Tree roots do a lot of quiet work – anchoring the tree, drawing up water and nutrients, and holding soil in place. Most of the time you never think about them. But as a root system matures and spreads, it can start pushing into places you’d rather it didn’t: under paving, toward pipes, or close to foundations. Here’s how tree root systems actually grow, and when they’re worth having a professional look at.
How Tree Root Systems Grow
Contrary to the popular image of a root system mirroring the canopy underground, most tree roots spread out sideways rather than straight down – often extending well beyond the tree’s drip line, but staying within the top 30–60cm of soil where oxygen, water and nutrients are most available. This wide, shallow structure is what gives large trees their stability, and why roots can travel much further from the trunk than most people expect.
When Tree Roots Become a Problem
Root systems generally coexist fine with a property, but a few situations are worth watching for:
- Structural damage – roots seeking moisture can grow into or under foundations, retaining walls and paving, causing cracking or lifting over time.
- Pipe intrusion – tree roots are drawn to the moisture in and around underground pipes, and can infiltrate small cracks or joints in older stormwater and sewer lines.
- Lifted pavement or paths – surface roots from established trees are a common cause of uneven paving and trip hazards.
- Competing with garden beds – large root systems can outcompete smaller plants nearby for water and nutrients.
Do You Need to Remove Tree Roots?
Not always – and it’s worth getting professional advice before doing anything, since cutting the wrong roots can destabilise a tree or void it needing removal altogether. In many cases, a licensed arborist can assess whether root pruning, a root barrier, or simply monitoring is the right call. Where a tree has already been removed and the root system is causing ongoing issues, full stump and root grinding is usually the most effective fix.
Frequently Asked Questions
How do tree root systems grow?
Most tree roots spread outward rather than downward, typically staying in the top 30–60cm of soil and often extending well past the edge of the canopy in search of water and nutrients.
Can tree roots damage my house or pipes?
Yes, in some cases. Roots are drawn to moisture and can contribute to cracking in paving or foundations, or intrude into small cracks in older underground pipes. Not every tree poses this risk – it depends on species, age, and proximity to structures.
Should I remove tree roots myself?
We don’t recommend it. Cutting roots incorrectly can destabilise a tree or damage its health, and root systems near pipes or foundations often need a proper assessment first. An arborist can advise on the safest approach for your situation.
Simpsons Tree Service provides arborist assessments and stump & root removal across Melbourne’s north eastern suburbs. See our arborist reports service or get in touch for a free quote.
