Older homes in Australia are notorious for problems with tree root pipe blockages in sewer lines, septic and storm water drains because older pipes were made of clay or earthenware and joined together with mortar or rubber rings. Mortar crumbles over time under ground just like the mortar around bricks above the ground and rubber rings perish and simply disintegrate. The pipe work starts to leak into the environment surrounding the pipe which in turn stimulates tree root growth. Tree roots grow into the pipe at the broken connection and may cause your sewer, septic or storm water drain to back up, sending raw sewage or storm water into the house or yard.
Clearing the drain and cutting the tree roots away is the only short term solution to get the drain working again however cutting tree roots inside a pipe is a similar process to pruning a hedge, it promotes growth, so where one tree root is cut another 2 or 3 will grow back. Over time as the roots multiply and grow big enough, they can rupture and destroy pipes, forcing you to repair or replace the sewer, septic or storm water drain.
In conclusion; tree roots generally don’t invade drainage pipes unless those pipes are already damaged and leaking and water is seeping into the surrounding soil (environment). Tree roots are opportunistic by nature and will always be stimulated by water and nutrients.
Older drainage pipes (usually clay or earthenware) are at least fifty years or more in age and will inevitably start leaking at some point in time. This is usually the time when tree roots will penetrate into a drainage network. This problem can easily be resolved by structural pipe lining technology or the replacement of old clay or earthenware pipes with modern PVC pipes.
Drainage pipe maintenance should be a part of overall property maintenance and should take place when pipes show the first signs of leakage or tree root intrusion.
People often mistakenly believe that simply removing a tree growing near to where a drain blockage is occurring will fix that problem – but this is usually not the case.
The overriding consideration should always be to treat the cause (pipes), not the symptom (tree roots).