Whether to get a drainage survey or not?

[loopylou31]

After some solid mumsnetter perspectives as going round in circles. We are buying a house built in 1973 and have just had our Homebuyers survey back. A number of things mentioned but nothing major and/or things picked up through solicitor enquiries. One issue that has been flagged by surveyor though is relating to the foul drainage;

Quote 'Where access could be obtained, the underground drains were partially blocked and need flushing through. The area surrounding the chamber is damaged and the chamber itself is in poor condition. It is possible that repairs are needed to the to reduce the possibility of blockages in the future.
The inspection cover, should be replaced.
The internal soil and vent pipe (main vertical drainage pipe) is not visible. However, there were no signs of dampness or significant disrepair where the pipe was located.
Condition Rating 3.
As this is serious you should instruct a reputable drainage contractor to inspect the drains and report to you before exchange of contracts.'
End quote

So given this, do we or do we not get a drainage survey? At the moment we are inclined not to as drains needing flushing through doesn't sound major. Of course we have no idea what's causing the blockage and the surveyor couldn't see which is the risk of not getting a drainage survey. We are just reluctant to get more surveys!! We aren't worried about needing to replace the cover or even repairing the chamber.
Anyone had this experience? Anyone decided to get a drainage survey or not to get one and regretted it either way?
Thanks in advance!

[busywheels]

In your case I would certainly get a contractor to jet the drain and carry out a CCTV survey to assess the condition of the drain. They should be able to provide you with a recording, which would be useful if you want to negotiate on the price of house if repairs are extensive. Blockages can occur for a variety of reasons from people flushing wet wipes down the toilet, fat blockages etc to the more serious collapse of the drain or tree roots growing into the pipe.

Repairs to drains can be expensive and you are unlikely to be covered by household insurance if it is down to fair wear and tear (and presumably if you are taking the property on knowing there is potentially a problem). Changes in 2011 mean the sewerage company e.g Thames Water is now responsible for the maintenance and repair of most shared sewers (pipe draining two or more properties). Individual Owners remain responsible for drains serving just their property until it joins in with the sewer. This includes drains outside the curtiledge of the property. You may wish to contact the sewerage company and speak to your surveyor to clarify where you responsibility for the drain ends.

A survey is likely to cost a few hundred pounds but could be worth it in the long run, or at least give you piece of mind that there is nothing more serious. Suggest you get two or three quotes. Get recommendations or try check a trade or Trading Standards buy with confidence scheme.

[noeyedeer]

We were advised to get a drainage survey for insurance reasons. Our (hopefully) new house has some shared drainage and other issues that mean if the drains collapse or something major goes wrong we'd be liable for repairs.

It has apparently been known in the area that we are buying for insurance companies to not pay out saying that the drains must have been in disrepair when properties were bought, thereby voiding insurance. We had one done just to prove this wasn't the case. £200 for survey vs £40 000 of repairs was no brainer for our situation.

[NaturalBaby]

We've just had our survey back with similar issues, but we have a septic tank and it was condition rating 2 so we are not going to get a drainage survey at this point because we will be looking into altering things anyway.
It depends whether the worst case scenario would mean you would pull out of the sale or not.

[fussychica]

Our drainage survey was £85 - we thought it was worthwhile as we knew of other houses built in the same period had issues. I'd do it in your case.

[minipie]

we had a drainage survey as our house survey flagged possible problems. turned out the main link to the public drains was half collapsed and needed replacing at cost of £5k. so yes definitely worth it in our case.

[loopylou31]

Hi everyone, just wanted to thank you all very much for your advice and thoughts. We've instructed a drainage survey which is taking place tomorrow so should have the report by the end of the week. So hoping that nothing comes up!
Thanks to busywheels for the reference to the Trading Standards buy with confidence website, great idea, not thought of that. Very useful website!

Thanks everyone, so appreciated you getting back to me and talking sense.