Square Downpipe Plastic Pipe Clip Description Freeflow is a range of innovative, high quality PVC-U rainwater systems that are the result of Freefoams culture of continuous innovation and investment in research and development. The Freeflow range has been designed to ensure both reliable, leak-free performance and quick installation. In addition, it is compatible with other rainwater systems with a range of adaptors. Freeflow products come in a range of standard colours including white, black and brown. Each rainwater system is co-extruded with a white interior and a range of exterior colours - Freefoams new innovative solution to the problems associated with rapid heat absorption and expansion of gutters. Widely published test results show that while a white surface exposed to sunshine can absorb heat and attain a surface temperature 10C or more over the air temperature, dark surfaces can rise a further 30-40C and exceed the softening point of the PVC. On large capacity gutters with a large surface area facing the sun, this can be a particular problem. While the interior will be exposed to sunlight as normal, its absorption of heat from the sun and subsequent expansion along its width and length will be significantly reduced, thus dramatically decreasing the probability of any associated problems.