Tree roots in your drains — the problem, the solution, the tree
Why roots find your drains, how much damage they cause, and how to stop them without removing every tree in the garden.
Why roots find your drains
Roots seek moisture. A slightly leaking pipe joint releases a plume of water vapour into the surrounding soil — irresistible to nearby tree roots, which grow towards it, find the joint, and gradually push fine root hairs into the pipe. Inside the pipe those hairs multiply into dense masses that eventually block flow.
Which trees are the worst offenders
Willow, poplar, cherry, sycamore and eucalyptus are the drainage-industry's usual suspects. Any mature tree within 10m of a drain run should be considered a candidate. Root systems can travel much further than the tree's canopy width, so distance alone isn't a full protection.
How to fix root ingress properly
The wrong way: send a jetter every 6 months to cut the roots. The roots re-grow within a few months because the entry point is still open.
The right way: cut the root mass with a rotating jetting head, then install a patch liner over the affected joint. The liner seals the entry point permanently and the roots can no longer get in.
Do you need to remove the tree?
Almost never. Removing a mature tree is a much bigger loss to the garden than sealing the joint the roots are entering through. A patch liner solves the problem for the design life of the liner — 50+ years.