CCTV Drain Survey London

CCTV Drain Surveys in London

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One of the most effective ways to investigate the drainage system is to carry out a CCTV camera inspection however this does not always provide all of the required information. Whilst it is used in all of our site surveys to examine the condition of the interior of the pipework and for any bends or lateral branch connections, sometimes further techniques and methods are necessary:

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Electronic Sonde Tracing

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This involves a small device being inserted into the drainage system and used in conjunction with the above ground component to pin point the route of the drain. This is useful if an excavation is required to replace a collapsed drain or locating a concealed manhole. We often use this to pinpoint the connection with a Local Water Authority asset when architects are in their planning stages, preparing for any Build Over Agreements.

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Fluorescein Dye Testing

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On occasion, the configuration of the drainage system prevents the camera from passing through the pipework and in these circumstances where we are unsure if a certain part of the drainage connects to the underground system, a small amount of coloured dye is dropped into system to see if it is connected in an unseen run.

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It is also helpful if there is a problem with damp because if it is flushed into the pipework and it emerges through the wall, it is evident the internal pipework is not watertight and contributing to the issue.

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Hydraulic Water Test

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Whilst the CCTV camera inspection will show if there are any fractures in the system, we can test the level of water loss in a drain by temporarily capping of the run at the manhole and filling the pipe with water to the top gully. If there is only a small reduction over a period of time monitored by our engineers, the loss is of minimal concern however if it rapidly drops, this will be having a large impact on the surrounding ground and requires urgent attention.