Tree roots are the most common cause of all blocked pipes and sewer drains, approximately 75% of all of the blocked drains that we clear are caused by tree roots. It only takes a small ‘hair’ root to get in through one of the joints in the pipe and when its finds the nutrient rich water it will grow rapidly into a large mass that will stop your dunny from draining away properly.
Fortunately these roots can be cut away from the inside of the pipe relatively easily and everything starts flowing away as it should. However, this is much like pruning a tree, the roots will grow back thicker and more vigorously than ever if the pipe is not repaired. There are two ways in which this can be done; either by excavating and replacing the root damaged section, or by installing a liner inside of the pipe. The latter option is achieved by sticking a new pipe to the inside of the old and can be done through your existing inspection openings and requires no excavation. This is ideal if there is any kind of structure or paved surface over the top of where the drain pipe is buried.
As always, prevention is better than cure, and with a little bit of forward planning it is possible to minimise the chances that this will ever become an issue for you. With this in mind, I have compiled a list of popular garden plants and set out the minimum distances that they should be planted away from any underground pipes. This list can be seen here
Of course, I couldn’t include every single species of plant in this list, but as a general rule of thumb the roots of a tree will spread to approximately one and a half times the vertical height of the tree.
At the bottom of the list I have also included a number of species that have particularly aggressive root systems and that are not recommended for planting in urban gardens.
If you are unsure of the exact location of your sewer drains you can give us a call and we will can survey and map your entire drainage system using our drain camera and locating equipment. This will not only allow you to see the condition of your buried pipes but also give you an exact location and depth so that your landscaping can be planned accordingly.
Also I have found that the staff at the local nurseries are very knowledgeable and they too will be able to offer advice as to how aggressive the root systems of particular plant species are.