How CCTV Drain Surveys Spot Blockages and Cracks

CCTV drain surveys involve a small camera being fed through your drains and the live footage being viewed by an operative above ground. In this article we will explain what the operative is looking for while viewing the footage from your drain.

A Partial Blockage Narrowing the Bore

Grease, silt and other debris can form a layer on the inside of pipes. This can reduce the bore of the pipe over time. The amount of clear diameter left in the pipe can be recorded by the operative and advice given on how to clear any blockages.

When the Camera Has to Stop

As the footage is being viewed by the above ground operative, it can often be seen that the drain is near-full blockage. In cases where near-full blockages are found, it is not usually recommended to push the camera head into the blockage as this could potentially cause damage to the equipment and possibly even move the blockage further into the drain. The operative would note the exact position of the blockage and recommend the necessary action to unblock the drain.

What a Crack Looks Like on Screen

Cracks and broken sections of pipes are another thing that can be identified during a CCTV drain survey. These appear as jagged, uneven edges of pipe and can in some cases allow soil and or daylight to enter the pipe. If the pipe is leaking groundwater into then this can appear as a fine trickle of water within the crack of the pipe. It is worth noting that responsibility for certain drains and sewers will lie with different people and it is generally the responsibility of the owner of the property where the drain or sewer enters the ground to repair any private pipework, whereas shared sewers are the responsibility of the local water authority.

Distinguishing Root Intrusion from Cracks

Root intrusion into a drain tends to enter the pipes through the joints of the pipes and can appear on a CCTV survey as fine root growth within the pipes filling part of the bore. In many cases the root growth will be in a matted mass however in other cases individual fine root strands can be seen entering the pipes through the joints. As the drain is made of hard materials such as clay, concrete etc a structural crack will have very sharp hard edges. There will be no sign of any root growth attached to the crack.

Spotting Sagging and Deformation

A sagging drain line will create a ‘dip’ in the pipe which will cause water to pool in this area. Also the waterline will drop and the invert of the pipe (the bottom of the pipe) will sag in places creating an uneven view on the screen. For CCTV Drain Survey Leicester, visit https://www.wilkinson-env.co.uk/drainage-services-cctv-surveys-midlands/cctv-drain-surveys/leicester.

Once you know what problems there are and where they are, you can make the correct repair.