Thames Water and me

[Shawki]

Hi. Thanks in advance. I was recently granted a planning permission to build a front porch. We called building control after preliminary excavation. Building control tells me we needed to run our application past Thames Water as there is a manhole in the front porch 1600 mm away from the front door which connects to the sewers. It's my drains basically. We checked. On investigation, we also found that the manhole 1600 mm from our house is actually 3.3 m deep. So thames water tells me two things I need to do..
1. I have to leave a 1 m space from the manhole. So I am left with 600 mm extension then. Why did the council then give me permission for a 1 meter extension. If I won't be given a 1m extension why not tell me before I spent any money. Plus why do I have to have a 3 m deep manhole.
2. Thames water are quoting the 45 degree rule. for my 3 m deep manhole.. How deep does my foundation have to go. 2 meters..1 meter..

Anyone else have any experience of this. I can post elevations and side views of necessary. My tradesperson is away on compassionate leave. So any help is appreciated.

 

[CBW]

Thames water will ultimately have the deciding factor because they own the drain. I don’t know why BC said you could have it and I would be speaking to them as they ought to know and would be seeking reimbursement/part reimbursement.

 

[Notch7]

Hi. Thanks in advance. I was recently granted a planning permission to build a front porch. We called building control after preliminary excavation. Building control tells me we needed to run our application past Thames Water as there is a manhole in the front porch 1600 mm away from the front door which connects to the sewers. It's my drains basically. We checked. On investigation, we also found that the manhole 1600 mm from our house is actually 3.3 m deep. So thames water tells me two things I need to do..
1. I have to leave a 1 m space from the manhole. So I am left with 600 mm extension then. Why did the council then give me permission for a 1 meter extension. If I won't be given a 1m extension why not tell me before I spent any money. Plus why do I have to have a 3 m deep manhole.
2. Thames water are quoting the 45 degree rule. for my 3 m deep manhole.. How deep does my foundation have to go. 2 meters..1 meter..

Anyone else have any experience of this. I can post elevations and side views of necessary. My tradesperson is away on compassionate leave. So any help is appreciated.

Tricky.

I hate to say it but the 3.3m deep sewer more or less makes your build a non starter.

45 degrees up from 3.3 metres means your foundation needs to be about 2.7m deep.

 

[Shawki]

I once heard someone tell me that he got away with a 1.2 meter foundation for a 3m manhole. The manhole is concrete lined with steps... Not positive at all and i paid the builder a big advance.. Do I have a case against the council.. Maybe a lawyer is the next port of call?

 

[freddiemercurystwin]

Is it a private sewer or a public sewer?

 

[Shawki]

It's a public one.. My waste as well as other households connect to it.

 

[freddiemercurystwin]

Thames water will ultimately have the deciding factor because they own the drain. I don’t know why BC said you could have it and I would be speaking to them as they ought to know and would be seeking reimbursement/part reimbursement.

The onus is on the applicant (or passed to their designer) to determine where the drains are prior to applying, ordinarily a full plans application and approval from the water company should be sought prior to any construction, the designer should have determined the proximity/depth of any drains and whether they're private or public and considered all of that before they ever drew anything. It's nothing to do with the council.

 

[Shawki]

Thanks.. I should have done better due diligence. I can see now why the previous owner sold and moved . Is there any chance to make a case for a lower depth of foundation. Failing that.. Is it really possible to do a 2 m deep foundation... Will digging so deep cause my own current house to become unsettled.. Distance from my own house would be 800 mm. I was expecting to go down to 1m. Didn't expect 2 m. Is it anymore than just digging more and pouring extra concrete etc.. Will it just double the cost of brick and concrete or are there any other issues... I have to do it or else sell and move. Thanks again..

 

[freddiemercurystwin]

A 2m foundation is no big deal really, you can't dig it without a digger, it's easiest to just do a deep concrete foundation, you don't want to be in bottom of such a trench laying blocks, cheaper to do a deep fill concrete foundation too.

 

[catlad]

You could build it out of timber and get it rendered or clad in in weatherboard, that way you would only need minimal foundations.

 

[freddiemercurystwin]

A timber frame construction will require he same foundations.

 

[catlad]

Now come on Freddy be realistic!

 

[freddiemercurystwin]

BC will expect a suitable foundation for a porch be it made made out of twigs or RC. And that foundation cannot (in TW eyes) impose any loads on the drain. So goodluck with deferring from a run of the mill deep strip foundation.