier 826 whereby the corrugations in the inclined roof section 824 can be clearly seen.

Barrier 826 comprises upright member 840, L-shaped member 842 and base 844.

As can be seen in figures 14 and 15 upright member 840 is constructed from deformed sheet material and comprises first flange 846, body 848 and second flange 850. The L-shaped member 842 comprises a first flange 852, an upright section 854, a sloped section 856, a flat section 858 and a second flange 860. The brace 844 comprises a flat section 862 and an upright section 864 approximately at right angles to each other.

The second flange 860 is contoured to fit the corrugations of inclined roof section 824 as can be seen in figures 15 and 15a. The second flange 860 of L-shaped member 842 therefore forms a seal with the corrugations of inclined roof section 824 such that water

cannot pass through the barrier 826. Furthermore, the second flange 860 of L-shaped member 842 is inclined with respect to the flat section 858 such that it is parallel with the horizontal or alternatively sloped in the same direction as the inclined roof section 824. Figures 15b and 15c show inclined roof sections 824 at decreasing inclinations represented by angle C and it can be clearly seen that in both cases the second flange 860 is parallel to the horizontal. As such water will not stagnate behind the barrier 826.

The barrier 826 is assembled using fasteners as will be described below.

A first row of fasteners 866 fastens the first flange 846 of the upright member 840, the flat section 862 of the brace 844 and the inclined roof section 824 together. As can be seen in figure 15, the first row of fasteners 866 are located at the top of the corrugations. A second row of fasteners 868 attach the second flange 850 of the upright member 840 to the first flange 852 of the L-shaped member 842. A third row of fasteners 870 attach the upright section 854 of the L-shaped member 842. A fourth row of fasteners 872 attach the flat section 862 of the brace 844 to the inclined roof section 824. Each of the fourth row fasteners 872 is generally in line with the first row of fasteners 866 as they are both located on the uppermost sections of the inclined roof section 824 corrugations.

It should be understood that other attachment means may be used instead of fasteners, for example nut and bolt combinations, adhesives or welding.

It will be understood that the barriers 826 can be installed horizontally (i.e. parallel with the roof ridge 801 or eaves 815) or, as shown in figure 12 at an incline 828 whereby the flow of liquid precipitation can be directed to a desired location.

During operation, rain falls on the inclined roof section 824 and travels towards the bottom of the roof where, for example, a gutter would normally be located. If the rain flows down the roof towards a barrier 826 it will first encounter the second flange 860 of L-shaped member 842 and be forced to flow along this member, along the flat section 858 of the L-shaped member 842 towards the sloped section 856. Due to the presence of the upright section 854 the water cannot pass and as such will collect behind the barrier 826. Referring

to figure 12, the inclination 828 of the barriers 826 directs rainwater into drainage channel 832 whereby it flows into the hopper 834 and consequently into the down pipe 836 and into water storage vessel 838. It will be understood that the barriers 826, as well as performing a water direction role, also perform a temporary water storage role in which large volumes of rain which fall in short durations of time can be managed by temporarily storing water behind barriers 826 and gradually releasing it into drainage channel 832. Therefore the problem of overflowing gutters resulting from such deluge rainfall is alleviated.

It will be appreciated that the storage of water on inclined roof section 824 may give rise to the requirement of additional sealing, and figures 13 and 16 show an inclined roof section 824 interfacing with a known end section 825 at which position extra flashing 874 is provided in the form of a deformed piece of flat material comprising first flange 876, second flange 878 and sloping section 880. In order to prevent water ingress between inclined roof section 824 and end section 825 the first flange 876 is sealed to the inclined roof section 824 and the second flange 878 is sealed to the end section 825.

An alternative embodiment of the present invention is shown in figure 17 whereby an elongate roof section 900 is shown comprising roof ridge line 902 from which the elongate roof section slopes down towards a valley gutter 904 of known type. As can be seen several barriers 826 have been installed in an inclined fashion such that any rainwater is directed to a channel area 906.

The valley gutter 904 comprises a pump assembly 908 located directly beneath the channel area 906. The pump assembly 908 sits in sump 910 installed into valley gutter 904. Sump 910 comprises an enlarged water reservoir in which accumulated water can collect before being pumped away.

The pump assembly 908 comprises a high performance water pump and floater switch combination connected to discharged pipe work 912 which leads to water storage vessel 914.

