Drains and sewers

Pre & Post conditional drainage surveys explained

CCTV drainage surveys are becoming increasingly popular with surveyors, engineers and architects.

From an architects point of view, the most important issues are Pre & Post Conditional drainage surveys for building extensions, this applies to both domestic and commercial properties but why are they so important?

The pre-conditional CCTV survey

The Pre-Con survey is designed to identify the current drainage system at any property which is due to be extended, it will map the drainage layout, identify drainage system ownership be that water company, private or a combination of both. It will also help to determine the drain depth and flow direction plus identify pipe size, shape, diameter and its condition. These are all very important factors and this is considered to be critical information required by architects in the planning stage as a new design cannot be properly completed until this information has been obtained.

The new drainage system layout is typically designed once this information has been provided.

The planning meeting

In many cases the drainage surveyor will be asked to consult on the new system layout and design, this is often referred to as the planning meeting which normally takes place on site with all parties.

The post-conditional CCTV survey

The Post conditional survey (Post-Con) is carried out once the new drainage system has been constructed, this is to ensure the new drainage system has been laid correctly by the building contractor and is fit for purpose. It will also ensure that the new system does not have any miss-connected drainage which can cause pollution to the connecting local water course i.e river, canal and streams and that the Part H of the building regulations have been adhered to.

Drainage surveys require due diligence

Pre & Post conditional drainage surveys are part of the due diligence process of any building project and should never be overlooked.

Always ensure that you are using fully certified drainage surveyors¹ to undertake this work in compliance with industry best practice and standards.

Here at Accelerated Drain Services we currently carry carryout between 700-800 of these surveys each year for a number of architects based in and around the London area. We are fully certified drainage surveyors and members of the NADC.

Contact qualified drainage contractors

If you require CCTV drainage surveys² and going forward would like to use qualified contractors, please get in touch with Accelerated Drain Services³.

1. https://www.london-drainage.co.uk/build-over-drainage-surveys/
2. https://www.london-drainage.co.uk/cctv-drain-surveys/
3. http://www.london-drainage.co.uk/contact/