AU2004100558B4 - Drainage system for balconies and rooves - Google Patents

Description

-1- DRAINAGE SYSTEM FOR BALCONIES AND ROOVES BACKGROUND TO THE INVENTION A high rise building may provide balconies for use by people on each floor, such as guests in a hotel for example. Rainwater tends to collect on the surface of each balcony unless a drainage system is provided. However, conventional drainage systems can cause undesirable effects. Similar problems can also arise on certain roof structures.

Rainwater may be removed from a balcony or flat roof in a range of different but generally unsatisfactory ways. Holes or pipes through the rim of the balcony can produce streams of water that impact on structures below or cause erosion of the rim. Water may be dispersed over the edge of a balcony without .a rim, but can cause staining and may allow solid objects to be lost over the edge. A system that carries water to a central downpipe is relatively complex and expensive. In this specification the "rim" of a balcony or roof includes structures often referred to as the "perimeter hob".

SUMMARY OF THE INVENTION It is an object of the invention to provide a system for draining rainwater from a balcony or roof structure without creating effects of the kind mentioned above, or at least to provide an alternative to existing systems.

The invention may broadly be said to consist in a drainage system for a balcony, roof or similar structure, including: a collector that receives rainwater from an upper surface of the structure, a conduit that carries the water from the collector to an outer part of the structure, and an outlet at the end of the conduit that disperses the water in droplets away from the structure. Preferably the outlet is angled downwards at approximately 45 degrees from horizontal and has a perforated exit face to assist the dispersal.

LIST OF FIGURES Preferred embodiments of the invention will be described with respect to the accompanying drawings, of which: Figures lA, IB show a drainage system for a balcony or flat roof, and Figures 2A, 2B show an alternative drainage system.

DESCRIPTION OF FIGURES Referring to the drawings it will be appreciated that the invention may be implemented in various ways for a range of different structures, and that this description is given by way of example only. The description refers generally to a balcony but it will be appreciated that rooves and similar structures are included.

Figure 1A is a vertical cross section through a balcony or roof structure with a drainage system for rainwater. The balcony has a horizontal platform 10 projecting from a support structure such as a building (not shown) and a rim II that defines an outer edge 12 of the balcony. Both the platform and the rim are made of a solid material such as concrete in this example, but may be constructed in a range of different ways. An upper surface 13 of the platform, such as a layer of tiles, is inclined so that rainwater runs toward a central collector 14.

The drainage system in Figure 1A includes the collector 14, such as a cup embedded in the platform, a conduit 15, such as a pipe connected at one end to the collector, and an outlet 16 such as a shorter pipe at the other end of the conduit. These components are preferably composed of plastics materials. The collector preferably has a removable grate 17 that lies flush with the surface of the platform. The collector may be located anywhere around the platform according to the design of the balcony and several collectors may be provided as independent or connected systems.

The collector 14 and conduit 15 in Figure lA are preferably arranged to trap particles such as silt that might block the outlet, or stain the balcony or other structures below. The -3conduit is connected a short distance above the base 18 of the collector which allows a small amount of water to pool below the entrance 19 to the conduit. The conduit is preferably also angled slightly upwards from horizontal to assist this process, but alternative arrangements are also possible. Material that accumulates in the collector may be emptied either by removing the grate 17 or temporarily removing the collector itself The outlet 16 in Figure IA allows water from the collector 14 to travel through the conduit as indicated by arrows, and be dispersed away from the balcony in the form of droplets that again become part of the rain. The outlet is preferably angled downwards from the conduit at about 45 degrees from horizontal, which enables the water to gather speed before passing head 20 of the outlet and leaving the balcony. The outlet is connected to the conduit using a standard pipe connector 21 and preferably emerges from the balcony at an edge or corner between the platform and the rim so that water is dispersed in a diagonal direction away from the balcony.

Figure 1B shows the face 22 of the head 20 of the outlet in Figure IA. The face is circular in this example, with a pattern of perforations that disperse water flowing through the head into droplets. A preferred pattern on the face places smaller perforations in a lower region 23 of the face, for relatively low water flows, and places larger perforations in an upper region 24 of the face for relatively high water flows. A flood aperture 25 is uppermost in this pattern to reduce the possibility that the flow of rain water from the balcony will be restricted in very heavy weather conditions. A variety of different shapes and faces for each outlet are possible.

Figure 2A is a vertical cross section through a balcony with an alternative drainage system, broadly similar to the system of Figure IA, but different in detail. A cup 30 is located in the platform 10, and a pipe 31 connects the cup to an outlet 32. The cup may be elongated at right angles to the page and similarly the pipe may be relatively flat along the same direction. Water pools in the cup before flowing into the outlet to be dispersed away from the outer edge of the balcony. A head 33 on the outlet is angled downwards and has an exit face 34 that assists conversion of the water into droplets.

-4- Figure 2B shows the face of the outlet in Figure 2A and the general shape of the conduit structure within the balcony. As in Figure IB the face has a pattern of perforations that assist dispersal of the water. Smaller holes 40 are placed lower on the face for light rainfall and low water flows, while larger holes 41 are placed higher to allow dispersal of larger flows in worse weather conditions. A flood aperture 42 is usually included for storm conditions.

Claims (4)

1. A drainage system for a balcony, roof or similar structure, including: a collector that receives rainwater from an upper surface of the structure, a conduit that carries the water from the collector to an outer part of the structure, and an outlet at the end of the conduit that disperses the water away from the structure in droplets.

2. A system according to claim 1 wherein the outlet is angled downwards at approximately 45 degrees from horizontal.

3. A system according to claim 1 wherein the outlet includes a perforated face through which the water is dispersed.

4. A system according to claim I wherein the outlet emerges at a corner of the structure and disperses water into the air diagonally away from the structure. A system according to claim 1 wherein the water pools in the collector before passing to the outlet.