External drains carry waste and rain water away from your home. They include gullies, manholes, inspection chambers and the pipe runs between them. Leaves, silt, grit and roots collect there over time. Because the pipes are outside, they get little attention.
Since these pipes lie underground, you may not spot a problem early. Water pooling near a cover or a smell outside are common clues. If a chamber is full, the blockage lies further along. If it is empty, the blockage may sit upstream.
Ownership matters for outside drains. Since 1 October 2011, shared drains and lateral drains beyond your boundary belong to the water company, which is South West Water in Devon and Cornwall. The pipe within your boundary that serves only your home stays yours, so ask the engineer which section has the blockage.
High-pressure jetting is common for outside runs. A camera can then show whether roots, cracks or a broken joint caused the blockage. If one did, clearing alone may not last. However, a clear pipe is still the first step.
Price depends on the length of pipe and what blocks it. Roots and packed silt can take more time than leaves. Since access also matters, a buried chamber can add work. Ask for a written quote, and ask whether a camera check is part of it.
That depends on whose pipe it is. The water company looks after shared drains and lateral drains beyond your boundary. You look after the pipe within your boundary that serves only your home. Ask the engineer which section has the blockage, because that decides who acts.
Yes, roots can push into joints and cracks, then grow inside the pipe. They narrow the flow over time. A camera check can show root growth before a full blockage forms. Still, roots may regrow after a clear-out.
There is no set rule, because it depends on trees, pipe age and past blockages. If a drain has blocked before, regular checks may help. Ask the engineer what suits your property. Keep a note of each clear-out, since patterns show up over time.
This page sits under drain unblocking, which covers the wider picture. For local details, see the pages for drain unblocking in Ivybridge and drain unblocking in Tavistock, since each town has its own page. You can also read 7 Warning Signs You Have a Blocked Drain for a wider guide.