Help with surveyors report on drainage please!!

[HotChocolate16]

Morning all

we received our surveyors report back on a house we are due to purchase , and this flagged as a 3 on the drainage section.

is the shared drainage system to the public sewer an issue, and likewise the foul and rainwater flowing into the same system an issue? I don’t understand much about this stuff but it’s flagged as a 3 so I’m thinking I should be worried?

furthermore, the rainwater flows directly above ground, there is no drain for some reason! How difficult / expensive is it to put a drain in?

Thank you all for any advice! :)

Historically houses used to have combined foul and rainwater drainage (My 1930s semi does). Its not been a problem for us, but we're not in an area where the system is subject to any type of flooding including flash flooding. We also have shared drainage with at least 4 other houses and a secondary school.

Hi - I'm not an expert but I think based on my own experience that the 3 score is not really due to the shared underground arrangements which the surveyor seems to be guessing about as he hasn't inspected - that's just about being cautious as the access is shared and you need to be sure your neighbours won't do /haven't done anything to block your joint pipework. I think the 3 relates to the downpipe and the fact that rainwater isn't being diverted properly. That can cause damp and problems with the house so does need to be looked at. We had similar and it's not an expensive job (less than a grand). Hope that helps!
I would also add that you should feel free to contact the surveyor directly and ask them to explain anything you are unclear on. You have paid for a service and they need to make sure you have all the information you need /want.

Thank you for your response! How did you get the drain issue sorted? Did the water company have to come out and fit it?

also, there’s a section in the report that says:

ask your legal advisor to check whether local authority permission was sought in respect of the repairs to underground drainage - it suggests that something was repaired right? But nothing was mentioned in the report about this either, it says he didn’t even look underground so I am confused about whether this is an issue or not as well?

For us (also 1930s semi) share sewer is a boon...mostly. Next doors sewer cuts across to our drive, joins ours and then heads out to the main road (long driveway too). It means we are at mercy of anything they put down the loo causing a blockage (they don't thankfully). But because it is shared we are not reponsible for clearing blockages/maintainence - the water company is.

Drainage on a property is your responsibility. The Water Companies provide rules.

The big problem here is water from guttering discharging straight into the ground. If you want to be green you could arrange for it to be collected and recycled onto the garden. What you don’t want is it collecting near the house. Many people divert it into the sewers but you need to check whether that is permissible now.

Shared drains are normal but no inspection chamber is a concern. You should have one.

We have shared sewers and rainwater running into them as well for all the houses round here, it was the way things used to be done, so it's not unusual. When we had our drive resurfaced we discovered that an inspection 'lid' had actually been tarmaced over at some point - we had assumed our neighbours had the only one. It was a pleasant surprise to discover it anyway. Just shows you how shoddy some workmanship can be.

Thanks for your responses everyone. It seems the shared sewers is common in older properties. This one is 1925 - 1930 I think.

so would people not class the fact that there is no drain for rainwater to go in (that instead it flows above ground) not an issue, as in I can just get a drain installed?

and would the fact that the report suggests that repair work has been done on the underground drainage worry anyone?

I think you need to ask your surveyor what he means by addressing the repair issue. As I said previously they are normally really helpful in explaining what they have put in the report. Sorting out the down pipe to address the rain water issue would be your responsibility not the water company and can be handled by any competent builder

I agree with Puppylucky. The downpipes issue can be resolved by a builder who may recommend a French drain or soakaway. It is unlikely to be very expensive.

Just to mention though, where I live all houses on the main street discharge rainwater just into gardens next to the house/onto the pavement (these are much older houses though) so it is not always a disaster as these houses have managed perfectly well for hundreds of years.

Ah ok thanks! I’ll probably give him a call on Monday then as he is suggesting repair works have been done but not mentioned it anywhere else in the report.

good to know a builder can sort a drain out for us though and that a shared system isn’t a bad thing :)

It does not sound bad from the report.
As the drainage system is a combined system then the roof water can go into any nearby existing grids such as bathroom drain or kitchen drain as they all go to the same place the sewage works.
In a separate system rainwater may go to a stream or watercourse and you shouldn't connect to sewage grids but many people do anyway.
Any drain underground which is from any other property on your property is the water authority for repair and maintenance plus anything from your property after it joins with another even on your garden/yard.
This will be free of charge as its covered by your water bill.
The corroded above ground pipe referred to is not likely to be a major issue may need replacing with plastic and refixing you probably should put a rodding eye on this pipe as it enables the drain to be accessed without a dig up as the jetting hose can go down it from there
Water from conservatory roof is unlikely to be a great deal if no drain nearby then a water butt can be used.