The barriers 826 direct rainwater into channel area 906 where it flows down the elongate roof section 900 and into sump 910 (see figure 17a). If the rainfall is significant (for example during a deluge), the sump 910 will fill to a point at which the flow switch activates the pump in pump assembly 908. The float switch is configured such that upon experiencing a certain level of water in sump 910 the water pump is activated as can be seen in figure 17b. The pump assembly then pumps rainwater along discharged pipe work 912 into water storage vessel 914.

It can be clearly seen that combining the channel area 906 and the sump 910 leads to the management of torrential rainfall. Therefore, overflowing of the valley gutter 904 is alleviated. It should also be appreciated that under normal rainfall conditions rain will simply travel down channel area 906 into sump 910 and consequently be discharged via valley gutter 904 as the water level in sump 910 will not reach a level significant enough to activate the float switch of the pump assembly 908.

Figure 18 shows a precipitation management system in the form of a barrier 1026 substantially similar to barrier 826 as previously described. Reference numerals for common features between barrier 1026 and 826 are incremented by 200. hi addition to barrier 826, barrier 1026 comprises first trace heating element 1082 and second trace heating element 1084. Trace heating elements 1082 and 1084 are electrical devices which produce heat upon the application of an electrical current. Although the trace heating elements in figure 18 are shown in specific locations they can be located at any position on the barrier 1026, although it is advantageous to place them on the inner surfaces of the various panels in order to prevent damage during use.

Trace heating elements 1082 and 1084 can be activated in low temperature conditions where snow, sleet or ice fall and would otherwise build on the inclined roof section 1024. As the ice or snow will tend to collect on the exposed surfaces of barrier 1026 such as the upright section 1054 and the sloped section 1056, increasing the temperature of these faces will melt the snow or ice in contact with them, which will be able to flow away in the way described for barrier 826. As the snow or ice proximate the barrier 1026 is melted, any snow or ice behind will move to the faces as the water flows away and consequently will be

melted. Therefore barrier 1026 provides a way of removing solid precipitation from inclined roof section 1024 thus alleviating the problem of overloading of the roof section during heavy snow or ice falls.

Alternatively, trace heating elements may be placed on other surface of the barrier 1026 such that the air inside said barrier is heated to a temperature at which solid precipitation is melted.

As an alternative to manual activation of the trace heating elements 1082 and 1084, a thermocouple 1086 may be positioned on the barrier 1026 to automatically detect low temperature conditions and subsequently activate the trace heating elements 1082 and 1084. In this manner the barrier 1026 provides an automatic way in which to reduce the solid precipitation loading on the roof, which is particularly advantageous as temperatures may be lowest when the building is unoccupied, e.g. at night.

The concept of heating the barrier 826 can be alternatively achieved by filling a cavity 882 formed by the upright member 840, the L-shaped member 842 and the brace 844 with a heated fluid such that any solid precipitation proximate the barrier 826 will be melted as described above. This may be achieved, for example by providing an air heater and pump which pumps warm air through the cavity 882. Alternatively ambient air from inside the building, which would typically be at room temperature may be pumped through the cavity 882 to provide this heating.

As an alternative to directing water, the heating concept described above may be used in combination with a dam 1100 as shown in figure 19. The dam 1100 comprises a dam body 1102 attached to an inclined roof section 1104 and a dam blade 1106. A dam blade 1106 is attached to the dam body 1102 and is configured to follow the profile of the inclined roof section 1104 but with a clearance between the dam blade 1106 and the roof section 1104 of distance G. As such, it is possible for fluid such as rainwater to flow through the gap G and down the inclined roof section 1104.

The dam 1100 further comprises trace heating element 1108 attached to the dam blade 1106. Trace heating element 1108 operates in a similar way as described above and heats the surface of the dam blade 1106 such that any solid precipitation such as snow or ice is melted. The melted snow or ice is able to move to the bottom of the dam blade 1106 under the action of gravity and flow through the gap G and into the known water collection system (e.g. a gutter) at the bottom of the inclined roof section 1104. As such, the dam 1100 prevents the build up of solid precipitation on the roof and thus alleviates the problem of roof overloading.

Numerous changes maybe made within the scope of the present invention.

All of the embodiments discussed above involve a multi piece assembly, however it is perfectly possible to use a single piece of shaped material to form a barrier or dam with or without trace heating.

Various materials may be used for the construction of the barriers or dam, for example sheet metal such as steels or alloys or even plastics material which can be heat treated to form the appropriate deformations.

This system is not limited to applications concerning corrugated roof sections, but may be used on a wide range of domestic and commercial inclined roofs, and the barriers may even be used on flat roofs to direct precipitation to the appropriate areas.