Is there a product that will eradicate roots that enter water drains, as opposed to sewer drains. I have a listed willow tree in my garden and its roots sometimes clog up the drains. I was wondering if there is a product that will help with this problem.
The usual solution, and reasonalbly effecitve, is to use a synthetic geotextile, such as Terram, which is used normally to protect the liner of artificial lakes and reservoirs.
Over a short distance, you could use 2 thicknesses of the heaviest gauge. It is possible that roots will grow through it eventually but it will be some years.
An alternative would be to use copper sheeting to enclose the water pipes because copper kills roots on contact. But there must be no gaps. This is more expensive but might be a solution worthwhile for a short run of up to twenty metres of pipe. The copper sheet can be very light as it is its chemical heavy metal action that kills the growing points of roots not the physical barrier.