A renovation is an exciting time — a new kitchen, an extension, a loft conversion finally taking shape. But some of the most expensive surprises on a building project happen below ground, long before anyone thinks to look. In Bromley, where a good deal of the housing stock is older and served by ageing pipework, the drains under your home deserve attention before the first wall comes down.
A CCTV drain survey sends a small camera through your drainage system to reveal its true condition and layout. Done at the planning stage rather than mid-build, it can save you from costly redesigns, failed signoffs and nasty discoveries once the diggers arrive. Here are seven things it can tell you before you renovate.
1. Hidden Cracks and Collapsed Sections in Older Pipework
Many older Bromley homes still rely on clay drainage pipes, which crack, craze and eventually collapse with age, ground movement and pressure from above. A collapsed section is one of the most serious and costly drainage faults — and it’s completely invisible from the surface until flow fails. A survey finds it while you still have options, not after your new extension is sitting on top of it.
2. Tree Root Intrusion from Mature Gardens
Established Bromley streets often come with mature gardens, and tree roots are relentless in their search for moisture. They work into drains through the smallest crack or joint, then expand until they restrict or block the pipe entirely. A camera survey shows exactly where roots have got in and how much damage they’ve done — essential to know before you landscape or build near existing runs.
3. The Exact Route Your Drains Take
This is one of the most valuable things a survey reveals, because it directly affects what you’re allowed to build. Under the Building Regulations, if you want to build over or within three metres of a public sewer, you generally need a build over agreement from your water company first. A survey maps precisely where your drains run, so your extension or foundations aren’t designed straight over a pipe you’ll later be forced to reroute.
4. Whether Your Drains Are Shared with Neighbours
Since the private sewer transfer of October 2011, drains serving more than one property largely became the responsibility of the water company as public sewers, while a drain serving only your home and sitting within your boundary usually remains private. That distinction matters enormously for a renovation: it changes who is responsible, whose consent you need, and what you can build where. A survey helps establish what you’re actually dealing with — and building over an inspection chamber or a junction on a shared sewer is normally off-limits without special consent.
5. Existing Blockages, Silt and Scale Build-Up
A drain that’s already half-choked with silt, scale or debris is a poor foundation for a renovation that’s about to add more demand to the system. A survey shows what’s lurking in there now, so it can be cleared and assessed before your new bathroom or kitchen starts pushing extra load through pipes that are already struggling.
6. Misconnections and Non-Compliant Previous Work
Older homes often carry the legacy of previous alterations — and not all of it was done properly. A common issue is a misconnection, where wastewater from a sink, washing machine or toilet has been plumbed into the wrong drain, sending foul water into a surface-water system or vice versa. Left undiscovered, problems like these can undermine new work or cause it to fail building control. Far better to find them before you build than to unpick them afterwards.
7. The True Condition and Capacity Before You Add Load
Every new bathroom, en-suite or extension adds demand to your drainage. Before you commit to a design, it’s worth knowing whether the existing system can genuinely cope, or whether it needs upgrading first. A survey gives you an honest baseline of condition and capacity — information that lets you and your builder plan properly rather than hope for the best.
What to Do With Your Survey Results Before Building Starts
A survey is only useful if you act on it. Armed with a clear picture of your drains, you can repair, reline or reroute problem sections before building work begins — when it’s still straightforward and comparatively cheap, rather than a mid-project emergency. The findings also feed directly into any build over application, and many water companies expect a CCTV survey as part of that process anyway.
The sensible first step is to have the system properly inspected while your plans are still on paper. If you’re renovating locally, booking a CCTV Drain Bromley survey gives you the underground picture you need before the building above it begins. A modest check now can spare you the single most expensive kind of renovation surprise — the one you didn’t see coming.
