Drain survey advice - house purchase

billybobster123

Hello there, first time poster here. Any advice would be much appreciated!

We’re in the process of buying a Victorian terraced house and have had a CCTV drain survey. It’s highlighted that there are multiple defects with the drains.

It show that there is an 8 metre section of drain under the house that is backfalling (along with age-related repairs - replacing a siphon trap, and descaling, cleaning and relining).  The backfalling drain is underneath a new kitchen extension and excavation would be required to fully investigate and fix. The quote to fix, with excavation, is c£11.5k. 

We’re in the process of seeking further advice but wanted to see if anyone else had similar experiences or any thoughts on this. 

Our main concern (other than the cost/inconvenience of excavating the kitchen) is that this could be due to ground movement (our house survey flagged a crack above the rear bedroom window and a section of sloping / springy floor downstairs) and the subsequent impact of insurance and future sales.

We can ask the vendors if they have any knowledge of drainage problems but don’t anticipate we’ll receive the full picture even if they have had problems.

We’re discussing it with surveyors and the drainage company but any thoughts or advice would be appreciated.

Thank you!

Section62

Victorian terraces tend to have shared drainage, in which case the drain is a public sewer the local water company are responsible for.

Did the drainage survey say anything about it being shared, rather than just serving this one property?

billybobster123

Thanks for your reply.

This relates to the drain running under the house which leads to the public sewer on the road at the front of the house. Searches have shown there is no shared drainage within the boundary. 

Section62

billybobster123 said:

Thanks for your reply.

This relates to the drain running under the house which leads to the public sewer on the road at the front of the house. Searches have shown there is no shared drainage within the boundary. 

Don't rely on the searches, these are usually based on information which is incomplete and inaccurate.

Your drainage survey would be the definitive source on whether the drainage is shared or not.  The surveyor should trace all accessible drains/sewers either to the point where there is a gulley or stack pipe, or to the property boundary.  Does the survey include a plan?