repairs
Tree roots in drains: signs, repair options and costs
Recurring blockages every spring? It's almost always tree roots. Here's what works long-term — and what doesn't.
Tree roots are responsible for a huge share of recurring drain blockages in older UK properties. The pattern is unmistakable: same drain, same time of year, every year.
How roots get in
Even a hairline gap at a pipe joint leaks moisture. Roots grow toward moisture. Once a fine root finds the gap, it thickens, and within a season you have a mesh that catches every passing piece of debris.
Signs you've got roots, not just a blockage
- Recurring blockage in the same drain
- Spring and autumn are common (growth season + leaf fall)
- Slow drainage between full blockages
- CCTV shows a fibrous mass at a joint, not just sludge
What works
- Cutting + jetting: removes the mat. Cheap and quick — but roots regrow within 12–18 months.
- Cutting + patch lining: seals each entry joint with a resin patch. This is the long-term fix. 10-year structural guarantee on the patch.
- Excavation: only needed where the pipe itself has been broken apart by major roots. Rare for the entry joints — common for collapsed sections.
What doesn't work
- Copper sulphate / 'root killers' — overhyped. Roots regrow as soon as the chemical washes away, and the products are illegal to discharge into a sewer in many areas.
- Cutting alone — see above; ~18 months.
- Cutting the tree down — sometimes overkill (and often illegal under TPOs). Sealing the pipe is far cheaper.
Typical costs
- Cut + jet only: from £180 + VAT
- Cut + single patch repair: from £550 + VAT
- Cut + multiple patches: discounted per patch
- Excavation: quoted on inspection
If this is the second time the same drain has blocked, it's time for a CCTV survey.