Klober single-piece Rainwater Outlets are designed to provide drainage for ventilated cold flat roofs which use insulation, rather than unventilated cold flat roofs which rely on a roof void. Installation is similar to a flat roof terminal whereby the downpipe penetrates the roof, into the roof void, which is then connected to a drainage system to drain away any surface water that may build up on a flat roof system, preventing ponding. This ponding of water can cause flat roof systems to fail over time and lead to damage or leaking. This specific rainwater outlet features a 100mm diameter downpipe ideal for connecting up to 100mm diameter drainage systems. Each Klober Rainwater Outlet - Single-Piece is ready for installation and use right out of the box, however an additional 100mm leaf filter grill is available to purchase and retrofit straight into the top of the downpipe to prevent any unwanted debris blocking the drainage system. This product does not include the leaf filter grill pictured. As this rainwater outlet is made using high impact PVC it is only suitable for use on multi-layer flat roof systems and is not suitable for use on flat asphalt roofs.